Seedling and durable resistance to stripe rust in two segregating wheat populations

Stripe rust is a worldwide epidemic, caused by divergent races of Puccinia striiformis responsible for considerable yield losses in wheat. Present study was conducted to explore the genetic resources of wheat for potential stripe rust resistance to combat with this biotic stress. Two segregating populations NIGAB-08 and NIGAB-09 have been developed in National institute for Genomics and Advanced Biotechnology (NIGAB), NARC, Islamabad as a potential genetic source for stripe rust resistance. In this study, these populations were explored for stripe rust resistance at seedling and adult plant stage. NIGAB-08 (F6 Segregating wheat Population) comprised of 48 wheat lines having genetic diversity for stripe rust. At seedling stage, 87% of this wheat population have seedling resistance with likely presence of Yr6, Yr7, Yr8, Yr9, Yr17, Yr27, Yrsp Yr2, Yr25, Yr31 and YrA genes whereas, 10% of population was found to have low genetic potential against stripe rust. Field data showed that the 16% of population was resistant while majority of population showed intermediate type of resistance against stripe rust. 86 wheat lines of NIGAB-09 (F6 Segregating wheat Population) showed its 83% of population resistant and 13% of population was observed to be susceptible at seedling stage, whereas, in field experiments, 79% of population was resistant while 10% of population was observed to be susceptible in field experiments. Seedling and Adult plant resistance both together will contribute to achieve durable and effective control against pathogen of stripe rust in Pakistan.