Water is a key factor influencing the growth and development of rice. Exploring mechanisms for efficient water utilization is vital for rice production. During the process of plant growth and development, the root system secretes various compounds into the surrounding environment, known as root exudates. These substances regulate plant growth and development by triggering rhizosphere effects and constitute an indispensable part of plant growth process. This paper systematically reviews the types, biosynthetic pathways of root exudates, and their physiological response mechanisms under drought stress. By providing an in-depth analysis of the function mechanisms of rice root exudates in water regulation, this review identifies existing problems in current research and proposes suggestions for future research directions.

Photo-thermo-sensitive genic male sterile (P/TGMS) lines are precious resources for hybrid rice breeding. Using the newly discovered rice P/TGMS line 19XS as material, its breeding process, agronomic traits, fertility conversion characteristics, hybrid progeny fertility, and genotype were analyzed. The results showed that in Wuhan area (sown in early May), 19XS maintained a stable sterile state for more than 45 days from heading in early August to late September; a small amount of fertility conversion began to occur after October 3. In Hainan area (sown in late November, heading in early March), 19XS generally appeared fertile, exhibiting photo- thermo-sensitive fertility conversion characteristics. Genetic analysis indicated that 19XS is a new recessive genic male sterile line, and its sterility is not interfered with by the genetic background. The hybrid progeny of 19XS and Xiang 78S (19XS/Xiang 78S) exhibited excellent agronomic traits, including compact plant type, large panicles with numerous grains, and high seed setting rate. Gene chip detection results showed that both 19XS and 19XS/Xiang 78S contain the thermo-sensitive male sterile gene TMS5. These findings provide a new material basis for hybrid rice breeding.

To identify the distribution of disease resistance functional genes in Xinjiang spring wheat materials and provide materials for genetic improvement of wheat disease resistance breeding, KASP technology was employed to detect genes associated with resistance to stripe rust, leaf rust, powdery mildew, and Fusarium head blight in 549 Xinjiang spring wheat materials. The results showed that 121 materials carried five stripe rust resistance alleles with relatively high frequencies (QYrqin.nwafu-2AL, Yr29, QYrsn.nwafu-1BL, QYrqin.nwafu- 6BS, Yr78); 352 materials carried two leaf rust resistance alleles with relatively high frequencies (Lr67, Lr46); and 142 materials carried three Fusarium head blight resistance alleles with relatively high frequencies (QFhb.Hbaas-5AS, QFhb.hbaas-5AL, QFhb.caas-5AL). No presence of the five powdery mildew resistance genes (Pm12, Pm21, Pm2a, Pm5e, PmV) was detected in any of the materials. In summary, Xinjiang spring wheat varieties exhibited high frequencies of resistance genes for stripe rust, leaf rust, and Fusarium head blight, but a notable lack of resistance sources for powdery mildew. Therefore, it is crucial to focus on introducing and utilizing new powdery mildew resistant materials to improve the disease resistance breeding capacity of Xinjiang spring wheat.

The resistance of 473 common bean resources to Acanthoscelides obtectus was identified by artificial inoculation method. The results showed that 49.1% of the resources showed varying degrees of resistance, mcluding 15 highly resistant resources, 60 resistant resources and 157 moderately resistant resources. In the highly resistant resources, F1432, F0645, F0675, F0004351 and F0004406 did not show any infected symptoms, manifesting as immunity. Research found that A.obtectus has a certain phototaxis. No significant differences in resistance were found among resources with different grain color, grain size, and seed coat luster. The screening and identification of A.obtectus resistant resources is beneficial for providing excellent resistance resources for subsequent resistance breeding.

Using SSR molecular markers, genetic diversity and population structure analysis were conducted on 104 local tartary buckwheat germplasm resources in China. The results showed that nine pairs of highly polymorphic SSR primers amplified a total of 22 alleles in the 104 tartary buckwheat germplasm resources. The number of alleles amplified per primer pair ranged from two to four, with an average of 2.444 alleles per locus. The average values for effective allele number (N_e), Shannon’s diversity index (I), observed heterozygosity (H_o), and expected heterozygosity (H_e) were 1.820, 0.629, 0.058, and 0.401, respectively. The polymorphic information content (PIC) ranged from 0.0096 to 0.6115, with an average of 0.3312. UPGMA clustering analysis divided the 104 tartary buckwheat germplasm resources into four groups. The tartary buckwheat from Inner Mongolia, Yunnan, Guizhou, and Sichuan showed similar distributions, primarily clustered in group III and IV. Materials from other provinces were more evenly distributed, demonstrating rich genetic diversity. Population structure analysis and two-dimensional principal coordinate analysis (PCoA) further confirmed that the grouping results were largely consistent with the cluster analysis. This study further clarified the genetic diversity and phylogenetic relationships among local germplasms of tartary buckwheat, and screened 17 genetically pure germplasm materials. This provides a theoretical basis for the effective utilization of tartary buckwheat germplasm resources and the breeding of new varieties.

To analyze the genetic diversity of rice germplasm resources in the border areas of Yunnan Province and identify SSR markers closely related to major agronomic traits, a total of 376 newly collected rice germplasm resources from Yunnan (China), and its adjacent Myanmar and Laos were used as experimental materials. These resources were divided into three analysis units, and 11 phenotypic traits were investigated. Genetic diversity and association with phenotypic traits were analyzed using 27 pairs of SSR markers. Results showed that a total of 142 allelic variation loci were detected, including 100 rare allelic variation loci and nine peculiar allelic variation loci. Based on the comprehensive evaluation of six genetic diversity parameters, the scoring order of rice germplasm resources from the three analysis units was: Yunnan, China analysis unit > Myanmar analysis unit > Laos analysis unit. Among the 27 pairs of SSR markers, RM214, RM1086, RM5481, RM6089, RM1509, and RM7479 were closely associated with phenotypic traits, could explain more than 10.0% of the variation in panicle length, panicle exsertion, filled grains per panicle, unfilled grains per panicle, grains per panicle, and 1000-grain weight. Principal component analysis of phenotypic traits extracted four principal components with a cumulative contribution rate of 77.218%. A total of 36 excellent germplasm resources (comprehensive score ≥1.000) were selected. Among these, Huake, Nalei 5, and Haonuolang had a score greater than 2.000. They demonstrated potential as parents for multiple-tillering and large-panicle type, large-panicle type, and glutinous type, respectively.

