Planting Adaptability of Four Kinds of Common Vegetabless in Shanghai

[Objectives]To explore the planting adaptability of vegetables in Shanghai.[Methods]In this paper,cowpea(Vigna unguiculate(L.)Walp.),cucumber(Cucumis sativus L.),eggplant(Solanum melongena L.)and potato(Solanum tuberosum L.)were selected as experimental materials and planted in the open air.The growth status,the occurrence of diseases and insect pests,and the taste evaluation of these four kinds of common vegetables were mainly studied.[Results]The results showed that the four kinds of common vegetables in Shanghai had strong growth,strong adaptability,less pests and diseases,and good taste.[Conclusions]The cowpea,cucumber,eggplant,and potato are suitable for planting in Shanghai.

Study on Germplasm Resources of Peach Cultivars

[Objectives]To study the germplasm resources of excellent peach cultivars.[Methods]Five peach cultivars were introduced,in-cluding‘Jinxiu’peach,‘Jinxiang’peach,‘Chunxiao’peach,‘Hujingmilu’peach and‘018 nectarine’peach.Then,these five cultivars were used to study the biological characteristics of peach trees,namely,as phenology,fruit quality,heat resistance,cold resistance and other resistance.[Results]Five cultivars of peach plants grew fast and robust,among which‘018 nectarine’had very crisp fruit,‘Jinxiu’,‘Jinxiang’,‘Chunxiao’and‘Hujingmilu’had very sweet fruitꎻthe peach trees of these five cultivars have good water resistance,heat resist-ance and cold resistance.[Conclusions]The results of this study can not only provide a reference for the introduction of peach trees,but also provide a practical basis for the large-scale planting of peach trees.

SbMYB3 transcription factor promotes root-specific f lavone biosynthesis in Scutellaria baicalensis

Scutellaria baicalensis Georgi produces abundant root-specific f lavones(RSFs),which provide various benefits to human health.We have elucidated the complete biosynthetic pathways of baicalein and wogonin.However,the transcriptional regulation of f lavone biosynthesis in S.baicalensis remains unclear.We show that the SbMYB3 transcription factor functions as a transcriptional activator involved in the biosynthesis of RSFs in S.baicalensis.Yeast one-hybrid and transcriptional activation assays showed that SbMYB3 binds to the promoter of flavone synthase II-2(SbFNSII-2)and enhances its transcription.In S.baicalensis hairy roots,RNAi of SbMYB3 reduced the accumulation of baicalin and wogonoside,and SbMYB3 knockout decreased the biosynthesis of baicalein,baicalin,wogonin,and wogonoside,whereas SbMYB3 overexpression enhanced the contents of baicalein,baicalin,wogonin,and wogonoside.Transcript profiling by qRT–PCR demonstrated that SbMYB3 activates SbFNSII-2 expression directly,thus leading to more abundant accumulation of RSFs.This study provides a potential target for metabolic engineering of RSFs.

Quercetin-derivatives painting the yellow petals of American lotus(Nelumbo lutea)and enzymatic basis for their accumulation

American lotus(Nelumbo lutea)is one of the two species in Nelumbo and has only yellow flower.Identification of total flavonoids showed wild American lotus contained almost only flavonols with quercetin 3-O-glucuronide to be the dominant pigment.The variation tendency of the total flavonol content was coincident with yellow color variation of petals during flower development.To understand the mechanism of accumulation and constituent of pigments in petals,three pivotal genes,NlFLS1,NlFLS2 and NlFLS3,which were predicted to encode flavonol synthases were isolated and characterized by analyses of basic bioinformatics,temporal and spatial expression patterns and enzymatic activity.Their temporal expression levels showed the same variation tendency,which was also consistent with the development-dependent variation of total flavonol content.Spatial expression patterns indicated the three genes should function in petals.All the three proteins were demonstrated to be bifunctional dioxygenase,possessing both flavonol synthase activity and flavanone 3-hydroxylase activity.Besides,other flavonol biosynthesis related genes were also investigated on their expression levels to give more clues on the mechanism.Substrate preferences of the three FLSs,substrate competitions between the FLSs and other flavonol biosynthesis related enzymes,and the greatly differential expression levels between F3’H(flavonoid 3-hydroxylase)and F3’5’H(flavonoid 3,5-hydroxylase)contributed to the flavonol constituent in the petals of America lotus,namely abundant quercetin-derivatives while very few kaempferol-derivatives and myricetin-derivatives.

