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 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.

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.

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.

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.

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.