The combining ability and heterosis of sorghum sterile line and restorer line in spring-sown early maturing regions were studied to provide theoretical basis for the parent selection of sorghum hybrid combinations in the future. Using 31 sorghum as parent materials, 206 hybrid combinations were prepared by incomplete diallel cross design, and 13 main traits including plant height, panicle length and combining ability and heterosis of parents and their hybrid F₁ were analyzed. The results showed that there were significant differences in various traits between the sterile and restorer lines of sorghum, and the combining ability of different materials was significantly different. Among the 31 materials, Ji 64A, SX44A, Ji 5535A, Ji 5575A, HLS×125×2999, HLS Zao and Ji R4334 had more advantages in plant height, panicle length, grain weight per panicle, yield, penultimate leaf angle, penultimate width, and antepenultimate leaf angle, etc. The general combining ability of other traits was also excellent, so the six materials were ideal parents. There was a large heterosis utilization potential in the hybrid combination, but the mid-parent heterosis was not prominent. Meanwhile, the yield of the hybrid combination was affected by both additive and non-additive effects. To select excellent parents attention should be paid to the comprehensive traits and general combining ability of the parents, as well as the special combining ability and the complementary effect of the parents.

Northern Japonica rice region is susceptible to cold damage, and breeding cold-tolerant rice varieties is the most direct and effective means to address this issue. In this study, 45 accessions of northern Japonica rice were used as experimental materials. Under 14 °C cold stress, seven indicators including germination potential, germination rate, germination index, vigor index of shoot, vigor index of root, average germination days, and germination coefficient were measured. Multivariate statistical methods such as correlation analysis, principal component analysis (PCA), membership function comprehensive analysis, and cluster analysis, were employed to evaluate cold tolerance. The results showed that all germination indicators exhibited varying degrees of decline under cold stress, with the vigor index of root showing the most obvious decrease. By calculating the membership function values of each indicator, the seven indicators were transformed into two comprehensive indicators through PCA. Cluster analysis was then used to categorize the 45 accessions into four groups, successfully screening 13 cold-tolerant materials. Furthermore, a regression equation was established, which identified that germination potential, germination rate, vigor index of root, and germination coefficient are the key indicators for evaluating cold tolerance in northern Japonica rice at the germination stage.

In order to understand the genetic background of flax germplasm resources and breed high-quality flax varieties, genetic diversity analysis, cluster analysis, principal component analysis and population structure were conducted on nine agronomic traits and six quality traits of 387 flax germplasm resources by phenotypic traits and molecular markers (SSR). The genetic diversity index of agronomic traits was between 0.70 and 2.08, and the coefficient of variation was between 5.55% and 129.18%. The genetic diversity index of quality traits ranged from 1.83 to 2.08, and the coefficient of variation ranged between 0.07% and 1.38%. A total of 320 SSR loci were amplified with an average of 11.81 loci per primer pair; the effective allele number was 1.1991-1.8230, PIC of primers varied from 0.2489 to 0.6257; at the genetic similarity coefficient of 0.66, the 387 flax germplasm resources could be divided into five groups, and cluster analysis based on agronomic traits and quality cluster analysis could also be divided the germplasm resources into five groups.

The absorption of selenium by tartary buckwheat to form selenium-enriched characteristics is of great significance for promoting the high-quality development of the tartary buckwheat industry. In this study, 30 representative tartary buckwheat germplasm resources were selected to measure their agronomic traits, dry matter accumulation and translocation characteristics, as well as yield and grain trait indicators. Foliar application of selenium fertilizer was set as a treatment. Principal component analysis (PCA), cluster analysis, and GGE biplot analysis were comprehensively utilized to conduct a thorough evaluation of the growth, development, and selenium response characteristics of different tartary buckwheat germplasms. The results showed that significant variations existed among different tartary buckwheat germplasm resources in terms of agronomic traits, dry matter accumulation and translocation characteristics, yield and its components, and selenium accumulation, distribution, and enrichment traits. Furthermore, foliar selenium application exhibited a promoting effect on all measured growth and development indicators of the germplasm resources. Through cluster analysis, ten selenium-sensitive, 12 selenium-intermediate, and eight selenium-insensitive germplasm resources were screened. GGE biplot analysis identified YYMY002 as a germplasm with high yield, high selenium enrichment, and relative comprehensive superior traits.

The main agronomic traits of 513 faba bean germplasm resources at home and abroad were analyzed. The results showed that the coefficient of variation of 15 agronomic traits ranged from 13.09% to 53.58%, indicating that there was a large genetic variation. The coefficient of variation for the number of pods per plant reached the highest value of 53.58%, with a variation range of 1.00 to 42.00, whereas pod width exhibited the lowest coefficient of variation at 13.09%, varying from 0.80 to 2.23 cm. Correlations among traits highlighted that the number of branches, number of effective branches, number of pods per plant, number of grains per plant, plant height, and height of the last pod are key for developing high-yielding faba bean varieties. The principal component analysis extracted five principal components, with the cumulative contribution rate reaching 72.098%, effectively representing the phenotypic characteristics of these germplasm resources. By calculating the membership function values, a comprehensive score (F-value) was derived, and the top 30 germplasm resources with the best comprehensive traits were identified. The cluster analysis subsequently divided the 513 faba bean germplasm resources into three group: Cluster I included 160 resources (31.19% of the total), characterized by high plant height and yield; Cluster II comprised 221 resources (43.08% of the total), suitable as parental selection and screening of excellent genes; and Cluster III contained 132 resources (25.73% of the total), representing specific germplasm.

