Genetic Diversity of Some Citrus (L) Genotypes As Revealed By Meiosis

Abstract

The Delta region especially in Qalubia governorate of Egypt is reported to be the new origin place and rich in diversity of Citrus (L.) species, where some species of Citrus appeared in their natural habitat. To have comprehensive information about the extent of genetic variability and the occurrence of cryptic genomic hybridity between and within various Citrus species, a combined approach involving cytogenetical approaches was adopted in the present study. Cytogenetic approaches are applied to five parents and their four crosses. Male meiotic studies showed a gametic chromosome number of n = 9, without any evidence of numerical variations. Bivalents outnumbered all other types of associations in pollen mother cells (PMCs) analyzed at diplotene, diakinesis and metaphase I. Univalents were frequently encountered in nine genotypes presently studied, though their presence appropriately did not influence the distributional pattern of the chromosomes at anaphases I and II.