Impact of growth promoters on seed germination of Withania somnifera

This book describes the effect of growth promoters on the seed germination of W. somnifera varieties Poshita and Jawahar-20 under various with different soaking time and temperature. Proper germination of seeds requires optimum concentration of growth hormone. 150 ppm GA3 with 24 h of soaking time was most effective as compared to IAA and IBA in case of jawahar-20. However, in case of poshita 100 ppm GA3 was found to be optimum with 24 h of soaking time at 220C for germination. Varieties Jawahar-20 and Poshita showed better plumule growth in 100 ppm and 150 ppm GA3, respectively. However, IBA was effective for radicle growth at 150 ppm. protease and alpha amylase activity was highest after 5 and 10 days of incubation period respectively. NR activity also showed a positive correlation with increasing age of plant. It was found maximum in 90 days old plants as compared to 45 days old plants in both the varieties. The carotenoid and chlorophyll content also increased with increasingage of plant. This study concluded that growth regulators and appropriate temperatures play a synergistic role in breaking the seed dormancy by influencing various metabolic activities at this moment.