Spongy tissue in 'Alphonso' mango. III. Radiotracer evidence for increased mobilization of water from mesocarp to seed.
Ravindra V., Shivashankar S., Reddy T. M., Kotur S. C.
Author Affiliation: Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore 560 089, India.
Current Science 99 : 571-574
Abstract : Results are presented of experiments conducted in Bangalore, Karnataka, India, during 2007-08 on developing mango cv. 'Alphonso' fruits to investigate (i) whether the mobilization of water from mesocarp to seed was occurring randomly or from a pre-destined region, and (ii) how the exogenously applied plant growth regulators gibberellic acid (GA3) and paclobutrazol (PBZ) were able to regulate amylase activity in the seed without affecting the same in the mesocarp, in spite of diffusing through the same. Three sets each of 100 developing fruits were dip-treated at ~60% maturity with GA3 at 1 g/l, PBZ at 1 g/l and water for 30 sec followed by tritiated water containing 5 µCi/ml 1H3 and APSA 80 at 0.2 ml/l, a non-ionic adjuvant, after 10 days. Moisture content, respiration rate, electrical conductivity, amylase activity, radioactivity of mesocarp and seed tissues as well as spongy tissue (ST) incidence were determined. The results have not only helped in resolving the enigma of ST in 'Alphonso' but have also provided insights to the understanding and management of similar disorders of many other tropical fruits endowed with recalcitrant seeds. The key to manage such internal fruit disorders clearly lies in down-regulation of the metabolism of recalcitrant seed, a common feature of tropical fruit crops.