Nitrogen, Phosphorus, and Potassium Interactive Effects for Improving Drought Resistance on Mung Bean Varieties

The planting areas of mung bean are mostly arid and semi-arid areas, and lack of irrigation conditions. Many studies have reported that fertilization can increase drought resistance. In our previous research, optimized nitrogen (N), phosphorus (P) and potassium (K) combined fertilization model was established in mung bean. In the present study, the optimal fertilization was conducted in pot trails, and mung bean varieties Bailv9 and Bailv11 were used as materials, while the four water regimes, and three fertilization ratios of F120 (optimal fertilization), F100 (conventional fertilization), F50 (half of conventional fertilization) treatments were set, to compare each fertilization ratio effects and non-fertilization condition under each water regimes respectively. Under different water conditions, the investigation of N, P, and K effects of optimal fertilization showed that the yield of Bailv9 was not sensitive to water stress and had strong drought resistance;their water sensitivity index and drought resistance coefficient were BaiLv9 as Di = 0.89 and DC = 0.79. The yield of Bailv11 was sensitive to water stress, and their drought resistance was weak;their water sensitivity index and drought resistance coefficient were BL11 Di = 1.76 DC = 0.59, and under different water treatment conditions, Bailv9 and Bailv11 all had the best yield and other related traits increase in the F120 fertilization mode compared with other fertilization and non-fertilization conditions, and the average yield increases were 31.56% and 28.08%, respectively. The pot trails conduct the drought stress treatments in mung bean varieties Bailv9, Bailv11, Bailv935 and Bailv985 to determine the function of NPK optimized fertilization for improving plants growth in drought stress condition. Compared with the mung bean varieties treated with F50, F100, and F120, the yield of Bailv9 increased by 56.20%, 81.27%, and 107.22%, respectively;compared with that of F0, the yield of Bailv11 increased by 10.18%, 19.42%, and 45.88%, respectively;Bailv935 increased by 26.52%, 61.90%, 74.16% respectively, and Bailv985 increased by 23.78%, 56.92%, 87.62% respectively. The significant performances of optimized fertilization were also verified in 20 mung bean varieties in our filed trails. The research establishes a theoretical basis for introducing the model into production practice in the next step.

The haplotype-resolved T2T reference genome highlights structural variation underlying agronomic traits of melon

Melon(Cucumis melo L.)is an important vegetable crop that has an extensive history of cultivation.However,the genome of wild and semi-wild melon types that can be used for the analysis of agronomic traits is not yet available.Here we report a chromosome-level T2T genome assembly for 821(C.melo ssp.agrestis var.acidulus),a semi-wild melon with two haplotypes of∼373 Mb and∼364 Mb,respectively.Comparative genome analysis discovered a significant number of structural variants(SVs)between melo(C.melo ssp.melo)and agrestis(C.melo ssp.agrestis)genomes,including a copy number variation located in the ToLCNDV resistance locus on chromosome 11.Genome-wide association studies detected a significant signal associated with climacteric ripening and identified one candidate gene CM_ac12g14720.1(CmABA2),encoding a cytoplasmic short chain dehydrogenase/reductase,which controls the biosynthesis of abscisic acid.This study provides valuable genetic resources for future research on melon breeding.

Genetic dissection of climacteric fruit ripening in a melon population segregating for ripening behavior

Melon is as an alternative model to understand fruit ripening due to the coexistence of climacteric and non-climacteric varieties within the same species,allowing the study of the processes that regulate this complex trait with genetic approaches.We phenotyped a population of recombinant inbred lines(RILs),obtained by crossing a climacteric(Védrantais,cantalupensis type)and a non-climcteric variety(Piel de Sapo T111,inodorus type),for traits related to climacteric maturation and ethylene production.Individuals in the RIL population exhibited various combinations of phenotypes that differed in the amount of ethylene produced,the early onset of ethylene production,and other phenotypes associated with ripening.We characterized a major QTL on chromosome 8,ETHQV8.1,which is sufficient to activate climacteric ripening,and other minor QTLs that may modulate the climacteric response.The ETHQV8.1 allele was validated by using two reciprocal introgression line populations generated by crossing Védrantais and Piel de Sapo and analyzing the ETHQV8.1 region in each of the genetic backgrounds.A Genome-wide association study(GWAS)using 211 accessions of the ssp.melo further identified two regions on chromosome 8 associated with the production of aromas,one of these regions overlapping with the 154.1 kb interval containing ETHQV8.1.The ETHQV8.1 region contains several candidate genes that may be related to fruit ripening.This work sheds light into the regulation mechanisms of a complex trait such as fruit ripening.

