Cytological stability of wheat-Agropyron Cristatum gaertn chromosome disomic addition lines

In order to understand the cytological stability of (chromosome) addition lines, the root tip (chromosome) numbers in open-pollinated (progenies) of 20 wheat-Agropyron cristatum (chromosome) addition lines were analyzed. Among the 20 disomic addition lines, cytological stability differed greatly. In the (progenies) of 10 lines, transmitting rates of 2n=44 plants were 33.3% to 100%, with the average of (74.78%). In the (progenies) of the remaining 10 addition lines, no plants with 2n=44 (chromosomes) were observed. However, with genomic in situ hybridization (GISH) analysis, one translocation line, (5112-4) and one substitution line 5111-1, between A. cristatum and wheat (chromosomes) were recovered from the 2n=42 plants. These results suggested that (progenies) with 2n=42 (chromosome) numbers of those (addition) lines do not mean the complete lost of alien (chromosomes), but may substitute for or be translocated to the (chromosomes) of wheat. In (addition), the facts that P-genome spontaneously translocated to the (chromosomes) of (St-genome) in genus Kengyilia Yen et J. L Yang, also suggested that P genome in the Tribe Triticeae should be understood anew.