Rosaceae Species Research Articles

Comparative genomic analysis of the PAL genes in five Rosaceae species and functional identification of Chinese white pear.

Phenylalanine ammonia lyase (PAL) plays an important role in the biosynthesis of secondary metabolites regulating plant growth response. To date, the evolutionary history of the PAL family in Rosaceae plants remains unclear. In this study, we identified 16 PAL homologous genes in five Rosaceae plants (Pyrus bretschneideri, Fragaria vesca, Prunus mume, Prunus persica, and Malus × domestica). We classified these PALs into three categories based on phylogenetic analysis, and all PALs were distributed on 13 chromosomes. We tracked gene duplication events and performed sliding window analysis. These results revealed the evolution of PALs in five Rosaceae plants. We predicted the promoter of the PbPALs by PLANT CARE online software, and found that the promoter region of both PbPAL1 and PbPAL3 have at least one AC element. The results of qRT-PCR analysis found that PbPAL1 and PbPAL2 were highly expressed in the stems and roots, while expression level of PbPAL3 was relatively low in different tissues. The expression of PbPAL1 and PbPAL2 increased firstly and then decreased at different developmental periods of pear fruit. Among them, the expression of PbPAL1 reached the highest level 55 days after flowering. Three PbPALs were induced by abiotic stress to varying degrees. We transfected PbPAL1 and PbPAL2 into Arabidopsis thaliana, which resulted in an increase in lignin content and thickening of the cell walls of intervascular fibres and xylem cells. In summary, this research laid a foundation for better understanding the molecular evolution of PALs in five Rosaceae plants. Furthermore, the present study revealed the role of PbPALs in lignin synthesis, and provided basic data for regulating lignin synthesis and stone cells development in pear plants.

Assembly and origin of the flora of the Chihuahuan Desert: The case of sclerophyllous Rosaceae

AbstractAimTo test hypotheses on the origin and assembly of the flora of the Chihuahuan Desert using as a system the hard‐leaved shrubby lineages of the Rosaceae distributed in North American Deserts.LocationNorth American Deserts, Chihuahuan Desert, Mexican Plateau, Tehuacán Valley.TaxaRosaceae, Amygdaloideae (Amelanchier paniculata, Lindleya mespiloides, Malacomeles denticulata, Vauquelinia angustifolia, Vauquelinia australis, Vauquelinia corymbosa, Xerospiraea hartwegiana), Dryadoideae (Cercocarpus fothergilloides, Cercocarpus pringlei, Cercocarpus rzedowskii, Purshia plicata)MethodsPhylogenetic analyses were conducted based on nine chloroplast and nuclear molecular markers of eleven newly sequenced species of Rosaceae distributed in the Chihuahuan Desert along with previous sequences of 41 species in 25 genera representative of the major clades in the family. Based on phylogeny, divergence times, migration, vicariance events and ancestral biogeographic areas were determined. Ecological niche‐based modelling will predict changes in distribution during Pleistocene climate oscillations. Traitgrams were constructed to visualize departure among lineages in the most significant climate variables.ResultsThe lineages studied diverged during the Eocene‐Oligocene (53–33 Mya). The ancestral area for most of the taxa was in the Mojave and Chihuahuan Deserts. Most dispersal events occurred from the Mojave Desert to the central area of the Chihuahuan Desert on the Mexican Plateau. Ecological niche‐based modelling suggests a contraction of suitable habitat during the Last Interglacial period (~120,000–140,000 years), followed by expansion during the Last Glacial Maximum (~22,000 years) and the Middle Holocene (~6,000 years).Main conclusionsOur results confirm the Axelrod's hypothesis of an origin of the flora of the Chihuahuan Desert in SW North America migrating to occupy North American arid lands. Vicariance and the expansion of arid lands allowed divergence, migration and permanence of the lineages studied on the Mexican Plateau. Divergence occurred prior to the onset of aridification. The Mexican Plateau acted as a refuge for hard‐leaved lineages during the Miocene. Shifts in ecological niches of related species allowed them to colonize new areas with different temperatures and precipitation. Current distribution of lineages is the most limited.

Homeotic transformation from stamen to petal in Eriobotrya japonica is associated with hormone signal transduction and reduction of the transcriptional activity of EjAG.

