云南粳稻耐低磷特性的主基因加多基因遗传分析

Genetic analysis of tolerance to low phosphorus using major gene plus poly-gene model in Yunnan japonica rice

磷高效水稻培育是提高土壤潜在磷利用效率的一种途径,通过对云南粳稻耐低磷特性的主基因加多基因遗传分析,可以明确耐低磷特性主基因的存在、对数及遗传效应的大小,为磷高效育种提供理论依据。本试验通过云南主栽粳稻品种合系35（Oryza sativa）与耐低磷极强早旱谷（Oryza sativa）配制P1、P2、F1、F2或F3世代,在云南省农科院进行低磷胁迫试验,对耐低磷鉴定和主基因加多基因联合遗传分析,结果表明：早旱谷的分蘖和株穗产量基因受两对主效基因＋多基因相互配合遗传控制的,两对主基因间存在上位性效应,两主基因间效应差异较大。分蘖力F2主基因遗传率为58.82%-72.13%,F3主基因遗传率为45.88%-57.96%;株穗产量F2主基因遗传率60.94%-83.08%,F3主基因遗传率为62.20%-75.80%。因此育种中应当充分重视主基因的利用,利用主基因应以第一对主基因的加性效应为主,对后代耐低磷性状的选择宜从F2代开始,杂交的后期世代也要注意耐性的选择。

Genetic breeding of high-phosphorous in crop is an efficient way to utilize potential phosphorous in soil. Genetic analysis of tolerance to low phosphorus of using major gene plus poly-gene model in Yunnan japonica rice were identified for existence and number of major gene, which can speed up rice breeding of high-phosphorous. In the low-P tolerance experiment, P1,P2, Fi, F2and F3 5 populations hybrided from parents （ Hexi35 and Zaohangu ） were planted under low phosphorous of soil （6.26 mg·kg^-1） and high level （40 mg·kg^-1） in Yunnan Academy of Agricultural Sciences, and its Iow-P tolerance genetic were analyzed about gene effect using major gene plus poly-gene mixed model. The main results are as follows： the genes of Iow-P tolerance of tiller and grain yield per panicle was controlled by two major gene and poly-gene, there were epistasis effects and obvious differences in genetic effects between the two major genes.F2 heritability of major gene of tiller was from 80.64% to 85.55%,and F3 heritability from 45.88% to 57.96%; F2 heritability of major gene of grain yield per panicle was from 60.94% to 83.08 %, and F3 heritability from 62.20% to 75.80%. So, It is suggested that utilizing major gene and additive effects of the first major gene during which, traits of tolerance to low-P should be screened from F2 segregating generation and upper generation, played an important role in rice breeding.