GrainGenes

II.37 Chromosome breakage in barley by specific and non-specific endonucleases.

N.C. Subrahmanyam, A.R. Gould and C.H. Doy, Genetics Department, Research School of Biological Sciences, The Australian National University, Canberra, A.C.T 2601. Australia. "R"

Hybridization between Hordeum vulgare (n=7) and H. bulbosum (n=7) is known to result in chromosome elimination and cytological investigation of such hybrids occasionally reveals chromosome degradation (Subrahmanyam and Kasha, 1973). In an attempt to mimic this cytologically distinguishable phenomenon, the restriction enzymes Hin D II and III (from Haemophilus influenzae Rd.) supplied to the root-tip cells of Hordeum vulgare and H. bulbosum resulted in the cleavage of chromosomes of both the species although the number of breaks per vulgare chromosome was more than per bulbosum chromosome (Subrahmanyam et al. 1976). To extend these studies, another restriction enzyme, Eco RI and a non-specific endonuclease pancreatic DNAase were used to treat root-tip cells of vulgare and bulbosum. Unlike Hin D II and III neither Eco RI nor Pancreatic DNAase treatments produced differential effects between vulgare and bulbosum. The number of breaks induced by pancreatic DNAase was, however, greater than the number of breaks after Eco RI treatments. The possible implications of the differential effect of Hin D II and III on vulgare and bulbosum and the practical applications of this technique have been discussed elsewhere (Subrahmanyam et al., 1976).

References:

Subrahmanyam, N.C. and K.J. Kasha. 1973. Selective chromosomal elimination during haploid formation in barley following interspecific hybridization. Chromosoma (Berl ) 42: 111-125.

Subrahmanyam, N.C., A.R Gould and C.H Doy. 1976. Cleavage of Plant Chromosomes by restriction endonucleases. Plant Science Letters, 6 (in press).

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