小豆(Vigna angularis (Willd.) Ohwi & Ohashi) 属于豇豆属亚洲豇豆亚属，是东亚各国传统种植作物。小豆营养丰富、医食两用，消费市场逐渐遍布全球。然而，小豆的遗传研究相对缓慢，导致育种技术落后、效率低下，难以满足生产和市场的需求。本研究基于高通量基因组测序技术构建了小豆SNP高密度遗传连锁图谱，该图谱共11条连锁群，含2904个标记，每条连锁群的标记数从208个（LG7）到397（LG1）个不等。图谱总长1365.0cM，标记间平均距离0.47cM，每条连锁群的长度从97.4cM（LG9）到155.6cM（LG1）不等。利用该图谱共发掘到两个与籽粒大小有关的主效QTL，分别位于LG2（22.1%） 和LG 9（18.8%）。此外，基于InDel侧翼序列，进一步开发了9718对引物，并随机选择200对进行PCR扩增检验，结果显示有75对在24份小豆种质中具有多态性。本研究中高密度图谱构建及籽粒大小的QTL 分析将进一步提升小豆重要性状基因的发掘等，而InDel标记的开发将有效促进小豆种质资源的遗传多样性分析、基因初步定位等研究。

Genetic diversity of 158 accessions of an applied core collection of adzuki bean (Vigna angularis) and 18 wild genotypes were assessed by using 85 microsatellite markers. With an average of 5.81 alleles per locus, 493 alleles were detected, and their distribution frequencies lower than 5% accounted for 73.02% of the total number. The distributions of alleles between the cultivated and the wild adzuki bean germplasm are different, with a higher allelic diversity in the wild germplasm than that of the cultivated ones. An obvious genetic differentiation was also observed between the wild and the cultivated adzuki beans, and SSR markers may be useful in study identification and classification of them. Among cultivated adzuki bean, the genetic similarity coefficient varied from 0.366 to 0.939. Genetic structure analysis can clearly separate the wild genotypes from the cultivated adzuki bean, and also can divide the cultivated ones into different populations, as these populations are closely agreeable with the ecological regions where they originally grow. The results of this study will be useful in arranging local breeding programs, especially in the aspect of parental combinations or identification of progenies. These SSR markers can also provide important information to explain the genetic relationship between the cultivated and wild adzuki beans, and to accelerate the wild gene resources in broadening the gene pool in breeding program.

Plants need to be efficient in nutrient management, especially when they face the temporal nutrient defficiencies. Understanding how crops respond to nitrogen (N) starvation would help in the selection of crop cultivars more tolerant to N deficiency. In the present work, the physiological responses of two wheat cultivars, Yannong 19 (YN) and Qinmai 11 (QM), to N starvation conditions were investigated. The two cultivars differed in biomass and N rearrangement between shoots and roots during N starvation. QM allocated more N to roots and exhibited higher root/shoot biomass ratio than YN. However, tissue measurement indicated that both cultivars had similar nitrate content in leaves and roots and similar remobilization rate in roots. Microelectrode measurement showed that vacuolar nitrate activity (concentration) in roots of QM was lower than that in roots of YN, especially in epidermal cells. Nitrate remobilization rates from root vacuoles of two cultivars were also identical. Moreover, vacuolar nitrate remobilization rate was proportional to vacuolar nitrate activity. During N starvation, nitrate reductase activity (NRA) was decreased but there were no significant differences between the two cultivars. Nitrate efflux from roots reduced after external N removal and QM seemed to have higher nitrate efflux rate.