Ultrastructure of the stigma and style of Mangifera indica L.
Wet E. de, Robbertse P. J., Coetzee J.
Author Affiliation: Margaretha Mes Institute for Seed Research, University of Pretoria, 0002 South Africa.
South African Journal of Botany 56 : 206-213
Abstract : Anatomical studies using LM and EM are reported on 2 low-yielding mango cultivars, Haden and Sensation. The stigma was shown to be non-papillate and wet, and the style was semi-solid. The exudate from the stigma and style was of the mixed type and was transported from vesicles in the secretory cells, via plasmatubules, to the surrounding cell walls. The cell walls of the transmitting tissue were bilayered. The outer wall layer was typically reticulate and the exudate accumulated between the loosely woven wall fibrils. At the base of the style a specialized obturator, the ponticulus, facilitated the direct passage of the growing pollen tubes towards the embryo sac. Since no obvious obstacles to pollen growth were found either in or on the stigma or style, the low fruit set associated with the 2 cultivars cannot be attributed to structural defects.