Karyotype Variations among Date Palm (Phoenix dactylifera L.) Cultivars of Sindh, Pakistan

Date palm (Phoenix dactylifera L.) is a monocot and dioecious plant species having uncertain diploidy levels because of scarcity of cytogenetic knowledge. Khairpur district in Sindh is known as the biodiversity center of date palm. Investigations were carried on the chromosome number and karyotype one of the seven indigenous commercial date palm varieties and four wild type date palm of Sindh province, Pakistan by using the traditional Fuelgen squash method. Results indicated that all seven commercial varieties and four wild types of date palm are diploid in nature and having 2n=36 chromosomes. First time detailed karyotype of these varieties have been developed which includes total chromosome length (TCL), relative length (RL) and centromeric index (CI). The chromosome complement consists of metacentric (m), submetacentric (sm), sub-telocentric (st) and telocentric (t) chromosomes and average length of chromosomes vary in all cultivars ranging from 0.99μm to 6.46μm. Results indicated that var. Wild03 have symmetric karyotype with 11m+4sm+3t. Wild03 was likely primitive karyotype as compared to var. Asul Khurmo which represented the advance karyotype by showing maximum number of telocentric chromosome.