Cytological Studies in Some Members of Tribe Senecioneae (Asteraceae) from North and Central India
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. (nϭ10), S. kunthianus Wall ex DC. (nϭ20) and S. sexatilis Sensu Hook. f. (nϭ10), are counted for the first time. Additional and/or variable cytotypes are recorded for 2 species, namely S. nudicaulis Buch.-Ham D. Don. (nϭ5, 10) and S. rufinervis DC. (nϭ10). Existence of B-chromosomes has been recorded in S. krascheninnikovii Schischk.
... ikovii Schischk. (nϭ10ϩ0Ϫ2B). Two species, S. vulgaris L. (nϭ20) and S. krascheninnikovii Schischk. (nϭ10), are explored for the first time from India. Besides these, cytomorphological variabilities have been observed in S. rufinervis (2nϭ20, 40) and S. nudicaulis Buch-Ham ex D. Don (2nϭ10, 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 2nϭ40. 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.