Historical Trends Analysis of Main Agronomic Traits in South China Inbred Indica Rice Varieties since Dwarf Breeding

Studying the evolutionary patterns of rice agronomic traits in South China and analyzing characteristics improvement can provide insights into developmental trajectory breeding guide further enhancement variety yield. In this study, widely promoted varieties core parents developed through dwarf southern region, as well landraces, were collected planted three different ecological regions. A total 18 investigated related to heading date, plant type, panicle grain yield, multiple comparisons, a correlation analysis, path analysis conducted. The results indicate that has significantly increased yield inbred indica China. However, reduction height also resulted flag leaf, shorter panicles, decreased biomass, which have led metabolic source storage capacity deficiencies limited potential. To address these limitations, breeders employed strategies such increasing leaf width, spikelet density, number primary branches, per panicle. These measures gradual increase Additionally, starting from 1980s, high-quality been pursued China, resulting slender shape reduced thousand weight. Given already weight cannot be further, enhancing effective tiller number, decreases year by year, becomes an important approach