DETECTION OF WHEAT (TRITICUM-AESTIVUM L) TRITICUM-TIMOPHEEVII ZHUK ADDITION AND SUBSTITUTION AND WHEAT RYE TRANSLOCATION BY C-BANDING AND IN-SITU HYBRIDIZATION/

Alien chromosomes and chromosome segments have been demonstrated in ge netic material produced in the Department of Genetics of the Agricultu ral Research Institute, Martonvasar and in Martonvasar wheat varieties using two cytogenetical methods, i.e. C-banding and in situ hybridiza tion. The advantage of C-banding is that individual chromosomes can be clearly identified by this method, but when applying in situ hybridiz ation shorter chromosome segments built into an alien genome can be re cognized, which do not carry typically stained bands. In addition, the translocation breakpoint in an alien translocation can be exactly det ermined using in situ hybridization. A 6G Triticum aestivum L./T. timo pheevi Zhuk. addition line and a 6G(6B) 1: timopheevii Zhuk.(T. aestiv um L.) substitution line were identified in the progenies from T. aest ivum L. x T. timopheevii Zhuk. crossing. The 44-chromosome 6G addition line is a BC2F1 progeny of the T. timopheevii Zhuk. x. T. aestivum L. cv. Mv 9 krl hybrid (Farshadfar et al. 1994) backcrossed with the whe at variety Mv 9. The 6G(6B) disomic substitution line was found among selected 42-chromosome progenies of a T. aestivum L. cv. Fleischmann 4 81 x T. timopheevii Zhuk. amphiploid (Belea 1961) backcrossed once wit h the wheat variety Mironovskaya 808 and three times with the wheat va riety Mv 14 and subsequently self-pollinated. The 1B/1R wheat/rye tran slocation occurring in Martonvasar wheat varieties was demonstrated by both C-banding and in situ hybridization. There was no difference in the size of the translocated rye chromosome arms among Martonvasar whe at varieties of different quality. The translocation breakpoint was at the centromere in each case.