Grain filling

Researchers pinpoint gene that 'improves rice yields':
""By selectively growing only those strains of rice with heavier grains, humans for thousands of years unknowingly have been increasing the frequency of rice populations that had modifications in the GIF1 gene," says co-author Ma Hong, a professor of biology at the US-based Pennsylvania State University.

The clear molecular mechanism can now be further used in cultivation. "Many rice varieties with high yield potential — including 'super-rice', usually with big panicles [large number of grains] — often suffer from bad grain filling. We believe that improvement of grain-filling, and hence grain weight, will greatly increase yield potential," He told SciDev.Net.

Separately, in the same issue of Nature Genetics, a team of Chinese scientists at the Beijing-based China Agricultural and Tsinghua universities report the molecular mechanism behind the ancient rice domestication practice of transforming limp growth of ancestral wild rice to erect growth, a critical event in rice domestication that improved plant architecture and increased grain yield.

They found that limp growth of wild rice is controlled by a gene called PROG1 (Prostrate Growth 1) and many modern rice cultivars disrupt PROG1 function and inactivate its expression, leading to erect growth, greater grain number and higher grain yield in cultivated rice."