野生大豆抗胞囊线虫核心种质构建及优异抗源发掘

Soybean cyst nematode (SCN) is one of the most devastating pests in soybean production worldwide and causes great economic losses. The total area of SCN-infected soybean increases each year in our country, leading to substantial yield losses, and SCN race 3(SCN 3) is predominant in the northeast region. Planting resistant cultivars are considered an effective method to control SCN, however over utilization of the few resistant germplasm in breeding program leads to genetic vulnerability of the resistant elite cultivars. It becomes urgency to incorpate novel genes into breeding program for resistant cultivars development to decrease the risk of virulent SCN populations occurrence. Wild soybean (G.soja) is believed an invaluable gene pool for increasing genetic diversity of SCN resistance, which probably has genetic variations not present in domesticated soybean collection. Although there are plenty of G.soja resources in our country, researches on G.soja resistance to SCN were a pretty few, and most focused on the primary study of resistant germplasm screening, there is little information about genetic diversity of G.soja resistant germplasm. Identification of G.soja resistant germplasm, as well as molecular genetic diversity of G.soja resistant germplasm should be strengthened for further rational utilizaiton. In case of the great loss due to SCN 3 and the narrow genetic background of the resistant cultivars, effort for SCN resistant germplasm seletion has been done in the past 4 years of our research group. In the program, we plan to screen resistant resources from G.soja core collection including 652 accessions and establish an applied core collection conferring SCN 3-resistance, and then investigate molecular genetic diversity of the applied core collection as well as their relationship with Glycine max resistant parental genotypes frequently used in breeding program and genetic mapping using SSR and SNP markers, mine novel resistant genotypes. We hope the novel resistant genotypes would be helpful for increasing genetic diversity of SCN resistance.

大豆胞囊线虫（Soybean cyst nematode，SCN）病是世界大豆生产上的重要病害，在我国有加重趋势，3号生理小种(SCN 3)是我国东北大豆产区的优势小种。抗病品种遗传基础狭窄给大豆稳产带来潜在风险，而野生大豆拥有丰富的抗病资源，是大豆抗病育种的重要基因资源。我国野生大豆抗SCN研究薄弱，且停留在"抗源筛选"这一初期研究阶段，制约了优异抗源的合理利用。因此，在继续鉴选抗源的同时，有必要开展抗病种质遗传多样性及优异抗源发掘研究。针对东北大豆产区危害较重的SCN 3和抗病品种抗性单一问题，项目申请人在前期研究基础上，以野生大豆核心种质为材料，从中鉴定抗SCN 3资源，并构建抗病核心种质,进而以国内外常用栽培大豆抗源为对照，采用SSR和SNP标记研究抗病核心种质的遗传多样性及其与国内外常用栽培大豆抗源的遗传关系，从中发掘新抗病资源，为合理利用野生大豆拓宽抗病品遗传基础提供种质参考。

大豆胞囊线虫（SCN）病是世界大豆生产上的重要病害，在我国有加重趋势，3号生理小种(SCN 3)是我国东北大豆产区的优势小种。抗病品种遗传基础狭窄给大豆稳产带来潜在风险，而野生大豆拥有丰富的抗病资源，是大豆抗病育种的重要基因资源。我国野生大豆抗SCN研究薄弱，且停留在“抗源筛选”这一初期研究阶段，制约了优异抗源的合理利用。.因此，针对东北大豆产区危害较重的SCN 3和抗病品种抗性单一问题，本项目以野生大豆核心种质为主要试验材料，从中鉴定出抗SCN 3资源，并构建了抗病核心种质，进而以10份国内外常用栽培大豆抗源为对照，采用SSR和SNP标记研究了61份抗病核心种质的遗传多样性及其与国内外常用栽培大豆抗源的遗传关系。具体研究内容包括：① 野生大豆抗SCN 3应用核心种质的构建。采用温室鉴定方法进行了供试665份野生大豆种质对SCN 3的抗性鉴定，明确了其抗病性，根据其生态区、种皮色、子叶色、蛋白质含量等鉴定数据比较完整的指标构建了由101份野生大豆种质组成的抗病应用核心种质。② 抗病种质的分子标记分析。以10份国内外常用栽培大豆抗源（Peking、PI88788、Forrest、Franklin、PI437654、PI90763、PI98772、CN210、哈尔滨小黑豆、灰皮支黑豆）为对照，选择47个SSR标记和112个SNP标记进行了61份抗病核心种质的基因型鉴定，明确其等位变异类型。③ 抗病种质遗传多样性研究及优异抗源发掘。研究了61份抗病应用核心种质在47个SSR和112个SNP位点的遗传多样性；探索了其与常用栽培大豆抗源间的遗传关系；发掘了3个新型抗病资源类群。.本项目为合理利用野生大豆拓宽抗病品遗传基础提供了种质参考。