Karyotypic studies in a few species of Barleria L. (Acanthaceae) from South India.

Abstract

Species of Barleria L. numbering about 230 (Airy Shaw 1973) show a wide range of mor phological variations. Some of them are of horticultural interest for their attractive flowers. Nineteen species are known to occur in South India (Gamble 1935). Cytological work in the genus, as in most other members of Acanthaceae, is very little. Though De (1966) and Datta and Maiti (1970) have described karyotypes for a few taxa from North India, those occurring in South India have not received due attention so far. The present work, however, unravels karyotypes in six species distributed in South India and discusses their relationship based on chromosome morphology.

Cytogenetics of two endemicBarleriaspecies (Acanthaceae) from the northern Western Ghats (India)

“…elata had the longest chromosomes, i.e. up to 7 μm (Ranganath and Krishnappa 1990). Longer chromosomes account for the higher TCL value of Barleria involucrata.…”

“…Barleria involucrata var. elata and B. strigosa have more asymmetrical karyotypes with 6 and 8 sub-terminal chromosomes, respectively (Ranganath and Krishnappa 1990).…”

“…Somatic counts deviating from 2n = 40 (i.e. 2n = 30, 32, 34, 36, 38 and 42) in different horticultural varieties of Barleria cristata have been ascribed to aneuploid alterations and hybridization (Ranganath and Krishnappa 1990). Most of the species in genus Barleria have symmetrical (2b) karyotypes with m-type chromosomes, except B. acuminata which has an asymmetrical karyotype with sm, st and t-type of chromosomes, which falls in category 3b (Devi and Mathew 1991).…”

“…Most of the species in genus Barleria have symmetrical (2b) karyotypes with m-type chromosomes, except B. acuminata which has an asymmetrical karyotype with sm, st and t-type of chromosomes, which falls in category 3b (Devi and Mathew 1991). However, Barleria gibsonii with 14 acrocentric chromosomes has been listed as having a more evolved karyotype than B. acuminata since it has no acrocentric chromosomes in its complement (Ranganath and Krishnappa 1990). The primitive nature of the karyotype of Barleria acuminata may further be corroborated by the presence of small chromosomes.…”

“…The primitive nature of the karyotype of Barleria acuminata may further be corroborated by the presence of small chromosomes. Ranganath and Krishnappa (1990), while studying the karyotype of six taxa of Barleria (B. acuminata, B. buxifolia, B. gibsonii, Barleria involucrata var. elata, B. noctiflora and B. strigosa) observed the shortest chromosomes (1.73 μm) in Barleria acuminata.…”