Double-flower loquat (Eriobotrya japonica) is a new germplasm with homeotic transformation of stamen into petal in whorl 3. However, little information is available on the molecular mechanism of this transformation. Herein, we analyzed the transcriptome, candidate genes and endogenous hormones to investigate the mechanisms underlying this homeotic transformation. Some transcription factors, such as MADS-box, TCP and MYB, were significantly differentially expressed. Importantly, we confirmed that one of these (DN39625_c0_g1), which encoded a C-class floral homeotic protein referred to as AGAMOUS ortholog (EjAG), was significantly downregulated. Subcellular localization of EjAG was found to be in the nucleus. Ectopic expression of EjAG rescued the development of stamens and carpels from the double-flower phenotype in an Arabidopsis ag mutant, suggesting that EjAG expression is associated with double-flower formation. Meanwhile, enrichment analyses showed that the differentially expressed genes (DEGs) were mainly involved in the metabolic pathways of hormone signal transduction. The DEGs of auxin, gibberellin A (GA) and cytokinin signaling pathways were mainly upregulated. However, the DEGs of abscisic acid (ABA) and the ethylene signaling pathway were mainly downregulated. Accordingly, the concentrations of indoleacetic acid, kinetin and GA3 were high at the petaloid stamen stage, but the ABA concentration remained low. The identified genes and pathways provide abundant sequence resources for studying the mechanisms underlying the homeotic transformation in loquat and other Rosaceae species.

Evolution of the R2R3-MYB gene family in six Rosaceae species and expression in woodland strawberry

R2R3-MYB gene family play important roles in plants development, metabolism, and responses to various biotic and abiotic stresses. In this study, 838 R2R3-MYB genes were identified from six Rosaceae species, including 105 in woodland strawberry (Fragaria vesca), 173 in European pear (Pyrus communis), 219 in apple (Malus domestica), 121 in peach (Prunus persica), 121 in Chinese rose (Rosa chinensis), and 99 in black raspberry (Rubus occidentalis). All R2R3-MYB genes in the six Rosaceae species were clustered into 51 species-specific duplicated clades with 109 genes and 50 lineage-specific duplicated clades with 242 genes according to phylogenetic analysis. R2R3-MYB genes were distributed on all chromosomes in each of the six species, with a small amount of tandem duplication events. The proportion of tandem repeat genes ranged from 0 to 25.1%. The R2R3-MYB protein was conserved in a clade and likely to share similar functions. The distribution of Ks showed the duplication times of R2R3-MYB genes in six Rosaceae species. Furthermore, most of the R2R3-MYB genes had Ka/Ks values less than 1, which indicated they were driven by purifying selection during the evolutionary processes. The GO term enrichment analysis revealed that R2R3-MYB genes in strawberry and black raspberry were more divergent than in other Rosaceae species. Analysis of transcriptomes of 42 different tissues and development stages of woodland strawberry showed that high expression levels of R2R3-MYB suggested that the R2R3-MYB genes in strawberry played a key role in growth and development of both vegetative tissues and fruits. The strawberry R2R3-MYB genes in sub-group of S1, S2, S11, S20, and S22 had high expression levels both in young leaves (YL) and old leaves (OL) strawberry tissues under drought treatments.

Genome-Wide Identification and Characterization of ABC Transporters in Nine Rosaceae Species Identifying MdABCG28 as a Possible Cytokinin Transporter linked to Dwarfing.

ATP-binding cassette (ABC) transporters constitute a large, diverse, and ubiquitous superfamily that is involved in a broad range of processes. The completion of genome sequencing provides an opportunity to understand the phylogenetic history of the ABC transporter superfamily among Rosaceae species. This study identified a total of 1323 ABC transporter genes from nine Rosaceae genomes: 191 from Malus domestica, 174 from Pyrus communis, 138 from Prunus persica, 118 from Prunus avium, 141 from Prunus dulcis, 122 from Fragaria vesca, 98 from Rubus occidentalis, 162 from Prunus mume, and 179 from Rosa chinensis. Their chemical characterization, phylogenetic analysis, chromosomal localization, gene structure, gene duplication, and tissue-specific expression were studied. Their subcellular localization, transmembrane structures, and protein motifs were predicted. All the ABC transporter genes were grouped into eight subfamilies on the basis of their phylogenetic relationships and structural features. Furthermore, cis-element and expression analysis of 10 potential phytohormone transporters in MdABCG subfamily genes were also performed. Loss of the W-box in the promoter region of MdABCG28 was found to reduce the gene expression level and was linked to the dwarfing phenotype in apple rootstocks. MdABCG28 overexpression promoted shoot growth of atabcg14 mutants in Arabidopsis.

