小麦中国春遗传背景的育种改良

 利用中国春与推广品种 (系 )杂交、回交进行小麦育种研究发现 :在与中国春的来源地有类似生态的育种条件下 ,中国春的适应性强、分蘖多、落黄好、多小花等优点能够用于小麦遗传改良 ,特别是在引入推广品种遗传背景时 ,中国春的“多小花”得到更好发育 ,导致穗粒数增多 ,可能是“增产资源”。而不利的遗传性状 ,如植株高、抽穗晚、易倒伏、株型差、千粒重低等能够被改进 ;单交组合的 1次回交和三交的方式 (中国春的血缘占 2 5 % )是育种效率最高的方式 ,其次是三交组合的 1次回交和单交组合的 2次回交 (中国春的血缘占 12 .5 % ) ,而单交 (中国春的血缘占 5 0 % )几乎不能获得理想的后代 ,是最差的方式

Utilization of Wheat Landrace Chinese Spring in Breeding

Chinese Spring (CS) is a well known special bread wheat, widely used in wheat genetic research and alien gene transfers through wide cross, by which produced many useful germplasms with alien genetic materials in CS genetic background. The purpose of present study is to search for effective methods to use CS genetic base in wheat breeding. The experiment was carried out in Dujiangyan city of Sichuan province, where has a similar ecological and environmental conditions to the native place of CS. The crosses involved in two or three parents and backcrosses were exploited in present breeding programs. The results suggested that: (1) The desirable agronomic characters in CS, such as good environment adaptation, good tiller ability, multi-florets, multi-spikelets, desirable color performance of mature plants etc., could be used in commercial wheat breeding. Moreover, the multi-florets developed better in cross progenies of CS with commercial cultivars than CS itself and resulted in more seed-sets, which may be useful for high wheat yield. (2) The undesirable characters in CS, such as high plants, bad plant type, low seed weight, late mature etc., could be improved by introduce genetic base from commercial cultivars. (3) Three-parent crosses or backcross one time to two-parent crosses were the most effective methods to use and improve CS in breeding. In this breeding procedure, the progenies had about 1/4 (25%) genetic base derived from CS. The next effective methods were backcross one time to three-parent crosses or backcross twice to two-parent crosses, and their progenies had about 1/8 (12.5%) genetic base derived from CS. The two-parent cross is ineffective method. Moreover, the utilization of CS and other landrace in wheat breeding were also discussed with some examples.