Data/hora: 13/06/2024 05:12:04

Provedor de dados: 	63	
País: 	Brazil	
Título: 	Phenotypic recurrent selection to improve protein quality in non-opaque maize populations	
Autores: 	Garcia,Antonio Augusto Franco; Souza Jr.,Cláudio Lopes de.	
Data: 	2002-12-01	
Ano: 	2002	
Palavras-chave: 	Tryptophan; Correlated response; Maize breeding.	
Resumo: 	Maize (Zea mays L.) protein is considered to be of low quality due to low levels of the essential lysine and tryptophan amino acids. An alternative to solve this problem is to use the opaque-2 gene, which improves the level of these amino acids, but has negative pleiotropic effects on agronomic characters. A phenotypic recurrent selection scheme was carried out in two non-opaque maize populations to verify the possibility of improving their protein quality without using this gene. Four cycles were completed and a 20% selection intensity for tryptophan content in the kernels was used in two populations, IG-1 and IG-2. The original and the four-cycle populations were evaluated in three locations for agronomic traits. For protein and tryptophan content, a separated trial was carried out because plants of the plots were hand-pollinated. No increase in tryptophan content was observed in the IG-2 population, whereas IG-1 presented a small increase (0.70% per cycle). The ratio tryptophan/protein increased 1.26% per cycle in IG-1 and the protein content did not increase in both populations. The ESALQ-VD2-opaque check was superior in relation to both populations for protein quality, as expected, even after completion of four selection cycles. The kernel yield (2.5% per cycle) prolificacy, plant and ear heights, decreased with selection cycles, as a correlated response to selection. Phenotypic recurrent selection in non-opaque maize was not able to increase, at reasonable rates, the protein quality of maize kernels.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162002000400018	
Editor: 	São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"	
Relação: 	10.1590/S0103-90162002000400018	
Formato: 	text/html	
Fonte: 	Scientia Agricola  v.59 n.4 2002	
Fonte: 	info:eu-repo/semantics/openAccess