Cytological studies in the genus Indigofera L.

Abstract

In the genus Indigofera L., meiosis was studied in 24 collections belonging to 23 species and karyotypes with the help of root tip mitosis were examined in 26 collections belonging to 23 species. Three species, namely I. endecephylla, I. parodiana, and I. pilosa were tetraploid. Among diploid taxa, I. parviflora had 2n=14 and other remaining collections had 2n=16. Karyotype asymmetry was assessed following the two way classification of Stebbins (1971). I. glandulosa belonging to class 2B had the most asymmetric karyotype and was therefore considered most advanced. The length of individual chromosome ranged from 3.59μ to 1.10μ. The total chromosome length varied from 26.52μ to 11.35μ in diploid collections and was 35.81μ in the solitary tetraploid collection of I. endecephylla. The chromatin volumes and nuclear volumes were also worked out and had significant linear regression on total chromatin lengths. Five diploid species (I. asperifolia, I. brevidens, I. circinella, I. cryptantha, and I. neglecta) and one tetraploid species (I. parodiana) were cytologically examined for the first time and karyotypes were worked out in 13 species for the first time.