Effects of functional phylogeny of light-response-related orthologous genes on seedling survival in a subtropical forest

Background: Light is an important environmental factor affecting the growth and survival of plants in forest communities. The competition for light resources and divergent responses to light may affect plant species coexistence in natural forests through niche partitioning and environmental filtering, respectively.Methods: In the present study, sequences of light-response-related functional genes were extracted from transcriptomic data of 99 tree species in a subtropical forest and average and nearest taxon phylogenetic diversity of adult(A_Apd’, A_NTpd’) and seedling neighbors(S_Apd’, S_NTpd’) around each focal seedling were calculated to evaluate effects of differentiation in light-response-related genes on community assembly processes.Results: The results showed that seedling survival was related to S_NTpd’, S_Apd’and A_Apd’of two chlorophyll ab-binding proteins involved in the assembly of photosystem Ⅱ and two genes responsive to light intensity,indicating seedlings surrounded by neighbors with distinct light responses tended to have high survival rates.Conclusions: Our results indicated that niche partitioning due to competition for light resources between plants may act as the key mechanism in determining seedling dynamics in subtropical forests.

Insights into cryptic speciation of quillworts in China

Cryptic species are commonly misidentified because of high morphological similarities to other species.One group of plants that may harbor large numbers of cryptic species is the quillworts(Isoetes spp.),an ancient aquatic plant lineage.Although over 350 species of Isoetes have been reported globally,only ten species have been recorded in China.The aim of this study is to better understand Isoetes species diversity in China.For this purpose,we systematically explored the phylogeny and evolution of Isoetes using complete chloroplast genome(plastome)data,spore morphology,chromosome number,genetic structure,and haplotypes of almost all Chinese Isoetes populations.We identified three ploidy levels of Isoetes in Chinaddiploid(2n=22),tetraploid(2n=44),and hexaploid(2n=66).We also found four megaspore and microspore ornamentation types in diploids,six in tetraploids,and three in hexaploids.Phylogenetic analyses confirmed that I.hypsophila as the ancestral group of the genus and revealed that Isoetes diploids,tetraploids,and hexaploids do not form monophyletic clades.Most individual species possess a single genetic structure;however,several samples have conflicting positions on the phylogenetic tree based on SNPs and the tree based on plastome data.All 36 samples shared 22 haplotypes.Divergence time analysis showed that I.hypsophila diverged in the early Eocene(~48.05 Ma),and most other Isoetes species diverged 3-20 Ma.Additionally,different species of Isoetes were found to inhabit different water systems and environments along the Yangtze River.These findings provide new insights into the relationships among Isoetes species in China,where highly similar morphologic populations may harbor many cryptic species.

Unveiling the spatial distribution and molecular mechanisms of terpenoid biosynthesis in Salvia miltiorrhiza and S. grandifolia using multi-omicsand DESI-MSI

Salvia miltiorrhiza and S.grandifolia are rich in diterpenoids and have therapeutic effects on cardiovascular diseases.In this study,the spatial distribution of diterpenoids in both species was analyzed by a combination of metabolomics and mass spectrometry imaging techniques.The results indicated that diterpenoids in S.miltiorrhiza were mainly abietane-type norditerpenoid quinones with a furan or dihydrofuran D-ring and were mainly distributed in the periderm of the roots,e.g.cryptotanshinone and tanshinone IIA.The compounds in S.grandifolia were mainly phenolic abietane-type tricyclic diterpenoids with six-or seven-membered C-rings,and were widely distributed in the periderm,phloem,and xylem of the roots,e.g.11-hydroxy-sugiol,11,20-dihydroxy-sugiol,and 11,20-dihydroxy-ferruginol.In addition,the leaves of S.grandifolia were rich in tanshinone biosynthesis precursors,such as 11-hydroxy-sugiol,while those of S.miltiorrhiza were rich in phenolic acids.Genes in the upstream pathway of tanshinone biosynthesis were highly expressed in the root of S.grandifolia,and genes in the downstream pathway were highly expressed in the root of S.miltiorrhiza.Here,we describe the specific tissue distributions and mechanisms of diterpenoids in two Salvia species,which will facilitate further investigations of the biosynthesis of diterpenoids in plant synthetic biology.

