OSMOTIC REGULATION IN LEAVES OF MANGO CULTIVARS 'AMRAPALI' AND 'LANGRA' DURING FLOWERING - A STAGE OF INTERNAL STRESS

P. Saxena, V.K. Singh, S. Rajan
Water stress in mango provides the stimulus for flowering and is known as a potential agent for floral induction. Osmotic adjustment is one of the important processes involved in plant adaptation to water stress a tree generally experiences during flowering. Trees under water deficit may synthesize and accumulate osmolytes which help in adjustment of water potential which allows water to move into cells, thereby maintaining the turgor potential (Ψ) and increasing tissue tolerance to low soil water potential. In the present study water potential and Relative Water Content (RWC) were evaluated in mango viz., ‘Amrapali’ and ‘Langra’ cultivars being regular and irregular bearing cultivars respectively in order to know their differential osmotic adjustment capacity in field condition. At fully saturated state of leaves, the water potential was found to be -4.0 MPa in both the cultivars, however, in field conditions where the tree experiences natural stress water potential was found to be -6.0 and -5.0 MPa at pre flower bud differentiation stage, -9.0 MPa and -7.0 MPa at flower bud differentiation (FBD) stage and -8.0 and -6.5 MPa at post flower bud differentiation stage in ‘Amrapali’ and ‘Langra’ respectively. On the other hand the relative water content of ‘Amrapali’ and ‘Langra’ was 78.0 and 75.0% at pre flower bud differentiation stage, 74.9 and 70.0% at flower bud differentiation and 75.0 and 70.0% at post flower bud differentiation stage, respectively. Osmotic adjustment at FBD allowed leaves of ‘Amrapali’ to reach leaf water potential to about -9.0 MPa, whereas it was -7.0 MPa in ‘Langra’. It is inferred from these studies that greater osmotic regulation of ‘Amrapali’ than ‘Langra’ during FBD, provides an important mechanism to avoid water loss more efficiently in ‘Amrapali’ than ‘Langra’.
Saxena, P., Singh, V.K. and Rajan, S. (2015). OSMOTIC REGULATION IN LEAVES OF MANGO CULTIVARS 'AMRAPALI' AND 'LANGRA' DURING FLOWERING - A STAGE OF INTERNAL STRESS. Acta Hortic. 1066, 135-139
DOI: 10.17660/ActaHortic.2015.1066.15
https://doi.org/10.17660/ActaHortic.2015.1066.15
mango (Mangifera indica L.), 'Amrapali', 'Langra', flower bud differentiation (FBD), fruit development, osmotic regulation
English

Acta Horticulturae