Identification of Phytophthora and nematode-resistant source-from opens pollinated progenies of black pepper (Piper nigrum) using a modified protocol

Abstract

Foot rot disease caused by Phytophthora capsici and slow decline disease caused by plant parasitic nematodes are serious diseases of black pepper (Piper nigrum L.). In this study open-pollinated seedling progenies of black pepper were screened during 2004-06 to identify sources of resistance against P. capsici and nematodes. A total of II 632 seedlings raised from 30 cultivars, 42 hybrids and I-open pollinated selection were subjected for preliminary screening. Forty progenies (21 Karimunda progenies, 10 progenies from other cultivars, 8 progenies from hybrids and 1 progeny from the selection 'IISR Shakti') that took no infection in the preliminary screening. against P. capsici were multiplied vegetatively and subjected to second round of screening adopting root inoculations. They were assessed for disease severity after 100 days of inoculation adopting a new protocol for the second and the final round of screening. The progenies were rated initially based on the time taken for mortality and then assayed for aerial infection and final score was based on average disease severity index which was not followed in the earlier screenings. Of the 11 632 progenies screened, 1 progeny, viz '04-P24-1' showed resistant reaction and I hybrid progeny, viz 04-HP-400-1 showed moderate resistant reaction towards P. capsici. Besides the progeny 04-H.P 1533 (2) showed resistant reaction towards the root-knot nematode M incognita. However, all short listed progenies were found susceptible to R. similis. The initially shortlisted phytophthora '04-P24-I' consistenlly showed resistant reaction even after repeated inoculations and is under field evaluation since 2006 onwards. This is the first report of identifying a Phytophthora-resistant source in black pepper (Piper nigrum L.) and this modified protocol can be used for screening open-pollinated progenies of black pepper.