现代美国马齿型玉米商业育种的种质基础

Germplasm Base of Contemporary U.S.Dent Maize in Commercial Breeding

现代商用自交系遗传基础来源广泛,包括衣阿华(Iowa)坚秆综合种、阿根廷Maiz Amargo、兰卡斯特(Lancaster)、Oh43、LH82、爱华马齿(Iodent)、Oh07-Midland、明尼苏达13(Minn13)、商业杂交种以及遗传基础广泛的外来种质、综合种和开放授粉群体等遗传背景。这些亚群之间以特定模式相互改良和杂交,选育了现代商业杂交种。在过去25年里,主要源于B73的SS种质的遗传贡献保持稳定,Holden公司的LH82从1994～2008年遗传贡献稳定在2.5%～2.8%;Mo17的遗传贡献由8.6%下降到1.7%;Oh43有所增长,由1.5%增长到3.9%。近10年来,Iodent对商业育种的遗传贡献保持增长态势。利用商业杂交种选育自交系,大大促进了先锋Iodent种质在其他育种公司的广泛利用,其中,先锋杂交种3737对现代商业种质提供了15.6%的遗传贡献;其次是3180、3535和3558,分别提供了3.4%、2.4%和1.1%的遗传贡献,这些杂交种对现代商业育种产生了巨大影响。

By pedigree lineage,these proprietary lines were from diverse backgrounds that include Iowa Stiff Stalk Synthetic（SS）,Argentine Maiz Amargo,Lancaster,Oh43,LH82,Iodent,Oh07-Midland,Minnesota 13,and commercial hybrid derived backgrounds and uncharacterized broad base sources from exotic,synthetic,and open pollinated populations.Intergroup recombinations have been successful between groups that each independently combined well opposite a common background in commercial hybrids.In the past 25 years,the genetic contribution of B73 remained constant,and LH82 remained from 2.5% to 2.8%,whereas the contribution of B14 and B37 has decreased;the public line Mo17 has decreased from 8.6% to 1.7%,and the contribution of the public line Oh43 increased from 1.5% to 3.9%.The contribution of Iodent germplasm increased concomitantly with its use across commercial breeding programs in the past decade.Using commercial hybrids as breeding germplasm facilitated the introgression of Pioneer Hi-Bred International（PHI） Iodent germplasm into competitor＇s breeding programs.Of these,the PHI commercial hybrid 3737 had the greatest impact to contemporary germplasm by contributing 15.6% of the genes,the next ones were 3180（3.4%）,3535（2.4%） and 3558（1.1%） mainly used in the seed companies outside of pioneer.