水稻成花素基因RFT1对抽穗期的促进作用

Effects of Florigen RFT1 for Promoting Flowering in Rice

进一步缩短早稻的生育期是我国南方双季稻区的重要育种目标之一。本研究以早籼稻珍汕97和中籼稻密阳46为亲本,构建了珍汕97早熟型遗传背景的近等基因系(NIL)和NIL-F2群体,分析成花素基因RFT1在早稻遗传背景和自然长日照种植条件下的遗传作用。结果表明,与RFT1的珍汕97等位基因相比,密阳46等位基因能够显著促进抽穗,同时对产量性状呈轻微负向作用。在2个群体中,RFT1对抽穗期的加性效应为0.84~1.21 d,贡献率为10.46%~18.62%。在NIL群体2年重复试验中,每穗总粒数、每穗实粒数、千粒重和单株产量的加性效应分别为3.06粒和2.02粒、2.98粒和1.48粒、0.12 g和0.08 g、0.63 g和0.38 g,贡献率在0.99%~2.76%之间。这些结果显示,密阳46的RFT1等位基因能够在较低产量代价下缩短早稻的生育期,为晚稻提供更充裕的生长时间,进而提高双季稻的生产潜能。

Shortening the growth period of early-season rice varieties is one of the important breeding objectives in the double-season rice region in southern China. In this study, near isogenic lines(NILs) and NIL-F2 populations that segregated the florigen gene RFT1 in the early-heading genetic background were developed using early-season rice variety Zhenshan 97 and middle-season rice variety Miyang 46 as the parents. The populations were tested for heading date and yield traits under natural long-day conditions. The results showed that the Miyang 46 allele of RFT1 could promote heading date and had a slight negative effect on yield traits. The additive effects on heading date ranged from 0.84 to 1.21 days for heading date, explaining 10.46% to 18.62% of the phenotypic variances. The additive effects estimated in two-year’s trials using the NIL population were 3.06 and 2.02 for the number of spikelets per panicle, 2.98 and 1.48 for the number of grains per panicle, 0.12 g and 0.08 g for 1 000-grain weight, and 0.63 g and 0.38 g for grain yield per plant, with the phenotypic variances explained ranging from 0.99% to 2.76%. Our results indicated that the Miyang 46 allele of RFT1 could further shorten the growth period of early-season varieties with slight penalty in grain yield, providing more abundant growth time for late-season rice which could increase the production potential of double-season rice.