Glabrous rice is an important germplasm resource with the characteristics of glabrousness,lodging resistance and good grain quality.The milling quality,appearance quality and cooking quality of the non-glabrous dual purpose male sterile line Y58S and four glabrous dual purpose male sterile lines derived from Y58S were analyzed and evaluated.Meanwhile,30 hybrid combinations were made from the above mentioned five male sterile lines as the female parent and six restorer lines according to the incomplete diallel cross design,and their grain quality traits were analyzed when they were planted as single-cropping late rice and double-cropping late rice,respectively.The results showed that the grain quality of 8CS963 and X8S010 reached the Ministry's standard of Grade 3.The combined results of two cropping seasons in grain quality revealed that,since the ratio of length to width of four glabrous sterile lines was significantly higher than that of Y58S(the control),most of their hybrid combinations had a higher ratio of length to width than the control group.Except for the hybrid combinations of X8S010/R028,X8S010/X9H003,8CS963/X9H003 and 7CS102/X9H003,which had a significantly higher head rice rate than that of the control group,the head rice rate of the other combinations was not better than that of the control group.The amylose content of the combinations of the glabrous sterile line X6S1791 was significantly higher than that of the other combinations in both cropping seasons.X8S010/X9H005 and Y58S/H070 reached the the Ministry's standard of Grade 3 when planted as single-cropping late rice.Y58S/H070 reached the Ministry's standard of Grade 2,and eight combinations including X8S010/X9H003 and 7CS102/X9H001 reached the Ministry's standard of Grade 3 when planted as double-cropping late rice.The other combinations failed to reach the quality standard mainly due to low alkali spreading value.The average variation values of chalky grain rate and chalkiness degree of the glabrous hybrid rice combinations between two cropping seasons were smaller than those of non-glabrous hybrid rice combinations,but the alkali spreading value was opposite,indicating that the chalky grain rate and chalkiness degree of glabrous hybrid rice combinations were less affected by temperature,but the alkali spreading value was more affected by temperature than that of non-glabrous hybrid rice combinations.
The development of dual-purpose male sterile lines and the registration and application of two-line hybrid rice varieties in China during 1973-2021 were analyzed.The results showed that by 2021,509 dual-purpose male sterile lines had been developed nationwide,and a number of two-line hybrid rice combinations had been developed and approved for commercial production by the national or provincial crop variety appraisal committees,the number of registered varieties increased from 28 during the Ninth Five-year Plan period to 1 550 during the 13th Five-year Plan period.The number of two-line super rice varieties identified by the Ministry of Agriculture and Rural Affairs is 31,which is slightly lower than that of the three-line super rice varieties,but in terms of the planting area per variety,the two-line hybrid rice is obviously higher than that of the three-line hybrid rice.
Jinchengyou 4245,derived from Jincheng 2A,a CMS line bred by Chengdu Academy of Agriculture and Forestry Sciences,and Yihui 4245,a restorer line bred by Yibin Academy of Agricultural Sciences,is a new three-line hybrid rice combination developed by Yibin Academy of Agricultural Sciences.The combination has the characteristics of high yield,high grain quality and strong stress resistance.It was approved by Sichuan Provincial Crop Variety Appraisal Committee in 2022,and is suitable for planting as late-maturing medium rice in the plains and hilly areas below 800 m altitude in Sichuan Province(excluding Panxi Ecological Area).
Liliangyou 8022,derived from the small-grain male sterile line Li 68S(1 000-grain weight at 13.8 g)and the restorer line R8022,is a new heterotic hybrid rice combination developed by Hunan Hybrid Rice Research Center.It has the advantages of large panicles,high seed-setting rate,fine grain quality,good plant type,high canopy but relatively low panicle layer,vigorous root system,excellent lodging resistance and high yield potential.In 2023,Liliangyou 8022 participated in the super high-yielding demonstration on a 100-mu scale in Dechang County,Sichuan Province,and yielded an average of 18.77 t/hm2.In this paper,the super high-yielding cultural techniques of Liliangyou 8022 were described in detail.
After more than 20 years of development in China,new plant variety rights have played an important role in protecting the rights and interests of breeders,improving the enthusiasm of breeders,promoting the original innovation of breeders and the healthy development of seed industry.Food security is the cornerstone of national development,super rice has made important contributions to ensure food security,and the protection of new plant variety rights of super rice and its parents should be paid attention to.The application and authorization of new variety rights of 135 super rice varieties and their parents,the average time for super rice to obtain new plant variety rights and the distribution of super rice breeding bodies were analyzed,aiming at improving the protection level of new plant variety rights of super rice and promoting breeders to develop more excellent super rice varieties.
