In Situ Hybridization To Identify Rye Chromosomes Genetic Variation In The Rye And Wheat Hybrids

The species of genus Secale L.?2n=14,RR?possess many excellent characters,including strong tillering ability,flourishing root system,well enough resistance to non-biological stress and a variety of common diseases,good seed setting and seed protein content.Therefore,they can provide plenty of beneficial genes for wheat quality improvment.The hexaploid triticale?AABBRR?not only has excellent characters of rye,but also retains the high nutritional value and early-maturing character of wheat.So the hexaploid triticale can provide more and better genetic resources for wheat breeding,it can be used to broaden or improve the resistance of wheat to diseases and insect pests,and develop wheat varieties with higher nutritional value and more benefit to modern management.In the present study,the hybrid between hexaploid triticale 06-2-13 and common wheat jinmai47 were produced and selfed to the F4 generation.Firstly,these materials were analyzed using fluorescence in situ hybridization?FISH?.Secondly,according to the FISH results,some materials were analyzed using molecular markers.At last,the agronomic traits across generations were observed in the field.The results are as follows:?1?With the probes Oligo-pSc119.2,Oligo-pTa535,Oligo-?GAA?₇ and Oligo-?CAA?₇,we obtained the standard FISH karyotypes of the triticale and wheat parents.The wheat-rye lines of rye chromosome's addition,substitution and translocation,translocation-addition and translocation-substitution,which providing a series of cultivars with good agronomic traits,were identified by FISH.This also confirmed that the hybrids between triticale and wheat have abundant genetic diversity.Besides,we verified the reults of FISH by molecular markers,and 12 PLUG primers with markers specially for different parts of 1–7R were screened out.?2?FISH technique was employed to investigate F2,F3 and F4 generation of the triticale and wheat hybrids.We found that the transfer rate of rye chromosomes in F2generation was the highest,which higher than that of F3 and F4 generation obviously.In F3 generation,the transfer rate of 2R was the highest,slightly higher than that of 1R,the rates of 6R,4R,3R and 7R followed,and the 5R transfer rate was the lowest.In F4generation,the transfer rate of 1R was the highest,the follows were that of 2R,6R,7R,4R and 3R,the minimum rate was found in 5R.?3?In F3 generation,the transfer rate of 5D was the highest,then 7D,2D,1D,6D and 3D,the lowest one was that of 4D.In F4 generation,5D chromosome transfer rate was the highest,then 3D,4D,6D,7D and 2D,the rate of 1D was the lowest.?4?After analyzing the agronomic traits of hybrids between triticale and wheat,we found that lose of wheat D chromosomes may cause extremely significant difference in the traits of spikelet length,thousand kernel weight and kernel width,while no significant difference of the three traits could be found in the hybrids added different R chromosomes.As to the resistance to stripe rust and tiller number,no significant difference was observed among hybrids missing different D chromosomes,but there were significant differences in the samples added different R chromosomes.The traits such as the resistance to powdery mildew,plant height,number of spikelets,kernel length,length and width of the secondary leaf,awn length and plant type,displayed extremely significant differences on the absence of different D chromosomes and addition of different R chromosomes.