Identification Of Hybrid Offsprings Between Wheat And Dasypyrum Villosum

Dasypyrum villosum is the relative genus of Triticum aestivum,which is an important source carrying fruitfully valuable genes for improving the common wheat.In this research,the Dasypyrum villosum was used to cross and bachcross with common wheat Mianyang11 released in southwest China in 20th century and the hybrid was backcross to MY11 2 times and then the backcrossed hybrid was selfed.The seeds of ealry gerenation were treated with 4000 roentgen ofγ-radiation.Of these progenies,35 seeds selected from BC₂F₅ generation were identified by morphology,cytology,GISH and SDS-PAGE.The main results are as follows:1.Cytological analysesChromosomal number of 35 materials counted at mitosis in root tip meristems ranged from 41 to 43,the Chromosome number of 128-3,128-4,128-6 and 131-1 is 41,the Chromosomal number of 135-2 and 139-2 is 43,and the number of rest materials is 42.The examination of pollen mother cells showed that no trivalent chromosome and multivalent has been found in 135-2 and 139-2 suggesting that one Dasypyrum's chromosomel might be added into 135-2 and 139-2,However the trivalent chromosome and multivalent were found in 130-2,andthe 12 materials including 128-4,129-1,129-3,129-6,131-4,133-4,132-2,136-2,137-3,137-4,138-1 and139-1 only have bivalent,which suggested these 12 materials might be stable.2.Agronomy characteristics analysesThe height of 35 materials ranged from 86cm to 124 cm,and all of them are higher than Mianyang 11.the other charctors,such as the length of ear the number of tillering exited charcters segregationr.This variation of the agronomic character showed that the gene of Dasypyrum villosum might have been transferred into the Mianyang11. 3.GISH analysesGISH was carried ou using the genomic DNA of Dasypyrum villosum as the probe and the genomic DNA of Triticum aesitvum var,"Chinese Spring"as the blocking.The results demonstrated that 135-2(2n=43) has a signal at one chromosomal,and it might be an alien additonal material,while 133-4(2n=42) might be a small fragment translocation material.4.SDS-PAGE analysesHigh molecular weigt glutenin subunit comprosition of the stable materials was analyzed by SDS-PAGE.Chinese Spring(subunit:null,7+8,2+12),Mianyang11 (subunit:1,7+8,5+12),and Dasypyrum villosum were used as contrasts.The results indicated that most the subunit comprosition of 7 materials studied were as same as the Mianyang11 (1,7+8,5+12),and that of the materials of 137-4,133-4 and 138-1 were 1,7,5+10.Further more,the material of 129-6 had a band which has not exited in any parents.