After more than 10 years of research, the research team led by Academician Zhang Zhihua of Huazhong Agricultural University discovered for the first time and successfully cloned a gene that controls the plant height, heading date and grain number per panicle at the same time. It was named Ghd7. The research team of the 5th The paper was published in the internationally renowned scientific research magazine Natural-genetics.
The researchers were able to confirm that a single gene, Ghd7, can determine three characteristics of rice plant height, heading date, and grains per spike. Previous studies have identified chromosome 7 regions that may determine more than rice characteristics, but are not accurate to any particular gene.
According to Zhang Qiu’s academician, in the past it was thought that many genes needed to be changed to increase rice yield. Now we only need to control a single gene to increase yield. The team also isolated the gene using map-based cloning techniques in the vicinity of the centromere of rice chromosome 7.
Studies have verified that most of the high-yield rice varieties contain the Ghd7 gene. Wild-type Ghd7 gene can greatly delay the heading period, and the plant height and grain number per panicle increased significantly. In the summer of Wuhan, the near-isogenic line containing the wild-type Ghd7 gene was 23 days earlier than the recurrent parent Zhenjing 97 at the head, the plant height increased by 30 cm, the number of grains per spike doubled, and the stem was stout and resistant. Plant production can be increased by 50%. The wild-type Ghd7 gene was transferred to some spikelets and early earing cultivars by biotechnology, and the number of grains per panicle of these cultivars increased exponentially, accompanied by increased plant height and delayed heading date.
The results also show that the gene is closely related to the ecological and geographical adaptability of rice varieties. In low latitudes, the wild-type Ghd7 gene can make full use of the light and temperature conditions of rice varieties and produce large spikes and high yields.
Zhang Qifa academician said that high yield and stable production has always been one of the ultimate goals pursued by crop science research. The factors affecting per unit area of ​​rice production include spikelets per panicle, number of effective panicles, 1000-grain weight, and seed setting rate. The growth period determines rice varieties. Seasonal and regional adaptability are the main factors affecting stable production. The successful cloning of the rice Ghd7 gene greatly enhances the understanding of the genetic and molecular basis of complex quantitative traits. In academic research, it is also a good example of the one-to-many effect that is rare in traditional genetics.
The successful isolation of the Ghd7 gene suggests that a complex quantitative trait such as yield can be improved by biotechnology as well as a qualitative trait. The relevant information of the gene can be directly used to discover excellent genes important for improving yield and ecological adaptability from the genetic resources of rice varieties and genetically improve the crop varieties. Due to the clear directionality, the successful separation of Ghd7 gene can also greatly shorten the screening time of high-yielding rice varieties, from the past 10 years to 5 years.
The famous British magazine "Nature" is the world's first international scientific journal. Since its inception in 1869, it has consistently reported and commented on the most important breakthrough in the global science and technology field. "Nature-Genetics" is one of the series of nature magazines. It is issued by the British Nature Publishing Group and publishes the most important new results and the highest level academic papers in the field of genetics every month.