Molecular Cytogenetic Analysis On Progenies Of Synthesis Amphiploids Between Wheat And Psathyrostachys Huashanica

Wheat is one of the most important food crops in the word. It is grown worldwide and gets more volume of production compared with the other crops. With the continuous growth of population, the improvement of living standard and the change of global climate, it is necessary to broaden the genetic base of wheat with multiple approaches. However, in the modern agricultural system, the narrow genetic base far can't meet people's needs. A lot of wheat relatives, carrying important traits such as high yield, good quality, disease resistance and stress tolerance, have been utilized frequently. Amphiploids, coming from the wide hybridization between wheat and its relatives, will be an important'bridge'to transfer desirable genes into wheat cultivars to enrich the genetic basic through the crosses between them.PHW-SA is a sythesized amphiploid of Triticum astivum L. and Psathyrostachys huashanica Keng ex Kuo. In this study, we try to identify the chromatin of P. huashanica in the F2 and BC1F1 progenies derived from PHW-SA×Chuanmai107 and PHW-SA×J-11 with morphological, cytogenetic, biochemical and molecular techniques. The main results are as follows:1. Morphological study showed that there was a wide range in average height of the F2 and BC1F1 plants. Compared with their parents, some plants were taller, and the others showed the same height. The p value was 0.0001, and the difference was very significant. The average tillers in the progeny were more than their parents or close to the parents, and the p value was 0.0231 with significant difference. The average spikelets were shorter or close to their parents, and the p value was 0.0001 with very significant difference. The average length of flag leaves was longer or shorter or intermediate their parents, and the p value was 0.1417 with no significant difference. The average number of spikelets per spike in the progeny was less or close to one of the parents, and the p value was 0.3336 with no significant difference. The results indicated that the F2 and BC1F1 plants were rich in genetic variation.2. All the plants in the field were immune to powdery mildew and scab.3. The total chromosome number ranged from 42 to 48 among the F2 and BC1F1 plants. The average chromosome number was 43.9. Plants with 42 and 44 chromosomes were 27.8% and 44.4%, respectively. The results indicated that different F2 and BC1F1 lost different numbers of chromosome, and the backcross could reduce chromosome number of the progeny fastly. 4. In the metaphase I of meiosis in the pollen mother cells among F2 and BC1F1 plants, the rang of average univalent was 0.06-5.10. The average bivalent was 20.42-22.23, among which the ring bivalent was 15.77-21.06, and the rod bivalent was 0.94-3.68. The rang of average trivalent was 0.06-0.11. The pairing configuration at metaphase I was totally different in the plants with different chromosome number. And No.143 and No.138 plants with 42 chromosomes presented just a few of univalents, 0.06 and 0.12, respectively. Actually, the meiotic pairing in the plants with same chromosome number is different as well. Trivalents and lagging chromosomes were observed in some cells. The results indicated that meiosis of the low generations was extreme disordered, and was genetically unstable.5. The SDS-PAGE results showed that a new band presented in PHW-SA and some F2 and BC1F1 plants, such as No.135,147 and 150, and was not present in P. huashanica and J-11. The LMW-GS results showed that PHW-SA and some progeny plants as No.138,139,141,144,145,148 and 149 presented one band as same as P. huashanica. The rusults indicated that the chromosomes or the chromosome fragments of P. huashanica had transferred into some F2 and BC1F1 plants.6. Among all the F2 and BC1F1 plants, No.134 plant had moderate infection to strip rust, No.138 had high infection to strip rust, No.141 had high resistance to strip rust, and the remaining plants had moderate resistance to strip rust.7. SSR analysis showed that 106,104,91 fragments were amplified by 13 SSR primers in P. huashanica, J-11 and PHW-SA. In the genetic background of J-11, PHW-SA had 42 polymorphic bands, the ratio accounted for the tolal number was 46.15%. In different sites all the primers Xwmc679, Xwmc553,Xbarc127 and Xgwm344 could amplify a band which presented in P. huashanica and PHW-SA, and was never present in J-11.