Germination of different seed size of pinto bean cultivars as affected by salinity and drought stress

The rapid and uniform establishment of pinto bean (Phaseolus vulgaris) seedling in stress condition is conductive to higher yields. The objective of this study was evaluation of germination and seedling growth components in response to drought and salinity stress. Two experiments were conducted using various osmotic pressures (OP) induced by PEG (0, -0.2, -0.4, -0.6 and -0.8 MPa) in drought experiment and by NaCl (the same OPs) in salinity experiment. In each experiment two cultivars and three seed sizes were used. Results showed time to 10% germination and root length in salinity experiment, and root length in drought experiment were affected by seed size. Seedlings from large seeds had greater root and shoot length than those from small seeds. Germination percentage, time to 10% germination and root and shoot length were affected by salinity and drought levels (exception T-10). Decreasing osmotic potential (OPs) progressively decreased both root and shoot length.