Phylogeny of Trigonotis in China-with a special reference to its nutlet morphology and plastid genome

The genus Trigonotis comprises nearly 60 species mainly distributed in East and Southeast Asia.China has the largest number of Trigonotis species in the world,with a total of 44 species,of which 38 are endemic.Nutlet morphology is useful for the taxonomic delimitation of Trigonotis.However,there are still controversial circumscriptions of nutlet shape in some species.In previous studies,interspecies phylogenetic relationships were inferred using few DNA markers and very few taxa,which possibly led to erroneous or incomplete conclusions.In this study,the nutlet morphology of 39 Trigonotis taxa and the characteristics of 34 complete chloroplast genomes(29 taxa)were investigated and analyzed.Then,the phylogenetic relationships were discussed within this genus based on complete chloroplast genomes.To the best of our knowledge,this study is the first comprehensive analysis of nutlet morphology and complete chloroplast genome of Trigonotis.Based on nutlet morphology,Trigonotis can be divided into two groups:Group 1,hemispherical or oblique tetrahedron with carpopodiums,and Group 2,inverted tetrahedron without carpopodiums.The chloroplast genome of Trigonotis exhibited a typical quadripartite structure,including 84-86 protein-coding,37 transfer RNA,and 8 ribosomal RNA genes,with a total length of 147,247-148,986 bp.Genes in the junctions were well conserved in Trigonotis,similar to those in other Boraginaceae s.str.species.Furthermore,Trigonotis chloroplast genomes showed relatively high diversity,with more conserved genic regions than intergenic regions;in addition,we detected 14 hot spots(Pi>0.005)in non-coding regions.Phylogenetic analyses based on chloroplast genome data identified highly resolved relationships between Trigonotis species.Specifically,Trigonotis was divided into two clades with strong support:one clade included species with hemispherical or oblique tetrahedron nutlets with carpopodiums and bracts,whereas the other clade included species with inverted tetrahedron nutlets without carpopodiums or bracts.Our results may inform future taxonomic,phylogenetic,and evolutionary studies on Boraginaceae.

Observation and Comparision on Morphological Characteristics of the Seed-like Fruits of Salvia shandongensis and Its Relatives

[Objective] This study aimed to compare and analyse the morphological characteristics of the seed-like fruits between Salvia shandongensis J. X. Li et F. Q. Zhou and its relatives. [Method] The morphological characteristics of the mature seed-like fruits of Salvia shandongensis and its three congeners, S. miltiorrhiza, S. miltiorrhiza f. alba and S. bowleyana, were comparatively observed using both optical microscope and scanning electron microscope. [Result] The results showed that there were distinct differences in the shape, size and exine sculpture of the seed-like fruits of the four Danshen congeners： the seed-like fruits of S. shandongensis that were elliptical and had areolate sculpture with subquadrangular convex meshes as well as densely filamentous transverse lines were easy to be distinguished from those of S. miltiorrhiza Bge., which were broadly elliptical and had reticulate sculpture with subquadrate concave meshes. The seed-like fruits of S. bowleyana were fusiform and their ektexine had reticulate sculpture with polygonal meshes, which were slightly convex at the center, which are obviously different from those of S. shandongensis. [Conclusion] This study first accumulates data of the seed-like fruits of S. shandongensis, which provides important bases for establishing its taxonomical status and studying its germplasm. The morphological characteristics and reticulate sculpture on ektexine of the seed-like fruits S. miltiorrhiza Bge. are consistent with the previous report. The results in this study not only provide references for uncovering the genetic relationships between S. shandongensis and S. miltiorrhiza Bge., as well as the interspecific classification and identification. In addition, this study also provides new scientific proofs for the identification of Danshen species and their introduction and cultivation, genetics and breeding.

A preliminary phylogenetic study of Paraphlomis(Lamiaceae)based on molecular and morphological evidence

Paraphlomis is a genus of Lamiaceae with about 30 species distributed mainly in subtropical China.In this study,we carried out the first molecular phylogenetic analyses to elucidate the relationships within the genus based on two nuclear and four plastid DNA regions.Our results,which recovered a species of Matsumurella within Paraphlomis,indicate that the genus is not monophyletic.The two sections and most of the series previously described within the genus are also shown to be polyphyletic.Combining with morphological evidence,our study indicates that nutlet morphology rather than calyx morphology is of phylogenetic value for the infrageneric classification of Paraphlomis.Moreover,P.jiangyongensis,a new species from southern China,is here described,and P.coronata,formerly treated as a variety of P.javanica,is here resurrected as a distinct species within the genus.

Nutlet Micromorphological Study on <i>Salvia</i>L. (Lamiaceae) from NE Iran

In the present research, micromorphological features of 10 Salvia L. nutlets (mericarp) growing in NE Iran were studied by SEM. These species were divided into three and four groups based on the shape and ornamentation of nutlets respectively. The variation in color, size and ornamentation of mericarp helped to identify species.