Genetic diversity and inferred ancestry of Asian lotus(Nelumbo nucifera) germplasms in Thailand and Vietnam

Tropical lotus(Nelumbo) is an important and unique ecological type of lotus germplasm.Understanding the genetic relationship and diversity of the tropical lotus is necessary for its sustainable conservation and utilization.Using 42 EST-SSR(expressed sequence tag-simple sequence repeats) and 30 SRAP(sequence-related amplified polymorphism) markers,we assessed the genetic diversity and inferred the ancestry of representative tropical lotus from Thailand and Vietnam.In total,164 and 41 polymorphic bands were detected in 69 accessions by 36 EST-SSR and seven SRAP makers,respectively.Higher genetic diversity was revealed in Thai lotus than in Vietnamese lotus.A Neighbor-Joining tree of five main clusters was constructed using combined EST-SSR and SRAP markers.Cluster Ⅰ included 17 accessions of Thai lotus;cluster Ⅱ contained three Thai accessions and 11 accessions from southern Vietnam;and cluster Ⅲ was constituted by 13 accessions of seed lotus.Consistent with the results from the NeighborJoining tree,the genetic structure analysis showed that the genetic background of most Thai and Vietnamese lotus was pure,as artificial breeding has been rare in both countries.Furthermore,these analyses indicate that Thai and Vietnamese lotus germplasms belong to two different gene pools or populations.Most lotus accessions are genetically related to geographical distribution patterns in Thailand or Vietnam.Our findings showed that the origin or genetic relationships of some unidentified lotus sources can be evaluated by comparing morphological characteristics and the data of molecular markers.In addition,these findings provide reliable information for the targeted conservation of tropical lotus and parent selection in breeding novel cultivars of lotus.

Remote sensing of subtropical tree diversity:The underappreciated roles of the practical definition of forest canopy and phenological variation

Tree species diversity is vital for maintaining ecosystem functions,yet our ability to map the distribution of tree diversity is limited due to difficulties in traditional field-based approaches.Recent developments in spaceborne remote sensing provide unprecedented opportunities to map and monitor tree diversity more efficiently.Here we built partial least squares regression models using the multispectral surface reflectance acquired by Sentinel-2 satellites and the inventory data from 74 subtropical forest plots to predict canopy tree diversity in a national natural reserve in eastern China.In particular,we evaluated the underappreciated roles of the practical definition of forest canopy and phenological variation in predicting tree diversity by testing three different definitions of canopy trees and comparing models built using satellite imagery of different seasons.Our best models explained 42%–63%variations in observed diversities in cross-validation tests,with higher explanation power for diversity indices that are more sensitive to abundant species.The models built using imageries from early spring and late autumn showed consistently better fits than those built using data from other seasons,highlighting the significant role of transitional phenology in remotely sensing plant diversity.Our results suggested that the cumulative diameter(60%–80%)of the biggest trees is a better way to define the canopy layer than using the subjective fixeddiameter-threshold(5–12 cm)or the cumulative basal area(90%–95%)of the biggest trees.Remarkably,these approaches resulted in contrasting diversity maps that call attention to canopy structure in remote sensing of tree diversity.This study demonstrates the potential of mapping and monitoring tree diversity using the Sentinal-2 data in species-rich forests.

Gap-free genome assembly and CYP450 gene family analysis reveal the biosynthesis of anthocyanins in Scutellaria baicalensis

Scutellaria baicalensis Georgi,a member of the Lamiaceae family,is a widely utilized medicinal plant.The flavones extracted from S.baicalensis contribute to numerous health benefits,including anti-inflammatory,antiviral,and anti-tumor activities.However,the incomplete genome assembly hinders biological studies on S.baicalensis.This study presents the first telomere-to-telomere(T2T)gap-free genome assembly of S.baicalensis through the integration of Pacbio HiFi,Nanopore ultra-long and Hi-C technologies.A total of 384.59 Mb of genome size with a contig N50 of 42.44 Mb was obtained,and all sequences were anchored into nine pseudochromosomes without any gap or mismatch.In addition,we analysed the major cyanidin-and delphinidin-based anthocyanins involved in the determination of blue-purple flower using a widely-targeted metabolome approach.Based on the genome-wide identification of Cytochrome P450(CYP450)gene family,three genes(SbFBH1,2,and 5)encoding flavonoid 3′-hydroxylases(F3′Hs)and one gene(SbFBH7)encoding flavonoid 3′5′-hydroxylase(F3′5′H)were found to hydroxylate the B-ring of flavonoids.Our studies enrich the genomic information available for the Lamiaceae family and provide a toolkit for discovering CYP450 genes involved in the flavonoid decoration.

