Gibberellic acid (GA3) improves heading characteristics of cytoplasmic male sterile (CMS) lines and seed yield of hybrid rice seed production
2003
Suralta, R.R. (Philippine Rice Research Inst., Munoz, Nueva Ecija (Philippines). Seed Production and Health Div.) Robles, R.P.
In order to assess the effect of GA3 as pre-flowering treatment for cytoplasmic male sterile (CMS) lines in hybrid rice seed production, one pot study and a field experiment were conducted during the dry season of 2002. The pot experiment determined differences in percentage of panicle exsertion and other heading characteristics among ten CMS lines applied with five levels of GA3 at 5-10% heading while the field experiment determined the outcrossing characteristics and seed yield of CMS line IR58025A under various levels and splitting of GA3 application. In the greenhouse, foliar application of GA3 to various CMS lines significantly increased the percentage of panicle exsertion from the flagleaf sheath by a maximum of 80% at 150 g GA3/ha application. Likewise, other morphological traits critical to outcrossing were also observed for most of the traits evaluated. In the field, foliar application of GA3 significantly increased the rate of panicle exsertion, seed set and seed yield by a maximum of 80%, 20% and 77%, respectively at 150 g GA3/ha concentration. Increase in seed yield was highly correlated with the increase in percentage of seed set (r square=0.99), which in turn improved by higher rate of panicle exsertion (r square=0.88), good panicle layer carriage (r square=0.96) and wider flagleaf angle (r square=0.99) and degree of spikelet openings (r square=0.88). Splitting the total amount of GA3 applied, increased by efficacy by 18% to 30% as evidenced by a significant increase in percentage of seed set. The optimum rate of GA3 application is 150 g/ha applied in two splits beginning at 5-10% panicle heading of the female parent population
显示更多 [+] 显示较少 [-]