Selection of Pulp Color and Thickness in Calabaza

Abstract

Abstract Genetic differences in internal color need to be detectable to select improved calabaza [Cucurbita moschata (Duchesne) Poir.] for regions where a dark orange pulp is preferred. For 2 years, data were collected from the cultivar ‘Borinquen’ to relate the effect of age of fruit on internal color. Several possible maturity indicators were also followed. Pulp color was quantified by a color chart assigned numerical values. Orange color increased with fruit age during both years, with a commercially desirable color having developed by 50 days after anthesis in ‘Borinquen’. Maturity indicators, such as dried tendrils or change in rind color, were too variable to be used reliably to choose fruit for detecting pulp color differences among lines. We found tagging of sample fruit at anthesis and harvesting 50 days later to be the most consistent method for selecting lines for orange pulp and/or fast maturation. Using this approach, highly significant differences were found among S1 (self-pollinated) lines for pulp color and thickness and among S2 lines for pulp color. S2 lines were equal or better in pulp color than ‘Borinquen’, even though they were derived from populations variable for pulp traits. Pulp color and thickness were also correlated in these lines. We concluded that both traits seem selectable with our method in early generations of self pollination.