ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 81 Number 3
Hormonal regulation and osmotic adjustment as mechanisms for drought tolerance in field-grown tea (Camellia spp) plants. (157)
Certain growth hormones and osmoregulators were studied during drought and crop seasons in field-grown tea (Camellia spp) clones to elucidate the basis of drought tolerance. The genotype of drought tolerant (DT) clones enabled them to survive through dry periods by increasing the levels of growth promoters such as gibberellic acid. The concentration of the inhibitor hormone, abscisic acid, was also found to be higher in dry periods than in crop seasons, with lower concentrations in DT clones. The accumulation of proline and amino acids during the dry season resulted in increase in osmolality, a measure of osmotic potential. It is postulated that osmoregulators in combination with growth hormones confer drought tolerance on tea plants during drought periods.
Keywords: Gibberellic acid (GA3); Abscisic acid (ABA); Proline (Pro); Amino acids (AA); Osmolality; Osmotic adjustment; Drought tolerant (DT); Drought susceptible (DS)