Comparative Micro-morphological and Karyomorphological Studies in Three Mulberry Varieties (<i>Morus</i> spp.)

This article reveals the micro-morphology and karyomorphological characters of three mulberry varieties, namely, Thysong, S41 and Morus multicaulis. Stomatal frequency, somatic chromosome number, ploidy level and karyotype analysis were studied for these varieties. Thysong is diploid with 2n=28, S41 is triploid with 2n=42 and Morus multicaulis is uneuploid with 2n=30 regarding somatic chromosomes numbers. The somatic chromosome length ranges from 1.26 to 2.83 μm, whereas the arm ratio ranges from 0.48 to 1.00 μm. Stomatal frequency is smaller in triploid varieties when compared to diploid and uneuploid mulberry varieties. In all the three varieties three to four types of chromosomes have been observed. Chromosomes are small sized with a narrow range of variation in length.