Morphological and phylogenetic relationships within Viola sect. Sclerosium (Violaceae) in Iran

Zeng

et al. 2021

Biology

To investigate the diversity and structure of soil bacterial and fungal communities in saline soils, soil samples with three increasing salinity levels (S1, S2 and S3) were collected from a maize field in Yanqi, Xinjiang Province, China. The results showed that the K+, Na+, Ca2+ and Mg2+ values in the bulk soil were higher than those in the rhizosphere soil, with significant differences in S2 and S3 (p < 0.05). The enzyme activities of alkaline phosphatase (ALP), invertase, urease and catalase (CAT) were lower in the bulk soil than those in the rhizosphere. Principal coordinate analysis (PCoA) demonstrated that the soil microbial community structure exhibited significant differences between different salinized soils (p < 0.001). Data implied that the fungi were more susceptible to salinity stress than the bacteria based on the Shannon and Chao1 indexes. Mantel tests identified Ca2+, available phosphorus (AP), saturated electrical conductivity (ECe) and available kalium (AK) as the dominant environmental factors correlated with bacterial community structures (p < 0.001); and AP, urease, Ca2+ and ECe as the dominant factors correlated with fungal community structures (p < 0.001). The relative abundances of Firmicutes and Bacteroidetes showed positive correlations with the salinity gradient. Our findings regarding the bacteria having positive correlations with the level of salinization might be a useful biological indicator of microorganisms in saline soils.

Section: Methodsmentioning

confidence: 99%

Responses of the Soil Microbial Community to Salinity Stress in Maize Fields

Zeng

et al. 2021

Biology

“…However, it is difficult to draw other parallels between the two lineages, which are neither closely related (Marcussen et al ., ) nor ecologically similar, V . uliginosa being a cool‐temperate bog species and taxa of section Sclerosium occuring in hot, dry, monsoon‐affected places around the Indian Ocean (Mohammadi Shahrestani et al ., , ). Of the deeper lineages of the genus, cleistogamy has been reported only from the tropical section Leptidium Ging.…”

Section: Discussionmentioning

confidence: 99%

Cleistogamy and phylogenetic position ofViola uliginosa(Violaceae) re-examined

et al. 2016

Self Cite

Viola uliginosa is an endangered species throughout its range in Central Europe. Based on an unusual combination of morphological characters, including a reported lack of cleistogamous (CL) flowers, it was previously placed in the monotypic subsection Repentes, section Viola. Available individual phylogenetic analyses identify V. uliginosa as a lineage deeply embedded in section Viola, but hitherto its exact position was unknown. Here we confirm the occurrence of cleistogamy in V. uliginosa. Unlike other species of section Viola, V. uliginosa produced both chasmogamous and CL flowers at the same time, not at different times of the year (seasonal cleistogamy). The two flower types differed conspicuously in morphology and microstructure, especially in size and shape of the pistil and stamens as confirmed by scanning electron microscopy. Secondly, we resolved the phylogenetic position of V. uliginosa as a lineage deeply embedded in subsection Rostratae by means of a multigene multispecies coalescent analysis using *BEAST. In this analysis, V. mirabilis and V. uliginosa were successive sisters to the rest of subsection Rostratae and, because allopolyploids exist between V. mirabilis and the last one, subsection Rostratae needs to comprise all these taxa to be monophyletic. The evolution of key morphological traits is briefly discussed.

“…Nine allopatric taxa have been described [1, 137, 250, 251] but most authorities have interpreted the variation as more or less continuous and have retained only one or two variable species [79, 252]. However, a detailed study of the Iranian taxa [91, 137] revealed three morphologically discrete species and allopolyploid relationships among them ( V. stocksii 4 x ; V. cinerea 8 x ; V. behboudiana 8 x ), which may suggest more taxa warrant recognition within the section. Section Sclerosium may have started to diversify in Late Miocene 3.5–10 Ma ago [137].…”

Section: [2] Viola Subg Violamentioning

confidence: 99%

A revised phylogenetic classification forViola(Violaceae)

Marcussen

Ballard

Danihelka

et al. 2022

Preprint

Self Cite

The genus Viola (Violaceae) is among the 40–50 largest genera among angiosperms, yet its taxonomy has not been revised for nearly a century. In the most recent revision, by Wilhelm Becker in 1925, the then known 400 species were distributed among 14 sections and numerous unranked groups. Here we provide an updated, comprehensive classification of the genus, based on data from phylogeny, morphology, chromosome counts, and ploidy, and based on modern principles of monophyly. The revision is presented as an annotated global checklist of accepted species of Viola, an updated multigene phylogenetic network and an ITS phylogeny with denser taxon sampling, a brief summary of the taxonomic changes from Becker’s classification and their justification, a morphological binary key to the accepted subgenera, sections and subsections, and an account of each infrageneric subdivision with justifications for delimitation and rank including a description, a list of apomorphies, molecular phylogenies where possible or relevant, a distribution map, and a list of included species. We subdivide the 658 species accepted by us into 2 subgenera, 31 sections, and 20 subsections. We erect one new subgenus of Viola (subg. Neoandinium, a replacement name for the illegitimate subg. Andinium), six new sections (sect. Abyssinium, sect. Himalayum, sect. Melvio, sect. Nematocaulon, sect. Spathulidium, sect. Xanthidium), and seven new subsections (subsect. Australasiaticae, subsect. Bulbosae, subsect. Clausenianae, subsect. Cleistogamae, subsect. Dispares, subsect. Formosanae, subsect. Pseudorupestres). Evolution within the genus is discussed in light of biogeography, fossil record, morphology, and particular traits. Viola is among very few temperate and widespread genera that originated in South America. The biggest identified knowledge gaps for Viola concern the South American taxa, for which basic knowledge from phylogeny, chromosome counts, and fossil data is virtually absent. Viola has also never been subject to comprehensive anatomical study. Study on seed anatomy and morphology is required to understand the fossil record of the genus.