In vitro morphogenesis in wheat/ Thinopyrum elongatum chromosome addition lines

The influence of individual Thinopyrum elongatum chromosomes on callus induction and morphogenic ability of in vitro cultivated immature embryos of wheat/ Thinopyrum elongatum addition lines was studied. An euploid form of cultivar Chinese Spring of Triticum aestivum (2n=42), AABBDD, seven disomic addition lines of Chinese Spring with chromosomes of Thinopyrum elongatum (2n=14) EE, and the amphidiploid Chinese Spring/ Thinopyrum elongatum (2n=56), AABBDDEE, were used as donor plants. Immature 14 days old embryos were in vitro cultivated. A relatively high number of calli were issued in embryocultures of all studied lines without significant variations among them. Relatively lower callus induction rate occurred only in the addition line containing 5E chromosome. Substantial differences were observed between the lines in respect to the number of both initiated morphogenic calli and regenerants obtained. The highest number of morphogenic calli and regenerants was obtained in cultures of lines containing the Thinopyrum elongatum chromosomes 1E and 6E and the lowest one — in the 4E addition line. The data suggest that the effect of Thinopyrum elongatum chromosomes could be due to existence of homeoalleles in those chromosomes, but the presence in Thinopyrum elongatum genome of genes and alleles affecting specifically in vitro response can not be excluded either