A total of 24 progenies from Saccharum robustum L. and Nanjian chewing cane through reciprocal crosses were used. Correlation analysis, principal component analysis, cluster analysis, and comprehensive evaluation associated with seven important agronomic traits were performed. The results showed that there were differences in agronomic traits among different germplasm materials in the same planting period experiment, and there were differences in agronomic traits among different planting period experiment in the same germplasm materials. The variation coefficient of agronomic traits ranged from 11.17% to 43.37%. The variation of sugar yield and sugarcane stalk yield was the largest, which was 43.37% and 42.20%, respectively, the variation of plant height was small. The correlation analysis showed that sugarcane stalk yield and sugar yield were significantly positively correlated with single stalk weight and effective stalk number, respectively, and sugarcane stalk yield was significantly positively correlated with sugar yield. The yield-sugar factor, stalk diameter-sugar factor and stalk diameter-quality factor were extracted via principal component analysis, and the cumulative contribution rate was 81.39%. The results of cluster analysis showed that the 24 germplasm materials were divided into three groups at the Euclidean distance of 6.00, which were basically consistent with the results of principal component scores. Among them, the seven agronomic indexes of group III were excellent, with high yield and high sugar. Yunrui 12-38-27, Yunrui 12-38-18, Yunrui 12-9-45, Yunrui 12-9-9 and Yunrui 12-38-29 ranked top five based on their comprehensive evaluation D values.

In order to clarify the suitable planting pattern and nitrogen application rate for rapeseed relay cropped rapeseed after wheat, a field experiment was conducted in Dalad Banner, Inner Mongolia. Five nitrogen application rate gradients (0, 30, 60, 90 and 120 kg/ha) were set under three planting modes, including straw removal+tillage (T1), straw returning+tillage (T2), and straw removal+no tillage (T3). The optimal nitrogen rate was determined based on rapeseed biomass, nutrient accumulation, and economic benefits. The results showed that the aboveground biomass, carbon accumulation and potassium accumulation of rapeseed under T2 treatment were all higher than those under T1 and T3 treatments. Under T2 treatment, the average of fresh grass weight, dry grass weight, carbon accumulation, and potassium accumulation of all nitrogen application treatments could reach 60.5 t/ha, 8.0 t/ha, 2981 kg/ha, and 253 kg/ha, respectively. Nitrogen application rate significantly affected the biomass and nutrient accumulation of rapeseed under different planting modes. The biomass and nutrient accumulation of rapeseed increased with the increase of nitrogen application rate within the nitrogen application rate range. Compared with no nitrogen application treatment, the fresh grass weight and dry grass weight of rapeseed increased by 39.8% and 35.1% respectively when the nitrogen application rate was 30 kg/ha, 63.0% and 67.9% at 60 kg/ha, 78.1% and 89.0% at 90 kg/ha, 86.5% and 98.1% at 120 kg/ha. The trend of nutrient accumulation of rapeseed green manure was basically consistent with that of biomass. The input costs and outputs of rapeseed for different purposes varied under different planting modes and nitrogen application rates. Considering the factors such as biomass, nutrient accumulation, and economic benefits of rapeseed for different purposes under different modes, rapeseed can be planted with no-tillage method with wheat straw removal following wheat harvest. The optimal nitrogen application rate for rapeseed as silage feed is 120 kg/ha, and for rapeseed as green manure, the optimal nitrogen application rate is 90 kg/ha.

Drought experiments were carried out in different stages of tuberous root differentiation and formation by potting soil cultivation to analyze the changes of reactive oxygen species metabolism and endogenous hormone content in sweetpotato roots. The results showed that drought stress caused the decrease of sweetpotato fresh tuber weight per plant, and the earlier the drought, the greater the effect. Compared with normal irrigation treatment (CK), the O₂^-. content in sweetpotato roots was significantly decreased and H₂O₂ content was significantly increased under drought stress. The increase of H₂O₂ was effectively inhibited after rehydration. Drought stress at different periods resulted in the decrease of activities of peroxidase (POD) and catalase (CAT) in sweetpotato roots, and ascorbate peroxidase (APX) activity increased significantly in early, middle and late stages of sweetpotato root differentiation and formation under drought stress. The results showed that the root system of sweetpotato mainly relied on APX to remove reactive oxygen species under drought stress, and SOD also made great contribution to the removal of reactive oxygen species during the early and middle stages of drought stress. After rehydration, the APX activity in sweetpotato roots decreased, while POD activity increased, indicating that sweetpotato root recovered the damage caused by drought stress by enhancing POD activity to improve antioxidant capacity after rehydration. In addition, the free proline content in sweetpotato roots increased under drought stress, and as an osmotic regulator to resist drought stress, the proline content in sweetpotato roots decreased after rehydration. Compared with CK, the contents of ABA and JA in sweetpotato roots for the treatments of D_8-14 and D_15-21 were significantly increased, while the contents of GA and IAA were significantly decreased, and the decreasing ranges were smaller than the increasing ranges of ABA and JA. When drought treatment (D_22-28) was carried out at late stage of root differentiation and formation, the contents of these four endogenous hormones in sweetpotato roots did not change significantly. These results indicated that when sweetpotato was subjected to drought stress in early and middle stages of tuberous root differentiation and formation, it responded strongly by increasing the contents of JA and ABA in roots. However, when sweetpotato was subjected to drought stress during tuberous root differentiation and formation stage, only JA had a significant increase.

