长江中下游地区小麦产量育种方向及策略探讨

The Breeding Strategies and Direction on Wheat Yield in region of Middle and Lower Reaches of the Yangtze River

为探讨长江中下游地区小麦产量育种的方向及策略,对这一地区近期育成的和大面积应用的小麦品种的产量性状,进行了遗传相关分析和通径分析。其主要结果为:在目前中高产水平下(6000～6750kg/hm2),总体以千粒重对产量的作用较大,单位面积穗数对产量的作用也较大,但其与环境相关值较高,每穗粒数对产量的作用较小,但其表型相关值较大;千粒重和穗数对产量的影响主要由本身的直接作用所致,而每穗粒数对产量的影响主要被通过穗数和通过千粒重的间接作用所分解;不同产量水平下试验品种的产量3因素表现为,在产量相对由低中产到较高产时,穗数增加较多,每穗粒数变化较小,千粒重提高较多,而在高产组次中,穗数基本稳定(或略有下降),每穗粒数增幅较大,千粒重明显提高。鉴于此,作者初步认为,长江中下游地区未来高产小麦育种,虽选育穗粒重齐头并进类型,或以大穗大粒为主类型,或穗粒并重类型似均有可行性,但根据长江中下游地区小麦生态条件的特点,在策略上宜稳定穗数,增加粒数,主攻(提高)粒重。同时,还探讨了相适宜的产量构成因素。

In order to discuss the breeding strategies and direction on wheat yield in region of middle and lower reaches of the Yangtze River, genetic and path analysis of yield traits were studied on wheat varieties which large plant in this region. The results showed that 1000-grain weight had main effects to yield construction from middle to high yield level. Spikes per unit area were second, but it was interrelated mostly with environment. Meanwhile, grains per spike had little role on yield construction. 1000-grain weight and spike number had primary action on yield. The effect of grains per spike on yield was broken down by spike number and 1000-grain weight. The three factors of yield construction showed different results under low to high yield level. The number of spikes and 1000-grain weight increased more from low to middle yield, however, in high yield level the number of spikes change little, grains per spike and 1000-grain weight increase mostly. Thus, the breeding strategy in this region should keep the spikes number as present and increase the grains per spike and improved kernel weight in future high yield breeding.