Abstract
Allium ampeloprasum cultivated in Kashmir is a tetraploid. The somatic complement of the cultivar consists of 32 median or submedian chromosomes, of which 8 have secondary constrictions. The tetraploid karyotype exhibits a great deal of heterozygosity which is taken as an evidence in support of the allopolyploid nature of the species. The tetraploid form is represented by the genomic formula AAA′A″. The three genomes show a great deal of similarity and are therefore taken to represent three varieties which have given rise to this cultivar through hybridity. — Despite this, no multivalents are formed by the species during meiosis. The shift from multivalent to bivalent type of pairing is attributed to the localization of chiasmata around the centromere. This type of chiasmata localization is a means adopted by some polyploid species to stabilize as diploids.
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Koul, A.K., Gohil, R.N. Cytology of the tetraploidAllium ampeloprasum with chiasma localization. Chromosoma 29, 12–19 (1970). https://doi.org/10.1007/BF01183658
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DOI: https://doi.org/10.1007/BF01183658