华南大豆种质对大豆疫霉根腐病的抗性分析

【目的】大豆疫霉根腐病是由大豆疫霉菌引起的严重影响大豆生产的世界性病害之一，选用抗病品种是控制该病最经济有效的措施。筛选抗大豆疫霉菌PGD1的优异抗源和多抗疫霉根腐病种质资源，推导大豆种质抗疫霉根腐病基因，为热带、亚热带地区大豆抗病育种提供有效抗源。【方法】采用下胚轴创伤接种法，利用在广东发现并分离的大豆疫霉菌PGD1菌株，接种鉴定主要来自广东、广西、福建、海南、湖南、江西和四川等华南省份631份大豆种质资源的抗病性，筛选抗大豆疫霉菌PGD1种质资源；再用其他6个不同毒力的大豆疫霉菌株接种鉴定抗大豆疫霉菌PGD1的种质，筛选多抗资源，通过基因推导方法分析抗病种质的抗病基因类型。【结果】631份大豆种质中有101份种质抗大豆疫霉菌PGD1，占鉴定种质的16.0%；73份为中间反应类型，占11.6%；457份表现感病，占72.4%。其中83份抗大豆疫霉菌PGD1的种质对其他6个不同毒力菌株Pm14、Pm28、PNJ1、PNJ3、PNJ4、P6497的侵染率分别为28.9%、34.9%、9.6%、66.3%、57.8%和10.8%。4份种质同时抗7个不同毒力的大豆疫霉菌株，分别为ZDD21538、ZDD21604、ZDD14286和明夏豆1号，占鉴定种质的4.8%。毒力频率为0的种质有15份，占鉴定种质的18.1%。83份大豆种质对7个不同毒力的大豆疫霉菌株共产生20种反应型，1种反应型与单个抗病基因的鉴别寄主Williams79反应型一致，可能含有抗病基因Rps1c；45份种质产生的9种反应型符合一些2个或2个以上已知抗病基因组合的反应型，这些种质可能含有已知抗病基因组合；38份种质共产生11种反应型既不同于任何含有单个已知抗病基因品种的反应型也不同于2个或2个以上已知抗病基因组合的反应型，它们可能含有新的抗病基因或基因组合。【结论】华南地区大豆种质中蕴藏着丰富的抗大豆疫霉菌PGD1和多抗大豆疫霉菌抗源，这些抗病种质可作为热带、亚热带地区大豆抗病育种的重要亲本和抗病基因定位的重要研究材料。

Analysis of Resistance Genes of Soybean Accessions from South China to Phytophthora Root Rot

【Objective】 Phytophthora root rot caused by Phytophthora sojae is a destructive disease of soybean in most soybean-growing regions throughout the world. Development of Phytophthora-resistant varieties is the most economical and effective way to control this disease. The aim of this study was to screen accessions with resistance to strain PGD1 and multiple Phytophthora-resistant accessions, and to analyze resistance genes of soybean accessions from South China to phytophthora root rot. 【Method】The 631 soybean accessions mainly from six provinces (Guangdong, Guangxi, Fujian, Hainan, Hunan, Jiangxi and Sichuan) were evaluated with strain PGD1 using the hypocotyl inoculation method with minor modifications. And eighty-three Phytophthora-resistant accessions to strain PGD1 were evaluated with other six strains. 【Result】One hundred and one accessions were resistant to strain PGD1 with the ratio of 16.0%, 11.6% accessions had the intermediate response and 72.4% were susceptible to strain PGD1. Eighty-three Phytophthora-resistant accessions to strain PGD1 were identified with Pm14, Pm28, PNJ1, PNJ3, PNJ4, and P6497, and the infection rates were 28.9%, 34.9%, 9.6%, 66.3%, 57.8%, and 10.8%, respectively. Four of 83 soybean accessions were resistant to seven strains which were ZDD21538, ZDD21604, ZDD14286 and Mingxiadou1. Overall, 18.1% of the accessions were resistant or intermediately resistant to seven strains (virulence frequency 0). Eighty-three soybean accessions elicited 20 different reaction types with the 7 strains of pathogen. One reaction type of 8 accessions was consistent with Williams79 carrying a single gene. Nine reaction types of 45 accessions were consistent with two-gene or three-gene combinations, and they were deduced that carry two-gene or three-gene combinations. Thirty-eight accessions in 11 new reaction types probably contain new Rps genes. 【Conclusion】These results revealed the availability of strain PGD1 resistant accessions and showed an availability of multiple Phytophthora-resistant accessions in South China. These Phytophthora-resistant accessions can be used for an important parent soybean resistance breeding in tropical and subtropical regions and mapping resistant gene in soybean.