Phenotypic evaluation and genetic dissection of resistance to Phytophthora sojae in the Chinese soybean mini core collection.
Phytophthora root and stem rot (PRR) caused by Phytophthora sojae is one of the most serious diseases affecting soybean (Glycine max (L.) Merr.) production all over the world. The most economical and environmentally-friendly way to control the disease is the exploration and utilization of resistant varieties.



We screened a soybean mini core collection composed of 224 germplasm accessions for resistance against eleven P. sojae isolates. Soybean accessions from the Southern and Huanghuai regions, especially the Hubei, Jiangsu, Sichuan and Fujian provinces, had the most varied and broadest spectrum of resistance. Based on gene postulation, Rps1b, Rps1c, Rps4, Rps7 and novel resistance genes were identified in resistant accessions. Consequently, association mapping of resistance to each isolate was performed with 1,645 single nucleotide polymorphism (SNP) markers. A total of 14 marker-trait associations for Phytophthora resistance were identified. Among them, four were located in known PRR resistance loci intervals, five were located in other disease resistance quantitative trait locus (QTL) regions, and five associations unmasked novel loci for PRR resistance. In addition, we also identified candidate genes related to resistance.



This is the first P. sojae resistance evaluation conducted using the Chinese soybean mini core collection, which is a representative sample of Chinese soybean cultivars. The resistance reaction analyses provided an excellent database of resistant resources and genetic variations for future breeding programs. The SNP markers associated with resistance will facilitate marker-assisted selection (MAS) in breeding programs for resistance to PRR, and the candidate genes may be useful for exploring the mechanism underlying P. sojae resistance.
National Center for Soybean Improvement/National Key laboratory of Crop Genetics and Germplasm enhancement, Key laboratory of Biology and Genetics and Breeding for Soybean, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Jing
J
Huang
National Center for Soybean Improvement/National Key laboratory of Crop Genetics and Germplasm enhancement, Key laboratory of Biology and Genetics and Breeding for Soybean, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Na
N
Guo
The National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI)/Key Lab of Germplasm Utilization (MOA), Institute of Crop Science, Chinese Academy of Agricultural Sciences, 100081, Beijing, People's Republic of China.
Yinghui
Y
Li
National Center for Soybean Improvement/National Key laboratory of Crop Genetics and Germplasm enhancement, Key laboratory of Biology and Genetics and Breeding for Soybean, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Jutao
J
Sun
National Center for Soybean Improvement/National Key laboratory of Crop Genetics and Germplasm enhancement, Key laboratory of Biology and Genetics and Breeding for Soybean, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Guanjun
G
Hu
National Center for Soybean Improvement/National Key laboratory of Crop Genetics and Germplasm enhancement, Key laboratory of Biology and Genetics and Breeding for Soybean, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Haipeng
H
Zhang
The National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI)/Key Lab of Germplasm Utilization (MOA), Institute of Crop Science, Chinese Academy of Agricultural Sciences, 100081, Beijing, People's Republic of China.
Yanfei
Y
Li
National Center for Soybean Improvement/National Key laboratory of Crop Genetics and Germplasm enhancement, Key laboratory of Biology and Genetics and Breeding for Soybean, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Xing
X
Zhang
National Center for Soybean Improvement/National Key laboratory of Crop Genetics and Germplasm enhancement, Key laboratory of Biology and Genetics and Breeding for Soybean, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Jinming
J
Zhao
National Center for Soybean Improvement/National Key laboratory of Crop Genetics and Germplasm enhancement, Key laboratory of Biology and Genetics and Breeding for Soybean, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China. hanx@njau.edu.cn.
Han
H
Xing
The National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI)/Key Lab of Germplasm Utilization (MOA), Institute of Crop Science, Chinese Academy of Agricultural Sciences, 100081, Beijing, People's Republic of China. qiulijuan@caas.cn.
Lijuan
L
Qiu
D002681:China; D060467:Disease Resistance; D015810:Linkage Disequilibrium; D010838:Phytophthora / Q000472:pathogenicity / Q000502:physiology*; D010935:Plant Diseases / Q000235:genetics* / Q000276:immunology* / Q000469:parasitology; D040641:Quantitative Trait Loci; D013025:Glycine max / Q000235:genetics* / Q000276:immunology* / Q000469:parasitology; D014774:Virulence
Association mapping; Genetic diversity; Phytophthora sojae; Resistance evaluation; Soybean mini core collection