CAJ | 학술논문

利用轮回选择进行群体改良,是玉米种质扩增与改良的有效方法,能为选育优良自交系提供基本素材,进而提高选育自交系及杂交种的效率。本研究以玉米窄基群体P4C0及其经过不同轮回选择方法改良的10个群体为材料,通过多点田间表型鉴定和配合力测定,研究不同轮回选择方法对玉米窄基群体的改良效果,利用 SSR 分子标记分析不同轮回选择方法对群体遗传多样性的影响。结果表明,几种轮回选择方法都能有效改良群体的主要性状及其一般配合力(GCA)。以时间计算,控制双亲混合选择(MS)对群体P4C0主要性状及其GCA改良效果优于半同胞-S2：3(HS-S2：3)轮回选择,但在株高和穗位高的改良上, HS-S2：3选择效果较好。以轮次计算,开放改良对群体P4HSC1主要性状及其 GCA 的改良效果优于 MS,但开放改良后,群体株高和穗位高有较大幅度的增加。不同轮回选择方法对群体遗传多样性和遗传结构的影响不尽一致。P4C0经过5轮MS后,在群体改良的低代,群体遗传多样性得到了较好的保持,而多代的改良导致群体遗传多样性下降；P4C0经过1轮HS-S2：3选择后,遗传多样性比P4C0有较大幅度的下降。P4HSC1经过1轮开放改良后,遗传多样性有较大幅度的增加。P4HSC1经过3轮MS改良后,群体遗传多样性呈增大的趋势,但每轮增加的幅度均较小。
이용륜회선택진행군체개량,시옥미충질확증여개량적유효방법,능위선육우량자교계제공기본소재,진이제고선육자교계급잡교충적효솔。본연구이옥미착기군체P4C0급기경과불동륜회선택방법개량적10개군체위재료,통과다점전간표형감정화배합력측정,연구불동륜회선택방법대옥미착기군체적개량효과,이용 SSR 분자표기분석불동륜회선택방법대군체유전다양성적영향。결과표명,궤충륜회선택방법도능유효개량군체적주요성상급기일반배합력(GCA)。이시간계산,공제쌍친혼합선택(MS)대군체P4C0주요성상급기GCA개량효과우우반동포-S2：3(HS-S2：3)륜회선택,단재주고화수위고적개량상, HS-S2：3선택효과교호。이륜차계산,개방개량대군체P4HSC1주요성상급기 GCA 적개량효과우우 MS,단개방개량후,군체주고화수위고유교대폭도적증가。불동륜회선택방법대군체유전다양성화유전결구적영향불진일치。P4C0경과5륜MS후,재군체개량적저대,군체유전다양성득도료교호적보지,이다대적개량도치군체유전다양성하강；P4C0경과1륜HS-S2：3선택후,유전다양성비P4C0유교대폭도적하강。P4HSC1경과1륜개방개량후,유전다양성유교대폭도적증가。P4HSC1경과3륜MS개량후,군체유전다양성정증대적추세,단매륜증가적폭도균교소。
The narrow basis of maize germplasm is the main factor blocked the development of maize breeding in China. The population improvement via recurrent selection is one of effective methods for the improvement and expansion of maize germ-plasm. In this study, three kinds of recurrent selection methods were carried out to improve the narrow base maize population P4C0:a) five cycles of biparental mass selection (MS);b) one cycle of half-sib and S2:3 family combining selection (HS-S2:3) followed by three cycles of MS;and c) one cycle of open improvement (OI) by crossing two inbred lines to the population. In different ecological environments, the phenotypes of the developed populations were analyzed and the combining abilities were tested according to an incomplete diallel model to study the effects of the different methods. The effects of the different methods on genetic diversity of the populations were also analyzed by using 51 pairs of SSR markers. It was found that the effects of different methods on the main traits, general combing ability (GCA) and the genetic diversity were different. The effects of MS on yield, yield components and their GCAs were greater than these of HS-S2:3. In addition, MS was more effective on maintaining the genetic diversity of the population. The HS-S2:3 were more beneficial to maintain plant height and ear height of the popula-tion. The OI was more effective on the improvement of yield, yield components and their GCAs than MS. Genetic diversity was maintained in the first two cycles of MS on P4C0 then decreased slightly from the 3rd cycle. Genetic diversity decreased after one cycle of HS-S2:3 and increased after 3 cycles of MS or 1 cycle of OI.