Study on Adaptability of Introduced Pear Varieties

[Objectives]To study the adaptability of introduced pear.[Methods]Five pear varieties,"Aidang"pear,"Taiwan Zaomi"pear,"Cuiguan"pear,"Tianjin Yali"pear and"Zaosheng Xinshui"pear,were introduced.Then,using these five varieties,the phenology of pear trees,various characters of fruit,stress resistance(heat tolerance and cold tolerance)of varieties were studied.[Results]The plants of 5 varieties of pear trees grew fast and were robust;in late March,it went into the flowering period;"Aidang"pear fruit had a certain number of stone cells;"Taiwan Zaomi"pear had the highest sweetness;"Cuiguan"pear had the largest fruit;these five varieties of pear trees had good water resistance,heat resistance and cold resistance.[Conclusions]This study can provide a reference for the introduction of pear trees,and can also provide a practical basis for the large-scale planting of pear trees.

Experimental Research on Pomegranate Varieties

[Objectives]To study the introduction performance of pomegranate(Punica granatum)varieties in Shanghai area.[Methods]In this experiment,five pomegranate varieties were introduced,namely‘American 002’pomegranate,‘Huohulu’pomegranate,‘Wanli No.1’pomegranate,‘Yicheng Hongpitian’pomegranate,and‘American Qingpisuan’pomegranate.Then,using these five varieties,various biological traits such as phenology and fruit quality of pomegranate,as well as stress resistance such as heat resistance and cold resistance were studied.[Results]Five varieties of pomegranates began to mature in succession in early September;the smallest single fruit weight was 90 g,and the largest was 110 g;the plants grew fast,the plants were strong,the flowers were single petal,and plants bore fruits which were ornamental and edible.In addition,the pomegranates of these five varieties had good water tolerance and heat resistance,and good cold resistance.[Conclusions]This study is intended to provide a certain reference for the introduction of pomegranate varieties,and also provide a practical basis for the large-scale planting of pomegranate.

Flower Characteristics and Resource Evaluation of Fruit Mulberry

[Objectives]In order to study the flower characteristics of mulberry and evaluate the resources of fruit mulberry.[Methods]Firstly,the resources of fruit mulberry were collected,and four varieties of fruit mulberry(‘Dashi’mulberry,‘Changguo’milk mulberry,‘agate’mulberry and‘Xiangjin’milk mulberry)were collected.Then,the flower characteristics,fruit quality,and adaptability of fruit mulberry were studied.[Results]Mulberry is a dioecious plant,and the inflorescences are lurocatkin.The male flowers will fall off automatically,while the female flowers will develop into fruit.The four varieties of fruit mulberry have good adaptability in Shanghai,and their fruits have their own characteristics.At the same time,in order to use the resources of fruit mulberry,mulberry fruit picking activities were carried out for many times.[Conclusions]This study provides a reference for the cultivation,collection,utilization and evaluation of mulberry.

Gene expression and metabolite profiles of cotton fiber during cell elongation and secondary cell wall synthesis

Cotton fibers elongate rapidly after initiation of elongation, eventually leading to the deposit of a large amount of cellulose. To reveal features of cotton fiber cells at the fast elongation and the secondary cell wall synthesis stages, we compared the respective transcriptomes and metabolite profiles. Comparative analysis of transcriptomes by cDNA array identified 633 genes that were differentially regulated during fiber development. Principal component analysis （PCA） using expressed genes as variables divided fiber samples into four groups, which are diagnostic of developmental stages. Similar grouping results are also found if we use non-polar or polar metabolites as variables for PCA of developing fibers. Auxin signaling, wall-loosening and lipid metabolism are highly active during fiber elongation, whereas cellulose biosynthesis is predominant and many other metabolic pathways are downregulated at the secondary cell wall synthesis stage. Transcript and metabolite profiles and enzyme activities are consistent in demonstrating a specialization process of cotton fiber development toward cellulose synthesis. These data demonstrate that cotton fiber cell at a certain stage has its own unique feature, and developmental stages of cotton fiber cells can be distinguished by their transcript and metabolite profiles. During the secondary cell wall synthesis stage, metabolic pathways are streamed into cellulose synthesis.

