Status of red rot resistance in wild relatives of sugarcane, Saccharum spontaneum, interspecific hybrids and intergeneric hybrids

Abstract

Identifying new sources for red rot resistance is a continuous process to enrich parental pools for disease resistance in sugarcane. Earlier, sugarcane varieties under cultivation, interspecific hybrids of Saccharum officinarum, S. spontaneum and S. barberi were screened for red rot caused by Colletotrichumfalcatum and resistant sources were identified. Subsequently to broaden sources of resistance different Saccharumspp clones and their derivatives referred as interspecific hybrids (ISH) were screened and resistant genotypes were identified. Recently intergeneric hybrids (IGH) involving Erianthusspp. with Saccharumspp or other hybrids were screened to identify red rot resistant sources. Earlier, these populations were screened at Karnal and Motipur under subtropical conditions and Kovvuru and Madhurantakam under tropical conditions against respective pathotypes of the region by plug method of inoculation. Later, the ISH / IGH populations were tested for red rot resistance under controlled condition at Coimbatore and this provided an opportunity to screen large clonal population in a shorter time. Field testing at different locations identified only a few clones exhibiting resistance across the locations. Among the centres, Kovvuru centre in Andhra Pradesh exhibited more susceptibility and only a few resistant types could be identified. Some of the cytoplasmic derivative clones and IGH clones in specific cross combinations exhibited greater red rot resistance. These studies provide an updated information in status of red rot resistance in wild relatives of Saccharum spp. and their derivatives.