Breaking seed coat impermeability to aid conservation and utilization of wild Vigna species

Abstract

The extent of hardseededness due to seed coat impermeability and pre-treatments to overcome it have been worked out in 34 accessions comprising 14 species of V. luteola (Jacq.) Benth. Mart., V. vexillata (L.) A. Rich., V. wightii (Bedd.) Babu and S.K.Sharma, V. pilosa (Klein ex.Willd.) Baker, V. parkeri Baker, V. reticulata Hook. f., V. dalzelliana (Kuntze) Verdc., V. hainiana Babu, Gopinath and S.K.Sharma, V. trinervia var. bourneae Gamble, V.radiata var. sublobata (Roxburgh) Verdc.(6), V. radiata var. setulosa (Dalzell) Ohwi and Ohashi, V. membranacea A.Rich., V. stipulacea (lam.) Kuntze, V. racemosa (G Don) Hutch. & Dalziel. The percentage of hard seeds ranged from 45 to 95 within accessions and species tested. All the pre-treatments, which are mechanical scarification, hot water soaking at 50 °C for 15, 25 and 30 min and at 80 °C for 15 and 30 min, reduced hard seed percentage and increased final germination significantly (p < 0.01) as compared to the controls. There were significant differences between the species, treatments and species over treatments. In general, mechanical scarification was the best pre-treatment in most of (eleven out of fourteen) species studied with germination ranging from 73 to 100% among the species. This was followed by hot water at 50 °C for 30 min (40–100%) and hot water at 50 °C for 25 min (43–99%).