Twenty years of Chinese vascular plant novelties,2000 through 2019

From 2000 to 2019,11,895 new names or new additions to the Chinese vascular flora were proposed by 4226 individuals(4086 articles and 140 books),as documented in the Chinese Plant Names Index(CPNI).During those 20 years,4407 new taxa of vascular plants were described from China,including 7 new families,132 new genera,3543 new species,68 new subspecies,497 new varieties and 160 new forms.Additionally,3562 new combinations and names at new rank and 306 new replacement names were also proposed.Among these various new names were 150 invalid names and 108 illegitimate names,including some that have not been resolved.Six hundred and forty three vascular plants were reported as new to China,while 2349 names were reduced to synonyms of 1406 taxa.The data show that the Chinese flora increased in size at the rate of about 200 taxa annually during those years.Despite the increased attention given to biodiversity in recent years,the evidence indicates that a large number of species in China have yet to be discovered.Further basic investigation of the Chinese flora is needed.Additionally,in the past two decades only 8.5%of the newly published species have been based on molecular evidence,but in the past five years such data have increased significantly,reaching about 20%.Molecular data will undoubtedly become increasingly significant in the discovery of new species in the coming years.Yunnan,Guangxi,Sichuan,Xizang and Taiwan were important sources of new discoveries,with more than 3300 new taxa and records from these five provinces.By area,Taiwan and Hainan,two islands in southern China,have the highest density of newly discovered species.Regional plant surveys are still needed,especially in areas in the southwest and on the southern islands.

Diversity and conservation of Chinese wild begonias

Begonia, one of the most diverse plant taxa and the fifth or sixth largest angiosperm genus, consists of over1800 accepted species. The number of species recognized within this genus has greatly increased over the past 20 years, rising from 80 to 200 species in China alone. Based on recent field surveys, the number of begonia species in China is predicted to be between 250 and 300. Given the large number of begonia species that still remain to be described, further taxonomical work is urgently required. This is especially true for Chinese Begonia, in which there is a huge diversity of habitat, habit, plant size, leaf type, flower and fruit morphology, and most species are narrowly distributed in isolated habitats that are subject to negative disturbances from climate change, as well as agricultural and industrial activities. Although the conservation status for the majority of species has been evaluated using the standards of the International Union for Conservation of Nature, the results don't represent the truth in many species, and also about11.5% of which are data-absent. In addition, illegal collection and over-harvesting of wild begonias for ornamental or medicinal use has increased due to the rapid development of internet commerce. Far more often than predicted, these species should be categorized as rare and endangered and require immediate protection. Ex situ conservation of Chinese begonias started in 1995 and over 60% of the total species have been so far introduced into cultivation by several major botanical gardens in China. However, only few research institutions, limited funds and human resources have been involved in Begonia conservation;moreover, no project has conducted reintroduction. Therefore, more conservation-based work remains to be done. Improved conservation of Chinese begonias in the future depends on further field survey, an improved understanding of population diversity, and integrative approaches, including in situ and ex situ conservation, seed banking, and plant reintroduction. Species-targeted conservation zones should be established for endangered species excluded from the existing nature reserves. Additionally, laws pertaining to plant protection should be extended to prevent the illegal collection and transaction of wild plants, particularly for those species with unique habitats and small populations.

Effective genome editing and identification of a regiospecific gallic acid 4-O-glycosyltransferase in pomegranate(Punica granatum L.)

Pomegranate(Punica granatum L.)trees are woody perennials that bear colorful and nutritious fruits rich in phenolic metabolites,e.g.,hydrolyzable tannins(HTs)and flavonoids.We here report genome editing and gene discovery in pomegranate hairy roots using Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)/CRISPR-associated protein 9(Cas9)(CRISPR/Cas9),coupled with transcriptome and biochemical analyses.Single guide RNAs(sgRNAs)were designed to target two UDP-dependent glycosyltransferases(UGTs),PgUGT84A23 and PgUGT84A24,which possess overlapping activities inβ-glucogallin(a galloylglucose ester;biosynthetic precursor of HTs)biosynthesis.A unique accumulation of gallic acid 3-O-and 4-O-glucosides(galloylglucose ethers)was observed in the PgUGT84A23 and PgUGT84A24 dual CRISPR/Cas9-edited lines(i.e.,ugt84a23 ugt84a24)but not the control(empty vector)or PgUGT84A23/PgUGT84A24 single edited lines(ugt84a23 or ugt84a24).Transcriptome and real-time qPCR analyses identified 11 UGTs with increased expression in the ugt84a23 ugt84a24 hairy roots compared to the controls.Of the 11 candidate UGTs,only PgUGT72BD1 used gallic acid as substrate and produced a regiospecific product gallic acid 4-O-glucoside.This work demonstrates that the CRISPR/Cas9 method can facilitate functional genomics studies in pomegranate and shows promise for capitalizing on the metabolic potential of pomegranate for germplasm improvement.

