BGN 19: The development of ditelotetrasomics in barley

The development of ditelotetrasomics in barley*

S. Wang and T. Tsuchiya
Department of Agronomy
Colorado State University
Ft. Collins, CO 80523, U.S.A.
*Supported by USDA-CSU Cooperative Research Project No. 58-82HW-6-8 and CSU Hatch Project.


Ditelotetrasomics (2n=14+2 homologous telocentric chromosomes) have been developed in barley. So far, ditelotetrasomics were obtained only for short arms; ditelo 1S (Tsuchiya, 1969; Fedak and Helgason, 1970), ditelo 3S, ditelo 5S, ditelo 6S, and ditelo 7S. Plants of ditelo 2S were found several times, but were too weak to set seed after heading (Wang and Tsuchiya, 1988). All the ditelotetrasomics found were derived from the selfed progenies of monotelotrisomics, and the ratios were shown in Table 1.

Table 1.The frequency of different ditelotetrasomics from the selfed monotelotrisomics (%).

Ditelotetrasomic plants were also found for the long arms of chromosome 2 (Riley and Tsuchiya, unpublished) and chromosome 4 (Wang and Tsuchiya, unpublished; Tsuchiya, unpublished). However, ditelo 2L died at early growing stage and ditelo 4L showed low seed fertility. No other ditelotetrasomics for the long arms have been found or reported.

The frequency of ditelotetrasomic plants observed is different for different telosomes. Furthermore, for telotrisomic 1S and 3S, no ditelotetrasome was obtained in the progenies of two-rowed type monotelosomes; all ditelotetrasomes were obtained in the six-rowed type.

References:

Fedak, G., and S.B. Helgason. 1970. The cytogenetics of ditelotetrasomic line in barley. Can. J. Genet. Cytol. 12:553-559.

Singh, R.J., and T. Tsuchiya. 1977. Morphology, fertility and transmission in seven monotelotrisomics of barley. Z. Pflanzenzuchtg. 78:327-340.

Tsuchiya, T. 1969. Status of studies of primary trisomics and other aneuploids in barley. Genetica 40:216-232.

Wang, S., and T. Tsuchiya. 1988. Study of ditelotetrasomics for the short arm of chromosome 2 (ditelo 2S) in barley. BGN 18:20-21.


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