Screening orchardgrass (Dactylis glomerata L.) germplasm for high rust resistance and high summer survival rate in a subtropical climate

Abstract

AbstractOrchardgrass (Dactylis glomerata L.) is one of the most important cool‐season forage grasses around the world, and is among the fourth top selling grass seed behind Lolium, Festuca and Phleum. However, the available orchardgrass varieties have low summer survival rates and are susceptible to rust caused by Puccinia graminis Pers., resulting in lower yields and poor quality growth in subtropical regions of China. The summer survival rate, degree of rust resistant, and the correlation of rust resistance with summer survival rate of 242 germplasm resources of D. glomerata, from five continents of the world, were investigated in a field screening for 2 years (2011 and 2012) at the southern part of China. Results showed that 13 accessions were scored high disease resistance for the 2 years, and 36 were scored a summer survival rate of 100%. Thirteen accessions of orchardgrass were screened for disease resistance and high summer survival rate (≥80%), including two accessions named PI325293 and PI308794 with a high disease resistance and summer survival rate of 100% in the 2‐year studies. The correlation between rust resistance and summer survival rate was low (r = 0.111 P = 0.295 in 2011, r = 0.112 P = 0.674 in 2012). These two accessions may serve as potential genetic materials to plant breeders for developing orchardgrass varieties that contain high rust resistance and summer survival rate. These results will also contribute to the conservation and utilization of orchardgrass germplasm.