Karyotype Variation and Cytophotometric Estimation of In Situ DNA Content in Some Minor and Associate Mangroves of India.

Detailed karyotype analysis and cytophotometric estimation of in situ 4C nuclear DNA amount as well as interphase nuclear volume (INV) were carried out in Aegialitis rotundifolia, Suaeda nudiflora and Thespesia populnea found in the mangrove forests of Orissa, India. Somatic chromosome number 2n=26, 34 and 54 were noted in T. populnea, A. rotundifolia, S. nudiflora respectively. Karyotype analysis revealed numerical variations and minute structural alterations of somatic chromosomes in different species. Critical analysis of nuclear DNA also showed significant variations in the 4C DNA content. S. nudiflora, a mangrove associate, showed variations at the ploidy level in root meristematic cells suggesting existence of cytotypes in the natural population. Significant correlation was found between chromosome length, volume and 4C DNA content.