Seed Germination and Heat Unit Accumulation in Association with Jelly Seed Disorder in Mango (mangifera Indica L.)

Introduction -Initiation of seed germination and heat unit accumulation in mango fruit have been at-tributed as major causes for jelly seed formation, which is increasingly becoming an important con-straint in quality fruit production of several mango varieties. We studied association of seed germina-tion and heat unit accumulation on occurrence of jelly seed in parthenocarpic and non-parthenocarpic fruits. Materials and methods -Jelly seed occurrence, growing degree days (GDD), scanning electron mi-croscopy (SEM), total soluble solid (TSS), calcium content and phenolic compounds in jelly pulp (JP) and non-jelly pulp (NJP) of parthenocarpic and non-parthenocarpic fruits was undertaken. Results and discussion -Our findings show that premature/ma-ture seed germination is not a requirement or cause of jelly seed disorder, as the symptoms occur in par-thenocarpic fruits that lack embryo. TSS and phenol were significantly lower in JP than in NJP in the same fruit. Furthermore, mesocarp (pulp) without jelly symptoms has higher calcium content than the fruit pulp with jelly symptoms within the same fruit. The formation of jelly seed in parthenocarpic fruits de-spite being exposed to a lower number of heat units suggests that excessive heat units are not the cause of jelly seed formation. Conclusion -Jelly seed disorder may not be caused by initiation of seed germination process, Caz+ imbalance and heat unit accumulation. Given that the disease has been reported in a variety of mango varieties and its incidence is higher in tree-ripe fruits than in non-tree-ripe fruits; there seem to be genetic and environmental factors and their interaction that governs the induction and level of incidence of this phenomenon. The current research provides background information for rejecting some recent hypotheses based on experimental data. A bet -ter understanding of the problem will aid in the de-velopment of a package of practices for reducing its adverse effects.