Preliminary Study Of Mechanism On Diversity Of Floral Orgen Variants In Anemone Rivularis Var. Flore-minore

Flower is a unique ornamental and reproductive organs to angiosperm,which is also an important classification of classical taxonomy.Ranunculaceae is one of the original branches of angiosperms,and many groups of this family showed a high plasticity overall.It has many original features of the phylogenetic population,while simultaneously shows multiple evolutionary features.Ranunculaceae flower development model is currently recognized as the “modified ABC model”: “Sliding boundaries model” and “Fading borders model”.Anemone rivularis var.flore-minore belongs to the genus Anemone rivularis.After several years' survey,a serious of nature floral organs variants of Anemone rivularis var.flore-minore were determined.Based on varation organ and varation level,variants were divided into 5 types: white,green-white,five-flap,green and extreme variation.The variation mechanism was studied preliminarily through molecular identification,morphological observations,and AP3-3 genes analysis.The main results were as follows:1.Sequence alignment showed both ITS2 and rbcL sequences from normal and variants had no difference after comparison,so the normal and variant plants were identified as the same species.The phylogenetic tree constructed by ITS2 and rbcL could separate Anemone rivularis var.flore-minore from the other species,but the NJ tree constructed by ITS2 sequence was more suitable for the identification of Anemone.The ITS2 secondary structures of Anemone rivularis var.flore-minore and Anemone rivularis were significantly different in the Helix ?.2.Morphological observation demonstrated that variant flowers had big differences in morphologys,which existed a variation gradient from outside,and all flower organs changed to green bracts.Electron microscopy revealed that some tepals had stomatas,and some had no stomata,moreover there were no significant differences in the stomatas.In addition,proportion and number of floral organs were all unstable except tepals numbers from normal and five-flap flowers,besides,tepals proportion was negative correlation with stamens/carpels,so it indicated that increased tepals in variant flowers were very likely transformed from stamens and carpels.3.Based on AP3-3 genes from normal and green-white plants,the rest AP3-3 genes of 4 variants were amplified.Sequence alignment displayed that the length of the 4 AP3-3 genes was the same,and the upstream regulatory region and coding region had no difference.The further alignment of AP3-3 from normal and variant plants showed that regulatory region had a insertion and CDS region had 1 base deletion.Both of insertion and deletion might involve in variation.Above all,the research preliminarily discussed the causes of diversity variation of Anemone rivularis var.flore-minore,which provide the theoretical basis for the study of molecular mechanism of floral organ development and the improvement of ABC model of angiosperms flower development.At the same time,as the basal eudicots,the study on Anemone rivularis var.flore-minore can provide more comprehensive understanding of angiosperm phylogeny and genetic evolution.