| Subgenus Amygdalus belongs to the Rosaceae,Prunoideae and Amygdalus L.There are 6species in China: Amygdalus triloba,Amygdalus pedunculata,Amygdalus dulcis,Amygdalus tenella,Amygdalus tangutica,and Amygdalus mongolica.Subgenus Amygdalus plants such as A.pedunculata,A.mongolica,A.tangutica and A.tenella are still in the wild and semi-wild.Chloroplast is the main place for photosynthesis in plant cells.It a semi-autonomous organelle with its own DNA and protein synthesis system.It is an important part of plant cell genetics.The chloroplast genome sequence in angiosperm cells is usually highly conserved,mostly derived from maternal parents.The genome size is suitable,and the gene evolution rate is moderate.It is feasible and highly reliable to construct plant system evolution analysis with chloroplast genes alone.Taking the whole chloroplast gene sequences of Subgenus Amygdalus as the core obtained by the research group,there are different levels between Amygdalus-Subgenus Amygdalus and Rosaceae.The main conclusions of this research are as follows:1.Using the Illumina Hiseq platform for high-throughput sequencing,the research team obtained 5 complete sequences of A.pedunculata,A.mongolica,A.triloba,A.tangutica,and A.tenella.The sequences of the chloroplast genome are saved and registered in the NCBI database.2.Analyze the basic characteristics of the chloroplast genomes of Subgenus Amygdalus,Subgenus Persica,Amygdalus L.and Rosaceae,and find that Subgenus Amygdalus,Subgenus Persica,Amygdalus L,and Rosaceae plant chloroplast genomes length is respectively between 157,851-158,596 bp,157,736-158,971 bp,157,736-158,971 bp and 157,736-158,971 bp,and the average length is respectively 158,163 bp,158,203 bp,158,181 bp,and 158,012 bp,all of which are typical tetrad structures.In Amygdalus-Subgenus Amygdalus and Rosaceae plants,the chloroplast genomes structure is very conservative,and the total length of the chloroplast genome of a species has no obvious correlation with its phylogenetic status.The total GC content in the chloroplast genomes is between 36.6%-37.3%,and most species are 36.8%.3.Analyze the codon usage in the chloroplast genome protein coding region(CDS)sequences of Amygdalus-Subgenus Amygdalus and Rosaceae,and find differences hierarchical taxonomic groups have similar species specificity.First,64 kinds of codons are used.Secondly,the aliphatic amino acid leucine(Leu)is the most frequently encoded codon,and the most frequent codon is UUU that encodes phenylalanine.In Amygdalus-Subgenus Amygdalus and Rosaceae chloroplast genomes the number of codon types RSCU value > 1is 29-31.It is similar to most angiosperms,prefering Codons encoded at the end of A,T.4.The SSR types of Amygdalus-Subgenus Amygdalus chloroplast genomes have similar species specificity.The repeat types are mainly single nucleotides Acid type.Trinucleotide types are not detected in SSR sites.There is strong base composition with A,T.5.There are collinearity in sequence differentiation of Amygdalus-Subgenus Amygdalus and Rosaceae chloroplast genomes.At the SC/IR boundary the plants have certain gene arrangement and species specificity.6.Subgenus Amygdalus in China is divided into two large branches and is inlaid in Amygdalus L,Armeniaca Mill.and Prunus L in the subfamily Prunoideae.The subfamily and genera of Rosaceae have different evolutionary relationships with Subgenus Amygdalus plants.Subgenus Amygdalus in China is closely related to Amygdalus L,Prunus L,and Armeniaca Mill..The peach group is at the top of the evolution of drupe fruits.Based on the evolutionary relationship of almonds,the classification of the Subgenus Amygdalus in molecular systematics can better reflect the evolution of the different stages of the stone fruits.According to the results of this study,it is concluded that peach group is at the highest stage of stone fruit evolutione.Some plants of Armeniaca Mill.,Prunus L.and Cerasus Mill.in the Flora of China,could been classified into Subgenus Amygdalus in the tribe Amygdaleae,Prunus s.l.. |
PDF Full Text Request