To determine a suitable nutrient solution for rapid propagation of virus-free sweet potato seedlings, four nutrient solutions at two concentrations each were tested using virus-free seedlings of Longshu No.9 in substrate culture to explore the effects of different treatments on the growth of virus-free seedlings. The results showed that both nutrient solution type and electrical conductivity significantly affected morphology and physiology of the virus-free seedling. The Longjiu treatments showed the best growth performance and root vitality, particularly Longjiu 2 resulted in superior stem vine length, stem node number, and aboveground fresh and dry weights compared with other treatments. These results indicated that Longjiu 2 was a suitable nutrient solution for rapid propagation of virus-free Longshu No.9 sweet potato seedlings.

Peanut oil content is a complex trait, which is easily affected by environmental conditions. It is critically important to detect oil content of peanut kernels in peanut breeding. A total of 150 lines of recombinant inbred lines (RIL) derived from the cross between Yuhua 18 (high oil) and AT215 (low oil) were selected as materials, the spectral data of single-kernel was collected by Antaris II near infrared spectrometer, and the oil content was determined. A near-infrared (NIR) detection model on oil content for single-kernel oil content was established by partial least squares (PLS). The Root-Mean-Squares Error of Cross-Validation was 1.04 and the correlation coefficient (R²) was 0.9589. Twenty-four peanut samples with obvious difference in oil content were selected for external validation, and the R² was 0.9730. Another F₂ population from the cross between Yuhua 14 (high oil) and Huayu 20 (low oil) was used as the test population, whose oil content was determined by this model and the present single-kernel model. The variation range of predicted values from these two models was from -0.52% to 1.92%, showing a narrow variation range. This model is relatively small, and is reliable for oil content confirmation, which can be used for the oil content selection and quality detection of peanut.

To clarify the alleviating effect of auxin regulators on low-temperature stress at seedlings stage of soybean, the variety Kennong 18 was used as the test material, and seed coating with sodium naphthaleneacetic acid (NAA-Na), potassium indolebutyrate (IBA-K), and their mixture were adopted as the treatment. From the perspectives of morphological phenotype, antioxidant defense and osmotic regulation, the alleviating effect of NAA-Na and IBA-K on the growth and yield of soybean under low temperature stress was investigated. The results showed that the coating treatment with NAA-Na and IBA-K could reduce the accumulation of reactive oxygen species and the production rate of superoxide anion (O₂^-. ), and significantly decrease the accumulation of hydrogen peroxide (H₂O₂) and malondialdehyde. The osmotic regulation ability of soybean seedlings was enhanced, and the contents of soluble sugar, soluble protein, and proline increased. The activities of antioxidant enzymes such as superoxide dismutase, peroxidase, and catalase were enhanced, and the ascorbic acid-glutathione (AsA-GSH) cycle was promoted, thereby alleviating the damage of low-temperature stress to soybean seedlings. The dry matter accumulation in the aboveground and root parts of soybean seedlings increased. The adverse effects of low temperature stress on soybean yield were mitigated, and the number of pods per plant, the number of seeds per plant, 100-seed weight, and the seed weight per plant were significantly increased.

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.

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).

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.

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.

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.

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.

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.