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Heterotic patterns of ninety-two white tropical CIMMYT maize lines [Electronic Resource]

By: Vasal, S.K.
Contributor(s): Córdova, H.S [coaut.] | Gonzalez Ceniceros, F [coaut.] | Han, G.C [coaut.] | Pandey, S [coaut.] | Srinivasan, G [coaut.].
Material type: materialTypeLabelArticlePublisher: 1992Subject(s): Combining ability | Germplasm | Inbred lines | Plant population | Yield components | Zea maysOnline resources: Access only for CIMMYT Staff In: Maydica v. 37, no. 2, p. 259-270620726, 620991Summary: Development of inbred-based populations which are heterotic to each other was considered one of the primary goals when CIMMYT started its hybrid maize program in 1985. The objectives of this study were to determine the combining ability and heterotic patterns of tropical maize (Zea mays L.) inbred lines developed at CIMMYT and to identify and form heterotic groups for the tropics. Ninety-two tropical late white inbred lines at S3-S6 levels of inbreeding derived. from nine CIMMYT populations and pools were crossed to four tester lines (two dent and two flint). The 368 line x tester combinations were divided into four sets, eachset comprising of crosses of 23 lines to the four testers and tested in multilocation trials during 1988 to 1990. Mean grain yield for the four sets ranged from 5.6 to 6.5 t/ha. General combining ability (GCA) and specific combining ability (SCA) estimates for grain yield were calculated using line x tester analysis. Twenty-one of the 34 lines from Population 21 had positive GCA estimates for yield. Of the nine lines tested from Population 43, seven showed positive GCA effects for yield. The four testers behaved differently for GCA effects in different sets except Tester 3 (Pop. 25) which showed positive GCA effects for yield in all the sets and in the combined data. SCA effects for yield were significant in each set. Several line x tester hybrid combinations yielded more than 7 t/ha. Generally, crosses of lines from Population 43 to Populations 32 or 25 had higher grain yields. Interpopulation crosses were usually superior to intrapopulation crosses. A few crosses within Population 21 and Population 25 gave yields comparable to some of the best interpopulation combinations. Based. on the testcross data, two tropical heterotic groups THG "A" and THG "B" were formed which will be useful for future hybrid development work at CIMMYT and national programs in the tropics. Several of the lines included in this study were announced as CIMMYT maize lines (CML) during 1991, and are available to both public and private breeders. Twelve of the 20 top-yielding crosses (five from each set) involved CML lines.
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Item type Current location Collection Call number Copy number Status Date due Barcode Item holds
Article CIMMYT Knowledge Center: John Woolston Library

Lic. Jose Juan Caballero Flores

 

CIMMYT Staff Publications Collection CIS-1756 (Browse shelf) 1 Available 620726
Article CIMMYT Knowledge Center: John Woolston Library

Lic. Jose Juan Caballero Flores

 

CIMMYT Staff Publications Collection CIS-1756 (Browse shelf) 2 Available 620991
Total holds: 0

Peer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0025-6153

Tables, references p. 270

Development of inbred-based populations which are heterotic to each other was considered one of the primary goals when CIMMYT started its hybrid maize program in 1985. The objectives of this study were to determine the combining ability and heterotic patterns of tropical maize (Zea mays L.) inbred lines developed at CIMMYT and to identify and form heterotic groups for the tropics. Ninety-two tropical late white inbred lines at S3-S6 levels of inbreeding derived. from nine CIMMYT populations and pools were crossed to four tester lines (two dent and two flint). The 368 line x tester combinations were divided into four sets, eachset comprising of crosses of 23 lines to the four testers and tested in multilocation trials during 1988 to 1990. Mean grain yield for the four sets ranged from 5.6 to 6.5 t/ha. General combining ability (GCA) and specific combining ability (SCA) estimates for grain yield were calculated using line x tester analysis. Twenty-one of the 34 lines from Population 21 had positive GCA estimates for yield. Of the nine lines tested from Population 43, seven showed positive GCA effects for yield. The four testers behaved differently for GCA effects in different sets except Tester 3 (Pop. 25) which showed positive GCA effects for yield in all the sets and in the combined data. SCA effects for yield were significant in each set. Several line x tester hybrid combinations yielded more than 7 t/ha. Generally, crosses of lines from Population 43 to Populations 32 or 25 had higher grain yields. Interpopulation crosses were usually superior to intrapopulation crosses. A few crosses within Population 21 and Population 25 gave yields comparable to some of the best interpopulation combinations. Based. on the testcross data, two tropical heterotic groups THG "A" and THG "B" were formed which will be useful for future hybrid development work at CIMMYT and national programs in the tropics. Several of the lines included in this study were announced as CIMMYT maize lines (CML) during 1991, and are available to both public and private breeders. Twelve of the 20 top-yielding crosses (five from each set) involved CML lines.

English

R92ANALY|MP|12541-R|3

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