Rice cancer has met its nemesis: breeding of a disease-resistant new variety succeeds

Since the beginning of this century, rice stripe virus disease has continued to break out over large areas, in severe cases even causing rice farmers to lose their entire harvest. Rice stripe virus disease has been regarded as the "cancer" of rice.

"Wuyujing 3", long recognized by the market as the main rice variety with the best taste and quality in Jiangsu Province and surrounding areas, has seen its planting area plummet in recent years because it is highly susceptible to rice stripe virus disease. Some stripe virus-resistant varieties either have shortcomings in yield and yield stability, or have not been fully recognized by the market for their rice quality. Rice farmers are looking forward to the replacement of quality rice varieties with resistance to rice stripe virus disease.

Good news recently came from Yangzhou University: the research group led by Professor Pan Xuebiao of the university has bred a new rice variety resistant to rice stripe virus disease, "Wulingjing 1", using molecular marker technology, greatly improving the level of disease resistance. Large-scale multi-point demonstrations in Jiangsu achieved good results. The project passed the Jiangsu Province new crop variety approval not long ago and was praised as a successful example of molecular breeding for rice disease resistance in China.

This work began in 2004. Professor Pan Xuebiao, together with researcher Jiang Qixiang of the Changzhou Wujin District Rice and Wheat Breeding Farm and the Jiangsu Provincial Seed Station, used the variety "Zhendao 88" as the donor parent for the rice stripe virus resistance gene Stvb-i. On the basis of fine mapping of this gene, they adopted molecular marker-assisted selection technology and, through backcross breeding, directionally improved the stripe virus resistance of "Wuyujing 3". The project used flanking molecular markers of the resistance gene to assist selection of the target gene, and used molecular markers to detect the degree of recovery of the recurrent parent genetic background in backcross progeny. In a short period, it rapidly bred "Kangtiao Wuyujing 3", namely "Wulingjing 1", which retained the original variety's yield, yield stability and excellent eating quality. The research was funded by the National Science and Technology Support Program and the major project of the Program for Introducing International Advanced Agricultural Science and Technology (948 Program).

In the 2008 Jiangsu Province new variety approval (recognition) trial summary for "single trait change", it was concluded that compared with "Wuyujing 3", "Wulingjing 1" had an average diseased plant rate of only 4.4% for stripe virus resistance in multi-point experiments, far better than the 53.2% of "Wuyujing 3", and its yield was high; when experts tasted the cooked rice quality, "Wulingjing 1" also scored high.

It is understood that the announcement of the variety right application for "Wulingjing 1" was published on September 1, 2008, and Jiangsu Jintudi Seed Industry Co., Ltd. has obtained the exclusive right to develop and operate the variety. At present, several million kg of seed of this variety have been propagated, and rice farmers are expected to be able to plant this new rice variety in 2010.