Cytological studies in some Citrus species of Arunachal Pradesh

Abstract

Arunachal Pradesh is natural home of many Citrus species and varieties which is indicated by its diversity of species existing in the tropical and subtropical forests and wide distribution pattern of species [1]. Phenotypic variations among the species is quite interesting as the genotype determines their characters [2] and it may further be modified due to variety of climatic and topographic conditions prevailing in the state. Now it has established that nine (n =9) is the haploid number [3] and polyploidy is a common phenomenon for this genus [4]. On the other hand, confusion and disagreement have prevailed in the interpretation of species in Citrus. The earlier pomologist, SWingle [5] classified Citrus into 16 species, Tanaka [6] divided into 162 species and recent molecular taxonomists Deng et al. [7] have considered only 3 genuine botanical species namely C. grandis, C. reticulata and C. medica. Hence a cytological investigation was carried out to confirm the systematic position of seven important species native to the state of Arunachal Pradesh.