Study On The Dynamic Changes Of The Chromosome In The Hybrid Progeny Of Octoploid Triticale And Common Wheat

Food crisis is related to human survival and development,has long been highly concerned about the global countries.Wheat is one of most important food crops of the world,and it represents the staple food for about 2/5 of the world population.The plant acreage and production of wheat are ranked first in the cereal crops.It plays a decisive role in human civilization and cultural development and is the basis for ensuring global food security.However,the low genetic diversity,the narrow genetic basis and the absence of resistance for various diseases seriously restricted the progress of wheat breeding.The relative species of wheat are important gene pools for wheat breeding.It is an effective way to broaden the genetic basis of wheat by wide hybridization to introduce the excellent gene of rye into wheat and obtain more new breeding material.In the present study,the Qinling rye(QL)was crossed with wheat cultivar,Mianyang 26(MY26),and F1 was doubled to obtain the amphiploid-octaploid triticale(MQ).The octoploid triticale was crossed with wheat cultivar Miangyang 26 to obtain hybrid F1.The hybrid F2 and F3 generations were obtained by selfing.The F2 and some of F3 generations were analyzed by fluorescence in situ hybridization(FISH).The main results were as follows:1.The number of chromosomes in the F2 generation was ranged from 2n=40 to 2n=56,and mainly between 43 and 44,2n = 44 accounted for 37.8%of the detected strains,followed by 2n = 43 accounted for 21.6%.In F3 generation,the range of chromosome number was between 2n = 42 and 43,of which 2n = 42 accounted for 78%.2.In the F2 generation,rye chromosomes were added in most plants analysed,among which 6R and 7R had the highest frequency and 4R were the lowest.In the F3 generation,rye chromosomes were rapidly lost,and some fragment of rye chromosomes were formed and detected in the plants.3.Fluorescence in situ hybridization analysis using Oligo-pSc119.2-1(green),Oligo-pTa535-1(red),Oligo-1162(red)as a probe showed that some of wheat chromosome structure changed in the plants of the offspring of octaploid tritical and common wheat hybrid.It was includs 1B,6B,7B.The terminal Oligo-pSc119.2-1 signal on wheat chromosome 1BS was disappeared in partial individual plants,while terminal Oligo-pSc119.2-1 signal appeared on wheat chromosome 6BS.In addition,different altered types of broken 6B with telomere absencein both the long arm and short arm was observed in different plants.A strong Oligo-pSc119.2-1 signal was inserted at the sub-end of the long arm of the 7B chromosome,accounting for 11%of the tested individuals.4.4BS/4BS and 5RL/5RL were two equal arms chromosome,wheat-rye translocation 4BS/2RL.2RS,and 3RS/6BL were detected in F2 generation.These altered chromosomes did not transmited into next generation.However,one new translocation chromosome of IRS/1AL was detected in F3 generation.