Relationship between physiological parameters and vigour indices in polyembryonic genotypes of mango (Mangifera indica).
Manish Srivastav, Mahesh Kumar, Dubey A. K., Singh A. K., Sairam R. K.
Author Affiliation: Indian Agricultural Research Institute, New Delhi 110 012, India.
Indian Journal of Agricultural Sciences 79 : 469-471
Abstract : A field study was conducted in New Delhi, India, during 2006-07, to investigate the relationships of various physiological parameters associated with vigour of mango seedlings. Nucellar seedlings of 16 polyembryonic mango genotypes were used for study. Vigour index was calculated in 2 ways by considering both the length of the seedling and dry weight of seedling. Physiological parameters, i.e. chlorophyll contents, stomatal density, net CO2 assimilation, relative water content, bark percentage and phenol contents, were determined at different intervals. Vigour index I and vigour index II had linear positive regression relationship with chlorophyll a, chlorophyll b and total chlorophyll among the 16 mango genotypes. It was evident that genotypes showing vigorous growth had higher assimilation rate/unit leaf area than the less vigorous genotypes. The relationship between net CO2 assimilation with vigour index I and vigour index II was linearly positive. However, stem bark percentage recorded in the 16 mango genotypes showed linear negative relationship with vigour index I and vigour index II. Similarly, vigorous genotypes had less phenol content in leaves and vice versa. Results showed that physiological parameters, i.e. chlorophyll a, net CO2 assimilation, RWC (%), bark (%) and total leaf phenol contents, are important criteria for determining the vigour of mango seedlings at nursery stage.