Abstract:

【Objective】 This study was aimed at developing genomic SSR markers for Phytophthora sojae and offering ideal molecular markers for studying it and relative species in depth on molecular level. 【Method】 Using Fast PCR software to screening SSRs in complete genome sequence of P. sojae, suitable sequence regions harboring SSR were selected for design of markers using Primer5.0 software, and synthesized primers were used to amplify genomic DNA of selected isolates of P. sojae and other Phytophthora species. 【Result】 Of the designed 260 primer pairs, 213 (81.9%) could amplify characteristic SSR fragments against 10 different isolates of P. sojae, and 114 (53.5%) primer pairs amplified polymorphic fragments among the 10 isolates. The results for transferability test showed that 14.6%-28.6% primer pairs could effectively amplify in 8 selected Phytophthora species, respectively. Clustering Phytophthora spp and P. sojae based on 10 SSR markers data, these markers could clearly differentiate selected Phytophthora species. 【Conclusion】 The genomic SSR markers of P. sojae are highly polymorphic, and should be the ideal tools for studies of genetic variation, genetic diversity, and development of genetic linkage maps of the pathogen. Some SSR primers have transferability in other Phytophthora species, and could be used in phylogenetic analysis, species identification and differentiation and SSR marker development of Phytophthora. Especially, these genomic SSR markers have been located in P. sojae genome, thus facilitating lagging and cloning the functional genes of P. sojae, and carrying comparative genomics study of Phytophthora.

Key words: Phytophthora sojae')">Phytophthora sojae, complete genome sequence, SSR markers, transferability