National Maize Improvement Center of China, China Agricultural University, 100193 Beijing, China.
Theor Appl Genet. 2010 Jan;120(2):333-40. doi: 10.1007/s00122-009-1213-0. Epub 2009 Nov 20.
The genetic basis of heterosis for grain yield and its components was investigated at the single- and two-locus levels using molecular markers with an immortalized F(2) (IF(2)) population, which was developed by pair crosses among recombinant inbred lines (RILs) derived from the elite maize hybrid Yuyu22. Mid-parent heterosis of each cross in the IF(2) population was used to map heterotic quantitative trait loci. A total of 13 heterotic loci (HL) were detected. These included three HL for grain yield, seven for ear length, one for ear row number and two for 100-kernel weight. A total of 143 digenic interactions contributing to mid-parent heterosis were detected at the two-locus level involving all three types of interactions (additive x additive = AA, additive x dominance = AD or DA, dominance x dominance = DD). There were 25 digenic interactions for grain yield, 36 for ear length, 31 for ear row number and 51 for 100-kernel weight. Altogether, dominance effects of HL at the single-locus level as well as AA interactions played an important role in the genetic basis of heterosis for grain yield and its components in Yuyu22.
利用分子标记，以永生 F2（IF2）群体为材料，在单基因座和双基因座水平上研究杂种优势的遗传基础，该群体是通过来源于优良玉米杂交种豫玉 22 的重组自交系（RIL）的成对杂交而建立的。IF2 群体中每个杂交的中亲杂种优势被用来定位杂种优势数量性状基因座。共检测到 13 个杂种优势基因座（HL）。其中包括 3 个与粒重有关的 HL、7 个与穗长有关的 HL、1 个与穗行数有关的 HL 和 2 个与千粒重有关的 HL。在双基因座水平上共检测到 143 个双基因座互作，涉及所有三种互作类型（加性×加性=AA、加性×显性=AD 或 DA、显性×显性=DD）。其中，粒重的双基因座互作有 25 个，穗长有 36 个，穗行数有 31 个，千粒重有 51 个。总之，HL 在单基因座水平上的显性效应以及 AA 互作在豫玉 22 的粒重及其组成部分杂种优势的遗传基础中起着重要作用。
