ABSTRACT:
Seed development is a complex phenomenon and is accomplished in stepwise manner. The gradual progression during development involves congregated physiological and metabolic alteration by cell division/ histo-differentiaticn, reserves deposition, maturation and maturation drying. In the current investigation, morphological, physiological and biochemical changes were assessed into eight consecutive stages; 10, 18, 26, 34, 42, 50, 58 and 66 days after fertilization (DAF), during development of AMadhuca latifolia seeds. Seed colour was finally found to turn dark-brown from initial creamish-white. Length, circumference, fresh and dry mass were observed to increase gradually throughout the analysis. In contrast, water content and electrical conductance were declined remarkably (r = -0.99, P< 0.05), suggesting deposition of storage reserves and improvement in the integrity of cellular membranes in parallel to developmental stages. Additionally, content of sugar was declined drastically (r -0.97, P<0.05), while starch and protein accumulations were increased by 4 and 13 folds respectively (r = 0.98, P< 0.05), indicating their supportive role in the germination and early seedling establishment. Activities of antioxidant enzymes exhibited rising trend between initial and final stages of development advocating their defensive function across the seeds developmental stages, and reached to their highest (SOD: 2.36 units /min Ig fresh mass, POX: 3.76 uM /min /g fresh mass, APX: 0.19 mM /min /g fresh mass) on 66 DAF, which were 161, 20.88 and 95 folds higher than their initial values. Accumulated data exhibited a strong correlation (r = 0.98, P < 0.05) between antioxidants level and seeds developmental stages. Data also suggested that the ideal time for harvesting of Madhuca latifolia seeds/ drupes was recommended to be 66 DAF.