To explore the effects of silicon (Si) on the physiological characteristics of oat leaves infected by Puccinia graminis f. sp. avenae and clarify the physiological mechanism of silicon-induced resistance to stem rust, a pot experiment was conducted using ʻBayou 1ʼ, an oat cultivar highly susceptible to stem rust, as the experimental material. Four treatments were established: CK (no silicon, no stem rust pathogen inoculation), +Si-P (silicon application, no stem rust pathogen inoculation), -Si+P (no silicon, stem rust pathogen inoculation), and +Si+P (silicon application, stem rust pathogen inoculation). This study investigated the effects of 1.5 mmol/L silicon application on the disease progression, reactive oxygen species content, and antioxidant enzyme activities of oat leaves after stem rust pathogen infection. The results showed that silicon application effectively delayed the disease development process of oat stem rust, and significantly alleviated disease symptoms. Stem rust pathogen infection led to a rapid increase in O₂^-. and hydrogen peroxide content in leaves. Simultaneously, the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), malondialdehyde (MDA) content, and relative electrical conductivity of leaves increased rapidly, while ascorbate peroxidase (APX) activity decreased rapidly. Within seven days after stem rust pathogen inoculation, silicon application reduced the reactive oxygen species content in leaves, while increasing the activities of SOD, POD, and CAT, and decreasing APX activity and MDA content. Furthermore, silicon application reduced the relative electrical conductivity of leaves within 11 days after inoculation. Silicon application enhanced the antioxidant defense ability of oat leaves, reduced the degree of membrane lipid peroxidation, and enhanced oat resistance to stem rust.

The effects of nitrogen (N) application on maize yield, root distribution, and N metabolism were analyzed under high-density planting by using the maize cultivar Xianyu 335 as material, setting up a conventional density treatment of 6.75×10⁴ plants/ha (D1) and a high-density treatment of 8.25×10⁴ plants/ha (D2), and applying N at five rates (0, 160, 220, 280, and 340 kg N/ha) per density treatment. The results indicated that with the increasing of N application rate, the maize yield showed a trend of increasing and then decreasing. The yield of D2 treatment was significantly higher than that of D1 treatment and the combination of high-density planting and optimized N application (160-220 kg N/ha) increased the yield by 39.1%-51.8% compared to conventional management. The optimized combination of N rates and planting densities increased root length, root length density, root surface area, root volume, specific root length, as well as the activities of glutamate synthase and glutamine synthetase in roots. The two enzyme activities were positively correlated with root growth distribution. In conclusion, an application of 160-220 kg/ha of N at a planting density of 8.25×10⁴ plants/ha is recommended. This combination enhances nitrogen metabolism enzyme activities, promotes root growth, and increases soil nutrient uptake, thereby improving maize yield. This can serve as a high-yield maize planting model for the Guanzhong region of Shaanxi.

To clarify the production status and limiting factors of intercropping systems in the Hetao Irrigation District, Hanggin Rear Banner, a representative area for crop cultivation in the Hetao Irrigation District, was selected as the research site for the survey. Based on 503 valid questionnaires from 24 administrative villages across eight townships of Hanggin Rear Banner, the results showed that the intercropping systems were widely applied in Hanggin Rear Banner. There were wheat/maize, wheat/sunflower, watermelon/sunflower and maize||soybean (mainly food and cash crops). The wheat/maize and wheat/sunflower relay were cropping the most prevalent, accounting for 42.5% and 23.5%, respectively. Both systems significantly improved land use efficiency, with land equivalent ratios of wheat/maize and wheat/sunflower were 1.48 and 1.29, respectively. There were two main limitations of applying intercropping in this region. On the one hand, field managements were more complex in intercropping than monocultures, with the average number of irrigations and weeding times were higher, with an average of 1.0 and 0.9 times higher than in monocropping, respectively; on the other hand, the average amount of nitrogen application in intercropping systems was 70.7% higher than in monocropping. Overall, it is necessary to further explore field management practices and fertilization strategies suitable for intercropping in the area to reduce water and fertilizer inputs. Meanwhile, the research and development of intercropping machinery, herbicides and other related production materials should be strengthened, and technical training should be carried out to enhance farmersʼ understanding of intercropping.

Using two rice varieties, Suijing 309 (SJ309) and Longqingdao 31 (LQD31), as experimental materials, the effects of chromium (Cr) stress on the physiological traits and morphological characteristics of rice leaves were investigated. The results showed that Cr was primarily enriched in the roots of rice, and SJ309 was more effective than LQD31 in reducing the absorption and translocation of Cr. Under high-concentration Cr stress (100 μmol/L), the physiological characteristics such as stomatal conductance, transpiration rate, water use efficiency, and photosynthetic pigments decreased in both varieties, while leaf vapor pressure deficit, intercellular CO₂ concentration, and malondialdehyde (MDA) content increased. After Cr stress treatment, only LQD31 exhibited an increase in the stomatal area of guard cells and closure of the stomatal aperture, whereas no significant changes were observed in SJ309. Compared with SJ309, the contents of abscisic acid (ABA) and salicylic acid (SA) in LQD31 increased significantly, leading to the overexpression of NCED1 and NCED2 genes involved in the regulation of stomatal aperture, which indicated that LQD31 was more sensitive to Cr stress. Furthermore, Cr stress significantly increased the density and length of non-glandular trichomes in SJ309, suggesting its ability to withstand UV damage and various environmental stresses. In summary, SJ309 demonstrates superior tolerance to Cr stress, and its hyperaccumulation characteristics can be utilized for the phytoremediation of Cr-contaminated soils.