Genetic diversity of the wild Asian lotus (Nelumbo nucifera) from Northern China

Asian lotus(Nelumbo nucifera Gaertn.)is an aquatic plant with ornamental,cultural,economic,and ecological values.China has abundant germplasm resources of Asian lotus.However,in many areas,the wild Asian lotuses have been destroyed and the germplasms is now facing extinction.In addition,the knowledge of the genetic diversity of the wild Asian lotus in China is poor.To identify and protect the germplasms of Chinese wild Asian lotus,eleven genomic-SSR primers,three EST-SSR primers,and three chloroplast DNA primers were used to investigate the genetic diversity among 69 samples of wild Asian lotus from 25 locations in northern China.The genetic diversity of 27 samples of wild Asian lotus from southern China and other countries,the ancient Asian lotus,Asian lotus cultivars from China,and Asian-American hybrids was also compared.The genetic diversity of the wild Asian lotus from northern China was characterized as medium,and themean values of observed heterozygosity(Ho)and expected heterozygosity(He)were 0.087 and 0.552,respectively.Based on a UPGMA dendrogram and STRUCTURE analysis,the wild Asian lotus samples in northern China were divided into three groups.The wild Asian lotus samples from northern China contained 16 haplotypes.The Nei’s genetic distance between the wild Asian lotus samples from the Songhua River basin and the Liao River basin in northeastern China was relatively small,and these germplasms might be relatively primitive compared to those from other regions.This study provides essential information regarding the genetic diversity of the wild Asian lotus resources in northern China,and provides a basis for further analysis of population-level genetic evolution through high-throughput sequencing.

Genome size evolution of the extant lycophytes and ferns

Ferns and lycophytes have remarkably large genomes.However,little is known about how their genome size evolved in fern lineages.To explore the origins and evolution of chromosome numbers and genome size in ferns,we used flow cytometry to measure the genomes of 240 species(255 samples)of extant ferns and lycophytes comprising 27 families and 72 genera,of which 228 species(242 samples)represent new reports.We analyzed correlations among genome size,spore size,chromosomal features,phylogeny,and habitat type preference within a phylogenetic framework.We also applied ANOVA and multinomial logistic regression analysis to preference of habitat type and genome size.Using the phylogeny,we conducted ancestral character reconstruction for habitat types and tested whether genome size changes simultaneously with shifts in habitat preference.We found that 2 C values had weak phylogenetic signal,whereas the base number of chromosomes(x)had a strong phylogenetic signal.Furthermore,our analyses revealed a positive correlation between genome size and chromosome traits,indicating that the base number of chromosomes(x),chromosome size,and polyploidization may be primary contributors to genome expansion in ferns and lycophytes.Genome sizes in different habitat types varied significantly and were significantly correlated with habitat types;specifically,multinomial logistic regression indicated that species with larger 2 C values were more likely to be epiphytes.Terrestrial habitat is inferred to be ancestral for both extant ferns and lycophytes,whereas transitions to other habitat types occurred as the major clades emerged.Shifts in habitat types appear be followed by periods of genomic stability.Based on these results,we inferred that habitat type changes and multiple whole-genome duplications have contributed to the formation of large genomes of ferns and their allies during their evolutionary history.

Ceratopteris chunii and Ceratopteris chingii(Pteridaceae),two new diploid species from China,based on morphological,cytological,and molecular data

Understanding how natural hybridization and polyploidizations originate in plants requires identifying potential diploid ancestors.However,cryptic plant species are widespread,particularly in Ceratopteris(Pteridaceae).Identifying Ceratopteris cryptic species with different polyploidy levels is a challenge because Ceratopteris spp.exhibit high degrees of phenotypic plasticity.Here,two new cryptic species of Ceratopteris,Ceratopteris chunii and Ceratopteris chingii,are described and illustrated.Phylogenetic analyses reveal that each of the new species form a well-supported clade.C.chunii and C.chingii are similar to Ceratopteris gaudichaudii var.vulgaris and C.pteridoides,respectively,but distinct from their relatives in the stipe,basal pinna of the sterile leaf or subelliptic shape of the fertile leaf,as well as the spore surface.In addition,chromosome studies indicate that C.chunii and C.chingii are both diploid.These findings will help us further understand the origin of Ceratopteris polyploids in Asia.