Data/hora: 31/05/2024 13:45:19

Biblioteca(s): | Embrapa Unidades Centrais.
Data corrente: | 20/07/2000
Data da última atualização: | 08/05/2020
Autoria: | VON BULOW, J. F. W.; HARLAN, J. R.; FLETSCHER, G.; WET, J. M. M. de.
Afiliação: | Joachim F. W. Von Bulow, In memorian; Jack R. Harlan, University of Illinois; Gilbert Fletscher, University of Illinois; Johannes M. J. de Wet, University of Illinois.
Título: | Morphology and combining ability studies of maize populations recorvered from the intergeneric Cross zea X Tripsacum.
Ano de publicação: | 1994
Fonte/Imprenta: | Pesquisa Agropecuária Brasileira, Brasília, DF, v. 29, n. 7, p. 989-1006. jul. 1994.
Idioma: | Inglês
Notas: | Título em português: Morfologia da capacidade de combinação de população de milho recuperadas do cruzamento intergenérico milho X Tripsacum.
Conteúdo: | The extent, diversity and breeding potentials of gene transfers between maize and gama grass were investigated. The original cross Zea mays x Tripsacum dactyloides (2n=72) was followed by seven backcrosses to several maize pollen sources resulting in a recovered maize bulk (2n=20). Four populations ranging from highly tripsacoid to maizoid were devrived through selection. They were studies for grain vield plus 17 plant and ear charcters, either per se or in F, or backcross (BC) combinations with inbreds 0h43, Mo17, and B73. Variance, correlation, stepwise multiple regression, and diallel analyses were used to differentiate populations. Polyacrylamide electroiphoresis performed on BC population A, B (tripsacoid), and C (maizoid) suggests genetic transfer from Tripsacum. Morphological studies show that the populations selected not aonly differ but also that they could be maintained during five generations for the intended kind and degree of tripsacoidy. Is was possible to derive a still more tripsacoid population D from population A. Phenotypic variability is greatest among traits indicative for tripsacoidy: length of lateral branches, number of ears, and kemel thickness decrease towards more maizoid introgression, whereas ear length, kernel number/ear, pith diameter, kernel and ear volumes increase in this direction. Correlation matrices show kernel thickness negatively correlated with eith ear and kernel traits for maizoid population C, while corresponding correlations for tripsacoid populations A, B and D are mostly non-significant or positive. Differences between populations C and D are strikingly obvious when comparing multiple regression response models for dependent trit kernel number/ear. Diallel analyses show significant differences due to general combining ability for prolificacy and ear length in BC's of populations A and B, and C respectively, with B73, Traits for significant specific combining ability are grain yield, prolificacy and ear length. The upper 17 diallel crosses averaged 5,225 kg/ha as compared to hybrid check's average vield of 5,417 kg/ha. Evidence points to B73 as the best inbred form maintenance of tripsacoide gene transfers during the described back-cross program. The successful controlled introgression procedure may encourage breeders trying to enrich the primary maize gene pool with different traits for plant architecture, floral and reproduction biology, and disease, pest, and drought resistance from Tripsacum.
Palavras-Chave: | dactyloides; Genetic transfer; Maizoid; Tetraploid T; Tripsacoid.
Categoria do assunto: | --
URL: | http://ainfo.cnptia.embrapa.br/digital/bitstream/item/108563/1/morphology.pdf
Registro original: | Embrapa Unidades Centrais (AI-SEDE)
Exemplares: | AI-SEDE - (20258-1) - UPE - AP - PP - 630.72081 - P474 -  - DIS