Somatic chromosomes of Aegle marmelos and Azadirachta indica through EMA method

Abstract

Chromosome number is important cytological character and is species specific. Somatic chromosome analysis particularly in tree species remains less attended due to their long breeding cycle and small size. Somatic chromosome determination and analysis from Aegle marmelos L. Corr. – common name Bael, and Azadirachta indicia A. Juss. – common name Neem, two very important age old medicinal trees, has been presented in this communication for the first time through enzymatic maceration and air drying method (EMA) along with Giemsa staining. Both the species revealed small to very small chromosomes. Aegle marmelos contains 2n =18 chromosomes with 1.60 μm average size of chromosomes. Length of individual chromosomes varies from 1.08 to 2.62 μm. Total chromatin length of Bael is calculated as 28.88 μm. While Azadirachta indica contains 2n =28 chromosomes with 1.10 μm average size of chromosomes, size of long and small chromosomes within the metaphase plates varies from 0.66 to 1.67 μm. Total chromatin length in Neem is calculated as 30.80 μm. Successful application of EMA method in two medicinally important tree species having small to very small chromosomes can be used in other important genera and species as an alternative method for chromosome number determination and analysis.