Effects of different treatments on seed germination and breaking seed dormancy in wild Luffa species

The wild species of Luffa require prolonged duration to germinate under normal environmental conditions due to prevalence of seed dormancy owing to variation in their seed size, degree of seed hardiness and variable lignin content in seed coat. Therefore, present study was conducted to identify best pre-sowing treatment for seed germination, seedling growth in two wild Luffa species namely Luffa graveolens Roxb and L. echinata Roxb. Seeds of four accessions of both the species (three of L. graveolens and one of L. echinata) were exposed to scarification, chemical treatment with gibberellic acid (GA₃) and potassium nitrate (KNO₃) at different concentrations. Among various applied treatments, scarification + GA₃ @ 200 ppm was found most effective in L. graveolens and scarification + KNO₃@ 0.2% for L. echinata for breaking of seed dormancy in freshly harvested seed. The seedling vigor in terms of shoot length, root length, seedling dry weight were recorded maximum in scarification + GA₃ @ 200 ppm for L. graveolens and scarification + KNO₃@ 0.2% for L. echinata for both fresh as well as one year old seed of same lot. It reflects the presence of hard seed coat and physiological dormancy in wild Luffa species, which can be broken to a greater extent with an additional pre-sowing treatment, to enhance seed germination and vigor for uniform plant stand.