Phytohormone dynamics during embryogeny and embryo desiccation in the recalcitrant seeds of Vateria indica L.

Abstract

Vateria indica L. is an endemic arborescent recalcitrant tree species, native to the South-Western-Ghats of India. The natural regeneration process of the species is hindered by many factors including seed recalcitrance. Recently the species has been categorised as vulnerable since the population is fragmented and rapidly declining. Seed development is a highly complicated process which involves the interaction between phytohormones which regulate the process at different stages of morphogenesis. The orthodox seed development is marked by three distinct stages such as histodifferentiation, reserve accumulation and drying but in recalcitrant seeds, drying phase is absent. Recalcitrant seeds show marked differences from orthodox seeds in development. The onset of different stages is marked by a definite peaking and lowering of phytohormones and the hormonal pattern varies in orthodox and recalcitrant seeds. The present study was conducted to understand the interplay of phytohormones during embryogeny and the following natural embryo desiccation in the recalcitrant seeds of Vateria indica L. The present study revealed that the embryogeny and embryo drying in the recalcitrant seeds of Vateria indica L. shows a striking dissimilarity with the characteristic pattern of hormonal flux in orthodox seeds.