A profile of chromosome counts, male meiosis and pollen fertility in 45 species of Asteraceae from Parvati Valley in Kullu district, Himachal Pradesh

Abstract

Chromosome counts including male meiotic studies have been made on 45 species (125 accessions) of Asteraceae collected from the Parvati Valley, Kullu district, Himachal Pradesh. Crepis foetida (n = 5) and Senecio pedunculatus (n = 20) have been counted chromosomally for the first time at global level. The genus Phagnalon has been worked out for the first time from India (P. niveum, n = 9). New chromosome counts/cytotypes have been reported for Gerbera lanuginosa (2n = 4x = 48), Gynura cusimbua (2n = 2x = 16) and Inula grandiflora (2n = 4x = 32). Intraspecific euploid cytotypes have been reported for the first time in Inula grandiflora (2x,4x). Three intraspecific euploid cytotypes (2x,3x,4x) have been reported from the valley in Taraxacum officinale complex. The triploid taxa re-recorded presently for Erigeron annuus (2n = 27), Eupatorium adenophorum (2n = 51) and Taraxacum officinale (2n = 24) exhibit abnormal meiotic course and high pollen sterility but seem to have reproduced successfully through apomictic means. Presence of multivalents in the 4x cytotype of Chrysanthemum leucanthemum (2n = 36) indicates the segmental allotetraploid nature of the taxon. Phenomenon of cytomixis involving chromatin transfer among neighboring meiocytes and associated meiotic irregularities have been detected in Artemisia maritima (n = 9), Aster peduncularis (n = 27), Crepis foetida (n = 5), Erigeron annuus (2n = 27), Inula grandiflora (n = 8), Lactuca dolichophylla (n = 8), Prenanthes brunoniana (n = 8), Senecio graciliflorus (n = 20) and S. rufinervis (n = 20). In the rest of the species, the present findings substantiate earlier chromosome reports from other parts of Himalayas in India.