Screening wheat genotypes for resistance to black point and the effects of diseased kernels on seed germination

Abstract

This study was carried out to identify wheat genotypes with high levels of resistance towards black point disease. In total, 403 genotypes were tested between the years 2010 and 2012 in the North China Plain (NCP). The effect of different percentages of diseased kernels on seed germination and seedling growth (root length, shoot length, dry root weight and dry shoot weight) was assessed using three highly susceptible genotypes. Black point incidence varied greatly among wheat genotypes, the lowest and the highest values were 0.3% and 66.7%, respectively. Among the 403 wheat genotypes studied, 37.5% were classified as resistant (151 genotypes), 62.5% were classified as susceptible (252 genotypes) and 36 wheat genotypes were highly resistant to black point disease. The average broad-sense heritability for black point disease resistance of 403 wheat genotypes was 58.6%, suggesting that black point was stronger affected by genetic factors compared to environmental factors. Furthermore, black point decreased the percentage of germinated seeds and inhibited seedling growth. The results provided information on germplasm resources for disease-resistant cultivar breeding as well as a reference for determining the suitable sowing rate in wheat production in the NCP.