Resistance to <i>Heterodera filipjevi</i> and <i>H. avenae</i> in Winter Wheat is Conferred by Different QTL

Abstract

The coexistence of cereal cyst nematode (CCN) species <i>Heterodera avenae</i> and <i>H. filipjevi</i>, often involving multiple pathotypes, is a limiting factor for wheat production in China. Some of the known genes for resistance to CCN are not effective against both nematode species, hence complicating breeding efforts to develop CCN-resistant wheat cultivars. Here, we demonstrate that the CCN resistance in wheat cultivar Madsen to both <i>Heterodera</i> spp. is controlled by different genetic loci, both of which originated from <i>Aegilops ventricosa</i>. A new quantitative trait locus (QTL), <i>QCre-ma7D</i>, was identified and localized in a 3.77-Mb genomic region on chromosome arm 7DL, which confers resistance to <i>H. filipjevi</i>. <i>QCre-ma2A</i> on chromosome arm 2AS corresponds to CCN resistance gene <i>Cre5</i> and confers resistance to <i>H. avenae</i>. This QTL is a new locus on chromosome arm 7DL and is designated <i>Cre9</i>. Three Kompetitive allele-specific PCR markers (BS00150072, BS00021745, and BS00154302) were developed for molecular marker-assisted selection of <i>Cre9</i> and locally adapted wheat lines with resistance to both nematode species were developed. <i>QCre-ma2A</i> on chromosome arm 2AS corresponds to CCN resistance gene <i>Cre5</i> and confers resistance to <i>H. avenae</i>. The identification of different loci underlying resistance to <i>H. filipjevi</i> and <i>H. avenae</i> and the development of adapted resistant entries will facilitate breeding of wheat cultivars that are resistant to these devastating nematodes in China.