Effect of Terminal Water Stress and Benzyl Adenine on Osmoregulants in Pearl Millet [Pennisetum glaucum (L.) R. Br.] Genotypes

The effect of benzyl adenine (BA) soaked seed treatment and terminal water stress in leaf tissues of four genotypes of pearl millet (J-2340, 95444B, J-2290 and JMS-101B) under field conditions was studied during summer season. The leaves were collected at terminal water stress stage and used for proline, free amino acids, soluble sugars and phenol estimation. Imposition of terminal stress increased all these four parameters. Free amino acids (FAA) were accumulated in all the genotypes on imposing terminal stress condition. The overall mean for FAA content was higher in drought sensitive genotypes J-2290 and JMS-101B as compared to tolerant genotypes. Water soaked seed treatment showed higher free amino acids. Terminal stress condition increased proline content (2.2 fold) than the irrigated condition and it was accumulated in all the genotypes with higher accumulation in J-2340 and J-2290. Among the presoaking treatments, less proline accumulation was observed in water soaked and BA soaked treatments. On exposure to the terminal stress, all the genotypes showed rise in the total soluble sugars and the greater accumulation was observed in genotype JMS-101B, while the least was in the genotype 95444 B. The overall mean of total soluble sugars was significantly higher in the genotype JMS-101B and the lowest in the J-2340. The presoaking treatments did not show any significant effect. The phenol content was also increased under the terminal stress condition in all the genotypes and a significant higher accumulation was in the genotype J-2290. The overall mean values of phenol in genotypes were the highest in JMS-101B and minimum in the genotype 95444B. The presoaking treatments viewed the highest content in the BA soaked treatment and the lowest in the control.