Chinese scholars and overseas collaborators have made new progress in the innovation and utilization of rice germplasm resources

Figure Perennial rice creation and its sustainable production

With the support of the National Natural Science Foundation of China (approval number: U1302264, 31660387) and other funds, after more than 20 years of exploration, Hu Fengyi's research team of Yunnan University and overseas collaborators have made new progress in the field of innovation and utilization of rice germplasm resources, through Asian cultivated rice (Oryza sativa) and Changxiong wild rice (O.
longistaminata).
Interspecific hybridization overcame the difficulty of interspecific distant hybridization, successfully created perennial rice materials, cultivated a series of perennial rice strains, and approved three perennial rice varieties, which is a milestone
in the field of global perennial food crop breeding 。 The study, titled "Sustained productivity and agronomic potential of perennial rice," was published online on November 7, 2022 in Nature.
Nature Sustainability
.
Link to the paper: _istranslated="1">.

Perennial rice can be planted continuously for 3~4 years, harvested 2 crops per year, with an average yield of 6.
8 tons/ha per season, which is comparable
to the yield of annual rice (6.
7 tons/ha).
Compared with the annual rice production method, perennial rice no longer needs to buy seeds, raise seeds, plow and rake and plant seedlings and other production links since the second season, saving 68~77 labor times per hectare per season and saving 46.
8~51%
of production input.
However, the study also pointed out that from the fifth year onwards, the yield of existing varieties began to decline significantly due to weed control and other problems, and it was necessary to strengthen field management or re-breed and transplant seedlings in production and application (Figure).

Based on the no-till production method, perennial rice sown once and harvested sustainably for many years improved the soil structure of the rice field cultivation layer, fertilized the soil, and its soil organic matter and total nitrogen increased
at a rate of 0.
95 tons/ha and 0.
11 tons/ha, respectively, per year.
According to preliminary assessments, perennial rice has a wide application potential
in the rice cultivation area where the average monthly temperature is not less than 13.
5 °C and the wintering period is lower than 4 °C for no more than 5 days, that is, in the frost-free rice cultivation area between 40 degrees north and south latitudes.
As of 2021, perennial rice has been successfully tested and demonstrated in many countries along the Belt and Road, including China, South Asia, Southeast Asia and Africa, benefiting more than 55,000 farmers
.

This study uses the asexual reproduction characteristics of the underground stem of Changxiong wild rice to cultivate perennial rice, and turns annual rice into perennial rice, which is an important breakthrough in the breeding of global perennial food crops, and is one of the most representative breakthroughs in the field of innovative utilization of rice germplasm resources in China, which provides reference for making full use of wild germplasm resources, and has an important reference role
for the genetic improvement of other perennial food crops and perennial forage.