Crossing it with Zaohui 89,a new two-line early hybrid rice combination,Jinliangyou 289,was developed and it was characterized with both high yield and good grain quality.

Zhuliangyou 08,developed by the Agricultural Research Institute of Xiangtan,Hunan,is a new two-line early hybrid rice combination derived from the corss of Zhu 1S,a PTGMS line which is of low critical sterility-inducing temperature and wide compatibility,and Tanzao 08,a newly-developed high-yielding and multi-resistant early indica rice line.

Jinliangyou 4,a new two-line early hybrid rice combination with both high yield and good grain quality,was developed by crossing Jinshan S-2 (a PTGMS line with low critical temperature and good grain quality) with the restorer line Zao R-10.

Study on heterotic ecotype of two-line hybrid rice in Yunnan;

Study on the characteristics of carbohydrate transfer of stem and sheath and grain-filling in two-line hybrid rice;

Studies on technique approaches for high yield in Two-line hybrid rice;

Peiliangyou500, a newly developed two line hybrid rice suitable for ratooning rice after the main crop planted as middle season rice, was released to farmers in March,2002.

Three two line hybrid rice combinations (Zao S/T113,Xuxuan S/T113 and 810S/T113) were used in the study of early rice.

In this article,we analyzed the status of 34 early hybrid rice combinations which were registered and released in Hunan Province during 1986—2005,and compared the differences in major characters between twoline early hybrid rice and three-line early hybrid rice based on the data of the regional trials from 2001 to 2005.