Role of the rice blast resistance genePi-cdin rice (Oryza sativa) breeding programmes

A series of DNA markers for various agronomic traits may accelerate the success of marker-assisted selection in practical plant breeding programmes. Here, we developed DNA markers for the blast resistance genePi-cd. In this study, we examined the effects of thePi-cdlocus on not only blast resistance but also agronomic traits in agriculture. We developed three pyramiding lines (PLs) couplingPi-cdwith three blast resistance genes,pi21,Pi35andPi39. The effect ofPi-cdon blast resistance was dependent on the coupled resistance genes. Then, we evaluated the effects ofPi-cdon 13 agronomic traits. Amylose content and 1,000-grain weight showed significant differences between the PLs and current commercial varieties, which had no negative effects on agronomic trait values. Furthermore, we investigated the distribution of genotype for thePi-cdlocus among varieties of upland rice. The KT genotype specific to rice blast resistance may be predominant in the varieties. The results suggested thatPi-cdhas the potential to be useful for improving blast resistance in rice breeding programmes.