CIMMYT和我国玉米种质群体的配合力及杂种优势分析

Combining Ability and Heterosis of 14 CIMMYT and 13 Domestic Maize Populations in an NCⅡ Mating Design

采用NCⅡ遗传交配设计,以丹340、Mo17、掖478和黄早四为测验种,通过2年1点田间试验,分析27个国内外玉米群体(14个CIMMYT热带、亚热带群体和13个国内群体)的主要性状配合力和产量杂种优势,并划分杂种优势群。结果表明,大多数CIMMYT群体的产量和产量性状配合力及杂种优势明显优于国内玉米群体,以Suwan l、Pob43、Pob21、Pob501、Pob32、Pob502、Pob49、Stay Green、Pob28等9个热带、亚热带群体和国内群体WBM-C4的产量GCA效应较高,且与产量相关性状的GCA效应也较高;但这些群体的植株、穗位较高。在改良和使用时需设法降低株高、穗位。产量对照优势以Suwan 1、Pob21、Pob32、Pob43、Pob49、Pob501、Pob502等7个群体表现较优,尤其Suwan 1与4个测验种所组配测交组合的对照优势值均较大,分别为33.4%、47.4%、23.6%和16.8%,是本研究中表现最优异的群体。在NCⅡ遗传交配设计中,依据产量SCA结合杂种优势划分群体比较合理可靠。除金皇后外,国内其他12个群体划群合理,与系谱记载吻合。14个热带、亚热带群体中有9个划群合理。Suwan 1和Pob32在本研究中游移于四平头和非Reid之间,但根据以往实验结果和系谱关系,将它们分别归入四平头和非Reid种质更有实践意义。Pob21游移于四平头和旅大红骨之间,但参考以往实验结果,将其划入旅大红骨群更合理。另外2个群体Pob49和Stay Green不能根据现有的试验资料确切地将其划分到4个杂种优势类群中去。

In the recent years, the research and promotion on maize breeding slowed down due to inadequate germplasm resources and lack of elite inbred lines. In order to solve genetic frangibility of domestic germplasm and make yield of hybrids breakthrough quickly, a large number of tropical and subtropical germplasm have been introduced and a large number of domestic germplasm have been evaluated. Information on the combining ability and heterosis of those maize germplasm is of great value to maize breeders. The objective of this study is to analyze combining ability, reference heterosis and heterotic groups of 27 maize （ Zea mays L. ） populations which were test-crossed with 4 domestic inbred lines （Dan 340, Mo 17, Ye 478 and Huangzao 4） as common testers in an NC- Ⅱ mating design. Among those 27 populations, 14 are of tropical and subtropical germplasm introduced from CIMMYT, and the other 13 are domestic populations. The 108 （27 × 4） test-crosses and 4 check hybrids were planted in Ya＇ an, Sichuan in 2001 and 2002. Fourteen biometric traits viz., plant height, ear position, lodging per plot, days to silking, days to pollen shedding, ear diameter, ear length, cob diameter, kernel rows per ear, kernels per row, 100-kernel weight, shelling percentage, yield per plant, yield per plot were investigated. The results showed that the yield combining ability and reference heterosis of CIMMYT maize populations were higher than those of domestic populations. The GCA of yield and yield components were relatively higher for the CIMMYT populations including Suwan 1, Pob43, Pob21, Pob501, Pob32, Pob502, Pob49, Stay Green, Pob28 and domestic population WBM-C4. But the plant stature was taller and ear position was higher for those populations compared with domestics. The reference heterosis of grain yield of Suwan 1, Pob21, Pob32, Pob43, Pob49, Pob501 and Pob502 were higher than others. Especially Suwan 1 was an unparalleled population, the reference heterosis of 4 combinations that used Suwan 1 as parent were obviously great： 33.4%, 47.4% , 23.6% and 16.8% , respectively. The clustering strategy based on yield SCA and heterosis is reasonable and reliable. The clustering results of 12 domestic populations were reasonable, and corresponding to their pedigree and characters with an exception of Golden Queen. Nine out of the 14 CIMMYT populations were clustered into the 4 domestic heterotic groups reasonably. Suwan 1 and Pob32 could be grouped into both Sipingtou and non-Reid germplasm in the study. However, it is likely more practice that the two populations were clustered into Sipingtou and non-Reid, respectively. Pob21 was grouped between Sipingtou and Lueda Red Cob germplasm in the study, but it is more reasonable to be classified into Lueda Red Cob based on its pedigree and former studies. Pob49 and Stay Green were not clustered well and truly.