Expression analysis of apple DORMANCY-ASSOCIATED MADS-box genes in ‘Fuji’ dormant flower buds during flower bud development

Most temperate fruit tree species enter dormancy in autumn and come out of dormancy after exposure to a certain amount of chilling. Recent global climate change affects bud dormancy of temperate fruit trees in Japan and might interfere with bud dormancy and blooming dates in apple trees (Malus × domestica) in the future. However, our knowledge of molecular mechanisms underlying endodormancy release and the genetic factors controlling chilling requirements and blooming date in apple is limited. In peach (Prunus persica) and P. mume (Rosaceae), DORMANCY-ASSOCIATED MADS-box (DAM) genes have been identified as candidate key factors controlling chilling requirements. We previously analysed gene expressions of two apple DAM-like genes, MdDAM1 (MD322567) and MdDAM2 (MD259294), in dormant buds collected from apple trees grown in Kyoto, Japan, and reported that MdDAM2 was constantly downregulated during dormancy release in the same manner as Prunus DAMs. In this study, we performed seasonal expression analysis of two apple DAM-like genes in ‘Fuji’ flower buds collected from trees grown in Nagano, Japan, with special attention to the morphological changes of internal flower structure. The analysis revealed that both genes were upregulated during the flowering initiation stage, from June to Aug. After inflorescence development, MdDAM2 was constantly downregulated during the flower organ differentiation stage, while MdDAM1 was expressed at a relatively higher level throughout the flower organ differentiation stage. Based on these results the relationship between flower organ development and the expressions of DAMs in fruit tree species of Rosaceae is discussed.

Rubus ovatisepalus (Rosaceae), a New Species from Yunnan and Xizang, Southwest China

Rubus ovatisepalus Huan C. Wang, a new species of Rosaceae from Yunnan and Xizang, southwest China, is described and illustrated. It is closely related to R. stans, but clearly differs from the latter by its arched main stems, flower-branchlets that are longer than 20 cm, 5–7 cm long and 3.5–5 cm wide terminal leaflets, terminal inflorescences having numerous flowers, racemiform cymes, ovate to triangular-ovate and adaxially tomentose sepals with a long-acuminate to caudate apex, white or light pink petals, and an ovoid to conical gynoecium.

Scaling Relationships between Leaf Shape and Area of 12 Rosaceae Species

Leaf surface area (A) and leaf shape have been demonstrated to be closely correlated with photosynthetic rates. The scaling relationship between leaf biomass (both dry weight and fresh weight) and A has been widely studied. However, few studies have focused on the scaling relationship between leaf shape and A. Here, using more than 3600 leaves from 12 Rosaceae species, we examined the relationships of the leaf-shape indices including the left to right side leaf surface area ratio (AR), the ratio of leaf perimeter to leaf surface area (RPA), and the ratio of leaf width to length (RWL) versus A. We also tested whether there is a scaling relationship between leaf dry weight and A, and between PRA and A. There was no significant correlation between AR and A for each of the 12 species. Leaf area was also found to be independent of RWL because leaf width remained proportional to leaf length across the 12 species. However, there was a negative correlation between RPA and A. The scaling relationship between RPA and A held for each species, and the estimated scaling exponent of RPA versus A approached −1/2; the scaling relationship between leaf dry weight and A also held for each species, and 11 out of the 12 estimated scaling exponents of leaf dry weight versus A were greater than unity. Our results indicated that leaf surface area has a strong scaling relationship with leaf perimeter and also with leaf dry weight but has no relationship with leaf symmetry or RWL. Additionally, our results showed that leaf dry weight per unit area, which is usually associated with the photosynthetic capacity of plants, increases with an increasing A because the scaling exponent of leaf dry weight versus A is greater than unity. This suggests that a large leaf surface area requires more dry mass input to support the physical structure of the leaf.

Evaluating the Ecological Services of Roof Greening Plants in Beijing Based on Functional Traits

