Cytological Studies in Some Members of Tribe Senecioneae (Asteraceae) from North and Central India

Abstract

Cytological studies have been made of 12 species of tribe Senecioneae (Asteraceae) from north and central India. Of these, 3 species, namely S. grahami Hook. f. (n=10), S. kunthianus Wall ex DC. (n=20) and S. sexatilis Sensu Hook. f. (n=10), are counted for the first time. Additional and/or variable cytotypes are recorded for 2 species, namely S. nudicaulis Buch.-Ham D. Don. (n=5, 10) and S. rufinervis DC. (n=10). Existence of B-chromosomes has been recorded in S. krascheninnikovii Schischk. (n=10+0−2B). Two species, S. vulgaris L. (n=20) and S. krascheninnikovii Schischk. (n=10), are explored for the first time from India. Besides these, cytomorphological variabilities have been observed in S. rufinervis (2n=20, 40) and S. nudicaulis Buch-Ham ex D. Don (2n=10, 20 and 40). Great variation in morphological characteristic have been noticed in different accessions of S. laetus Edgew, however all the accessions are found to exist at 2n=40. Meiotic configurations in the form of multivalents and/or secondary association of bivalents are found in Gynura nepalensis DC., Senecio laetus Edgew, S. kunthianus Wall ex DC., S. krascheninnikovii Schischk. and S. nudicaulis Buch-Ham ex D. Don.