To address the issues of soil structure deterioration, decreased organic carbon content, and low maize yield caused by soil wind erosion in semi-arid aeolian sandy regions, a long-term field positioning experiment was conducted in Durbod Mongolian Autonomous County, Heilongjiang Province. Four treatments were established: rotary tillage with ridging (CK), no-tillage with straw mulching for one year (T1), continuous no-tillage with straw mulching for three years (T2), and continuous no-tillage with straw mulching for seven years (T3). The effects of each treatment on soil aggregate distribution characteristics, organic carbon accumulation, and maize yield across different soil layers were analyzed. The results showed that in the 0-30 cm soil layer, compared with the other treatments, the T3 treatment significantly reduced soil bulk density and significantly increased soil moisture content. Meanwhile, the T3 treatment enhanced the percentage of >0.25 mm water-stable aggregates, the organic carbon content, and the contribution rate within these aggregates, while also increasing the mean weight diameter and geometric mean diameter. No-tillage with straw mulching significantly increased maize yield, with the increase ranging from 14.98% to 39.54% compared with the CK treatment. In summary, no-tillage combined with straw mulching helps improve soil aggregate stability, the organic carbon content of aggregates across all size classes, and maize yield in semi-arid areas, with the T3 treatment yielding the best results.

Using Wanzhi 21 sesame as the experimental material, four harvesting periods of sesame leaf vegetable were set as follows: starting from the 40th day (P40), the 50th day (P50), the 60th day (P60), and the 70th day (P70) after the emergence of sesame, with the without harvesting sesame leaf vegetable as control (PCK). Through the two year continuous experiment, the effects of different harvesting periods on the main economic traits and yield of sesame leaf vegetable were studied, and a comprehensive benefit analysis was conducted. The results showed that the effects of the harvesting period of sesame leaf vegetable on the plant height, capsule axis length, effective node number, number of capsules per plant, number of seeds per capsule, and 1000-seed weight reached a significant level. The later the harvesting period of leaf vegetable, the slower the decline in the economic traits, which was specifically reflected as PCK > P70 > P60 > P50 > P40. The later the harvesting period of leaf vegetable, the higher the yield of sesame seeds, and the lower the reduction rate of seed yield. On the contrary, the earlier the sesame leaf vegetable harvesting, the higher the yield and net benefit of sesame leaf vegetables, but the lower the dry-fresh ratio of leaf vegetable. Specifically, the dry-fresh ratio showed an order of P40 < P50 < P60 < P70. The benefit from sesame seeds was just the opposite, and the later the sesame leaf vegetable harvesting, the higher the benefit from sesame seeds. The comprehensive benefit of harvesting leaf vegetable was the highest at P70 treatment, which increased by 39.06%-58.22% compared with PCK treatment. Therefore, the 70th day is the best harvesting period for sesame leaf vegetable, which can achieve the greatest comprehensive benefit of sesame cultivation.

Using wild oats and cultivated oats as research subjects, an experiment was conducted using wild population materials (Atl-03, Atl-05, Atl-06, Atl-08, Atl-11) and cultivated population materials (ITAO-32, ITAO-36, ITAO-38, ITAO-49, ITAO-50). Photosynthetic parameters including net photosynthetic rate, stomatal conductance, intercellular CO₂ concentration, transpiration rate, and relative chlorophyll content (SPAD value), as well as agronomic traits such as plant height, panicle length, total tiller number, 1000-grain weight, and mean surface area of seed, were measured at heading stage, early grain-filling stage, late grain-filling stage, and maturity, respectively. The results showed there were significant differences in photosynthetic characteristics between wild oats and cultivated oats. The coefficients of variation of wild oats were higher than those of cultivated oats, but cultivated oats exhibited stronger and more stable photosynthetic performance. Furthermore, significant differences were also observed in agronomic traits between wild oats and cultivated oats. Correlation analysis indicated that net photosynthetic rate, flag leaf area, and SPAD value were all significantly positively correlated with 1000-grain weight. Among the wild populations, Atl-11 exhibited the optimal photosynthetic characteristics and agronomic traits; among the cultivated populations, ITAO-36 showed the optimal photosynthetic characteristics and agronomic traits, and both can serve as excellent germplasm resources.

In order to precisely formulate weed control strategies for soybean field under maize-soybean and wheat-soybean rotation modes, the species and quantities of weeds were investigated in these two rotation modes. The results showed that during the two-year experiment, the weed occurrence in the maize-soybean rotation mode was 1.89 and 1.49 times higher than that in the wheat-soybean rotation mode, respectively. In the maize-soybean rotation mode, a total of 11 weed species were consistently observed over the two years, including two gramineous weeds and nine broadleaf weeds. The dominant weed species were the gramineous Echinochloa crusgalli and the broadleaf Chenopodium album and Abutilon theophrasti. The subdominant species were the gramineous Eriochloa villosa and the broadleaf Amaranthus retroflexus and Solanum nigrum. For the wheat-soybean rotation mode, eight weed species were commonly observed over the two years, including two gramineous weeds and six broadleaf weeds. The dominant species included the gramineous E.crusgalli and the broadleaf C.album and A.theophrasti, while the subdominant species was the broadleaf Solanum nigrum. The maize-soybean rotation mode exhibited two weed occurrence peaks: one from late May to mid-June, and another from late June to early July, with the weed occurrence during the first peak period being greater than that during the second. Conversely, the wheat-soybean rotation mode showed only one weed occurrence peak, primarily concentrated in early to mid-June.

