Genetic Dissection of Tan Spot Resistance in Wheat
Abstract
Tan spot, caused by the necrotrophic fungal pathogen Pyrenophora tritici-repentis (Ptr), is a major foliar disease in wheat. QTL mapping and meta-QTL analysis are effective methods to understand genetic basis of tan spot resistance, which can further facilitate resistant variety development. A number of QTL mapping studies have been conducted in hexaploid bread wheat whereas few mapping studies have been carried out in tetraploid wheat. Four interconnected tetraploid wheat mapping populations were evaluated for resistance to race 2 isolate 86-124. Twelve QTL were identified in three of the four mapping populations. To further extend understanding of tan spot resistance, meta-QTL analysis was conducted by using reported QTL from 14 previous QTL mapping studies. Three meta-QTL located on chromosomes 2A, 3B, and 5A showed large genetic effects in multiple populations and conferred resistance to multiple races. Integrating those race-nonspecific QTL could provide high and stable tan spot resistance in wheat.