大豆耐酸雨胁迫种质资源的筛选和优异基因发掘

Acid rain is a serious worldwide problem that has adverse impacts on environment and crop productivity. The effects of acid deposition on plants are numerous and complex, including visible symptoms of injury, and invisible effects such as reduced photosynthesis, nutrient loss from leaves, altered water balance. Soybean is a major source of edible oil and protein in the world, and its production is important for soybean breeding. In order to sustain soybean yield under the stress of acid rain, the most effective approach is to deploy tolerant cultivars to enhance plants adaption to acid rain. At present, the research on the soybean tolerance to stresses was mainly about drought, cold and salt, but few study on the genetic basis of soybean tolerance to the acid rain have been reported. In this study, we aim to investigate the effect of acid rain on important agronomic traits in soybean germplasm resources from different ecological areas and screen some excellent soybean genotypes tolerant to acid rain. Two RILs (NJRIKY and NJRSXG) will be used to conduct QTL mapping of agronomic traits associated with acid rain tolerance in soybean. Association mapping of agronomic traits in response to acid rain stress would be performed in a natural population containing 300 soybean genotypes. Meanwhile, we will combine linkage and association mapping to discover the genes or allelic loci and exploit the functional molecular markers for soybean acid rain stress response. The prospective results will certainly help us understand the response mechanism of soybean to acid rain stress and provide reliable theoretical basis for improving the acid adaptation of soybean. This knowledge could lead to a more efficient strategy in soybean breeding for durable tolerance to acid rain stress. In addition, this study can also provide theoretical basis for the further study on the other legume tolerance to acid rain.

酸雨是气候变化三个主要方面之一，对环境和农作物的生长有严重影响。大豆是人类食物中植物蛋白质和油脂的主要来源，耐酸雨大豆资源的鉴定、筛选和优异基因的发掘利用是耐酸雨大豆新品种选育和品质改良的最有效途径。本研究拟进一步对来源于全国不同生态区的300多份具代表性大豆资源材料组成的核心种质进行酸雨胁迫响应的鉴定，筛选出一批对酸雨具有稳定、可靠的强耐性和强敏感性的大豆种质。利用酸雨耐性差异显著的双亲衍生的RIL群体NJRIKY和NJRSXG进行酸雨胁迫下大豆重要性状基因的连锁作图；并以300份核心种质组成的自然群体进行大豆耐酸雨基因的关联分析。综合连锁作图和关联分析结果对大豆耐酸雨优异基因进行发掘，探索大豆耐酸雨性的分子遗传机制，寻找和设计与耐酸雨优异等位基因紧密连锁的功能分子标记，为耐酸雨大豆的分子设计育种和大豆耐酸雨优异等位基因的功能研究奠定基础。

酸雨是气候变化三个主要方面之一，对环境和农作物的生长有严重影响。大豆是人类食物中植物蛋白质和油脂的主要来源，耐酸雨大豆资源的鉴定、筛选和优异基因的发掘利用是耐酸雨大豆新品种选育和品质改良的最有效途径。项目组对441份栽培大豆和172份野生大豆组成的自然群体进行了多年酸雨胁迫响应鉴定，从栽培大豆群体中筛选出纳雍猫儿灰、公安黄茶豆等22份强耐酸雨型基因型和金华大豆、广丰马料豆等23份酸雨强敏感型基因型，从供试野生大豆群体中筛选出ZYD5218、ZYD4481等8份强耐酸雨型基因型和ZYD5062、ZYD16-4346等9份酸雨强敏感型基因型，这些特异大豆种质资源可为大豆耐酸雨遗传研究和耐酸雨品系的培育提供材料。应用WinQTLCart 2.5软件的CIM方法对重组自交系群体NJRIKY耐酸雨性评价性状进行连锁作图，共检测到38个QTL，单个QTL的贡献率变化在4.79～14.27%，其中Gm05上satt648-sat_356为除每荚粒数外的8个性状的酸雨响应多效性区间，Gm06上satt286-satt365为籽粒产量和总粒数等5个性状的酸雨响应多效性区间。应用TASSEL 2.1软件的MLM方法对上述自然群体中耐酸雨性评价性状进行关联分析，在栽培大豆亚群体中共检测到68对显著的标记-性状相关，其中6对在对照和酸雨处理下均能检测到，单个位点解释的遗传变异为1.67～19.06%；在野生大豆亚群体中共检测到47对显著的标记-性状相关，其中1对在对照和酸雨处理下均能检测到，单个位点解释的遗传变异变化在0.64～44.27%。这些结果可为耐酸雨大豆的分子设计育种和大豆耐酸雨优异等位基因的功能研究奠定基础。