BMC Plant Biology最新文献

Background: Guava (Psidium guajava L.) is a major pantropical fruit crop, valued for its nutritional composition, wider adaptability, and economic significance. Since its introduction in India during the 17^th century, guava cultivars have exhibited a narrow genetic base, with most existing genotypes arising from open-pollinated selections or crosses involving a limited number of genotypes. Furthermore, much of the available germplasm has been named based on fruit characteristics or place/regions of origin, leading to confusion in classification and hindering the precise identification and utilization of genetic resources in guava breeding programs. To address this, 49 morpho-biochemical parameters were assessed in 51 diverse Psidium genotypes, including cultivars, varieties, hybrids, related wild species, and exotic/USDA introductions.

Results: Substantial variability was observed among globally collected guava germplasm for fruit traits, with fruit weight ranging from 11.67 g (Psidium molle) to 379 g (S. N90-53), seed number from 8 (S. N11-3) to 512 (S. N15-3), leaf length from 5.57 to 17.17 cm, leaf width from 2.07 to 7.90 cm, and petiole length from 0.17 to 0.77 cm. Germplasm also differed in qualitative descriptors, including branch orientation, bark colour, leaf morphology, tip structure, and fruit surface traits, with wild species forming distinct morphological groups. Additionally, biochemical traits varied widely, including the contents of total soluble solid (6.8-13.8 °Brix), acidity (0.25-1.60%), total sugars (3.62-9.21 g/100 g FW), ascorbic acid (88.36-302.46 mg/100 g FW), ferric reducing antioxidants power (7.74-20.69 µM TE/g FW), free radical scavenging activity (2,2-diphenyl-1-picrylhydrazyl assay)(85.72-98.47%), lycopene (0.05-8.91 mg/100 g FW), and total carotenoids (0.05-2.76 mg/100 g FW). Besides, principal component analysis indicated PC1 (22.1%) related to fruit size and PC2 (15.2%) to biochemical traits. Furthermore, cluster analysis grouped 51 guava genotypes into three clusters, distinguishing wild from cultivated types.

Conclusions: The study confirms the presence of wide morpho-biochemical variability in Psidium germplasm, offering valuable genetic resources for genetic improvement programs, aimed at enhanced fruit quality with rich antioxidants, bio-fortification, and the tailoring of novel guava genotypes with reduced seed content, enhanced seed mellowness, and tenet branching, fitting in high-density planting and improved yield efficiency.

Background: Hibiscus L., the largest genus in the Malvaceae family, comprises numerous species of significant ornamental value. However, it remains a phylogenetically contentious taxon that has been historically neglected in systematic evolutionary studies.

Results: In this study, we sequenced and analyzed the chloroplast genomes of 51 samples from 36 Hibiscus species and related genera. Multiple analyses were performed to reveal their genome structures, GC contents, codon usage, cross-species Ka/Ks ratios, SSR distributions, and nucleotide diversities. Concatenated and coalescent-based approaches were used for phylogenetic analyses. Several methods, including the calculation of concordance factors (gCFs and sCFs), MSCquartets and reticulate networks, were employed to explore the causes of phylogenetic conflicts. Furthermore, using branch-site model, we identified positively selected genes. Our results revealed that the chloroplast genomes of Hibiscus species were highly conserved in structure. Their sizes ranged from 160,068 to 163,579 bp, encoding approximately 130 genes, and their GC content varied only between 36.55% and 37%. Notably, 15 highly polymorphic loci (e.g., trnS-GCU, trnS-UGA, and trnG-GCC) were identified as candidate molecular markers for population genetics and horticultural breeding. Phylogenetic analysis revealed that Hibiscus and related genera are polyphyletic and could be divided into three well-supported groups. Novel species relationships were first detected at the plastome level. We also revealed significant phylogenetic conflicts between Hibiscus and related genera, attributed to incomplete lineage sorting (ILS) and reticulate evolution, which collectively explain the complex and polyphyletic relationships among them. Evolutionary rate analyses revealed a Ka/Ks ratio > 1.0 for the ycf1 gene, while positive selection analysis identified eleven genes (e.g., accD, atpF and ndhA) harboring amino acid sites under selection, primarily involved in photosynthetic pathways.

Conclusions: Our results highlight the complex relationships within Hibiscus species and their close relatives, characterized by blurred intergeneric boundaries. Moreover, Hibiscus species and their close relatives have undergone significant purifying selection, with many photosynthesis-related genes playing pivotal roles. This study provides essential genomic resources and evolutionary insights to guide future taxonomic and phylogenetic studies in Hibiscus.

Background: Gypsophila species are rich in saponins and phenolic compounds that exhibit antibacterial, cytotoxic, and antioxidant activities; however, there is not much information about their herbicidal, insecticidal, or fungicidal effects.

Result: This study was to investigate the phytochemical composition and examine the herbicidal, antifungal, and insecticidal effects of Gypsophila pilosa Huds., a species of the Caryophyllaceae family, to evaluate its potential as an environmental friendly biopesticide for sustainable agriculture. The soil properties at the collection site were evaluated, and plant material was collected from Kırşehir Province, Turkey. The phytochemical structure of the aerial parts (leaves+flowers+shoots) methanol extract was analysed using LC-ESI-MS/MS. A phytochemical study found eight phenolic compounds, with rosmarinic acid (17,710 mg/kg), ferulic acid (13,955 mg/kg), and rutin (2,994 mg/kg) being the main components. Methanol and hexane extracts were prepared and tested for their herbicidal activity against Rumex crispus L., Taraxacum officinale F.H. Wigg. and Triticum aestivum L., as well as their antifungal activity against Rhizoctonia solani Kühn., Sclerotinia sclerotiorum (Lib.)de Bary, Phytophthora infestans (Mont.) de Bary and Monilinia fructigena (Pers.) Honey. Additionally, they were tested for their insecticidal activity against Sitophilus granaries. Herbicidal research indicated a significant decrease of germination and seedling development in R. crispus and T. officinale, with methanol extracts exhibiting total suppression of T. officinale at increased treatments. Antifungal assays showed that both methanol and hexane extracts inhibited the mycelial growth of R. solani, P. infestans, and M. fructigena, although S. sclerotiorum showed resistance. Insecticidal experiments demonstrated a dose- and time-dependent mortality of S. granarius, with the methanol extract obtaining a mortality rate of up to 61% at a 20% concentration after 96 h.

Conclusions: This research is the first demonstration of the biopesticidal properties of G. pilosa, showing significant herbicidal, antifungal, and insecticidal effects. The findings indicate that G. pilosa could be used as an environmental friendly alternative for chemical pesticides, improving integrated pest management strategies while supporting sustainable farming practices.