Search Results (8)

A taxonomic revision of the family Apocynaceae (Gentianales) from Tunisia is presented. Field surveys carried out during the last two decades allowed us to identify new records at the national level, i.e., Asclepias curassavica, Carissa macrocarpa, Cascabela thevetia, and Cryptostegia grandiflora (the latter three are new to the non-native Mediterranean and North African woody vascular flora). The genus Asclepias is new at a national level, whereas Carissa, Cascabela, and Cryptostegia are recorded here for the first time in the Mediterranean basin. Information is provided about nomenclature (accepted names, main synonyms, and types), morphology, chromosome number, chorology, occurrence in Tunisia, habitat, phenology, and taxonomic annotations, and original photos are prepared. Diagnostic keys relating to generic and species ranks are also given. Using typificitions, the identity of the Linnaean names Cynanchum erectum and C. monspeliensis, Pourret’s Vinca difformis, and Roxburgh’s Nerium grandiflorum is discussed. Full article

The plant mitochondrial genome (mitogenome) has a complex organization and carries genetic traits of value in exploiting genetic resources. In this study, the Ilex macrocarpa mitogenome was sequenced and assembled to understand the genetic diversity and phylogenetic relationship. The mitogenome has a cyclic molecular structure and is 539,461 bp long with a GC content of 45.53%. It contained 39 protein-coding proteins, 19 tRNA genes, and 3 rRNA genes. The 146 simple sequence repeats and 591 dispersed repeat sequences were identified in the mitogenome. Codon usage analysis revealed a preference for codons ending in A/T. A total of 517 C to U RNA editing sites were predicted, with nad4 and ccmB being edited most frequently (39 times). Phylogenetic analysis via mitochondrial protein-coding genes showed that the Aquifoliales order contains sister plants to Lamiales, Solanales, and Gentianales. In addition, the conflicts between chloroplast and mitochondrial phylogeny were also observed. This study provides a theoretical framework for understanding the evolution, classification, and identification of the Ilex genus, which lays an important foundation for future molecular breeding investigations. Full article

Globally, food and medicinal plants have been documented, but their use patterns are poorly understood. Useful plants are non-random subsets of flora, prioritizing certain taxa. This study evaluates orders and families prioritized for medicine and food in Kenya, using three statistical models: Regression, Binomial, and Bayesian approaches. An extensive literature search was conducted to gather information on indigenous flora, medicinal and food plants. Regression residuals, obtained using LlNEST linear regression function, were used to quantify if taxa had unexpectedly high number of useful species relative to the overall proportion in the flora. Bayesian analysis, performed using BETA.INV function, was used to obtain superior and inferior 95% probability credible intervals for the whole flora and for all taxa. To test for the significance of individual taxa departure from the expected number, binomial analysis using BINOMDIST function was performed to obtain p-values for all taxa. The three models identified 14 positive outlier medicinal orders, all with significant values (p < 0.05). Fabales had the highest (66.16) regression residuals, while Sapindales had the highest (1.1605) R-value. Thirty-eight positive outlier medicinal families were identified; 34 were significant outliers (p < 0.05). Rutaceae (1.6808) had the highest R-value, while Fabaceae had the highest regression residuals (63.2). Sixteen positive outlier food orders were recovered; 13 were significant outliers (p < 0.05). Gentianales (45.27) had the highest regression residuals, while Sapindales (2.3654) had the highest R-value. Forty-two positive outlier food families were recovered by the three models; 30 were significant outliers (p < 0.05). Anacardiaceae (5.163) had the highest R-value, while Fabaceae had the highest (28.72) regression residuals. This study presents important medicinal and food taxa in Kenya, and adds useful data for global comparisons. Full article

The dynamic evolution of mitochondrial gene and intron content has been reported across the angiosperms. However, a reference mitochondrial genome (mitogenome) is not available in Rubiaceae. The phylogenetic utility of mitogenome data at a species level is rarely assessed. Here, we assembled mitogenomes of six Damnacanthus indicus (Rubiaceae, Rubioideae) representing two varieties (var. indicus and var. microphyllus). The gene and intron content of D. indicus was compared with mitogenomes from representative angiosperm species and mitochondrial contigs from the other Rubiaceae species. Mitogenome structural rearrangement and sequence divergence in D. indicus were analyzed in six individuals. The size of the mitogenome in D. indicus varied from 417,661 to 419,435 bp. Comparing the number of intact mitochondrial protein-coding genes in other Gentianales taxa (38), D. indicus included 32 genes representing several losses. The intron analysis revealed a shift from cis to trans splicing of a nad1 intron (nad1i728) in D. indicus and it is a shared character with the other four Rubioideae taxa. Two distinct mitogenome structures (type A and B) were identified. Two-step direct repeat-mediated recombination was proposed to explain structural changes between type A and B mitogenomes. The five individuals from two varieties in D. indicus diverged well in the whole mitogenome-level comparison with one exception. Collectively, our study elucidated the mitogenome evolution in Rubiaceae along with D. indicus and showed the reliable phylogenetic utility of the whole mitogenome data at a species-level evolution. Full article