To investigate the response of drought-resistant quinoa seedlings to drought stress, the strongly drought-resistant quinoa variety Longli No.1 (LL1) and the new breeding line LQ18 were selected as experimental materials. PEG-6000 solution was used to simulate drought environment. Three treatments were set: normal irrigation (CK), mild drought stress (5% PEG-6000), and severe drought stress (20% PEG-6000). We investigated quinoa seed germination rate, germination potential, germination index; seedling plant height, leaf area, root length, aboveground and underground dry weights; soluble protein and proline contents; superoxide dismutase (SOD) and peroxidase (POD) activities; and malondialdehyde (MDA) content. The results showed that severe drought stress reduced plant height, leaf area, and aboveground dry weight in both varieties (lines), but increased root length, underground dry weight, and root-shoot ratio. Specifically, the reductions in leaf area and aboveground dry weight, as well as the increases in root length, underground dry weight, and root-shoot ratio were all smaller in LQ18 than in LL1. Under drought stress, the soluble protein content of LL1 gradually decreased, while that of LQ18 first increased and then decreased to a level with no significant difference from CK. Under severe drought stress, the proline content of both varieties (lines) significantly increased, and the proline content of LQ18 was significantly higher than that of LL1. Drought stress influenced the activities of SOD and POD and increased MDA content in both varieties (lines). Under severe stress, the SOD activity of LQ18 decreased slightly, whereas its POD activity increased significantly; furthermore, its MDA content remained significantly lower than that of LL1.

A field experiments was conducted to investigate the effects of different microbial fertilizers of biological and compound formulations on soil physicochemical properties, growth and development, disease resistance, photosynthetic characteristics, economic traits, chemical composition, and sensory evaluation of tobacco leaves. The results showed that the application of microbial fertilizer could effectively improve the soil available nutrients, ameliorate soil acidification, and promote the growth and development of flue-cured tobacco, showing better plant height, leaf length, stem girth and effective leaf number. Among all the treatments, the treatment of biological agents, purple spotted fungus had the most obvious effect. In addition, the application of purple spotted fungus increased the net photosynthetic rate, intercellular CO₂ concentration and relative chlorophyll content (SPAD value). Compared with the CK treatment, the application of microbial fertilizer affected the occurrence of tobacco disease. The application of root rot control agent (double dosage) and thick- walled verticillium improved the resistance to common mosaic virus, while the application of root rot control agent, purple spotted fungus, oxmayl and fluorescent pseudomonad improved the resistance to black shank disease. The appearance quality of flue-cured tobacco, economic properties, chemical composition of cured tobacco leaves and the total score of sensory evaluation were the best in the treatment of biological agents. This indicated that the application of purple spotted fungus in biological-based microbial fertilizer could improve soil physicochemistry properties to a certain extent, promote the growth and development of flue-cured tobacco and improve disease resistance. At the same time, it could cause changes in the appearance quality and chemical composition of flue-cured tobacco, thus improving the quality and yield quality of flue-cured tobacco.

Aiming at the issues of poor soil structure, insufficient nutrient supply, and low potato yield in the agro-pastoral ecotone in the Northern piedmont of Yinshan Mountain, Inner Mongolia, a two-year field randomized block experiment was conducted. Taking conventional fertilization as the control (CK), three treatments were set up, including chemical fertilizer reduction combined with sheep manure (NPK+SD), chemical fertilizer reduction combined with biochar (NPK+B), and chemical fertilizer reduction combined with microbial fertilizer (NPK+MF). The dynamic changes of leaf area index (LAI), SPAD value, photosynthetic performance, plant nutrient accumulation and dry matter accumulation of potato plants under different treatments were compared and analyzed. The results showed that during the tuber bulking, NPK+MF treatment significantly improved LAI and leaf photosynthetic performance of potato, with leaf SPAD value significantly increased by 8.04% compared to CK, and no significant difference compared to NPK+SD and NPK+B treatments. The net photosynthetic rate of NPK+MF treatment was significantly increased by an average of 11.31%, 7.66%, and 4.92% compared to CK, NPK+SD, and NPK+B treatments, respectively. Under the NPK+MF treatment, with the growth process of potato, plant nutrients are transported from stems and leaves to tubers, and the accumulation of N, P, and K in potato leaves, stems, roots, and tubers were significantly increased. During the late stage of potato growth, the distribution ratio of nitrogen, phosphorus, and potassium in the tubers increased by 90.58%, 178.78% and 226.06%, respectively. The yield of NPK+MF treatment was the best, with an average of 40 054 kg/ha, which was 25.58% higher than that of CK. This experiment identified that chemical fertilizer reduction combined with microbial fertilizer was an effective fertilization method for soil fertility improvement and efficient utilization of soil and fertilizer resources in the agro-pastoral ecotone of the northern piedmont of Yinshan Mountain.

A two-year field experiment was conducted from 2022 to 2023 in Zunyi, Guizhou Province. Five fertilization treatments, no fertilization (T1), farmerʼs habit fertilization, basal application ordinary compound fertilizer 900 kg/ha and topdressing of pure N 45.0 kg/ha during panicle stage (T2), basal application type I fertilizer 1800 kg/ha, no topdressing (T3), basal application type II fertilizer 3000 kg/ha, no topdressing (T4), basal application type III fertilizer 1500 kg/ha and topdressing of pure N 90.0 kg/ha during panicle stage (T5) were set up to study the effects of different organic-inorganic compound fertilizers from distillerʼs grains on sorghum yield, quality, nutrient uptake and utilization. The result showed that compared with T2 treatment, the sorghum yield of T3, T4, and T5 treatment increased by 76.57, 107.57, 164.66 kg/ha and total biomass increased 328.40, 358.98, and 463.54 kg/ha. Compared with T2 treatment, the amylopectin content in sorghum from T3 to T5 treatment increased by 1.13%-7.02% and and tannin content increased by 1.63%-4.35%. Compared with T2 treatment, the nitrogen accumulation of T3, T4 and T5 treatments were increased by 7.27, 6.22, 9.07 kg/ha, the phosphorus accumulation were increased by 1.27, 1.72, 2.47 kg/ha, the potassium accumulation were increased by 13.35, 12.38, 9.15 kg/ha. After harvesting of sorghum, T3, T4 and T5 treatments could all maintain or increase soil nutrient content. The two-year average net benefit of T5 treatment were 45 189.7 yuan/ha, and output/input ratio were 2.679, higher than T2, T3, and T4 treatments. In summary, both the one-time basal application of Type I and Type II and basal application of Type III + topdressing of nitrogen at panicle stage methods could improve the yield, nutrient absorption and utilization, and maintain soil fertility levels. We suggested that when labor is in sufficient, the former is preferred; when labor is sufficient, the latter is an alternative.

