Late blight resistance status in wild potato species against Indian population of Phytophthora infestans

Abstract

Late blight caused by oomycete pathogen Phytophthora infestans is the most destructive disease affecting potato crop world-wide with losses up to 90% in India. Resistant varieties offers safe and economical mean for management of the disease. Wild species of potato are the reservoirs of resistance against many insect pest and diseases including late blight. In the present study, 539 clones of 91 potato accessions belonging to 18 wild species maintained at CPRI, Shimla were evaluated for presence of durable resistance against late blight. The clones SS 1764-19 (S. alandiae), SS 1763-09 and SS 1763-25 (S. albicans), SS 1769-04, SS 1769-08 and SS 1770-14 (S. arnezii), SS 1784-07 (S. berthaultii), SS 1794-07 (S. brevicaule), SS 0551-02, SS 0680-06, SS 1671-01 and SS 1671-03 (S. chacoense), SS 1835, SS 1846-05, SS 1847-09, SS 1850-0, SS 1850-01 and SS 1850-04 (S. demissum), SS 1926-09, SS 1926-10, SS 1926-11 and SS 1926-13 (S. microdontum), SS 2615-01, SS 2616-01, SS 2616-02, SS 2655-01, SS 2656-02, SS 2658-01, SS 2658-02 and SS 2658-03 (S. pinnatisectum), SS 1664-02 and SS 1724-40 (S. sparsipilum), SS 2038-04 and SS 2048-0 (S. tuberosum ssp. andigena) and SS 2082-0 (S. vernei) were found to be most promising having high late blight resistance under laboratory and field testing. Although some difficulties exist in direct utilization of these clones due to ploidy and EBN differences, but these can be overcome through both short and long-term breeding strategies viz., ploidy and EBN manipulation, bridging species, embryo rescue, somatic hybridization and molecular techniques.