Selecting suitable species to enhance ecological functions is crucial for improvements in the planning and design of roof greening and in maintaining sustainable urban development, especially in rapidly urbanized areas. Assisted by field trips to enhance studies, the present project assessed the ecological functions of 207 plant species used for roof greening in Beijing based on their key functional traits. The results indicate that regulating, cultural, supplying, and supporting functions differed significantly among species and families in the study area. Rosaceae species have higher levels of overall ecological functions than other species, and a large number of Compositae species have lower-level functions. Compared to other families, Araliaceae and Nyctaginaceae have higher mean values of cultural and supporting functions and the highest mean overall function value of 37. Ulmaceae, Sapindaceae, Ginkgoaceae, Berberidaceae, and Aceraceae have higher mean regulating, cultural, supporting, and overall function values. Amaranthaceae, Umbelliferae, Lamiaceae, Saxifragaceae, Ericaceae, and Gramineae have lower values. The existing roof greening in Beijing includes some pitfalls with respect to plant composition as well as plant selection that does not consider ecological functions. The following measures could be proposed to increase ecological functions: (1) Increasing the number of plants with shallow roots and with strong adaptation traits to roof conditions; (2) Enriching ecological communities with diverse plants with high ecological functions; and (3) Carrying out rational ecological planning and management based on detailed and objective data on plant species. Future studies should focus on specifying plant functional traits to enhance ecological functions.

Identification of Shaker K+ channel family members in Rosaceae and a functional exploration of PbrKAT1.

PbrKAT1, which is inhibited by external Na+ in Xenopus laevis oocytes, is characterized as encoding a typical inward rectifying channel that is mainly expressed in guard cells. Potassium (K+) is the most abundant cation in plant cells necessary for plant growth and development. The uptake and transport of K+ are mainly completed through transporters and channels, and the Shaker family genes are the most studied K+ channels in plants. However, there is far less information about this family in Rosaceae species. We performed a genome-wide analysis and identified Shaker K+ channel gene family members in Rosaceae. We cloned and characterized a Shaker K+ channel KAT1 from pear (Pyrus × bretschneideri). In total, 36 Shaker K+ channel genes were identified from Rosaceae species and were classified into five subgroups based on structural characteristics and a phylogenetic analysis. Whole-genome and dispersed duplications were the primary forces underlying Shaker K+ channel gene family expansion in Rosaceae, and purifying selection played a key role in the evolution of Shaker K+ channel genes. β-Glucuronidase and qRT-PCR assays revealed that PbrKAT1 was mainly expressed in leaves, especially in guard cells. PbrKAT1 displayed a typical inward-rectifying current when expressed in Xenopus laevis oocytes. The activity of PbrKAT1 was inhibited by external sodium ions, possibly playing an important role in the regulation of salt tolerance in pear. These results provide valuable information on evolution, expression and functions of the Shaker K+ channel gene family in plants.

Purification and characterization of an esterase from larval Diplolepis fructuum (Rübsaamen, 1895) (Hymenoptera: Cynipidae)

Diplolepis fructuum (Rübsaamen, 1895) (Hymenoptera: Cynipidae) is one of the important insect species that causes damages on Rosaceae species. With this study commenced in 2018 at the laboratory of Department of Biochemistry, Faculty of Science, Cumhuriyet University to get a biochemical data, an esterase (EC 3.1.1.X) from the larvae of D. fructuum was purified using Q Sepharose anion exchange, phenyl Sepharose CL-4B and Sephacryl S100 HR gel filtration chromatography, respectively. The enzyme had 6.94 U/mg protein specific activity, about 29-fold purity, and 8.8% yield. Only one activity band was observed in native-PAGE studies. The molecular weight of the esterase was estimated as 60 kDa using native-PAGE and SDS-PAGE techniques. By the kinetic data, optimum temperature and pH for the enzyme was determined as 40ºC and 9.0, respectively. The enzyme was stable for 4 h at 40ºC and pH 8.0. K m and V max values were found to be 0.035 mM and 1.41 µmol/mL.min., using 4-nitrophenyl butyrate (p-NPB) as substrate. The enzyme exhibited its highest activities on p-NPB (100%) and 4-nitrophenyl acetate (52%). All of these data indicate that the enzyme might be a typical esterase with different kinetic properties and molecular weight than esterolytic enzymes reported from other insect species.

On the identity and occurrence of Rubus racemosus (Rosaceae) in India with note on its neotypification

Rubus racemosus is an endemic species of Rosaceae and the distribution is strictly restricted to southern parts of the Western Ghats. The present paper provides a detailed taxonomic description, colour photographs and discusses the taxonomic affinity of the taxon with its allied taxa. And also, the name Rubus racemosus is neotypified here.