To investigate the mechanism of the coupled effects of precipitation, nitrogen (N) fertilizer, and straw mulching on dryland spring wheat yield under different precipitation year types, the APSIM model was calibrated using spring wheat yield, soil, and meteorological data under no-tillage and no-tillage with straw mulching from 2013 to 2018. Combined with historical data from 1970 to 2022 to drive the calibrated model, yields were simulated under 5×5×5 combinations of precipitation changes (±20%, ±10% and 0%), nitrogen application rates (0.0, 52.5, 105.0, 157.5, and 210.0 kg/ha), and straw mulching rates (0, 1125, 2250, 3375, and 4500 kg/ha). The coefficient of variation of yield under single-factor was analyzed for each year type, and quadratic orthogonal polynomial stepwise regression, single-factor analysis, and interaction effects were employed to study the impacts of various factors on yield. The results showed that the APSIM model performed well, with R² > 0.8, NRMSE < 10%, and M_E > 0.8 for both tillage practices. In dry, normal, and wet years, the individual and interactive effects of the three factors all positively influenced yield, with the order of effect intensity being: precipitation change > nitrogen application rate > straw mulching rate. Based on the natural precipitation of the current year, the optimal yields and cultivation measures for each year type were as follows: in dry years, an optimal yield of 2203.65 kg/ha was achieved by increasing precipitation by 20%, applying 153.13 kg/ha of nitrogen, and mulching with 4500 kg/ha of straw; in normal years, an optimal yield of 2838.77 kg/ha required a 20% increase in precipitation, 170.76 kg/ha of nitrogen, and 4500 kg/ha of straw mulching; in wet years, an optimal yield of 3447.11 kg/ha required a 20% increase in precipitation, 188.58 kg/ha of nitrogen, and 4500 kg/ha of straw mulching. In conclusion, within the simulated experimental range, increasing precipitation, nitrogen application rate, and straw mulching amount under no-tillage conditions can enhance the simulated yield of spring wheat, but the degree of impact varies with precipitation year types. For local spring wheat, water, fertilizer, and mulching strategies should be formulated according to the specific year type to achieve high and stable yields.

In order to screen the suitable mowing period with high forage yield, good quality and good silage fermentation quality of triticale in Northern Henan. Triticale varieties ʻYounengʼ and ʻLeishenʼ were used as experimental materials, and four mowing periods were set up to determine the dry matter yield, nutritional quality and silage fermentation quality. The results showed that from the heading stage to the milk stage, the dry matter yield of triticale gradually increased, with Youneng and Leishen reaching the highest of 15.64 and 16.67 t/ha, respectively. The whole plant moisture content, crude protein and crude ash contents all decreased with the delay of mowing period, the neutral detergent fiber and acid detergent fiber contents increased first and then decreased, and the principal component analysis of nutritional indicators indicated that the nutritional quality score peaked at the heading stage. The pH of silage was 4.05-4.50, the lactic acid content was 2.11%-4.00%, with no detection of butyric acid. Youneng and Leishen had better fermentation quality when mowed from flowering to filling stage, from heading to filling stage, respectively. In summary, Youneng and Leishen are suitable for mowing at the flowering and heading stages, respectively. At these stages, both varieties achieve high dry matter yields along with excellent nutritional and silage fermentation quality.

In order to accurately simulate the initiation process of tobacco leaves and provided reference for precise management and control of tobacco production, field comparison experiments of different transplanting date treatments were carried out for two consecutive years from 2022 to 2023 to establish dynamic models of tobacco leaf changes based on different scales, and the simulation accuracy of different models was analyzed. The results showed that the rate of leaf initiation accelerated with the delay of the transplanting date, and the time to reach the maximum number of leaves was shortened. The final number of leaves (A value) in different transplanting dates was basically the same. The leaf initiation models of tobacco was an atypical “S” type growth curve with no stable growth period. The accuracy of the growing degree days model was higher than that of the growing day model, which had better practicality when the temperature changed in the appropriate range. The accuracy of the thermal-photo effectiveness model was higher than the growing degree days model, however, the prediction accuracy fluctuated across different years. The accuracy of the physiological development time model was higher than other models. The time for the tobacco leaves number to reach the maximum value was 37.63- 46.62, the growing degree days was 440.06-483.04, the thermal-photo effectiveness value was 30.17-34.36, and the physiological development time was 29.13-31.80, in the transplanting date from late April to late May in Shandong tobacco area. The simulation model of tobacco leaf initiation based on physiological development time had higher reliability and universality, which could accurately characterize the process of plant development and provide support for the precise management of tobacco production.

