Not AvailableMango (Mangifera indica L.), a commercially important and leading fruit crop of India, exhibits both mono- and polyembryony. Most commercial varieties are monoembryonic. Polyembryonic varieties are not commercially cultivated for table purpose, but are believed to produce true-to-type seedlings for use as the rootstock. Besides, unambiguous identification of a variety is essential to germplasm conservation and in breeding programmes. Distinguishing nucellars from zygotic seedlings in germinating stones of polyembryonic varieties is critical for the nurseryman and breeder alike. A study combining stomatal density and SSR markers was made for identifying maternal and sexual embryos in the polyembryonic variety, Moreh, at ICAR-IIHR during 2014-2015. Three trees (Tree No. 13, 14 and 15) were selected for the study. Trees of polyembryonic varieties are traditionally presumed to be clonal in origin, i.e., these are believed to have arisen from polyembryonic stones. This variety can produce up to six seedlings per stone. Stage of leaf development and the specific sector of the leaf to be used for stomatal count were optimized initially in the present study. Petiolar end, median sector (mid-lamina) and leaf-tip end of fully-expanded leaf were optimized for analysis. Stomatal count recorded in three mature trees of ‘Moreh’ was analyzed by the scatter diagram. Significant differences were observed in distribution of stomata within a leaf, with the petiolar-end registering the highest stomatal count/density. Stomatal count in leaf-tip and mid-sector of the leaf were similar in all the three trees as per R2 values. However, Tree number 13 differed from the other two trees in terms of stomatal density. To corroborate this stomatal data, SSR markers were used for generating DNA profiles in the three individuals of ‘Moreh’. Ten polymorphic genomic SSRs were tested for genotyping and allelic data was generated. Results on stomatal density matched SSR allelic data indicating, that, a combination of both these test strategies can help establish unambiguously the identi of a variety. Our study provides information for correct identification of a genotype and is helpful in differentiating mother trees and, in turn, for distinguishing nucellars from zygotic seedlings.Not Availabl