The complete chloroplast genome sequence of Eriobotrya fragrans

Eriobotrya fragrans Champion ex Bentham is a potential medicinal plant of the genus Eriobotrya Lindl in the family Rosaceae. To better determine its phylogenetic location with respect to the other Rosaceae species, the complete chloroplast genome of E. fragrans was sequenced. The whole E. fragrans chloroplast genome is 159,286 bp in length, consisting of a pair of inverted repeat (IR) regions of 26,343 bp, one large single-copy (LSC) region of 87,301 bp, and one small single-copy (SSC) region of 19,299 bp. The overall GC content of the whole chloroplast genome is 36.7%. Further, phylogenetic analysis using maximum likelihood with TVM + F+R2 model strongly supports the relationship: sisterhood of E. fragrans and E. japonica, followed by three species of Pyrus L.

Comparative Evaluation of Total Phenolics, Total Flavonoids Content and Antiradical Activity in Six Selected Species of Family Rosaceae Using Spectroscopic Method

Comparative Evaluation of Total Phenolics, Total Flavonoids Content and Antiradical Activity in Six Selected Species of Family Rosaceae Using Spectroscopic Method

Floristic inventory and biological spectra of Balakot, District Mansehra, Pakistan

This study was conducted to assess the floristic composition, biological spectra and phenology of Tehsil Balakot. Frequent visits were made in different seasons during 2012–13. Field notebook was used to record the data within field. Biological spectrum and leaf sizes classes were determined. The floristic diversity revealed 228 plant species belonged to 184 genera and 72 families. Asteraceae family contributed maximum number of species (27) followed by Rosaceae (18), Apiaceae and Lamiaceae (12) species each, Papilionaceae (11) species while remaining 67 families contributed less than 10 species. Herbaceous growth form was the most leading one (71%), followed by shrub (15%) and tree (14%), respectively. Biological spectrum revealed that hemicryptophytes (32.45%) were the most prevalent, followed by therophytes (31.57%), nanophanerophytes (15.35%), megaphanerophytes (13.59%) and chamaephytes (4.38%). Leaf spectra showed that microphyll (28.94%) were dominant, followed by nanophyll (27.19%), leptophyll (22.80%), mesophyll (14.03%) and megaphyll (7.01%). The flora was influenced by two flowering seasons i.e. March to August and September to February. In the first spell, 193 species were recorded, of these 15.54% trees, 15.02% shrubs, 63.21% herbs, 3.62% grasses and 2.59% ferns; while in the second spell, there were 35 species having 2.85% trees, 17.14% shrubs, 74.28% herbs, and 5.71% grasses. The flowering data shows that June and July were the utmost flowering months with 28.50% in 65 and 20.17% in 46 plant species.

Lamina shape does not correlate with lamina surface area: An analysis based on the simplified Gielis equation

The simplified Gielis equation (SGE) can approximately describe the leaf shapes of many different broad-leaved plant species by replacing two parameters of the SGE with leaf width and leaf length with a floating ratio (c–value) to adjust for leaf length. In this study, we tested the validity of the SGE in predicting leaf area using 20 bamboo species, 12 species of Rosaceae, 5 species of Lauraceae, and 5 species of Oleaceae. We find that c–values in leaf length for 20 bamboo species are all smaller than zero, whereas, for most tree species, c–values are larger than zero. Using c–values, there was a strong correlation (>0.99 for most of the species investigated) between actual and predicted leaf area. Also, using the SGE to fit the leaf profile data, the predicted leaf width approaches its actual value, whereas the predicted length is larger than or smaller than its actual value (for bamboo species and most tree species, respectively). Although c–values ranged from −15% to zero for bamboo species and from zero to 17% for tree species, the mean percent error in leaf area for most species did not exceed 5%. These findings indicate that leaves exhibit more variation in length than in width, i.e., leaf area is fairly conservative despite considerable variation in leaf shape. Given that the SGE adequately describes the areas of leaves with complex forms (e.g., several species of Rosaceae), our data indicate that the SGE is a useful tool for describing leaf morphometrics and may open a door for the study of leaf shape evolution.

Determination of the content of ursolic and oleanolic acid in the cuticular wax of fruits of different species of Rosaceae

Ursolic acid (UA) and oleanolic acid (OA) are two widely distributed triterpenes in fruits, especially those belonging to Rosaceae family. These triterpene isomers are of great pharmacological interest due to their multiple bioactive properties. For this reason, the objective of this study was to determine the content of UA and OA extracted from the cuticular wax of five highly edible fruits (quince, loquat, pear, peach and apple) all belonging to the Rosaceae family. The acids were analyzed by high performance liquid chromatography. Both UA and OA are present in all these fruits, however, UA is in greater quantities.

Finding a Compatible Partner: Self-Incompatibility in European Pear (Pyrus communis); Molecular Control, Genetic Determination, and Impact on Fertilization and Fruit Set.

