Abstract

PADILLA RAMIREZ, José Saúl et al. Variance between and within the index of repeatability of quantitative characteristics of guava fruit. Rev. Mex. Cienc. Agríc [online]. 2014, vol.5, n.8, pp.1423-1432. ISSN 2007-0934.

We estimated the variance between and within, an index of repeatability (IR) and the phenotypic correlations of ten quantitative characteristics of fruit (weight, polar and equatorial diameter, PD/ED ratio, hull thickness, number and weight of seeds, weight per seed, cavity diameter of calyx and total soluble solids) in 14 genotypes of the guava of the INIFAP seed bank, established in the Experimental Site "Los Cañones" in Huanusco, Zacatecas. Fruit characteristics were recorded in five fruits of each genotype in production cycles 2010 and 2012. The variance between genotypes showed the highest values in both years, which was reflected in the index of repeatability, which fluctuated between 0.85y 0.98. This indicates the large variability of genotypes, attributed to the different origins and the environmental effect (temperature and precipitation) in each cycle. The correlation coefficient (r) between the fruit weight and the polar and equatorial diameters, hull thickness and cavity diameter of calyx had values from 0.74 to 0.96 (p≤ 0.01), while the TSS had the lowest values of correlation with the other variables. The results show the availability of germplasm that can be used in breeding programs considering the wide variability of the traits evaluated, as well as using the fruit weight as a selection criterion for fruits of larger diameter and hull thickness.

Keywords : Psidium guajava; collections; descriptors; germplasm.