Resumo

DE SOUSA-VIEIRA, Orlando  e  MILLIGAN, Scott B. Interrelationships of cane yield components and their utility in sugarcane family selection: Path coefficient analysis. INCI [online]. 2005, vol.30, n.2, pp.93-96. ISSN 0378-1844.

Progeny testing is used to identify sugarcane families with superior, stable performance at the first selection stage of the Louisiana Sugarcane Variety Development Program, USA (LSVDP). Research to optimize the current progeny-testing methodology examined the relative importance of family and intra-row plant spacing in terms of effectiveness of the testing procedure. Knowledge of the interrelationship among the various traits considered important in selection plays an important role in the success of the LSVDP. Path coefficient analysis was used to measure the direct and indirect influence of plant weight components on the estimation of plant weight by partitioning phenotypic and genotypic correlation coefficients into components of direct and indirect effects. Phenotypic and genotypic direct effects were all positive, indicating that selection for any of the plant weight components should translate into an increase in plant weight. Number of stalks per plant, stalk diameter, and stalk length accounted for almost all of the variation in plant weight as indicated by the coefficient of determination. Irrespective of plant spacing, path coefficients revealed that, relative to the correlation coefficients values, stalk diameter and number of stalks per plant had the largest direct positive effect on plant weight at both phenotypic and genotypic levels.

Palavras-chave : Genotypic Correlation; Phenotypic Correlation; Saccharum spp; Sugarcane Breeding.