Research Advances in Functional Constituents of Chickpea

Based on the generalization and summary of the research on the functional constituents of chickpea at home and abroad in recent years,the research advances in some rich functional constituents including isoflavones,proteins and peptides,carbohydrates,saponins and trace elements in chickpeas was reviewed in this paper. It provides a basis for the research,development and utilization of the functional constituents of chickpea in the future.

Two major er1 alleles confer powdery mildew resistance in three pea cultivars bred in Yunnan Province, China

Powdery mildew, caused by Erysiphe pisi D.C., is an important disease of pea(Pisum sativum L.).The use of cultivars carrying powdery mildew resistance alleles at the er1 locus is the most effective and economical means of controlling this disease. The objectives of this study were to screen Chinese elite pea cultivars for resistance to E. pisi and to identify the responsible gene at the er1 locus. Among the 37 pea cultivars tested, three(Yunwan 8, Yunwan 21, and Yunwan 23) were immune to E. pisi infection in phenotypic evaluations. The full-length cD NA sequences of the er1 candidate gene, PsM LO1, from the three resistant cultivars and control plants were analyzed. Comparison of the cD NA sequences of 10 clones revealed differences among the powdery mildew-resistant cultivars, susceptible controls, and wild-type cultivar Sprinter. The observed resistance in Yunwan 8 plants resulted from a point mutation(C → G) at position 680 of PsM LO1 that introduced a stop codon, leading to premature termination of protein synthesis. The responsible resistance allele was identified as er1–1. Powdery mildew resistance in Yunwan 21 and Yunwan 23 plants was caused by identical insertions or deletions in PsM LO1. Three distinct PsM LO1 transcripts were observed in Yunwan 21 and Yunwan 23 plants. These transcripts were characterized by a129-bp deletion and 155- and 220-bp insertions, respectively. The responsible resistance allele was identified as er1–2. We have characterized two important er1 alleles in three E. pisi-resistant pea cultivars bred in Yunnan Province, China. These cultivars represent important genetic resources for the breeding of powdery mildew-resistant pea cultivars.

黄河甘肃段底栖动物群落结构及水质评价

为探究人类活动对黄河上游水生态系统的影响程度,于2021年8月对黄河甘肃段10个采样点的底栖动物群落和水体理化性质进行了调查研究。本次采样共鉴定出底栖动物32种,其中节肢动物25种(78.13%),软体动物5种(15.63%),环节动物2种(6.25%);对整个研究区域而言,优势种为横纹划蝽(Sigara substriata)、短脚溪泥甲(Ampumixis sp.)、秀丽白虾(Palaemon modestus)、钩虾(Gammarus sp.)、耳萝卜螺(Radix Auricularia)和卵萝卜螺(Radix ovata)等6种;底栖动物现存量空间差异性显著,表现为下游段(271只·m^(-2)、18.0105 g·m^(-2))>上游段(95只·m^(-2)、4.1275 g·m^(-2));Shannon-Wiener多样性指数、Margalef丰富度指数均表现为下游段大于上游段,而Pielou均匀度指数沿程变化较小。BI指数和综合污染指数水质评价结果较为一致,黄河甘肃段上游段水质整体优于下游段水质,且Y6样点水质最佳;黄河甘肃段水质总体达到Ⅱ类和Ⅲ类地表水标准,河流经水库和湿地净化后,水质有显著提升。水温和高锰酸钾盐是影响黄河甘肃段底栖动物群落结构的关键环境因子。库区和湿地水环境最优,上游自然河段水质优于下游自然河段,但下游段生物多样性及丰度高于上游段。