Comparison of Main Agronomic Traits and Identification of Important Genes in Japonica Rice Cultivars Grown in the Jianghuai Region

An exploration and understanding of cultivar adaptability to specific environmental conditions are critical in rice breeding. This study aimed to compare the agro-morphological data of 36 japonica rice cultivars (Oryza sativa L.) from Chinese rice accessions grown under two different environments (Fengyang and Hexian) and to identify important genes associated with key traits in the cultivars. Higher significant differences were observed between Fengyang and Hexian in traits like, grain width, grain length, yield per plot, plant height, and tiller number with cultivars grown in Hexian having the greatest values. This revealed that the environment in Hexian favored these traits, and most cultivars performed better in Hexian than in Fengyang. Correlation analysis also showed strong positive correlations between tiller number and yield per plot in both environments, indicating the influence of tiller number on rice yield potential. The PCR analysis showed the amplification of DEP1, Ghd7, Wx, Chalk5, COLD1, DST, Xa13, and Bph6 in most japonica cultivars, indicating presence of these genes in the cultivars. This study suggests that differences in agronomic performance between the cultivars grown in Fengyang and Hexian might be caused by differences in environmental conditions. This finding could be valuable for future breeding of high-yielding and climate-resilient cultivars.