Production And Cytomolecular Identification Of Wheat-Agropyron Cristatum 1P And 5P Disomic Addition Lines

Wheat,being the staple food crop of the world,need to broaden genetic background and develop tolerance to prevalent biotic and abiotic stresses.As is known to all,the alien gene introgression plays an important role in utilization of wild genetic resources to enhance the genetic diversity of cultivated wheat varieties.Wheat alien disomic addition lines are usually considered as key materials to transfer superior alien genes into common wheat.In this study,wheat-Agropyron cristatum derivatives?-3-1and?-11-1 were backcrossed by common wheat Fukuho and identified by in situ hybridazation,molecular markers and agronomic traits investigation to obtain new addition lines.The main results are as follows:1.Chromosome composition analysis of wheat-A.cristatum derivatives?-3-1 and?-11-1.The mitotic and meiotic GISH results showed that wheat-A.cristatum derivatives?-3-1 consists of 40wheat chromosomes and 4 A.cristatum chromosomes and formed 20 bivalents of wheat and 2 bivalents of A.cristatum.The mitotic GISH-FISH results indicated the lacking chromosomes of?-3-1 are a pair of 1A.The additional A.cristatum chromosomes were confirmed to be 1P and 2P by mitotic FISH and EST-STS markers detection.Similarly,results of mitotic GISH,FISH and EST-STS markers showed that wheat-A.cristatum derivatives?-11-1 contains the whole 42 wheat chromosomes and 4 A.cristatum chromosomes of 2P and 5P,respectively.Therefore,?-3-1 is a 2P addition and 1A-1P substitution line,while?-11-1 is a 2P and 5P double disomic addition line.2.Production of wheat-A.cristatum 1P disomic addition and substitution line.A wheat-A.cristatum 2P disomic addition line,a wheat-A.cristatum 1P disomic addition line and a 1A-1P substitution line were isolated from?-3-1 by backcrossing,cytological and molecular marker identification.The wheat-A.cristatum 1P disomic addition line was backcrossed by common wheat Fukuho to construct BC₁F₂ and BC₂F₂ populations.It is confirmed that the existence of chromosome 1P can reduce plant height and increase spike length and tiller numbers by the agronomic traits evaluation of BC₁F₂ and BC₂F₂ populations.Besides,chromosome 1P also contains a gene controlling long bristles on glume ridges which can be a morphology marker.3.Production of wheat-A.cristatum 5P disomic addition line.A wheat-A.cristatum 2P disomic addition line and a wheat-A.cristatum 5P disomic addition line with agronomic differences were separated from?-11-1 by backcrossing.Wheat-A.cristatum 5P addition line is an important material for further study of chromosome 5P and location of genes on it.The mitosis and meiotic observation of wheat-A.cristatum derivatives?-11-1 and 5P addition line?-11-1a revealed that chromosome 5P possesses gene?s?that can enhance the frequency of homeologous pairing and produce translocation by inducing breakage of chromosomes.So chromosome 5P can be a new implemental material for wheat chromosome mutation breeding.