Structural heterozygosity and cytomixis driven pollen sterility inAnemone rivularisBuch.-Ham. ex DC. from Western Himalaya (India)

Structural Heterozygosity for Reciprocal Translocations Affecting Chiasma Frequency and Pollen Fertility of a Natural Tetraploid of <i>Anthoxanthum odoratum</i> L. from Northwest Himalayas

“…In the species, there seems to be a direct correlation of pollen sterility with structural heterozygosity. Similar effects of structural heterozygosity resulting in non-viable pollen grains has been reported in a number of plants, namely, Chrysanthemum zawadskii (Kim et al 2008), Artemisia parviflora (Gupta et al 2010), Astragalus chlorostachys (Rana et al 2012), Saxifraga diversifolia (Kumar and Singhal 2013), Achillea millefolium (Singhal et al 2014) and Anemone rivularis (Kumar et al 2015). Gohil and Koul (1978) and Sharma and Gohil (2003) have reported that structural heterozygotes of Allium consanguineum and A. roylei depicted complete gametic sterility due to reciprocal translocations, respectively.…”

“…The accessions with higher percentage of chromosomes involved in translocations showed higher values of chiasma frequency and thereby increased recombination value. Kumar and Singhal (2013) in Saxifraga diversifolia, Singhal et al (2014) in Achillea millefolium, and recently Kumar et al (2015) have also found direct correlation between chiasma frequency and incidence of translocations. The existence of heterozygosity for translocations in the tetraploid taxon indicates that the species is quite active and has exploited structural chromosomal alterations to create specific gene combinations in addition to intraspecific polyploid chromosomal races (2x, 3x, 4x) and B-chromosomes.…”

“…The structural heterozygotes are known to induce a high frequency of non-viable male gametes following the duplication or deficiencies of genes. The pollen sterility in a translocation heterozygote largely depends upon whether the orientation of multivalents is of adjacent or alternate type at M-I (Ghaffari et al 2009, Gupta et al 2010, Kumar et al 2015. Analysis of data in the presently analysed accessions revealed that there is a direct correlation between the frequency of multiple chromosomal associations and amount of pollen sterility.…”

Structural Heterozygosity for Reciprocal Translocation in <i>Tanacetum artemisioides</i> Sch. Bip. ex Hook. f. from Ladakh Division of Jammu and Kashmir

“…In the presently studied accession of Tanacetum artemisioides, the majority of the PMCs showed the adjacent type of orientation of quadrivalents/hexavalents (ring or chain) and the alternate (zigzag) orientation was seen in only one PMC, resulting in a considerable amount of pollen sterility (30-35%), which appears to be the result of duplications and deficiencies of genes as mentioned by Ghosh and Datta (2006) in Nigella damascene. Similar effects of structural heterozygosity leading to nonviable pollen grains have been reported in a number of plants, namely, Citrus jambhiri (Singhal and Gill 1981), Chrysanthemum zawadskii (Kim et al 2008), Artemisia parviflora (Gupta et al 2010), Astragalus chlorostachys (Rana et al 2012), Saxifraga diversifolia (Kumar and Singhal 2013), Tradescantia spathacea (Koul et al 2013), Achillea millefolium (Singhal et al 2014), and Anemone rivularis (Kumar et al 2015). Gohil and Koul (1978) and Sharma and Gohil (2003) have reported that structural heterozygotes of Allium consanguineum and A. roylei depict complete gametic sterility due to reciprocal translocations.…”

“…From this laboratory, the naturally occurring reciprocal translocations have been reported in individuals of Artimisia parviflora (Gupta et al 2010), Astragalus chlorostachys (Rana et al 2012), Saxifraga diversifolia (Kumar and Singhal 2013), Achillea millefolium (Singhal et al 2014), and Anemone rivularis (Kumar et al 2015). Kaul (1977) opined that breakage and exchange of heterologous chromosomes in a structural heterozygote are genetically conditioned and controlled, thereby eliminating the chance factor operating for the predominance of either ring or chain or both types of multiple associations of chromosomes.…”