Development of primary leaves of Phaseolus vulgaris L. from seeds subjected to acute gamma irradiation

Abstract The growth of primary leaves of two varieties of the common bean ( Phaseolus vulgaris L.) after seed exposure to acute doses of gamma radiation was assessed for growth inhibition. The area, fresh weight and dry weight at 3 weeks of age were severely decreased at exposure of 10 and 15 krad. The number of estimated spot-chloreses increased with increased exposure. However, there were no indications of any other kind of morphological abnormalities. The results are consistent with the postulate that the resultant small spots in higher numbers are due to an advanced state of development and comparatively large number of cells of embryonic leaves at the time of irradiation. Furthermore, it appears that radiation treatments resulted in a considerable reduction in size of the midrib and an inconsistent decrease in leaf thickness. In general the effects were manifested at 2 weeks of age.