Pyrus species display a gametophytic self-incompatibility (GSI) system that actively prevents fertilization by self-pollen. The GSI mechanism in Pyrus is genetically controlled by a single locus, i.e., the S-locus, which includes at least two polymorphic and strongly linked S-determinant genes: a pistil-expressed S-RNase gene and a number of pollen-expressed SFBB genes (S-locus F-Box Brothers). Both the molecular basis of the SI mechanism and its functional expression have been widely studied in many Rosaceae fruit tree species with a particular focus on the characterization of the elusive SFBB genes and S-RNase alleles of economically important cultivars. Here, we discuss recent advances in the understanding of GSI in Pyrus and provide new insights into the mechanisms of GSI breakdown leading to self-fertilization and fruit set. Molecular analysis of S-genes in several self-compatible Pyrus cultivars has revealed mutations in both pistil- or pollen-specific parts that cause breakdown of self-incompatibility. This has significantly contributed to our understanding of the molecular and genetic mechanisms that underpin self-incompatibility. Moreover, the existence and development of self-compatible mutants open new perspectives for pear production and breeding. In this framework, possible consequences of self-fertilization on fruit set, development, and quality in pear are also reviewed.

Rubus huagaoxiensis and R. lingtianus (Rosaceae), two new species from Sichuan, China

Rubus huagaoxiensis and R. lingtianus, two new species of Rosaceae from Sichuan, Southwest China, are described and illustrated. Rubus huagaoxiensis is morphologically similar to R. setchuenensis, but differs from the latter by gray tomentose branchlets, thicker leaves which are usually adaxially pubescent, larger and subflabellate stipules, 0.3–0.5 cm long pedicels, sepals which are triangular to ovate and abaxially densely gray tomentose-villous, white petals which are abaxially and adaxially villous along midrib, villous styles, and spheroidal pollen grains. Rubus lingtianus is morphologically similar to R. setchuenensis and R. huagaoxiensis, but differs from R. setchuenensis by having leathery leaves, acute lobes of leaf blade, larger and subflabellate stipules, broadly ovate sepals with acute or obtuse apex, white flowers, red fruits, and subprolate pollen grains with verrucate-striate-perforate ornamentation. Rubus lingtianus differs from R. huagaoxiensis by having leathery leaves, mature leaf blade which is adaxially glabrous or soft-hairy along veins only, usually glabrous petals, styles base with few soft hairs, red fruits, and subprolate pollen grains with verrucate-striate-perforate ornamentation. Morphological comparison among these three species is given.

Comparative genomic analysis of the IDD genes in five Rosaceae species and expression analysis in Chinese white pear (Pyrus bretschneideri).

The INDETERMINATE DOMAIN (IDD) gene family encodes hybrid transcription factors with distinct zinc finger motifs and appears to be found in all higher plant genomes. IDD genes have been identified throughout the genomes of the model plants Arabidopsis thaliana and Oryza sativa, and the functions of many members of this gene family have been studied. However, few studies have investigated the IDD gene family in Rosaceae species (among these species, a genome-wide identification of the IDD gene family has only been completed in Malus domestica). This study focuses on a comparative genomic analysis of the IDD gene family in five Rosaceae species (Pyrus bretschneideri, Fragaria vesca, Prunus mume, Rubus occidentalis and Prunus avium). We identified a total of 68 IDD genes: 16 genes in Chinese white pear, 14 genes in F. vesca, 13 genes in Prunus mume, 14 genes in R. occidentalis and 11 genes in Prunus avium. The evolution of the IDD genes in these five Rosaceae species was revealed by constructing a phylogenetic tree, tracking gene duplication events, and performing a sliding window analysis and a conserved microsynteny analysis. The expression analysis of different organs showed that most of the pear IDD genes are found at a very high transcription level in fruits, flowers and buds. Based on our results with those obtained in previous research, we speculated that PbIDD2 and PbIDD8 might participate in flowering induction in pear. A temporal expression analysis showed that the expression patterns of PbIDD3 and PbIDD5 were completely opposite to the accumulation pattern of fruit lignin and the stone cell content. The results of the composite phylogenetic tree and expression pattern analysis indicated that PbIDD3 and PbIDD5 might be involved in the metabolism of lignin and secondary cell wall (SCW) formation. In summary, we provide basic information about the IDD genes in five Rosaceae species and thereby provide a theoretical basis for studying the function of these IDD genes.