Polymorphism Analysis Of Wheat-Psathyrostachys Huashanica Amphiploids With AFLP

AFLP (Amplified Fragment Length Polymorphism) which has the advantage of high sensitivity, high speed, good repeatability, high detected rate and so on is a kind of molecular marker technology combined with RFLP (restricted fragment length polymorphism) and PCR (Polymerase Chain Reaction) technology. At present, AFLP is widely used in some research fields of wheat germplasm resources, such as genetic diversity detection, genetic mapping, gene cloning, expression, molecular marking and location and so on.In modern agriculture, the drawbacks of common wheat varieties are becoming more and more obvious because of their narrow genetic basis,(diminishing genetic differences) and serious genetic diversity losses, so common wheat varieties become more and more vulnerable too in the face of various biotic and abiotic environmental stress, which severely restrict the output’s sharp increase and quality’s further improvement. In order to enhance their output and resistance, it is very necessary to reform their genetic backgrounds. Psathyrostachys huashanica Keng ex Kuo (2n=2x=14,NsNs), as an important kind of wild relative plants of wheat, belonging to the third genebank resource and having many advantageous traits, is one of the most valuable foreign species for the genetic improvement of wheat. The amphiploid developed from cross between Triticum aestivum and Psathyrostachys huashanica can be used as a bridge to transfer genetic substances from Psathyrostachys huashanica to Triticum aestivum, and then serve wheat breeding work, so it is extremely essential to realize the genetic variation conditions of the material-Wheat-Psathyrostachys huashanica amphiploids (PHW-SA). This research compared and analyzed the AFLP markers of common wheat (J-11), Psathyrostachys huashanica and PHW-SA, discussed the genetic variation conditions of PHW-SA; at the same time, the research recovered, cloned and sequencd Ns specific AFLP markings of PHW-SA and Psathyrostachys huashanica, discussed the variation of foreign genetic substances of distant hybridization materials, which could provide the theoretical basis for the development of chromosome Ns specific markings in future. The main research results are as follows:1.17726markers were obtained in this3materials by195pairs of primers,90.9bangding by every primer on average. Of which, J-11, Psathyrostachys huashanica and PHW-SA respectively had5136,3953and5637markers, accounted for29.00%、22.3%and31.8%of the total. There were1715co-markers in all3materials, accounted for33.4%,43.4%and30.4%of its total markers of J-11, Psathyrostachys huashanica and PHW-SA. According to these, the ratio of total markers amplified by AFLP primers in this3materials changed little.2. To the polymorphism of AFLP markers, J-11had more abundant genetic polymorphism than PHW-SA. There were2484co-markers between J-11and PHW-SA, which accounted for48.4%and44.1%of themselves, respectively;81.8%markers of J-11were amplified in PHW-SA.3. There were246co-markers existed between PHW-SA and Psathyrostachys huashanica, which accounted for4.4%of total amplification markers in PHW-SA and6.2%in Psathyrostachys huashanica;49.6%markers of Psathyrostachys huashanica were amplified in PHW-SA.4. There were66markers of its parents disappeared in PHW-SA, which respectively accounted for1.3%,1.7%and1.2%of total amplification markers quantity in J-11, Psathyrostachys huashanica and PHW-SA.232new markers which did not exist in its parents were amplified in PHW-SA and occupied4.1%of its total amplification markers. The results showed that chromosome changed quickly during the synthesizing process of PHW-SA.5.69pairs DNA fragments were successfully selected from492Ns specific AFLP markings of PHW-SA and Psathyrostachys huashanica, of which52pairs fragments were successfully sequenced. Compared by NCBI database, there only existed6pairs of identical fragments in Chromosome Ns, which accounted for11.5%of all sequencing fragments.In conclusion, chromosome Ns emerged rather great genetic variation in the process of transferring from Psathyrostachys huashanica to PHW-SA; the chromosome Ns of octoploid PHW-SA had taken severely adaptive changes in the progress of allopolyploidization.