【摘要】 “九二０”施用时期和施用量的两组试验的结果分析表明：（１）在不同时期施用不同量的“九二０”，均能使Ｋ１９Ａ的株高、包颈长和节间长等发生规律性变化。当株高在１２４ｃｍ，包颈长在１ｃｍ左右，Ｋ１９Ａ异交结实率最高。（２）在用量为１０８ｇ／ｈｍ２时，“九二０”的最佳喷施期在抽穗率２２％～２６％之间.更多还原

【Abstract】 K19A,a new indica CMS line with japonica cytoplasm,was studied on its optimum sprayingdosage and spraying time of GA3 in order to increase its outcrossing rate in its multiplication and hybrid seedproduction.The results indicated that different dosages and different spraying stages of GA3 would makeK19A change regularly in plant height,panicle exsertion and elongation of internodes,and K19A showed ahighest outcrossing rate when its plant height was at 124 cm with 1 cm panicle enclosed in the sheath.Theoptimum dosage was found to be 150g/hm2 when GA3 was sprayed at the heading time of 20%panicles;theoptimum time to spray GA3 was the heading stage of 22%～26%panicles when the dosage was at 108 g/hm2.更多还原