Histochemical and physiological studies of seed (nut) and pseudocarp (apple) of Anacardium occidentale L

Abstract

The growth rate, structure, development, time-course of deposition and distribution of major storage components, minerals and path of transport of assimilate in seed (nut) and pseudocarp (apple) of Anacardium occidentale L. were investigated. Both nut and apple growth starts at the same time, however, nut grows faster than the apple and reaches the maximum length and breadth by about 40 days after fertilization (DAF). The pseudocarp growth is slower at the beginning and after about 30 DAF the rate of growth increases and the apple reaches maximum length and breadth by about 55 DAF and full maturity by about 60 DAF. Histochemical studies revealed the pattern of distribution of lipids, protein, starch, iron, ascorbic add and phenols in cotyledons. The study indicated that the pattern of distribution of these compounds is same in all the varieties examined. Phloem specific fluorochrome 5(6) carboxyfluorescein (CF) used to study the path of movement of assimilates in pseudocarp, placenta and cotyledons showed that CF movement was much faster in pseudocarp than in cotyledons. The study further revealed that vascular bundles of pseudocarp and placenta are important transport tissues and nutrients supply from pseudocarp to developing cotyledons occurred only through placenta.