Genetic Diversity Of Storage Proteins In Triticum Polonicum L.

Triticum polonicum L.(2n=28, AABB) is the most importance species with agronomic traits of large grains, more spikes and higher tillering ability in Emmer-reihe wheat of Triticum. It is one of the best genetic resources for wheat breeding program. In this study, the genetic diversity of gliadins and high-molecular-weight gluetnin subunits (HMW-GS) in 72 T. polonicum accessions collected around the world, were investigated using APAGE and SDS-PAGE methods, respectively. Moreover, the genetic relationships among T. polonicum accessions, and HMW-GS combinations were analysized. A few new subunits were detected, which have not been reported among common wheat. The possibility of T. polonicum applied to wheat quality breeding was also discussed. It is useful to utilize these genetic resources for the improvement of quality of common wheat. The main results were described as following:1, The abundant variations of gliadin in 72 T.polonicum accessions were detected by APAGE. A total of 48 gliadin patterns were observed. There were 15, 9, 11 and 13 allelic of gliadin patterns at ω,β , α and γ zones, respectively. Frequency of each pattern ranged from 1.4% to 90.3%, with an average of 33.7%. Eight to 24 patterns cound be identified in each accession. Among a few accessions, the gliadin patterns were similar to each other, and these accessions cound not be distinguished by APAGE.2, The genetic similarity (GS) among T. polonicum accessions were calculated using NTSYS2.1 software according to the Nei &Li (1979) 's method. The genetic similarity varied from 0.1429 to 1.000, with the average of 0.5132. The gliadin diversity of T.polonicum accessions from different geography was estimated. Higher genetic diversity among these accessions from western and mid-Asia, which were recognized as the origin center of Triticeae species, were detected, with an average GS of 0.5473 and 0.4165, ranging from 0.1935 to 1.000 and 0.1935 to 0.6061 respectively. Furthermore, Theclustering results indicated that genetic relationships among T. polonicum based on the gliadin were associated to its geography distributions.3, HMW-glutenin variation among 72 T. polonicum accessions were investigated by using one dimensional SDS-PAGE. A total of 10 subunit combinations were found. Among which, the highest frequency of subunit combinations (N, 20) was 41.67%, following the second frequent was (N,7) subunit combination. Three and 5 allelic variations were found in Glu-AI and Glu-Bl locus, respectively. The most abundant subunit combinations were detected in those materials from Europe.4, Among these accessions, a few new subunits,which had not been reported in common wheat, were found. One unknown subunit(?) coded by Glu-AI locus was detected, which mobility was faster than that of subunit 1 and 2*, but slower than that of subunit 5. And another unknown subunit type (?1+?2) in Glu-Bl locus was found, and its x-type subuint had the faster electrophoretic mobility than that of subunit 7, while the mobility of y-type subunit was slower than that of subunit 8. Meanwhile, this subunit was different with subuint 14+15 in cultivar Xiaoyan 6. To identify these two subunits accurately, the more comparison analysis and molecular cloning technology wound be used.