Thrips hawaiiensis is a common thrips pest of various plant flowers with host preference. Plant volatiles provide important information for host-searching in insects. We examined the behavioral responses of T. hawaiiensis adults to the floral volatiles of Gardenia jasminoides Ellis, Gerbera jamesonii Bolus, Paeonia lactiflora Pallas, and Rosa chinensis Jacq. in a Y-tube olfactometer. T. hawaiiensis adults showed significantly different preferences to these four-flower plants, with the ranking of G. jasminoides > G. jamesonii > P. lactiflora ≥ R. chinensis. Further, 29 components were identified in the volatile profiles of G. jasminoides, and (Z)-3-hexenyl tiglate (14.38 %), linalool (27.45 %), and (E3,E7)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (24.67 %) were the most abundant. Six-arm olfactometer bioassays showed that T. hawaiiensis had significant positive responses to (Z)-3-hexenyl tiglate, linalool, and (E3,E7)-4,8,12-trimethyltrideca-1,3,7,11-tetraene tested at various concentrations, with the most attractive ones being 10⁻³ μL/μL, 10⁻² μL/μL and 100 μg/μL for each compound, respectively. In pairing of these three compounds at their optimal concentrations, T. hawaiiensis showed the preference ranking of (Z)-3-hexenyl tiglate > linalool > (E3,E7)-4,8,12-trimethyltrideca-1,3,7,11-tetraene. Large numbers of T. hawaiiensis have been observed on G. jasminoides flowers in the field, which might be caused by the high attraction of this pest to G. jasminoides floral volatiles shown in the present study. Our findings shed light on the olfactory cues routing host plant searching behavior in T. hawaiiensis, providing important information on how T. hawaiiensis targets particular host plants. The high attractiveness of the main compounds (e.g., linalool, (E3,E7)-4,8,12-trimethyltrideca-1,3,7,11-tetraene, particular (Z)-3-hexenyl tiglate) identified from volatiles of G. jasminoides flowers may be exploited further to develop novel monitoring and control tools (e.g., lure and kill strategies) against this flower-inhabiting thrips pest. Full article

Scyphiphora hydrophyllacea Gaertn. f. (Rubiaceae) is an endangered mangrove species found in China, and its only known location is in Hainan Island. Previous studies conducted on S. hydrophyllaceae have mainly focused on its location, biological characteristics, and medical effects. However, to date, there has been no published report regarding the genetics or genome of this endangered mangrove species. In this study, we developed valuable chloroplast genome-related molecular resources of S. hydrophyllaceae by comparing with it related Rubiaceae species. The chloroplast genome of S. hydrophyllaceae was found to be a circular molecule with a total size of 155,132 bp, and it is observed to have a quadripartite structure. The whole chloroplast genome contains 132 genes, of which 88 and 36 are protein-coding and transfer RNA genes, respectively; it also contains four ribosomal RNA genes with an overall GC content of 37.60%. A total of 52 microsatellites were detected in the S. hydrophyllacea chloroplast genome, and microsatellite marker detection identified A/T mononucleotides as majority simple sequence repeats in all nine Rubiaceae chloroplast genomes. Comparative analyses of these nine chloroplast genomes revealed variable regions, including matK, rps16, and atpF. All nine species shared 13 RNA-editing sites distributed across eight coding genes. Phylogenetic analyses based on the complete sequences of the chloroplast genomes revealed that the position of S. hydrophyllaceae is closer to the Coffeeae genus than to Cinchoneae, Naucleeae, Morindeae, and Rubieae in the Rubiaceae family. The genome information reported in this study could find further application in the evolution and population genetic studies, and it helps improve our understanding of the endangered mechanism and the development of conservation strategies of this endangered mangrove plant. Full article

Gentiana section Cruciata is widely distributed across Eurasia at high altitudes, and some species in this section are used as traditional Chinese medicine. Accurate identification of these species is important for their utilization and conservation. Due to similar morphological and chemical characteristics, correct discrimination of these species still remains problematic. Here, we sequenced three complete chloroplast (cp) genomes (G. dahurica, G. siphonantha and G. officinalis). We further compared them with the previously published plastomes from sect. Cruciata and developed highly polymorphic molecular markers for species authentication. The eight cp genomes shared the highly conserved structure and contained 112 unique genes arranged in the same order, including 78 protein-coding genes, 30 tRNAs, and 4 rRNAs. We analyzed the repeats and nucleotide substitutions in these plastomes and detected several highly variable regions. We found that four genes (accD, clpP, matK and ycf1) were subject to positive selection, and sixteen InDel-variable loci with high discriminatory powers were selected as candidate barcodes. Our phylogenetic analyses based on plastomes further confirmed the monophyly of sect. Cruciata and primarily elucidated the phylogeny of Gentianales. This study indicated that cp genomes can provide more integrated information for better elucidating the phylogenetic pattern and improving discriminatory power during species authentication. Full article

Swertia mussotii is an important medicinal plant that has great economic and medicinal value and is found on the Qinghai Tibetan Plateau. The complete chloroplast (cp) genome of S. mussotii is 153,431 bp in size, with a pair of inverted repeat (IR) regions of 25,761 bp each that separate an large single-copy (LSC) region of 83,567 bp and an a small single-copy (SSC) region of 18,342 bp. The S. mussotii cp genome encodes 84 protein-coding genes, 37 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. The identity, number, and GC content of S. mussotii cp genes were similar to those in the genomes of other Gentianales species. Via analysis of the repeat structure, 11 forward repeats, eight palindromic repeats, and one reverse repeat were detected in the S. mussotii cp genome. There are 45 SSRs in the S. mussotii cp genome, the majority of which are mononucleotides found in all other Gentianales species. An entire cp genome comparison study of S. mussotii and two other species in Gentianaceae was conducted. The complete cp genome sequence provides intragenic information for the cp genetic engineering of this medicinal plant. Full article