Combining Ability Trial of Hybrid Rice at Pine Bluff, Arkansas

Combining Ability with yield and other traits of 30 new hybrids were tested at Pine Bluff, Arkansas in 2014. The hybrids were developed from 6 female parent sterile lines, UP-1s, UP-2, UP-3s, 11A, 13A, and 15A, to 5 male parent restorer lines, PB5, PB11, PB14, PB15, and PB16. The inbred variety Francis, which is a popular variety in the rice production, was used as the check (CK). Results showed that the grain yields of 8 hybrids were 20.5% ~ 27.4% higher than that of CK Francis. The milled rice yields of 8 hybrids were 16% ~ 24.9% higher than that of CK Francis. The head rice yields of 6 hybrids were 11% ~ 19% higher than that of CK Francis. The chalky rice rates of 3 hybrids were less than that of CK Francis. The sterile lines UP-3s, UP-2s, UP-1s and 15A have good combining ability and the average grain yields of their hybrids were over CK by22.7%, 16.4%, 14.7% and 14.1%, respectively. The restorer lines PB15, PB16, and PB05 have good combining ability and the average grain yields of their hybrids were over CK by 19.6%, 15.3% and 15.1%, respectively. The major traits (grain yield, head rice, less chalky, lower height, earlier heading date) of hybrids of two-line system were better than that of hybrids of three-line system. These results indicated that these top hybrids and their parents of the sterile lines and restorer lines are good to be used in the hybrid rice breeding and production in the future.