Genome Composition And Phylogenetic Relationships Of Avena Species Based On Fluorescent In Situ Hybridization

The genus Avena L.belong to the tribe Aveneae,subfamily Pooideae,Poaceae,consists of approximately 30 species.The genus Avena comprise of four genomes:A,B,C and D.And there are four polyploid species with AB,AC or CD,CC and ACD genomes.Due to the complexity of ploidy and genomic composition,together with the overlap of geographical distribution and the similarity of morphological characters,there are many problems in the evolution and classification of Avena species,which limited the use of Avena wild species.As a result,clarifing the classification of Avena species and the origin of polyploid species,which are the key to improvement oat variety and breed new varieties.Base on those problems,to explore the evolutionary path of Avena species and the genome of AC?CD?-tetraploid Avena,we utilized oligonucleotide probes for FISH analysis of Avena.Meanwhile,we proposed a new nomenclature system of A,C and D genomes according to the polymorphism of karyotype and FISH signals.1.Fluorescence in situ hybridization?FISH?was used to detect AC?CD?-tetraploid Avena and ACD-hexaploid Avena using probes oligo-pAs120a,oligo-pAm1,oligos?CAA?₅,oligos?CAG?₅ and oligos?CTT?₅.In this study,?1?the genome is CCDD rather than AACC for three AC?CD?-tetraploid Avena.?2?AC?CD?genome tetraploid Avena have been involved in the origin of hexaploid Avena.?3?There is a small difference between C genome of AC?CD?-tetraploids and ACD-hexaploids.?4?In AC?CD?-tetraploid Avena,A.maroccana and A.insularis are more closely related,and A.murphyi is far from them.2.Probes oligos?CAA?₅,oligos?CAG?₅ and oligos?CTT?₅ were employed for A genome diploid Avena in FISH.In this study,?1?A genome diploid species is rich in genetic diversity.?2?As genome diploid A.lusitanica and other As genome diploid species showed significant differences.?3?As genome diploid A.lusitanica and Ad genome diploid A.damascena has high homology.?4?Al genome diploid species A.longiglumis and As genome diploid A.hispanica and A.brevis have relatively close relatives.3.Analysising the FISH signals of oligonucleotide probes of A genome diploids,AC?CD?genome tetraploids and ACD genome hexaploids.In this study,?1?As genome diploids A.strigosa,A.wiestii,A.brevis,A.altantica,A.hispanica and A.nuda have the same oligos?CTT?₅ hybridization signal as the D genome in polyploid.?2?Ad genome diploid A.damascena or Al genome diploid A.longiglumis might be served as the A genome donor of ACD genome hexaploid Avena.4.According to the polymorphism of karyotype and FISH signals,we proposed a new nomenclature system of A,C and D genomes.Those chromosomes of A genome were named 8A,11A,13A,15A,16A,17A and 19A.C genome chromosomes were named 1 C,2 C,3 C,4 C,5 C,6 C and 7 C.And D genome chromosomes were named 9D,10D,12 D,14D,18D,20D and 21D.