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999 _c21404
_d21404
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003 MX-TxCIM
005 20240919021142.0
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040 _aMX-TxCIM
090 _aCIS-2975
100 1 _aNarro, L.A.
245 0 0 _aDiallel and triallel analysis in an acid soil tolerant maize (Zea mays L.) population
260 _c2000,
_aBergamo (Italy) :
_bConsiglio per la Ricerca e la Sperimentazione in Agricoltura,
340 _aPrinted
500 _aPeer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0025-6153
520 _aThe diallel analysis was used mainly to estimate general-(GCA) and specific combining ability (SCA) effects for a fixed sample of parents and less frequently to estimate components of variance for a random sample of parents of the reference population. In both cases, only additive and deviations due to dominance effects can be estimated, assuming that epistasis is negligible. The triallel analysis allows the estimation of epistasis variance because more ancestors are available and more covariances among relatives can be estimated. The maize population SA-8 was used to estimate components of variance through the generation of single- and three-way crosses with a random sample of 50 S1 lines. Replicated trials were planted in ten environments, including seven acidic and three non-acidic soils. Each trial consisted of 400 entries, 100 single- and 300 three way-crosses. Yields on non-acidic soils averaged 70% greater than on acidic soils. Within a given soil type (non-acidic or acidic), single crosses were similar to three-way crosses in overall mean, highest, and lowest values for grain yield, days to 50% silk emergence, and plant height. For these traits, GCA and SCA sum of squares were highly significant using the triallel and diallel analyses for acidic soils, and across environments; although an overestimation for GCA effects for the diallel analysis was observed. Estimation of components of variance using the triallel and diallel data for the full model showed that σ2AD, and σ2AA explained 79 and 19% of the genetic variance, respectively, and both were highly significant; σ2A explained less than 2% of the genetic variance. On the other hand, using the reduced model, σ2A and σ2D were significant and explained 37 and 63% of the genetic variation, respectively. The results, using the diallel data only, are in agreement with the reduced model. These results suggest that epistasis was important in the SA-8 maize population. The similar grain yields for single- and three-way crosses in the present study suggest that both types of hybrids would be suitable to increase maize yields in acidic and non-acidic environments of the developing countries.
536 _aGenetic Resources Program|Global Maize Program
546 _aEnglish
591 _a0104|AL Maize Program|R01JOURN|AJ|3
594 _aCCJL01|INT2062
595 _aCSC
650 1 0 _aAcid soils
650 1 7 _aBreeding methods
_gAGROVOC
_2
_91030
650 1 0 _aDiallel crossing
650 1 7 _aMaize
_gAGROVOC
_2
_91173
650 1 0 _aSoil types
_92200
650 1 0 _91314
_aZea mays
650 1 7 _aPlant breeding
_gAGROVOC
_2
_91203
700 1 _aArias, M.P.,
_ecoaut.
700 1 _aFranco, J.
_8CFRN01
_gFormerly Genetic Resources Program
_9494
700 1 _aPandey, S.,
_ecoaut.
_91500
700 1 _aPérez, J.C.,
_ecoaut.
700 1 _aSalazar, F.,
_ecoaut.
700 1 _aCrossa, J.
_gGenetic Resources Program
_8CCJL01
_959
773 0 _tMaydica
_n628353
_gv. 45, no. 4, p. 301-308
942 _cJA
_2ddc
_n0