Evaluating populations derived from complex crosses involving both bread wheat and durum wheat parentage for partial resistance to crown rot

Abstract

Crown rot in durum, caused by Fusarium pseudograminearum and Fusarium culmorum, can reduce yields up to 90% in seasons characterised by limited spring rainfall. To decrease this potential loss, breeding of partially resistant cultivars could complement agronomic approaches. However, the limited variation in durum has meant that development of partially resistant lines is still a major objective to overcome. The aim of this study was to evaluate, through genotypic and phenotypic-based approaches, durum lines with partial resistance to crown rot. The germplasm under study consisted of 252 durum lines obtained by crossing durum parents with partially resistant bread wheat varieties. Phenotypic assessment of the symptoms, accomplished by visual assessment of the fungal necrosis of the stems, led to the identification of 120 partially resistant lines. Genotypic assessment, performed through a SNP array, identified associations between marker genotype and crown rot severity for the family originating from the parents EGA Bellaroi 38a and Sumai 3. Moreover, the frequency of QTL for crown rot partial resistance already published was investigated in the populations under study through the multiplex ready PCR technique. These findings confirm that bread wheat varieties can be exploited to reduce crown rot severity in durum.