Indian Journal of Genetics and Plant Breeding (The)
Year : 1967, Volume : 27, Issue : 2
First page : ( 252) Last page : ( 263)
Print ISSN : 0019-5200. Online ISSN : 0975-6906.

Comparative Karyotypic Studies in Emmer Wheats. I. Inter-Specific Variations in Karyotypes

Patil V. P., Deodikar G. B.

Maharashtra Association for the Cultivation of Science, Poona-4, India

Accepted:  9  May,  1967.

Summary

Karyotypes of nine tetraploid species of Triticum have been studied along with that of T. monococcum. Inter-specific differentiation in karyotypes has been critically analysed and the extent of differentiation among them has been assessed in terms of their relative asymmetry indices. Total lengths of the chromosome complements in T. monococcum and tetraploid wheat species do not parallel the ploidy level Further, there are interspecific differences among the tetraploid wheats as regards the total chromosomal lengths at comparable phases. This has been partly attributed to differential degrees of spiralization and linear condensation. Still wider variations exist as regards the difference between longest and shortest members in the complement (L-S), index ratios (short arm/long arm) and number of SAT-chromosomes.

Karyotypes of typically wild species like T. timopheevi are more symmetrical compared to those of cultivated species which show progressively higher indices for asymmetry co-extensive with their spread in agriculture. Significant inter-specific variations were observed in respect of number as also the morphology and relative sequence numbers of the two SAT-chromosome pairs.

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