Chromosome count, meiotic abnormalities, pollen fertility and karyotype of Elymus semicostatus (Nees ex Steud.) Meld. (Family: Poaceae) from North-west Himalaya

ABSTRACT

The present study includes chromosome count, meiotic abnormalities, pollen fertility and karyotype of Elymus semicostatus from north-west Himalaya, India. This is the first attempt to present karyotype morphometric data of the species from India [2n = 4x = 28 = 22m(2sat) + 6sm]. At present 28 wild accessions of the species have been analysed, all of which shared the same tetraploid (4x) chromosome count of 2n = 28. In addition, seven accessions also showed the presence of 0–2 B-chromosomes in the meiocytes. Meiotic abnormalities were frequent and 17 accessions showed the phenomenon of cytomixis, involving chromatin transfer among meiocytes and associated meiotic irregularities in spindle activity and chromosomal segregation. Consequent to such meiotic abnormalities, these accessions showed pollen malformation in the form of sterile and variable sized pollen grains. Cytomixis in the species seems to be a natural phenomenon under the control of genetic factors and is responsible for inducing meiotic disturbance and pollen malformation.

KEYWORDS:

• Poaceae
• Triticeae
• karyotype
• male meiosis
• cytomixis
• unreduced gametes

Acknowledgements

The authors are very grateful to the head of the Department of Botany, Punjabi University, Patiala and Director, Botanical Survey of India, Kolkata and Head of Office, NRC, Dehradun, for necessary laboratory, Herbarium (PUN, BSD) and library facilities. .

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the University Grants Commission (UGC), New Delhi (UGC-BSR-Fellowship) [Award letter no. 15610/Research dated 3 June 2015]; Department of Biotechnology, New Delhi (DBT-IPLS project) [BT/PR4548/INF/22/146/2012]; and Science and Engineering Research Board-Department of Science and Technology (SERB-DST) Start Up Research Grant (Young Scientists) [vide SERB sanction No. SB/YS/LS-182/2014 dated 8 September, 2015].