Molecular Cytogenetic Identification Of Common Wheat-aegilops Ovata Hybrid Derivatives

Wheat is one of the world’s most important food crops, very serious wheat germplasmhomogenization has been a problem after long-term artificial directional selection. narrowgenetic basis of common wheat will make breeding objectives of high-yield, high quality,high resistance very difficult to achieve in the short term. Wheat has a large number ofrelatives and distantly related species, and these species contain a large number of beneficialgenes which constitute three wheat gene pools. Transfering useful genes from wheat relativesor distantly related species gene pools into wheat through distant hybridization method is aneffective way of wheat genetic improvement. In this study, common wheat Chinese Spring(China Spring) and its related species goat grass (Aegilops ovata) were hybridized, then F1generation obtained were backcrossed with wheat varieties Shanyou225, then progeny frombackcrossing selfed three times, the BC1F2and BC1F3generation were identified, and theresults are as followings:(1)The field traits survey results show that among19BC1F2generation materials,7plants had big leaves and spikes, more spikelets than normal, mature late;4plants were dwarf,had narrow leaves and spikes similar to the goat grass panicle morphology, and spikes wereeasy to fall after mature, mature late, the morphology of others are between parents;157BC1F3generation materials were obtained from BC1F2generation. Both BC1F2and BC1F3generation materials were tested for powdery mildew resistance at both seedling and adultstage, results showed that16plants of BC1F2generation were immune to powdery mildew,3plants were highly susceptible, and results at both seedling and adult stage were the same;results of powdery mildew resistance test on157BC1F3generation plants at seedling stageshowed that55plants were immune to powdery mildew, and the rest are susceptible; resultsfor most plants at adult stage coincided with results of seedling stage, except4plants whichwere resistant at seedling stage but susceptible at adult stage. In addition, all resistant plantsof BC1F3generation are progenies of resistant material of BC1F2generation, and offsprings ofsusceptible materials of BC1F2generation were all susceptible.(2)The cytological identification results showed that chromosome number of BC1F2generation plants ranged from50to60, indicating that BC1F2generation plants did possess a number of chromosomes from Aegilops ovata, and was in line with phenotypic characteristicsof BC1F2generation; cytological Identification was conducted on55BC1F2generation plantswhich were immune to powdery mildew, results show that chromosome number range from44to56, all chromosome numbers were less than the previous generation, indicating thatthere was chromosome loss during selfing of previous generation.(3)400pairs of SSR primers were screened for Aegilops ovata specific primers,351pairs of primers could amplify bands, and20pairs of primers could amplify Aegilops ovataspecific bands;20pairs of specific primers were applied in19BC1F2generation plants, and10pairs of primers could amplify specific bands.(4)GISH experiment system for Aegilops ovata chromosome identification wasestablished after repeated experiments, two plants of BC1F3generation which has56chromosomes respectively were identified using GISH system established, the results showedthat Plant which possess56chromosomes has14additional Aegilops ovata chromosomes.