Reif J C, Zhang P, Dreisigacker S, Warburton M L, van Ginkel M, Hoisington D, Bohn M, Melchinger A E
Institute of Plant Breeding, Seed Science, and Population Genetics, University of Hohenheim, 70593, Stuttgart, Germany.
Theor Appl Genet. 2005 Mar;110(5):859-64. doi: 10.1007/s00122-004-1881-8. Epub 2005 Feb 3.
It has been claimed that plant breeding reduces genetic diversity in elite germplasm which could seriously jeopardize the continued ability to improve crops. The main objective of this study was to examine the loss of genetic diversity in spring bread wheat during (1) its domestication, (2) the change from traditional landrace cultivars (LCs) to modern breeding varieties, and (3) 50 years of international breeding. We studied 253 CIMMYT or CIMMYT-related modern wheat cultivars, LCs, and Triticum tauschii accessions, the D-genome donor of wheat, with 90 simple sequence repeat (SSR) markers dispersed across the wheat genome. A loss of genetic diversity was observed from T. tauschii to the LCs, and from the LCs to the elite breeding germplasm. Wheat's genetic diversity was narrowed from 1950 to 1989, but was enhanced from 1990 to 1997. Our results indicate that breeders averted the narrowing of the wheat germplasm base and subsequently increased the genetic diversity through the introgression of novel materials. The LCs and T. tauschii contain numerous unique alleles that were absent in modern spring bread wheat cultivars. Consequently, both the LCs and T. tauschii represent useful sources for broadening the genetic base of elite wheat breeding germplasm.
有人声称，植物育种会降低优良种质的遗传多样性，这可能会严重危及作物持续改良的能力。本研究的主要目的是考察春性面包小麦在（1）驯化过程中、（2）从传统地方品种转变为现代育成品种过程中以及（3）50年国际育种过程中的遗传多样性丧失情况。我们研究了253份国际玉米小麦改良中心（CIMMYT）或与CIMMYT相关的现代小麦品种、地方品种以及小麦D基因组供体节节麦材料，使用90个分布于小麦基因组的简单序列重复（SSR）标记。从节节麦到地方品种，以及从地方品种到优良育种种质，均观察到遗传多样性的丧失。小麦的遗传多样性在1950年至1989年期间变窄，但在1990年至1997年期间有所增加。我们的结果表明，育种者避免了小麦种质基础的变窄，并随后通过导入新材料增加了遗传多样性。地方品种和节节麦含有许多现代春性面包小麦品种中不存在的独特等位基因。因此，地方品种和节节麦都是拓宽优良小麦育种种质遗传基础的有用资源。
