利用单片段代换系测交群体定位玉米产量相关性状的杂种优势位点

杂种优势利用是提高农作物产量与品质的一种重要途径, 而明确杂种优势的遗传机制将促进优良玉米新品种的选育, 但是截至目前其遗传机制仍然不清楚。本研究以玉米自交系lx9801背景的昌7-2的单片段代换系为基础材料, 利用与自交系T7296的测交群体, 对昌7-2和lx9801对应染色体片段与T7296之间存在差异的杂种优势位点进行了分析, 共检测出64个不同穗部性状和产量的杂种优势位点(HL), 其中23个在2个环境中同时被检测到, 包括4个穗长的HL, 4个穗粗的HL, 4个穗行数的HL, 7个行粒数的HL和4个产量的HL, 并在多个染色体片段上鉴定出同时包含产量及其构成因子的杂种优势位点, 该研究为进一步解析玉米产量杂种优势形成的遗传机制奠定了材料基础。

Identification of Heterotic Loci for Yield and Ear Traits Using CSSL Test Population in Maize

Heterosis plays an important role in enhancingcrop yield and quality.Dissecting the genetic basis of heterosis can promote hybrid maize selection, however that is unclear up to now. In this study, a set of chromosome segment substitution lines (CSSLs) population,which was constructed using the inbred line lx9801 as the receptor parent and the inbred line Chang7-2 as the donor parent, was crossed with the inbred line T7296 to construct the corresponding test population. The test population was used to identify the heterotic loci (HL) for grain yield and ear traits in maize,which showed significant difference inheterosisbetween the corresponding chromosomal region of the inbred line Chang7-2 and lx9801as well as the test inbred line T7296. A total of 64HL were identified for gain yield and ear traits, and among them 23 HL were identified at the two environments simultaneously, including 4 HL for ear length, 4 HL for ear width, 4 HL for row number, 7 HL for kernels per row, and 4HL for grain yield. Additionally, the HL for both grain yield and its components simultaneously were found on many chromosomal regions.This study could offer a basic material for thoroughly dissecting the genetic basis of heterosis for grain yield and its components in maize.