Prospecção de híbridos experimentais de quiabeiro por análises genéticas biométricas
Carregando...
Data
2019-10-22
Autores
Silva, Edgard Henrique Costa
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O quiabeiro é uma cultura de destacada importância socioeconômica em regiões tropicais e subtropicais. Seus usos e aplicações são variados, pois apresenta características nutracêuticas interessantes, bem como potencial para exploração industrial. A produtividade de quiabeiro não tem acompanhado a evolução que se verifica para outras culturas olerícolas. Provavelmente, pelo fato da cultura do quiabeiro ser sistematicamente negligenciada do ponto de vista da pesquisa e inovação, não havendo desenvolvimento de genótipos superiores e de técnicas de manejo mais eficientes. A exploração da heterose seria a forma mais rápida para se aumentar a produtividade, pois verifica-se, no cenário brasileiro, predominância de cultivares de polinização aberta. Assim, com o objetivo final de obter híbridos produtivos de quiabeiro, este trabalho foi dividido em: (1) caracterização morfoagronômica e divergência genética de parte do Banco Ativo de Germoplasma da Embrapa Hortaliças; (2) análise dialélica parcial de híbridos experimentais e comparativo de desempenho agronômico com cultivares comerciais. Na primeira etapa, 47 genótipos foram caracterizados quanto a descritores nacionais e internacionais e a divergência genética foi explorada por meio da estratégia Ward-MLM (Modified Location Model). Formou-se sete grupos com número variável de genótipos. Esta informação foi utilizada na escolha dos genitores para a próxima etapa. As características comprimento e largura de folhas, tamanho do pecíolo, diâmetro da haste na base da planta e altura da primeira flor foram as que mais contribuíram para a variação genética. Na segunda etapa, as linhagens selecionadas foram cruzadas em esquema de dialelo parcial, com sete genótipos em um grupo e dois genótipos em outro grupo, totalizando 14 híbridos. Obteve-se também os respectivos recíprocos de cada híbrido. Os híbridos experimentais foram avaliados no inverno e no verão de Jaboticabal – SP quanto à produtividade, número de frutos e precocidade. Nenhuma linhagem apresentou capacidade geral de combinação significativa. Oito combinações híbridas apresentaram capacidade específica de combinação significativa para a característica número de frutos. Destas combinações, observou-se estimativas positivas para quatro, sendo estes considerados híbridos promissores, que foram comparados por meio de contraste ortogonal com cultivares comerciais. No verão, não se observou diferenças significativas entre os híbridos experimentais e os híbridos comerciais. No inverno, os híbridos experimentais 1x8 e 3x8 apresentaram desempenho produtivo superior aos híbridos comerciais e são potenciais genótipos para o cultivo de entressafra.
- Okra is a crop of outstanding socioeconomic importance in tropical and subtropical regions. Several uses and applications are practiced, as okra has interesting nutraceutical characteristics as well as potential for industrial exploitation. Although its importance and potential, okra yield has not improved as observed for other vegetable crops. Probably because okra is systematically neglected from the point of view of research and innovation, with no development of superior genotypes and more efficient management techniques. The exploitation of heterosis would be the fastest way to increase yield, as open-pollinated cultivars predominate the Brazilian scenario. Thus, with the ultimate goal of obtaining productive okra hybrids, this work was divided into: (1) morphoagronomic characterization and genetic divergence of part of the Embrapa Hortaliças Okra Active Germplasm Bank; (2) partial diallel analysis of experimental hybrids, and comparative of agronomic performance with commercial cultivars. First, the accessions were characterized according to national and international descriptors and genetic divergence was explored through the Ward-MLM (Modified Location Model) strategy. Seven groups with variable number of genotypes were formed. This information was used in the choice of parents for the next step. The characteristics leaf length and leaf diameter, petiole length, stem diameter at plant base, and first flowering height contributed the most to the genetic variation. Then, in the second stage, the selected lines were crossed in partial diallel scheme, with seven genotypes in one group and two genotypes in another group, totaling 14 hybrids. The respective reciprocals of each hybrid were also obtained. The experimental hybrids were evaluated in winter and summer of Jaboticabal - SP for yield, fruit number and precocity. No line showed significant general combining ability. Eight hybrid combinations presented significant specific combining ability for the characteristic number of fruits. From these combinations, positive estimates were observed for four, which were considered promising hybrids, being subsequently compared by orthogonal contrast with commercial cultivars. In winter, the experimental 1x8 and 3x8 hybrids presented superior performance than the commercial hybrids. In summer, no significant differences were observed between experimental and commercial hybrids. Keywords: Abelmoschus esculentus L. (Moench), heterosis exploitation, yield, parental selection.
- Okra is a crop of outstanding socioeconomic importance in tropical and subtropical regions. Several uses and applications are practiced, as okra has interesting nutraceutical characteristics as well as potential for industrial exploitation. Although its importance and potential, okra yield has not improved as observed for other vegetable crops. Probably because okra is systematically neglected from the point of view of research and innovation, with no development of superior genotypes and more efficient management techniques. The exploitation of heterosis would be the fastest way to increase yield, as open-pollinated cultivars predominate the Brazilian scenario. Thus, with the ultimate goal of obtaining productive okra hybrids, this work was divided into: (1) morphoagronomic characterization and genetic divergence of part of the Embrapa Hortaliças Okra Active Germplasm Bank; (2) partial diallel analysis of experimental hybrids, and comparative of agronomic performance with commercial cultivars. First, the accessions were characterized according to national and international descriptors and genetic divergence was explored through the Ward-MLM (Modified Location Model) strategy. Seven groups with variable number of genotypes were formed. This information was used in the choice of parents for the next step. The characteristics leaf length and leaf diameter, petiole length, stem diameter at plant base, and first flowering height contributed the most to the genetic variation. Then, in the second stage, the selected lines were crossed in partial diallel scheme, with seven genotypes in one group and two genotypes in another group, totaling 14 hybrids. The respective reciprocals of each hybrid were also obtained. The experimental hybrids were evaluated in winter and summer of Jaboticabal - SP for yield, fruit number and precocity. No line showed significant general combining ability. Eight hybrid combinations presented significant specific combining ability for the characteristic number of fruits. From these combinations, positive estimates were observed for four, which were considered promising hybrids, being subsequently compared by orthogonal contrast with commercial cultivars. In winter, the experimental 1x8 and 3x8 hybrids presented superior performance than the commercial hybrids. In summer, no significant differences were observed between experimental and commercial hybrids. Keywords: Abelmoschus esculentus L. (Moench), heterosis exploitation, yield, parental selection.
Descrição
Palavras-chave
Abelmoschus esculentus L. (Moench), Exploração da heterose, Produtividade, Seleção de parentais