Grain yield of single cross maize hybrids, derived from S0 populations, and relationship with genetic distance based on microsatellite markers / Produtividade de hÃbridos de milho, derivados de populaÃÃes S0, e associaÃÃo com distÃncia genÃtica baseada em microssatÃlites.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

This work was carried out with the objective of evaluate the viability of producing inter and intrapopulation hybrids of maize from S0 populations of single cross hybrid, and to correlate the genetic distances obtained from microsatellites markers among the parents and the grain yield and heterosis of the hybrids. Three S0 populations from the single cross hybrids (P30F45, Dow657 and DKB333B) were used. One hundred and sixty three hybrids, being 110 inter and 53 intrapopulation crosses were obtained. All 163 inter and intrapopulation hybrids, were evaluated using commercial hybrids and their S0 as checks in Lavras and Lambari with a single 13 x 13 lattice design. Plant and ear height, number of ears, unhusked ears yield and grain yield were measured. The two best and the two poorest hybrids from the inter and intrapopulation crosses were selected. Their parents were maintained by selfing of the second ear of each S0 plant, and were genotyped with 47 microssatellite markers (SSR). Then, 48 S1 inbred lines were identified and selected for the analysis. Genetic distances were calculated from SSR data for all possible pair of S1 inbred lines using modified Rogers distance (MRD). Spearman rank correlation coefficients were estimated between the genetic distance with grain yield and heterosis for all hybrids. Interpopulation hybrids more productive than the commercial hybrid and their S0 checks were identified in both places. There were not identified intrapopulation hybrids more productive than the checks due probably to the few number of hybrids, only 53 against 110 interpopulation hybrids. Intrapopulation hybrids with average grain yield of 10 t ha-1 were identified, and could be considered of high productivity. The average genetic distance among all S1 inbred lines was 0.75, varying between 0.40 and 0.89, indicating the existence of great genetic variability among the inbred lines. The correlation between MRD and grain yield were high and significant for the interpopulation crosses (r = 0,84 P  0,01) and low and not significant (r = 0,18, P  0,05) in the intrapopulation crosses.

ASSUNTO(S)

ssr maize heterose genetic divergence milho plant breeding melhoramento vegetal maize divergÃncia genÃtica divergÃncia genÃtica heterosis milho zea mays l ssr genetic divergence melhoramento vegetal heterose heterosis plant breeding ssr agronomia zea mays l ssr

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