Production and meiotic pairing behaviour of new hybrids of winter wheat (Triticum aestivum) x winter barley (Hordeum vulgare).

New winter wheat (Triticum aestivum L.) x winter barley (Hordeum vulgare L.) hybrids produced using cultivated varieties (wheat 'Martonvásári 9 krl'(Mv9 krl) x barley 'Igri', Mv9 krl x 'Osnova', 'Asakazekomugi' x 'Manas') were multiplied in tissue culture because of the high degree of sterility and then pollinated with wheat to obtain backcross progenies. Meiotic analysis of the hybrids Mv9 krl x 'Igri' and 'Asakazekomugi' x 'Manas' and their in vitro regenerated progenies with the Feulgen method revealed 1.59 chromosome arm associations per cell in both initial hybrids. The number of chromosome arm associations increased after in vitro culture to 4.72 and 2.67, respectively, in the two combinations. According to the genomic in situ hybridization (GISH) analysis, wheat-barley chromosome arm associations made up 3.6% of the total in the initial Mv9 krl x 'Igri' hybrid and 6.6% and 16.5% of the total in in vitro regenerated progenies of the 'Asakazekomugi' x 'Manas' and Mv9 krl x 'Igri' hybrids, respectively. The demonstration by GISH of wheat-barley chromosome pairing in the hybrids and especially in their in vitro regenerated progenies proves the possibility of producing recombinants between these two genera, and thus of transferring useful characters from barley into wheat. In vitro conditions caused an increase in chromosome arm association frequency in both combinations and in fertility in some regenerants.