To identify suitable plant growth regulators in flax production, enhance lodging resistance and increase yield, different levels of paclobutrazol [975 (D1), 1125 (D2), 1275 g/ha (D3)], uniconazole [750 (X1), 900 (X2), 1050 g/ha (X3)] and chlormequat [1200 (A1), 1800 (A2), 2400 mL/ha (A3)] were applied. The changes of plant growth and development, lodging resistance, seed yield and related traits of flax at different levels were studied with clear water as control (CK). The results showed that spraying three plant growth regulators affected the main agronomic traits of flax. Compared with CK, the number of effective branches of D1 treatment decreased, and the number of effective branches and the number of effective capsules per plant of A1 treatment were lower than those of CK. There was no significant difference in root length among the treatments. The root diameter of A2 treatment was significantly higher than that of CK, and the number of seeds per capsule of each treatment was lower than that of CK. The yield per plant of X2 and A2 treatments was significantly higher than that of CK, and the 1000-grain weight of D1 treatment was significantly lower than that of CK. The plant height and center of gravity height of X3 treatment decreased the most, which were 13.63% and 10.34%, respectively. The stem diameter of each treatment was increased compared with CK, and the D2 treatment increased the most, which was 17.5%. There was no significant difference in yield between any treatment and CK. The stem breaking resistance of A2 treatment was significantly higher than that of CK, and there was no significant difference between the other treatments and the control. The lodging index of each treatment was lower than that of CK, except for D1 and D2 treatments, the other treatments were significantly different.The correlation analysis showed that the effective number of capsules per plant, effective branch number, breaking resistance and root diameter were significantly correlated with the yield per plant, and the fresh weight and crown weight were significantly correlated with the lodging index. Through comprehensive analysis, uniconazole was better than chlormequat, chlormequat was better than paclobutrazol, and uniconazole 900 g/ha had better effect in flax production.

To investigate the characteristics of aerial roots in maize inbred lines with different genetic backgrounds and their relationship with lodging resistance, 56 maize inbred lines were used as experimental materials. Eight aerial root traits were comprehensively analyzed using correlation analysis, path analysis, and cluster analysis. Stalk anti-thrust was measured using a plant stem strength tester as an evaluation index for lodging resistance, and the relationship between aerial root traits and lodging resistance was analyzed. The results showed that the coefficients of variation (CV) for all aerial root traits were relatively large, with the CV of the aerial root angle being the largest (31.70%) and that of the aerial root emergence time being the smallest (10.77%). Among the aerial root traits, all except emergence time and puncture resistance exhibited significant correlations with one another. Specifically, the number of aerial roots and the aerial root anchoring radius were highly significantly and positively correlated with stalk anti-thrust, with correlation coefficients of 0.560 and 0.522, respectively. Additionally, aerial root puncture resistance and the number of aerial root tiers also showed significant positive correlations with stalk anti-thrust. Path analysis indicated that both the direct and indirect effects of the number of aerial roots and the aerial root anchoring radius on the lodging resistance evaluation indicators were relatively large. Therefore, strengthening the selection and improvement of these two traits in lodging resistance breeding would help enhance the lodging resistance of maize varieties. Cluster analysis classified the tested inbred lines into four groups. Inbred lines in Group II, such as Xun M6968 and LH190, were characterized by high mean values for both stalk anti-thrust and aerial root traits, providing a germplasm foundation for the breeding of new lodging-resistant varieties.

In order to investigate the influence mechanism of pH level on the growth and development of rice and nutrient uptake under different nitrogen forms, rice cultivar Guanghui 751 was grown with five pH treatments (pH 3.5, 4.5, 5.5, 6.5, and 7.5) to study the effects on the biomass accumulation, root morphology, and nutrient uptake of rice under ammonium-nitrogen and nitrate-nitrogen conditions hydroponically. The results showed that under ammonium-nitrogen conditions, the highest rice biomass accumulation was found at pH 6.5 treatment; compared with the pH 3.5 treatment, the shoot and whole-plant biomass accumulation increased by 146.6% and 142.5%, respectively. Plant height and maximum root length increased significantly; total root length, root surface area, and root volume increased by 612.6%, 317.8%, and 147.1%, respectively. The uptake of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn) increased by 159.5%, 114.3%, 181.9%, 241.4%, 124.4%, 74.9%, 173.4%, 366.2%, and 3058.0%, respectively. Under nitrate-nitrogen conditions, the highest rice biomass accumulation was found at pH=4.5 treatment; compared with the pH=3.5 treatment, the shoot, root, and whole-plant biomass accumulation increased by 36.7%, 49.6%, and 38.6%, respectively. Plant height and maximum root length increased significantly; total root length, root surface area, and root volume increased by 129.9%, 83.0%, and 47.5%, respectively. The uptake of N, P, K, Ca, Mg, Cu, Zn, Fe, and Mn increased by 40.0%, 27.7%, 51.0%, 78.5%, 71.2%, 53.9%, 292.1%, 1449.5%, and 695.1%, respectively. In conclusion, the optimum pH values for rice under ammonium-nitrogen and nitrate-nitrogen conditions were 6.5 and 4.5, respectively. Under their respective optimum pH conditions, ammonium-nitrogen and nitrate-nitrogen primarily increased rice biomass accumulation by promoting root growth and development and increasing nutrient uptake.

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.

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.

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.

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.

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.

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.

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.