Molecular Cytogenetics Study On Cold Resistance Of Perennial Agropyron In Cold Region

In this study,perennial Trititrigia with cold resistance was used as the material that the hybrid offspring of octaploid Trititrigia"wheatgrass 8"and Agropyron intermedium,as well as 7 cold-sensitive Trititrigia as contral.The cold hardiness and chromosome configuration of perennial Trititrigia were analyzed and discussed by means of morphology,cytology and molecular markers,which provides theoretical and material basis for the study of genetic characteristics of perennial Trititrigia in cold region.The test results of morphology and cold hardiness showed that 12 of 13 perennial Trititrigia materials were safe for overwintering in Harbin under-30?and had strong cold resistance,except line 16-425294.There were three materials that had the strongest cold resistance,as well with five live years and underground rhizomes.Line16-42529912 of four live years had the highest seed setting rate that was more than100%and the plants were luxuriant.The result of cytological examination showed that the chromosome numbers were from 42 to 46 in 12 materials of perennial Trititrigia with the cold resistance and there were three types of chromosomes number,42,44 and46,respectively.The chromosome numbers of lines 16-42529356 and 16-51820443were stable during a couple years,which was 44 and 46.The observation of meiosis showed that there was the rod bivalent,univalent and polyvalent in pollen mother cells for all materials.Through the detection of molecular marker and in situ hybridization,it was found that 12 materials contained the components of E(J~S)and St chromosome.The St chromosome number was from 2 to 14,the J chromosome number was from 2 to 9,the J~s chromosome number was from 0 to 3 and ABD chromosome number was from 16to 38 in perennial Trititrigia.The alien chromosome number of wheat was St>J>J~s.Compared with the control materials,the proportion of alien chromosomes in perennial Trititrigia was higher.It showed that the cold resistance and perennial character was decided by the chromosome proportion between St+J,St+J+J~s and ABD in perennial Trititrigia.The result of this project plays an important role for breeding the perennial Trititrigia with cold resistance.Moreover,these materials are large,high and luxuriant,and can be harvested for many times after sowing.It has a positive effect for increasing grain yield and improving land use.