An efficient phenotyping technique for wild Arachis species and groundnut breeding lines resistant to stem rot disease under field conditions

Abstract

Stem rot of groundnut caused by Sclerotium rolfsii Sacc. is one of the major constraint to groundnut production in many countries. In groundnut, up to 30 percent yield losses were recorded in farmers’ field, but can reach over 80% in heavily infested fields. The pathogen is ubiquitous, soil inhabitant and non-target. Host plant resistance is an important component for the management of this disease which is currently not fully exploited mainly because of lack of efficient phenotyping technique. In the present study, a simple but efficient phenotyping technique with high disease pressure under field conditions has been reported. Twenty-five wild Arachis accessions and 178F3 progenies along with two parent lines were screened under pot and field conditions, respectively. Mortality ranged from 10 to 100%. Two wild Arachis accessions (NRCG12035 and NRCG12047) and three F3 progenies (GG20 x CS19-5-8, GG20 x CS19-15-1 and GG20 x CS19-15-3) were found resistant to stem rot with mortality less than 20% and 10%, respectively.