Molecular Cytogenetic Study On The Resistance And Regeneration Of Wheat Thinopyrum Hybrid Progeny

Thinopyrum is a relative species of wheat.It carries abundant resistance and stress genes and is the third-class gene bank of wheat.In this study,the hybrid progenies of Octoploid Tritelytrigia and Thinopyrum intermedium were used as research materials.By using morphological,cytological,molecular marker and in situ hybridization methods,the new wheat Thinopyrum intermedium Germplasm with scab resistance and regeneration characteristics after cutting in autumn was selected.The purpose of this study is to provide new germplasm resources for improving wheat quality,and to study the disease resistance and regeneration of Thinopyrum intermedium chromosome for scientific basis.The results of morphological examination showed that the materials studied were Tritelytrigia type,and there was a great difference in spike type.The seed setting rate of 4 lines was more than 100%,which were 5-1,5-6,5-7 and 5-14,respectively.There were another 10 lines,the seed setting rate was more than 80%.The seeds of most materials were red,slender type,consistent with the seed morphology of Tritelytrigia.Materials XJ9,XJ 43,XJ77,XJ 194 and SX18-3646 had post-harvest of regrowth(PHR).The results of grain protein test showed that the grain protein content of 15 lines was more than 18%,which 5-4,5-5,5-11,5-12 and 5-16 were more than 20%,and the highest was 25.44% in 5-12.The screening results of scab resistance showed that 5 lines had resistance to 2 grades.4 materials,5-10,5-12,5-19,5-20 Y,and 5-20 N with resistance to scab above 2 grades were stable,which were selected in the early research.The results of chromosome detection showed that there were 56 chromosomes in 21 materials and 42 chromosomes in 3 materials.Among them,XJ 43,XJ 77,XJ 194 and SX18-3646 with PHR had 56 chromosomes and XJ9 had 42 chromosomes.The chromosome number of Scab Resistant Materials was 56.The results of molecular markers showed that the genetic components of 1J,4J,5J and 7J were found in all three Scab Resistant Materials.GISH results showed that the early selection of the scab resistant material was octoploid Tritelytrigia,HS2-2 and HS2-4 had not only 42 wheat chromosomes,but also 10 J-chromosomes and 4 JS or St chromosomes.HS2-5 and HS2-14 were totally composed of 42 wheat chromosomes and 14 and 12 J-chromosomes.Therefore,the J-chromosomes from Th.intermedium was closely related to scab resistance.There were 10 St chromosomes in SX18-3646,12 St chromosomes in XJ77 and 5 St chromosomes in XJ194.It is suggested that St chromosome is related to regeneration and needs further analysis.