A Case of Structural Heterozygosity Affecting Chiasma Frequency and Pollen Fertility in Natural Populations of <i>Artemisia roxburghiana</i>

Abstract

Meiotic studies have been carried out on six accessions of Artemisia roxburghiana from four regions of Western Himalayas. The accessions collected from Chamba, Kinnaur and Kullu districts of Himachal Pradesh and Kargil district of Jammu and Kashmir showed a normal meiotic course leading to high pollen fertility. However, the accession collected from Drass region of cold deserts of Ladakh, Jammu, and Kashmir showed abnormal meiosis caused by structural heterozygosity for reciprocal translocations. The present study adds the first report of structural heterozygosity in the species. Chiasma frequency was also calculated in the accessions to see the effect of reciprocal translocations. Besides, reciprocal translocation, the accession also showed various meiotic abnormalities in the form of the early disjunction of bivalents, chromatin bridges and laggards leading to abnormal microsporogenesis. Structural heterozygosity and other meiotic abnormalities in the accession seem to be responsible for a reduction in pollen fertility.