Abstract
Microsperma lentil is an important grain legume of Pakistan. This detailed study tells the seed variability in size and color from callus regenerated plants of lentil cv. Masoor-85. Cotyledonary nodes with cotyledons from germinating seedlings were promising explants especially with scrapping of axillary portions of basal nodes that considerably enhanced callus and regenerations in MS medium. These developed callus and shoot primordia in the presence of BA (5 mg l -1 ) and 3% fructose. Cotyledonary nodes from germinating seeds produced healthy calli in dark conditions in K (10 mg l -1 ) + GA (1 mg l -1 ). The maximum callus mass gave maximum regenerations in light in the same medium. The number of elongated shoots were very low as compared to the green dots that appear on the callus surface. Bud dormancy was a problem. Auxins had stimulatory effects on rooting. However, auxins were removed for root elongation. Four days exposure of auxins IBA 0.008% + NAA 0.002% in simple talc dusted to shoot bases seemed optimum for rooting. Rooting speeded up by high humidity. There was no or poor rooting in continuous dark. General health of shoots also influenced rooting. Removal of leaves had adverse effects and active shoot growth promoted rooting. Basal stem in regenerated shoot had maximum rooting potential. Polarity requirement were necessary. The survival rate of callus regenerated plants (R0) in the field was 12.1%. Variability was observed in R0, R1, R2, R3 and R4 as compared to control Masoor-85 in vegetative and yield characteristics. A plant was selected in R2 for large seed size with lighter seed color as compared to control and the stability of seed characters was observed till R4. It was the most important seed clone of callus regeneration. This study clearly indicated the importance of somaclonal variation for improvement of lentil cultivar.
