论文部分内容阅读
为了探讨水稻不育系抽穗包颈性状的遗传基础,且为选育不包颈或包颈轻的不育系提供依据,本研究利用W9593S(抽穗包颈轻)与培矮64S(抽穗包颈重)2个光温敏核不育系杂交、回交构建遗传群体,采用植物数量性状主基因+多基因混合遗传体系的6世代联合分离分析方法,剖析了水稻不育系抽穗包颈性状的遗传模型,并与F2群体QTL定位结果进行比较分析。结果表明:经分离分析,穗粒外露度、包颈长均表现为B-1模型(2对加性-显性-上位性主基因模型);包颈度、顶1节间长和剑叶鞘长的最适模型分别为D-4(1对负向完全显性主基因+加性-显性多基因遗传模型)、D-1(1对加性-显性主基因+加性-显性多基因遗传模型)和C-0模型(加性-显性-上位性多基因遗传模型)。对F2分离群体进行QTL定位,共检测到分别与穗粒外露度、包颈长、包颈度、顶1节间长和剑叶鞘长有关的25个QTL,分布于第1、第2、第4、第5、第6、第7和第12染色体上,表型贡献率变幅为2.85%~16.73%。其中位于第12染色体与SSR标记RM3331连锁的QTL以及位于第6染色体分别与SSR标记RM439和RM3765连锁的QTL均同时影响穗粒外露度、包颈长和包颈度3个性状,位于第4染色体分别与SSR标记RM255和RM3687连锁的QTL同时影响顶1节间长和剑叶鞘长2个性状,这5个QTL位点可能是调控不育系抽穗包颈性状的重要位点。QTL定位结果与6世代分离分析结果在某种程度上具有相似性,又不完全一致,可能与这两种方法依据的遗传群体不同以及数量性状受环境影响较大有关。
In order to investigate the genetic basis of heading and trait-neck traits in CMS lines and to provide a basis for selection of sterile lines without or with light-necked cultivars, W9593S (heading light neck) and Pei’ai 64S Heavy) two photo-thermo-sensitive genic male sterile lines were crossed and backcrossed to construct a genetic population. Six-generation combined segregation analysis method of major gene + polygene mixed genetic system of plant quantitative traits was used to analyze the characteristics of heading and trapping neck traits Genetic model and compared with the QTL mapping results of F2 population. The results showed that the B-1 model (2 pairs of additive-dominance-epistasis major gene model) showed that the spikelet outgrowth and the bag-neck length were all segregated, including the neck length, The best long-term models were D-4 (1 pair of negative complete dominant major gene plus additive-dominant polygene genetic model), D-1 (1 pair of additive dominant gene plus additive Polygenic model) and C-0 model (additive-dominance-epistatic polygenic model). Twenty QTLs for F2 segregation populations were detected, and 25 QTLs were detected related to exsertion of spikelets, length of neck covered, neck length of top, length of top 1 and sheath length of flag leaf respectively. The QTLs were located in the 1st, 2nd, 4, the 5th, 6th, 7th and the 12th chromosome, the phenotypic contribution rate ranged from 2.85% to 16.73%. Among them, the QTL linked to SSR marker RM3331 on chromosome 12 and the QTL linked to SSR markers RM439 and RM3765 on chromosome 6 all had three traits of spike exposure, including neck length and package neck, and located on chromosome 4 QTLs linked to SSR markers RM255 and RM3687, respectively, affected both the length of the top 1 and the length of the flag leaf sheath. These 5 QTLs may be important sites for controlling the trait of the heading neck of the CMS line. The result of QTL mapping is similar to that of the 6 generation segregation analysis to a certain degree and not completely the same, which may be related to the different genetic groups and the quantitative traits affected by the environment.