Estimation of competition parameters in common bean plants / EstimatiÃÃo de parÃmetros de competiÃÃo entre plantas do feijoeiro
AUTOR(ES)
Vanessa Maria Pereira e Silva
DATA DE PUBLICAÇÃO
2007
RESUMO
The objective of this study was to compare the auto and allo-competition at the plant level; to estimate parameters related to the capacity of competing or competition tolerance; and to identify promising lines to develop multilines. The experiments were conducted in three growing seasons (sowing in July 2005, November 2005 and February 2006). Eight common bean lines from different origins with carioca type grains were used. Eight experiments were conducted in each season, which differed only in the line in competition. In each experiment, the plants were arranged in a system of nine hills; data were collected from the central plant (test) while the others of the same line exerted competition. In each row, the test hill was replicated eight times. The spacing between rows and between hills in the row was 30 cm. Three seeds per hill were sown and thinned to just one plant. The competing plants were harvested individually. The number of pods, number of grains and grain weight (g/plant) of each plant was evaluated. The following competition-related parameters were estimated with the mean data, using a model similar to the diallel: general competition ability (ci), competition tolerance (tj), specific competition ability (sij) and the per se performance of the line (aj). The mean performance of the lines in autocompetition was similar to the allo-competition, whereas the response to allo-competition differed in the lines. In the case of PÃrola it was positive and negative for Majestoso and TalismÃ. The association of the parameter estimates related to per se performance (aj) with the competing ability (ci) was positive while the association with the competition tolerance capacity was negative and high. None of the lines associated low competing ability (ci high) with high competition tolerance capacity (tj high). The highest estimate of aj and ci was observed in line Majestoso and it can therefore be recommended for the development of isogenic lines in a multiline synthesis program.
ASSUNTO(S)
competition melhoramento vegetal competiÃÃo common bean feijÃo multilines multilinhas
