Plant morphology improvements have led to increased grain yield in japonica inbred rice in East China since the 1980s. By studying rice cultivars released between 1983 and 2013, researchers found that traits like spikelets per panicle, leaf width, and leaf area increased over time, leading to higher yields. These changes also included enhanced leaf photosynthetic capacity, stronger stems, and optimized sink size. Overall, the improved plant characteristics have contributed to the progressive yield increases of japonica inbred rice in East China.