Mining a Collection of triticum diccoccoid Landraces for Resistance to Races of Puccinia graminis f. sp. tritici at Seedling Stage

Abstract

Stem rust caused by Puccinia graminis Pers. f. sp. tritici Eriks. and E. Henn. (Pgt), is one of the most destructive pathogen of wheat which causing  considerable yield losses. It has become a renewed threat to global wheat production after the emergence and spread of new race known as TTKSK or  Ug99 and related races from Africa. Races of the pathogen in the “Ug99 lineage” are of international concern due to their virulence for widely used stem  rust resistance genes and their spread throughout Africa. Seedlings of 183 diccocciod wheat accessions which were assembled by University of Bologna,  department of agricultural sciences were evaluated for their response to stem rust (Puccinia graminis f. sp. tritici) infection under greenhouse condition  at University of Minnesota St. Paul campus during 2012 with an objective of identifying diccoccoid wheat accessions that could serve as sources of  resistance to stem rust to enhance durable resistant variety development. Seedling infection types were evaluated using three stem rust races viz TTKSK,  TRTTF and TTTTF. A high level of phenotypic variation was observed in response to races TTKSK, TRTTF and TTTTF in the test entries, allowing for selection  in these germplasm as a pre-breeding work. Out of the tested accessions, 32 diccoccoid wheat accessions exhibited low infection types (0–2)  response to all the three races and hence selected as a source of resistance to stem rust. These wheat germplasm which are identified as resistant along  with adult plant resistant germplasm will be promising genetic stocks for accumulating resistances genes to acquire durable resistance and long lasting  variety/ies.