Cytogenetical Studies on Some Members of the family Asteraceae of Nepal
Date
2014-11
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Department of Botany
Abstract
Karyotypic studies of 45 taxa belonging to 33 genera in 10 tribes of the family
Asteraceae are reported from Nepal. Chromosome number in somatic cells are
recorded to be 2n=20 in Ageratum conyzoides and Taraxacum officinale ; 2n=18 in
Ageratum houstonianum, Blumea lacera, Blumea laciniata, Dichrocephala
integrifolia, Rhynchospermum verticillatum, Sonchus asper and Sonchus arvensis;
2n=32 in Artemisia indica, Blumea lacera var. glandulosa and Xanthium strumarium ;
2n=34 in Artemisia vulgaris, Cirsium arvense, Parthenium hysterophorus; 2n=36 in
Artemisia abronatum, Aster ageratoids, Bidens pilosa var. minor, Chrysanthemum
morifolium, Spilanthes acmella, Spilanthes calva, and Senecio laetus; 2n=28 in
Anaphalis triplinervis var. triplinervis, Calendula officinalis and Gnaphalium
purpureum ; 2n=16 in Crepis japonica, Erigeron annuus, Galinsoga parviflora and
Ixeris Polycephala ; 2n=14 in Gnaphalium affine; 2n=22 in Blumea fistulosa, Blumea
mollis, Conyza canadensis, Eclipta prostrata and Stevia rebaudiana; 2n=40 in Aster
barbellatus, Aster peduncularis subsp. nepalensis and Crassocephalum crepidioides,
2n=26 in Coreopsis grandiflora and Tridax procumbens ; 2n=24 in Tagetes patula,
Centaurea cyanus and Zinnia elegans ; 2n=50 in Eupatorium adenophorum and
2n=30 in Wedelia wallichii. Meiotic studies are done in floral buds of 20 species.
Lowest haploid chromosome in Crepis japonica ( n=8) and highest in
Crassocephalum crepidioides (n=20) are found in present study. The highest pollen
stainability was found in Galinsoga parviflora (98.9 %) and lowest in Stevia
rebaudiana (61.3%). Chromosome number for the four taxa Aster peduncularis
subsp. nepalensis, Aster barbellatus , Artemisia indica and Senecio laetus are reported
for the first time in this study. For the eleven taxa viz. Ageratum conyzoides,
Ageratum houstonianum, Blumea fistulosa, Blumea lacera var. glandulosa, Cirsium
arvense, Erigeron annuus, Eupatorium adenophorum, Spilanthes acmella, Spilanthes
calva and Xanthium strumarium new chromosome number have been added. The
chromosome counts for 41 taxa in this study are new for the flora of Nepal.
Description
Keywords
Ageratum conyzoides, Chromosome, Centaurea cyanus L.