Abstract
Twenty three teasle gourd (Momordica dioica Roxb.) accessions were collected from different agro- ecological zones of Bangladesh for this study. Field experiments were conducted at the field of Crop Botany Department, Bangladesh Agricultural University, Mymensingh during the period from 2008 to 2010 to study 33 morphological characters with the objective to find out the best accession. Significant variations were found among the accessions in respect of leaf, flower, fruit and seed characters were recorded. Nine plants were found female whereas 14 plants were male out of 23 accessions. Maximum yield (2.4 kg plant') and fruit weight (68.4 g fruit') were obtained in accession TG0022. In case of all female plants this accession (TG0022) obtains the highest leaf area, petiole length, internode length and peduncle length. The 8th node from the base of the male plant (TG007) produced first flower which was earlier than the rest of the accessions. In case of all male plant accession TG007 possessed larger flower, higher leaf area, larger petiole length, longer internode length and also long peduncle. To develop in vitro regeneration protocol, internode, node, leaf, petiole, shoot tip, cotyledon, epicotyle, endosperm and anther explants were used from accession # TG0022. Several hormones (BA, NAA and IBA) were used for callus, shoot and root formation. Cotyledon was found to be the best explants. BA at 1.0 mgl' was found to be the best for callus initiation and shoot regeneration. IBA at 0.3 mgl' was the best for root initiation in 1⁄2 MS medium supplemented with 3% sucrose. Rooted plantlets of about 4-6 cm height (2-3 nodes) were subsequently transferred to different media for acclimatization. Plants grown in mixture of soil and cowdung at the proportion of 3:1 and showed 100% of survival rate during rainy season. Mature calli were soaked in colchicine solution of 0.05% concentration for short duration (1, 2, 4 & 8 hours). Simultaneously, 4 different concentrations of colchicine (10, 20, 30 & 40 mgl1) at longer durations (3, 6 & 9 days) were used. Four hours treatment of colchicine at 0.05% concentration resulted in vigorous vegetative growth but had no effect on fruit size and number of seeds. Fruit setting was delayed (80 days) in colchicines treated plants compared to control (60 days) and regenerated (66.2 days) plants. Number of fruits plant from control, regenerated and colchicine treated regenerated plants were 8.2, 7.4, 7.0 respectively. Colchicine treated regenerated plants produced medium sized (6.6 cm long) fruit which was larger than control (6.1 cm) but smaller than regenerated one (9.1 cm). The seed number of fruit from colchicine treated plant was found to be drastically reduced to 14.6 compared to 32.2 in control and 26.6 in regenerated plant respectively. The protein content of fruits flesh varied in control, regenerated and colchicines treated regenerated plant. Edible flesh of 17 days old regenerated plant fruit had the highest (7.08%) protein content whereas the colchicines treated regenerated plant fruit flesh had 4.62% protein followed by control fruit flesh (5.54%).