Stem anatomical characters in relation to tree vigour in mango (Mangifera indica L.).
Kurian R. M., Iyer C. P. A.
Author Affiliation: Division of Fruit Crops, Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore 560?089, India.
Scientia Horticulturae 50 : 245-253
Abstract : Studies conducted with 24 mango cultivars of widely varying vigour indicated that low tree vigour was associated with a higher primary phloem to primary xylem ratio in young shoots. Width of cortex or pith did not show any relationship to tree vigour. There was no significant difference among the cultivars with respect to the number of xylem vessels or the size of metaxylem vessels. Higher phloem to xylem ratio was also observed in the case of trees of cultivar Alphonso dwarfed by the external application of up to 10 g paclobutrazol/tree. This was mainly due to fewer xylem vessels and smaller metaxylem vessel diameters. The radial width of half pith (from the centre of sections to the inner periphery of vascular bundles) was also reduced but those of the cortex and phloem were unaffected. Since there was significant negative association between phloem:xylem ratio and tree vigour and size, this character could be employed in the early screening of genotypes for tree vigour.