Multienvironmental evaluation of wheat (Triticum aestivum L.) germplasm identifies donors with multiple fungal disease resistance.

Production and productivity of wheat crop is hampered by the biotic and abiotic stresses putting the world food security at risk. Among the biotic stresses, rusts are the major threat throughout the wheat growing areas in the world whereas Karnal bunt, powdery mildew, Fusarium head blight and loose smut are of minor importance. These diseases severely affect the yield and quality of wheat grain. Till date these diseases have been contained by the use of host resistance alongwith the chemical fungicides. However, the host resistance is overcome with the evolution of new virulent pathotypes. Deployment of diverse and durable sources of resistance in breeding programmes is the most economic and effective means of reducing yield losses caused by these diseases.With an aim to identify novel sources of resistance to these pathogens, 247 Indian wheat accessions were evaluated for multiple disease resistance at six different hot spots in order to identify potentially new sources of resistance. Of the 247 accessions of wheat, 14 accessions highly resistant to stripe rust, 142 for Leaf rust and 146 for stem rustwere identified. Thirty-two accessions were found resistant to all the three rusts. Thirty accessions showed immune reaction to powdery mildew and 61 were recorded resistant. Data obtained from spot blotch experiment revealed one accession immune to spot blotch infection while two accessions were recorded resistant with 10% infection. Karnal bunt (KB) resistance (infection level < 5) was observed in 186 lines. Out of 247 lines 69 and 93 accessions were found to have resistance against spot blotch and loose smut respectively. Accession No. IC128643 was found to be the most promising accession that has resistance against three rusts, powdery mildew, Karnal bunt, loose smut and spot blotch. Accession no. IC36900, IC397999 and IC416249 showed resistance against three rusts, powdery mildew, Karnal bunt and loose smut while accession no. IC415971 and IC415977 showed resistance against three rusts, powdery mildew, spot blotch and loose smut. The resistant germplasm lines, identified in this study can be used for introgressing resistance to high yielding backgrounds and are expected to contribute towards food security at national and global levels. [ABSTRACT FROM AUTHOR]