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Abstract: Cassia angustifolia, C. italica, C. occidentalis, C. obtusifolia andC. pumila were exposed to water stresses of different levels for 20 days, after which their growth performance and survival values were observed. As the water stress increases the plant growth reduces drastically.

Abstract: Germination and seedling growth were studied on sevenCassia species with relation to salt solutions of different osmotic potential (Ψs).C. angustifolia, C. italica andC. pumila are more resistant to low osmotic potential andC. tora, C. auriculata, C. occidentalis andC. obtusifolia are very sensitive.

Summary InA. longifolia andR. tuberosa, the radicle growth was inhibited and that of hypocotyl promoted in blue and red lights when compared with the white one. A distinct increase in hypocotyl growth took place in red and blue radiations as an interaction of gibberellin-A3. Thus, this increase in hypocotyl growth in white light was distinct inA. longifolia for all the gibberellin-A3 concentrations but only upto 10 ppm inR. tuberosa when compared with their controls. This was just reverse for those in total darkness. The beneficial effect of gibberellin-A3 interaction on radicle growth was visible at 5 ppm in white light and at 10 ppm in red light forR. tuberosa; and only at 5 ppm in red light forA. longifolia.

Summary: Phenotypically there appeared to exist no diversity in different individual plants in a population ofCalotropis procera. The diversity in imbibition and germination behaviour of seeds from different plants was revealed only after detailed studies were undertaken. Seeds from six individual plants were collected and stored separately for a period of two years. Ordinarily the seeds of this species did not exhibit any dormancy and were found to germinate immediately after harvest. Two years old seeds did not loose their viability in any of the six lots indicated above. It was discovered that the weight and size of seeds, the rate of imbibition of water, the amount of water imbibed, the loss of water upon drying, the rate of germination, the percentage of germination, and the germination behaviour in continuous illumination and total darkness, all exhibited diversity to some extent in the six lots studied. It was evident that there did not exist seeds exhibiting homogeneous behaviour in a population ofCalotropis procera.