To explore the optimal nitrogen application rate for different wheat varieties in various environments and provide a scientific basis for enhancing the mineral element content in wheat grains, this study used 15CA73, Jimai 22, Zhongmai 255, and Zhongmai 578 as experimental materials. Five nitrogen application treatments were established across four environments: Anyang (Henan), Hefei (Anhui), Weifang (Shandong), and Liaocheng (Shandong). These treatments included no nitrogen application (N₀), basal application of 45 kg/ha pure nitrogen + topdressing of 45 kg/ha pure nitrogen at the jointing stage (N₄₅₊₄₅), basal application of 90 kg/ha pure nitrogen + topdressing of 90 kg/ha pure nitrogen at the jointing stage (N₉₀₊₉₀), basal application of 135 kg/ha pure nitrogen + topdressing of 135 kg/ha pure nitrogen at the jointing stage (N_135+135), and basal application of 180 kg/ha pure nitrogen + topdressing of 180 kg/ha pure nitrogen at the jointing stage (N_180+180). The results showed highly and extremely significant correlation coefficients (P < 0.01) between the contents of elements such as K and P (r = 0.72), and Zn and Cu (r = 0.69) in grains. Compared with the N₀ treatment, the N_180+180 treatment resulted in the highest contents of Ca, Cu, Mg, and S in wheat grains at the Weifang site across all environments, with increases of 11.06%, 10.78%, 0.15%, and 7.83%, respectively. The Zn content at the Weifang experimental site was highest under the N_135+135 treatment, showing a 46.01% increase compared to the N₀ treatment. Furthermore, compared with the N₀ treatment, the N_180+180 treatment led to the highest contents of Cu, Fe, Mg, Mn, and S in Zhongmai 255 grains among all tested varieties, with increases of 2.42%, 3.50%, 1.65%, 4.23%, and 16.10%, respectively. The Zn content in Zhongmai 255 grains was the highest under the N_135+135 treatment, increasing by 13.26% compared to N₀ treatment. In summary, increased nitrogen application enhanced the contents of Ca, Cu, Fe, Mn, S, Mg, and Zn in wheat grains. K content was less affected by nitrogen application, while P content showed a declining trend. Concurrently, the P/Mg, P/Fe, and P/Zn ratios decreased, further improving the bioavailability of Mg, Fe, and Zn in the grains. Therefore, the recommended optimal nitrogen fertilizer treatments for wheat cultivation at the experimental sites are N_135+135 for Anyang, N₀ for Hefei, N_180+180 for Liaocheng, and N_180+180 for Weifang. Moreover, N₀ is determined to be the optimal nitrogen fertilizer treatment for 15CA73 and Jimai 22, whereas N_180+180 is optimal for Zhongmai 255 and Zhongmai 578.

A field experiment was conducted to investigate the effects of planting densities and nitrogen application levels on the growth, biomass allocation and yields of Salvia prionitis Hance. Three planting density levels, high density (666 666 plant/ha), medium density (200 000 plant/ha), and low density (95 238 plant/ha); and three fertilization levels [no nitrogen application, low nitrogen (22.5 g/m²) and high nitrogen (45 g/m²)] were set. The results showed that both the density and nitrogen level significantly affected plant size, biomass allocation and yield of S.prionitis. However, the interaction effect only extremely significantly affected the parameters related to biomass allocation. In general, nitrogen application increased the plant height, number of flower stalks, and number of primary branches flower stalks of S.prionitis under all planting densities, and leaf length, leaf width, and plant height of the two low density treatment were greater than those of the high density treatment under all nitrogen levels. Nitrogen level did not significantly affect the root biomass ratio and root- shoot ratio of S.prionitis at medium density treatment, while the root biomass ratio and root-shoot ratio at low and high densities were significantly reduced with the increasing of nitrogen application. Under each densities, the root biomass, supporting structure biomass, total biomass, whole plant yield and root yield of S.prionitis were the greatest in the low nitrogen treatment, then followed by the high nitrogen treatment. under every nitrogen application levels, the root biomass, supporting structure biomass and total biomass of S.prionitis increased significantly with the decreasing of density, However, the whole plant yield and root yield increased significantly with the decreasing of density. In all treatments, whole plant yield and root yield of S.prionitis were the greatest at high density (666 666 plant/ha) with low nitrogen level (22.5 g/m² pure nitrogen, urea).

This study used 17 selected quinoa lines as experimental materials and established three sowing dates: November 10, 2022 (T1), December 15, 2022 (T2), and January 5, 2023 (T3), to analyze the effects of sowing date on quinoa agronomic traits and yield. The results showed that delaying the sowing date shortened the average growth period from 191.7 d (T1) to 148.1 d (T3), a reduction of 44.0 d for late sowing compared to early sowing. Under T3 treatment, quinoa exhibited the highest average plant height but the lowest 1000-grain weight. Under T2 treatment, the average stem diameter, number of effective branches, and yield per plant were all the highest. Under T1 treatment, the average main panicle length was the shortest. Correlation analysis showed that the yield per plant had a highly significantly positive correlation with stem diameter, number of effective branches, and 1000-grain weight. Two-way ANOVA showed that plant height, main panicle length, 1000-grain weight, and growth period were most strongly affected by sowing date. In contrast, number of effective branches and yield per plant were only significantly affected by the line and the interaction between line and sowing date. In conclusion, the most suitable winter sowing date for quinoa in the low-heat valley area of the Jinsha River in northwest Yunnan is mid-December (T2). Under this sowing date, lines Q201909, Q201807, and Q201913 exhibited the best comprehensive performance in agronomic traits and yield, making them suitable for winter cultivation in the low-heat valley areas of Yunnan and similar climatic regions.

In order to clarify the pathogenicity and the potential risk of major corn pathogens to soybean root rot in corn-soybean inter planting, this study artificially inoculated non-co-occurring pathogens onto soybean roots and observed the symptoms in pots, and identified the infection grades of pathogens on soybean root rot. The results showed that Curvularia lunata causing corn curvularia leaf spot, Bipolaris maydis causing southern corn leaf blight, and Exserohilum turcicum causing northern corn leaf blight were non-co-occurring pathogens and could cause soybean root rot. Isolation and identification confirmed that the isolated strains were identical to the inoculated pathogens; C.lunata could cause soybean root rot up to Grade 5, B.maydis and E.turcicum could lead to soybean root rot up to Grade 3. The above results indicated that all three pathogens were causal agents of soybean root rot, and there was a potential risk of causing soybean root rot.