The Effect of Varying Doses of Gamma Radiation on the Morphology of Phaseolus vulgaris L. var. pole Sitao in the M1 Generation

Abstract

Viable seeds of kidney-shaped beans var. pole sitao (Phaseolus vulgaris L.) were obtained from the Bureau of Plant Industry in San Andres, Manila. 150 smooth, shiny, full-seeded seeds were chosen and these were later grouped into six (25 seeds per group, with each group assigned to a particular dose of gamma radiation. Using the gamma cell-irradiator facility of the Philippine Nuclear Research Institute in Diliman, Quezon City, the following doses of gamma radiation were used: 25 krad, 50 krad, 75 krad, 100 krad, and 125 krad. One group served as the control (0 krad). After irradiation, seeds were allowed to germinate in trays with wet tissue papers. After 12 days, root lengths (in cm) and seedling heights (in cm) were recorded. Root lengths and seedling heights decreased as the dose of gamma radiation was increased. Thereafter, the seedling were transplanted in a vacant lot beside the Cytogenetics Building in the PNRI. After 30 days, data on morphological parameters namely: average leaf area per plant (in sq. cm), mature shoot height (in cm), and number of leaves per petiole were recorded. As the dose of gamma radiation is increased, both the average leaf area per plant and the mature shoot height decreased. There was no effect however, on the number of leaves per petiole regardless of the dose used.