| Replacement of traditional puddled transplanted rice（PTR）by direct-seed rice（DSR）is an effective
method to solve the problems of the rice industry, including low economic benefit, waste of water resources, and serious
greenhouse gas emission. Though DSR has been rapidly promoted in China in recent years, many restraints in DSR remained
unsolved, such as weed management, seedling emergence rate, and lodging. Breeding of rice with high early seedling vigor,
ability to germinate at low oxygen and temperature environment, and lodging resistance, is the base of materials for DSR.
Rice gene pools contain a lot of resources and functional genes that can solve these problems. Characterizing and utilizing
these resources and genes to breed rice varieties suitable for DSR is the key to DSR promotion. However, while most of the modern rice varieties were bred for PTR, many genes related to DSR desired traits were lost in modern varieties. More diverse
germplasm and nodern genomics techniques are needed to identify functional genes and underlying molecular mechanisms for
DSR desired traits, to speed up the breeding process of varieties suitable for DSR. In this review, we summarized the progress
on resources identification, genetic analysis, functional gene cloning, and molecular mechanisms dissecting of key traits related
to DSR, including early seedling vigor, ability to germinate under low oxygen and temperature, and lodging resistance. We also
prospected the utilization of these results in DSR related traits improvement, as well as breeding of varieties suitable for DSR.
This review may provide a valuable reference for basic theoretical research and breeding application researche of rice directseeding-related traits. |
