Direct and indirect effects of seed related characters on number of seed in guava (Psidium guajava']java L.) fruits

Dessert quality of guava fruit is considerably reduced by high seed content. Number of seeds in guava is associated with different seed and fruit characters. Influence of different seed characters on number of seeds per fruit (NSPF) was studied by analysing character association and direct and indirect effects on NSPF and seed related traits for 68 genotypes of guava collected from diverse sources and conserved at National Active Germplasm Site, CISH, Lucknow. Seed related characters were studied at the colour break stage of the fruits using image analysis software for counting number of seeds. The data was subjected to path analysis to find out direct and indirect effects of different characters on number of seeds in the fruits. At genotypic and phenotypic levels, NSPF was significantly and positively associated with seed weight per fruit (SWPF), number of seeds 100 g(-1) pulp (NSPHP) and fruit weight (FW). The genotypic (0.0029) and phenotypic (0.0563) residual values were fairly very low, which revealed that variables included in this study had significant contribution in determining NSPR The NSPHP exhibited high positive direct effect on NSPF. The maximum direct response (P = 0.737, G = 1.004) of this component was attributed to the indirect positive effects of the SWPF and fruit: seed weight proportion (FSWP). SWPF also had a very high positive direct effect (P = 0.521, G = 0.694) on the NSPR Correlation and path coefficient analysis revealed that SWPF, NSPHP and 100-seed weight (100SW) were deciding factors for realizing improvement for NSPF. The importance of small seeded genotypes in selection of less seeded varieties was emphasized. (c) 2007 Elsevier B.V. All rights reserved.