The technique to create rice varieties is higher than the head, yield 30 tons / ha

For the first time, the 'respiratory mutation' method has been successfully implemented to allow the creation of new rice varieties that collect elite genes from many different varieties.

The method of "respiratory mutation" was published by Vietnamese and Japanese scientists in MDPI's Sustainability Science Journal on February 18. This is a prestigious scientific journal of ISI scientific information system, with a coefficient of 2.075. Associate Professor Tran Dang Xuan, Hiroshima University (Japan), who chaired the project, said that he and his colleagues had 10 years of research on this technique and achieved unexpected results.

The technique of successful "respiratory mutation" is only allowed in a few decades after high rice varieties such as reed, reed, and yield reach 30 tons / ha or more, well tolerant to pests, flood, and drought. . will appear in the field. In the future, Vietnam will be able to produce up to 150-200 million tons of rice by this method, or at least 5-6 times higher than Vietnam's total production in 2017 of 27 million tons / year.

RM503 molecular marker, one of a series of molecular markers in the hybrid generation between two varieties, TBR1 (mother) and KD18 (father) in the F3 hybrid generation, shows that RM503 is completely inherited according to the mother.(Photo: NVCC).

The experiments were used by the research group N-methyl-N-nitrosourea (MNU) with a very small amount, causing a sudden impact in about 3 - 6 months, through the method " respiratory mutation " . This method only produces small dissociation, allowing simultaneous hybridization of many rice varieties in order to create a new breed with the desired gene. There is currently no place to do this method.

Previously to breed a new rice variety, many hybrid methods were applied such as individual selection, hybridization, hybrid superiority of rice in F1 generation, mutant (using gamma rays, chemical substance .) acts on different parts such as grain, germ, flower bud, pollen, to cause mutations in the genome.

These hybrid methods have the disadvantages of being costly and time consuming (crossing two varieties together takes 8-10 years, 10-15 varieties can take up to 100 years but no one can do it). In the method of chemical or physical mutations that damage the genome (DNA) create deformed rice varieties (bearded seeds, crooked, mixed colors .) and only intermingle a few Required traits (delicious, aromatic, pestilent rice seeds .).

These restrictions are overcome in the new method. Professor Xuan said that this method also allows genetics in the mother gene, unlike most of the important genes in the cell nucleus and inherited according to the father. Thanks to this advantage, it is possible to limit obstacles when the hybrids are inherited good traits from the father but when grown in the climate and soil of the mother breed, the good traits are lost in a short time ( seed degeneration).

This is also the deadlock many scientists have encountered. One of them is Prof. Tsuzuki Eiji (Japan) who hoped to create fragrant Japanese rice varieties by hybridizing aromatic rice seeds from Vietnam and Bangladesh, with Japanese mother rice varieties. He spent his life researching, creating two aromatic rice varieties, but after only two years, those genes were completely lost when grown in Japan.

Cultivating J02 rice seed in Hai Phong yielded 8.5-9 tons / ha of summer 2017 harvest. (Photo: Loan Le).

Associate Professor Tran Dang Xuan said that the method of "respiratory mutation" was successful when breeding on wild rice and pure rice in Vietnam, promising to create lines with precious characteristics (resistant to pests and diseases, with little resistance). more than the impact of climate change, bringing many precious compounds .) of wild rice in a short time.

As soon as there are answers about mutant methods to create new varieties with elite genes, over the past 5 years, Associate Professor Tran Dang Xuan, colleagues and many professors in the field of breeding and molecular biology of Japan, including Hidemi Kitano (Nagoya University), continues to study to decipher the role of the newly created gene. The existence of this gene (known as the X gene) is thought to create the link between elite genes from parents and breeds, without causing strong dissociation when impacted by mutations as usual. see. This work has completed over 80% initially identifying the role of the new gene, allowing rice to be capable of carrying thousands of seeds, but accompanied by good qualities (different from the previous hybrid methods that are capable of High productivity often comes with poor quality), with new biological mechanisms not known.

"It is interesting to have an answer about the role of X gene when cross-breeding 10-15 varieties of rice, or more together to create a hybrid in a short time. The next study will have answers. words for the mechanism to create new genes, " said Prof. Xuan, and explaining the mechanism is the basis for creating future super-varieties.