Chromosome Structure Of Thinopyrum Bessarabicum L(?)ve Introduced Into Common Wheat Revealed By Molecular Markers

Thinopyrum bessarabicum L(?)ve with high salinity tolerance is an important resource for wheat improvement.Use of SSR and EST-SSR markers from wheat,rye and barley, chromosome homoeology and structure of Thinopyrum bessarabicum introduced into wheat was identified and the result was as following.Of 219 wheat SSRs amplified in Chinese Spring and Thinopyrum bessarabicum, 173(79.00%)could produce stable amplicons in the two species,46(21.00%)without any amplicon in Thinopyrum bessarabicum.19 SSRs produced specific loci of Thinopyrum bessarabicum.Of 428 EST-SSR or STS markers,95.79%(410)produced stable amplicons in the two species,4.21%(18)without any amplicon,26.40(113)produced specific loci. Genetic similarity between the two species revealed by SSRs and EST-SSRs or STS were 0.35 and 0.57,respectively,indicating more variation occurred in simple sequence repeats than in genes during speciation.In comparison with postions in chromosomes of wheat,rye and barley,6 chromsomes of Thinopyrum bessarabicum introduced into wheat were analyzed using the 132 specific markers(19 SSR and 113 EST-SSR or STS).16 markers could be used to tag chromosome 7J added in DAJ1,rearrangements with 3J and 4J was also revealed.18 makers could be used to trace the chromosomes added in DAJ3,a deduced reciprocal translocation between 6J and 2J might occur in this line,the chromosome was designated as T6JS·2JL.27 markers could be used to trace the chromosome 3J added in DAJ7,rearrangement with 7J was also confirmed.A new translocation T6AS·6AL-2JS between wheat and Thinopyrum bessarabicum was developed,10 markers could be used to trace the alien segments involved in this translocation,the break point was positioned between marker Xgwm132 and Xwmc553 in 6AL,and between Xgwm497 and Xgwm515 in 2JS.In addition to a pair of translocation chromosome T6AS·6AL-2JS in TJ01 and TJ02,a pair of intact 6J was confirmed with 27 specific markers in TJ01,while two different chromosomes(6J and T6JS·2JL)were discovered in TJ02 with 38 specific markers.20 markers could be used to trace the translocation chromosomes added in TJ03,which also involved rearrangement between 3J and 2J.A pair of telosomic 6JL was confirmed in TJ04,besides one pair of translocation T2BL·2BS-2JS revealed by 17 specific markers,the break points was positioned between marker Xgwm429 and Xwmc265 in 2BS,and between Xgwm497and Xgwm515 in 2JS.The other 58 markers could be used to tag 1J,4J or 5J.