Seed storage behavior of Knema attenuata, an endemic species of Western Ghats, India

We performed desiccation and storage trials to better understand storage behavior of Knema attenuata seeds. Mature seeds with moisture content （MC） of 31% exhibited 73% germination. During the period of desiccation （open lab condition） seeds with MC 23% showed 40% germination. After further drying to MC 21% germination was reduced to 16%. Complete loss in viability resulted when seed moisture was reduced to 18%. The seeds stored at -10℃, 0℃, 10℃ and 28±2℃ （open lab condition） lost their viability within 10 days. Seeds stored in sealed polythene hags and moist sand retained viability for more days than did seeds stored under all other storage conditions. Sensitivity of seeds to lower temperature and desiccation suggest that the storage behavior of K. attenuata seeds is recalcitrant. Seeds stored in moist conditions can, at best, be stored for a period of two months.

Effect of desiccation on viability and biochemical changes in Knema attenuata seeds

We studied effect of desiccation on Knema attenuata seeds in the laboratory conditions （28 ± 2℃） for 8 days. We also monitored biochemical changes during germination by following standard procedures. Seeds lost their viability in 8 days by decreasing to 18% of moisture content from its original value of 31%. The total sugar, protein and lipid contents decreased during seed ageing. An increase was noticed in the protease activity during desiccation. The phenolic content in seed exudates was increased during ageing. The result confirms the degradation of stored biomolecules in seeds during ageing. Desiccation sensitiv- ity and biochemical changes during dehydration confirm its recalcitrant nature.

Chemical compositions,cytotoxicity and antioxidant activity of the endophytic fungus Fusarium napiforme isolated from Psidium guajava

The bioactive secondary metabolites from the endophytic fungus Fusarium napiforme was evaluated for the cytotoxic effect and antioxidant activity.The total antioxidant capacity(TAC)of the extract was determined by 2,2-diphenyl-1-picrylhydrazyl(DPPH),phosphomolybdate,and reducing power assay methods.The cytotoxicity of the extract was evaluated against lung adenocarcinoma(A549)cells and mouse embryo fibroblast(NIH3T3)cells by methyl thiazolyl tetrazolium(MTT)method.The major composition of the crude extract was identified by the Gas Chromatography-Mass Spectrometry(GC-MS)analysis.Estimation of the endophyte crude extract revealed a high amount of the total flavonoid content(TFC)and total phenolic content(TPC).The extract showed high cytotoxic activity against the A549 cell line with the mean cytotoxicity of 69.74±0.49%.The extract did not show any cytotoxic effect against the NIH3T3 cell line.The extract exhibited high antioxidant activity as a function of the concentrations.At a test concentration of 1 mg ml-1,the extract showed the highest inhibition against DPPH radical at 75.4607%±0.47688,ferric ion reducing power at 0.882±0.0120,and 255.434±21.404 AAE/g of the extract by phosphomolybdenum assay(PMA).There is a significant correlation between TPC and antioxidant activity at p<0.05.The correlation between reducing power and DPPH is significant at p<0.01.The major types of bioactive compounds identified by the GC-MS have shown the presence of nine major compounds.This result strongly exhibits that the endophyte F.napiforme can be a potential source for the formulation of natural anticancer drugs and protecting the body from oxidative damages.