Microsatellite Markers Based Identification of Zygotic and Nucellar Embryos in Polyembryonic Mango (Mangifera Indica L.) Genotypes Vellaikulamban and Olour

Abstract

The nucellar seedlings from polyembryonic mango seeds are useful as clonal rootstock while zygotic seedlings could be valuable for genetic variability. However, discriminating zygotic from nucellar seedlings originating from a single kernel based on morphology is impractical. The current study aimed to differentiate zygotic and nucellar embryos among multiple embryos in polyembryonic genotypes Vellaikulamban and Olour using nine SSR markers. Observed heterozygosity ranged from 0.182 (MiIIHR23) to 1.0 (MiIIHR17). LMMA12 had the maximum (0.823) polymorphic information content (PIC), and MiIIHR23 the minimum (0.562). Dendrogram using the Neighbor-joining method demonstrated that embryos developed from nucellus grouped in the same cluster with the maternal parent, whereas zygotic embryos clustered in a distinctly different group. Six SSR markers identified the farthest embryo from the funicular point as zygotic in Olour, while in Vellaikulamban some discrepancy was observed for two markers.