Stripe rust resistance and its association with yield contributing traits in wheat (Triticum aestivum L.) genotypes

Stripe rust is a major yield-limiting factor worldwide. The current study evaluated the response of wheat genotypes to stripe rust disease, focusing on the diversity of wheat genotypes towards stripe rust resistance. The study was conducted in the field research area of the Department of Plant Breeding and Genetics (PBG), Faculty of Agriculture and Environment, Islamia University of Bahawalpur during Rabi 2023-24. The experiment employed an augmented design that increased the precision and accuracy of the results by including additional genotypes in the experimental design. Thirty genotypes and one susceptible check variety, “Morocco”, from the Regional Agriculture Research Institute (RARI) in Bahawalpur, were tested. Disease severity varied from 0 to 100%, with some genotypes showing resistance, moderate resistance, moderate susceptibility, susceptibility, or immune responses. Data were recorded for various traits, such as plant height, number of tillers, spike length, peduncle length, spikelet per spike, thousand grain weight, grain filling period, grain yield per plant, coefficient of infection, chlorophyll content (SPAD), and disease severity percentage. The mean values of disease severity ranged from 100 to 0%, with G1 being the most susceptible and G15 being the most tolerant. A positive correlation was observed between disease severity percentage and plant height and coefficient of infection, while a negative correlation was observed between chlorophyll content, grain-filling period, and disease severity percentage, but this relationship was not statistically significant. There was negative yet non-significant relationship between thousand-grain weight, grain yield per plant, and disease severity percentage, as the regression model was not statistically significant. Genotype (G15) found as most resistant genotype against stripe rust in the available germplasm, and it can aid in breeding programs to develop new wheat cultivars with enhanced resistance to the disease.