Variation among guava (Psidium guajava L.) accessions in seed hardness and its association with fruit characteristics

Abstract

Guava is an important tropical fruit crop with considerable economic potential but to further increase popularity and demand, the soft seeded cultivars needs to be developed. Breeding for soft seeded cultivars is one of the major objectives of guava breeding programmes but limited research on seed hardness and its association with other fruit characters has been conducted. A study was carried out to determine the genotypic and phenotypic variation in and association among the fruit traits of weight, height, diameter, firmness and the seed characters of weight and number of seeds per fruit, fruit seed weight ratio, 100-seed weight and seed hardness. Trait values were estimated in 50 accessions grown under subtropical conditions. High genotypic (GCV) and phenotypic (PCV) coefficients of variation were found in all the traits studied. Estimates of heritability ranged from 0.499 (fruit firmness) to 0.988 (fruit seed weight ratio). All the traits except 100- seed weight, showed almost similar magnitude of genetic advance, and exceptionally high genetic advance for fruit weight, number of seeds per fruit and fruit: seed weight ratio. At genotypic and phenotypic levels, seed hardness was significantly and positively correlated with 100-seed weight of the fruit and inversely with number of seeds fruit-1. In path analysis, residual values at genotypic (0.076) and phenotypic (0.268) levels were fairly low and indicate that variables included in this study had significant association with seed hardness. Correlation and path coefficient analysis revealed that 100-seed weight was the most important character for realizing improvement in seed hardness.