Estimates of repeatability and path coefficients on grapes.

• Autor(a) principal: LEAO, P. C. de S.
• Data de Publicação: 2003
• Outros Autores: COSTA, J. G. da
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/133683
• topic: Uva de mesa; Melhoramento de planta; Correlação genética; Repetibilidade; Uva; Vitis Vinifera; Grapes

The objective of this study was to estimate the repeatability coefficient, the minimum number of evaluations top which a trait should be subjected and the effect of the inter-relationships of five charactersn grapevine (Vitis spp.) yield, aiming at getting useful information for breeding strategies of this fruit crop. Repeatability coefficients were estimated for the follwing characters: total soluble solids (TSS); total tritable acidity (TTA); TSS/TTA ratio; berry length, diameter and weight; bunch length, width and weight, and number and yield of bunches per plant on eleven seedless grape varieties in five yield cycles (1997 and 1998) in Petrolina-PE. The repeatibility estimates were obtained by the main components methods from the correlation matrix. The simple correlation coefficients were calculated and they were partitioned into direct and indirect effects by the path analysis. The estimated repeatibility coefficients ranged from 0,4750 to 0,8372 associated to the coefficients of determination from 81.9% to 96.26%. The traits TSS, TTA and bunch length presented low repeatibility coefficients, meaning a low regularity of performance from one measurement to another. The other characters showed regularity on the repetition of the behavior of the genotypes. The results of the path analysis showed that the studied variables satisfactorily explain the character yield per plant.