Malvaceae s.l., the most diverse family within Malvales, includes well-known species of great economic importance like cotton, cacao, and durian. Despite numerous phylogenetic analyses employing multiple markers, relationships between several of its nine subfamilies, particularly within the largest lineage /Malvadendrina, remain unclear. In this study, we attempted to resolve the relationships within the major clades of Malvaceae s.l. using plastid genomes of 48 accessions representing all subfamilies. Maximum likelihood and Bayesian analyses recovered a fully resolved and well-supported topology confirming the split of the family into /Byttneriina (/Grewioideae +/Byttnerioideae) and /Malvadendrina. Within /Malvadendrina, /Helicteroideae occupied the earliest branching position, followed by /Sterculioideae, /Brownlowioideae, /Tiliodeae, and /Dombeyoideae formed a clade sister to /Malvatheca (/Malvoideae +/Bombacoideae), a grouping morphologically supported by the lack of androgynophore. Results from dating analyses suggest that all subfamilies originated during hot or warm phases in the Late Cretaceous to Paleocene. This study presents a well-supported phylogenetic framework for Malvaceae s.l. that will aid downstream revisions and evolutionary studies of this economically important plant family.

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Hepatocellular Carcinoma is one of the most frequently diagnosed cancer and highly refractory for chemotherapeutics agents. Therefore, the study aims to explore the new therapeutic agents for HCC. Phenolics rich fraction of leaves of P. lanceifolium was studied against hepatic cancer cell lines (HepG2) and NDEA-induced HCC rat model system. The obtained results showed that PLE induces reactive oxygen species (ROS) generation and chromatin condensation in nucleus and, alters the mitochondrial membrane potential (MMP) in HepG2 cell lines. The acridine orange/propidium iodide analysis and annexin-V FITC/PI analysis confirms that PLE induces apoptosis-mediated cell death in HepG2-cell lines. In In Vivo analysis, the administration of PLE in NDEA-induced rats declined the elevated biochemicals markers (ALT, AST, ALP, and GGT), interleukins, TNF-α, α-fetoprotein, carcinoembryonic antigen, and total bilirubin. PLE reinstated the level of antioxidant enzyme (GSH, GST, catalase, SOD, and GPX) and the expression of pro-apoptotic (p53, caspase-3, caspase-9, and Bax) and anti-apoptotic (Bcl-2) genes in a dose-dependent manner. The GC-MS analysis of Pterospermum lanceifolium fraction (PLE) represents the presence of palmitic acid, myristic acid, β-sitosterol, and catechin as major bioactive phytocompounds. The study discloses the new lead for HCC that can be further useful for development of new chemopreventive agent.

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Allelopathy and resource competition are considered to be two primary mechanisms responsible for loss of biodiversity in plantations of Eucalyptus species. However, these two processes are usually studied separately, and they have been rarely tested on native woody species. In this study, we used a bioassay to assess sensitivities of twenty broad-leaved tree species on roots, stem growth and seed germination to leaf aqueous extracts of Eucalyptus urophylla S.T. Blake and categorized them into two types: inhibited and uninhibited (including stimulated and unaffected). To compare the relative importance of allelopathy and resource competition, we planted these two species groups into the E. urophylla plantation separately and treated with three gradients of irrigation-nutrients. The results showed that the allelopathic effects of aqueous extract of E. urophylla were species-specific and could be inhibitory, neutral or stimulatory. Compared to the inhibited species, the uninhibited species grew faster and survived better after they were planted in an E. urophylla plantation for approximately 10 years, suggesting that allelopathy from E. urophylla is an important restraining factor on native woody communities. Individuals from both species groups grew faster following higher resource treatment at the early but not the late stage of growth. Saplings did not vary in their survival rates across resource gradients. This indicates that resource competition between E. urophylla and native woody species has only a limited role in reducing the diversity of native species in an E. urophylla plantation. We conclude that allelopathy is more important than resource competition in mediating the reduction in plant biodiversity in E. urophylla plantations. Our study suggests that mixing certain types of species (e.g. Helicia cochinchinensis, Pterospermum lanceaefolium, Cinnamomum burmanni, Machilus chinensis, Acmena acuminatissima and Castanopsis chinensis) in E. urophylla plantations can mitigate against plant diversity loss.

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Allelopathy is widely considered to be one of the causes of biodiversity reduction in Eucalyptus plantations. However, most research conducted on the allelopathic effects of Eucalyptus is performed in the laboratory with weeds and crops as receptors, which fail to fully reflect natural ecosystems. In this study, we conducted two field trials and a greenhouse trial to assess the influence of soil allelopathy, allelochemical volatilization, and foliage litter decomposition on seed germination and seedling growth of three native (Acmena acuminatissima, Cryptocarya concinna and Pterospermum lanceaefolium) and one introduced (Albizia lebbeck) tree species in a Eucalyptus urophylla and Pinus elliottii plantation. In order to avoid confounding factors relating to management strategies and environmental influences, only one plantation of each species was used for experimentation. In the allelopathy experiment, the root length of the three native species was significantly inhibited in the E. urophylla plantation compared with that in the P. elliottii plantation. In the volatilization experiments, the seedling survival rate of the three native species was greater in the E. urophylla plantation, but significant differences were found for A. acuminatissima and C. concinna. Root length and dry weight of P. lanceaefolium increased significantly in the E. urophylla plantation, in the foliage litter decomposition experiments. There was no significant difference between the two plantations for A. lebbeck, except that the seedling survival rate was greater in the E. urophylla plantation in the foliage litter decomposition experiment. We concluded that allelopathy in the E. urophylla plantation was selective, which inhibited the growth of the native tree species but had no significant influence on the introduced A. lebbeck species. Allelopathy from volatilization and foliage litter decomposition contributed little to the inhibitory effects. We suggest that the introduced nitrogen-fixing species, A. lebbeck could be a potential choice for the establishment of mixed stands with Eucalyptus.

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Background The nuclear DNA amount in an unreplicated haploid chromosome complement (1C-value) is a key diversity character with many uses. Angiosperm C-values have been listed for reference purposes since 1976, and pooled in an electronic database since 1997 (http://www.kew.org/cval/homepage). Such lists are cited frequently and provide data for many comparative studies. The last compilation was published in 2000, so a further supplementary list is timely to monitor progress against targets set at the first plant genome size workshop in 1997 and to facilitate new goal setting. Scope The present work lists DNA C-values for 804 species including first values for 628 species from 88 original sources, not included in any previous compilation, plus additional values for 176 species included in a previous compilation. Conclusions 1998-2002 saw striking progress in our knowledge of angiosperm C-values. At least 1700 first values for species were measured (the most in any five-year period) and familial representation rose from 30 % to 50 %. The loss of many densitometers used to measure DNA C-values proved less serious than feared, owing to the development of relatively inexpensive flow cytometers and computer-based image analysis systems. New uses of the term genome (e.g. in 'complete' genome sequencing) can cause confusion. The Arabidopsis Genome Initiative C-value for Arabidopsis thaliana (125 Mb) was a gross underestimate, and an exact C-value based on genome sequencing alone is unlikely to be obtained soon for any angiosperm. Lack of this expected benchmark poses a quandary as to what to use as the basal calibration standard for angiosperms. The next decade offers exciting prospects for angiosperm genome size research. The database (http://www.kew.org/cval/homepage) should become sufficiently representative of the global flora to answer most questions without needing new estimations. DNA amount variation will remain a key interest as an integrated strand of holistic genomics.

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