Genetically Diverse Long-Lived Clonal Lineages of Phytophthora capsici from Pepper in Gansu, China

• Published in: Phytopathology Vol. 103; no. 9; pp. 920 - 926
• Main Authors: JIAN HU, ZHILI PANG, YANG BI, JINGPENG SHAO, YONGZHAO DIAO, JIANGUO GUO, YONGGANG LIU, HEPING LV, LAMOUR, Kurt, XILI LIU
• Format: Journal Article
• Language: English
• Published: St. Paul, MN American Phytopathological Society 01.09.2013
• Subjects: Alanine - analogs & derivatives; Alanine - pharmacology; Biological and medical sciences; Capsicum - parasitology; China; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fungicides, Industrial - pharmacology; Genetic Markers - genetics; Genetic Variation; Genome - genetics; Genotype; Geography; Microsatellite Repeats - genetics; Phytopathology. Animal pests. Plant and forest protection; Phytophthora - drug effects; Phytophthora - genetics; Phytophthora - isolation & purification; Phytophthora - physiology; Phytophthora capsici; Plant Diseases - parasitology; Asia; China; Stramenopila; Plant; Plant pathogen; Oomycota; Phytophthora capsici
• DOI: 10.1094/PHYTO-01-13-0016-R
• ISSN: 0031-949X

Phytophthora capsici causes significant loss to pepper production in China, and our objective was to investigate the population structure in Gansu province. Between 2007 and 2011, 279 isolates were collected from pepper at 24 locations. Isolates (or subsets) were assessed for simple sequence repeat (SSR) genotype, metalaxyl resistance, mating type, and physiological race using cultivars from the World Vegetable Center (AVRDC) and New Mexico recombinant inbred lines (NMRILs). The A1 and A2 mating types were recovered from nine locations and metalaxyl-resistant isolates from three locations. A total of 104 isolates tested on the AVRDC panel resolved five physiological races. None of 42 isolates tested on the NMRIL panel caused visible infection. SSR genotyping of 127 isolates revealed 59 unique genotypes, with 42 present as singletons and 17 having 2 to 13 isolates. Isolates with identical genotypes were recovered from multiple sites across multiple years and, in many cases, had different race types or metalaxyl sensitivities. Isolates clustered into three groups with each group having almost exclusively the A1 or A2 mating type. Overall it appears long-lived genetically diverse clonal lineages are dispersed across Gansu, outcrossing is rare, and functionally important variation exists within a clonal framework.