Whole Genome Duplication Events Likely Contributed to the Aquatic Adaptive Evolution of Parkerioideae.

As the only aquatic lineage of Pteridaceae, Parkerioideae is distinct from many xeric-adapted species of the family and consists of the freshwater Ceratopteris species and the only mangrove ferns from the genus Acrostichum. Previous studies have shown that whole genome duplication (WGD) has occurred in Parkerioideae at least once and may have played a role in their adaptive evolution; however, more in-depth research regarding this is still required. In this study, comparative and evolutionary transcriptomics analyses were carried out to identify WGDs and explore their roles in the environmental adaptation of Parkerioideae. Three putative WGD events were identified within Parkerioideae, two of which were specific to Ceratopteris and Acrostichum, respectively. The functional enrichment analysis indicated that the lineage-specific WGD events have played a role in the adaptation of Parkerioideae to the low oxygen concentrations of aquatic habitats, as well as different aquatic environments of Ceratopteris and Acrostichum, such as the adaptation of Ceratopteris to reduced light levels and the adaptation of Acrostichum to high salinity. Positive selection analysis further provided evidence that the putative WGD events may have facilitated the adaptation of Parkerioideae to changes in habitat. Moreover, the gene family analysis indicated that the plasma membrane H+-ATPase (AHA), vacuolar H+-ATPase (VHA), and suppressor of K+ transport growth defect 1 (SKD1) may have been involved in the high salinity adaptation of Acrostichum. Our study provides new insights into the evolution and adaptations of Parkerioideae in different aquatic environments.

Neottiamaolanensis, a replacement name for Neottiabifida M.N.Wang (Orchidaceae).

According to Articles 53.1 of the International Code of Nomenclature for Algae, Fungi, and Plants (Shenzhen Code), Neottiabifida M.N.Wang (as 'bifidus'; PhytoKeys 229: 222, 2023) is an illegitimate name, and hence a new name Neottiamaolanensis M. N. Wang is proposed here.

Neottiabifidus (Orchidaceae, Epidendroideae, Neottieae), a new mycoheterotrophic species from Guizhou, China.

Neottiabifidus, a new mycoheterotrophic orchid, found in Maolan National Nature Reserve in Guizhou Province, China, is described and illustrated here. The new species is close to N.nidus-avis, N.kiusiana and N.papilligera but differs in having a finely pubescent rachis with fewer flowers, a finely pubescent pedicel, and a fishtail-shaped lip that is deeply bilobed to the middle of the lip, with the lobes diverging at an acute angle (45°) to each other and mesochile with many papillae. Additionally, N.bifidus is well supported as a new species by molecular phylogenetic results based on ITS and chloroplast genome. The chloroplast genome of the novelty, which contains an LSC region of 33,819 bp, SSC region of 5,312 bp and IRs of 46,762 bp was assembled and annotated. A key to mycoheterotrophic Neottia species in China is also provided.

[Effects of landscape complexity and local management on bee pollinator diversity in apple orchards in Changping District, Beijing, China.] / åŒ—äº¬æ˜Œå¹³åŒºæ™¯è§‚å¤æ‚åº¦å’Œå±€åœ°ç®¡ç†å¯¹è‹¹æžœå›­ä¼ ç²‰èœ‚å¤šæ ·æ€§çš„å½±å“.

Pollinators provide important ecosystem services for crop production and food security. With the development of agricultural economy and the increasing intensity of land-use, a large number of natural or semi-natural habitats have been converted to croplands. Landscape homogenization and intensive management lead to the decline of wild bee diversity and threaten the sustainable agricultural production. In this study, we investigated the effects of landscape complexity (proportion of semi-natural habitats), local management practices (local flowering plant diversity and soil total nitrogen), and their interactions on diversity of bee pollinators in apple orchard in Changping District, Beijing. A total of 8642 bee individuals were captured, including 5125 honey bees and 3517 wild bees from 5 families, 14 genera, and 49 species. The optimal landscape scale for the response of bee diversity to landscape complexity and local management intensity was 500 m. Within 500 m radius of the site, the abundance of overall bees and wild bees significantly increased with increasing proportion of semi-natural habitats. The landscape complexity interacting with local flowering plant diversity significantly affected the richness of overall bee and wild bee. When the proportion of semi-natural habitats surrounding the apple orchards was low (≤29.9%), we found a positive effect of flowering plant diversity on the richness of overall bee and wild bee, whereas a reversed trend was found when the proportion of semi-natural habitats surrounding the apple orchards was high (>29.9%). In addition, the abundance of honey bees significantly increased with the increase of local flowering plant diversity and soil total nitrogen. The soil total nitrogen interacting with local flowering plant diversity significantly affected the honey bee abundance. At low levels of soil total nitrogen (≤1.9 g·kg-1), there was a positive effect of flowering plant diversity on honey bee abundance; whereas this trend was reversed at high levels of soil total nitrogen (>1.9 g·kg-1). Increasing the proportion of semi-natural habitats in agricultural landscape was beneficial to the increase of wild bee abundance, and flowering plant diversity could promote bee diversity but depending on landscape scale (proportion of semi-natural habitats) and local scale (nitrogen application). Therefore, multi-scale factors should be considered to develop conservation strategies to maintain the diversity of wild bees in agricultural landscape. Maintaining a higher proportion of cultivated land as much as possible is still a long-term requirement for production, while maintaining intermediate landscape complexity, increasing the diversity of flowering plants on the ground, and reducing the application of nitrogen fertilizer would be effective ways to promote the diversity of pollinating bees in apple orchards.

Two new dibenzyl derivatives from the stems of Dendrobium catenatum.

Two new dibenzyl derivatives, dendrocandins V-W (1-2), together with six known compounds (3-8), have been isolated from the dried stems of Dendrobium catenatum. Their structures were mainly elucidated on the basis of HRESIMS, one- and two-dimensional NMR techniques. The isolated compounds 5-8 were evaluated in vitro for their antioxidant and hypoglycemic activities. Compound 8 showed moderate potent DPPH scavenging activity with IC50 value of 34.45 ± 1.07 µM. And compounds 5, 7-8 exhibited significant ABTS radical scavenging activities with IC50 values of 10.03 ± 0.88, 5.32 ± 1.13 and 9.01 ± 1.39 µM. Compounds 6-7 showed potent α-glucosidase inhibitory activities with IC50 values of 36.05 ± 0.67 and 159.59 ± 0.86 µM.

Phylogeography and conservation genetics of the rare and relict Bretschneidera sinensis (Akaniaceae).

Bretschneidera sinensis, a class-I protected wild plant in China, is a relic of the ancient Tertiary tropical flora endemic to Asia. However, little is known about its genetics and phylogeography. To elucidate the current phylogeographic patterns and infer the historical population dynamics of B. sinensis, and to make recommendations for its conservation, three non-coding regions of chloroplast DNA (trnQ-rps16, rps8-rps11, and trnT-trnL) were amplified and sequenced across 256 individuals from 23 populations of B. sinensis, spanning 10 provinces of China. We recognized 13 haplotypes, demonstrating relatively high total haplotype diversity (hT = 0.739). Almost all of the variation existed among populations (98.09%, P < 0.001), but that within populations was low (1.91%, P < 0.001). Strong genetic differentiation was detected among populations (GST = 0.855, P < 0.001) with limited estimations of seed flow (Nm = 0.09), indicating that populations were strongly isolated from one another. According to SAMOVA analysis, populations of B. sinensis in China could be divided into five geographic groups: (1) eastern Yunnan to western Guangxi; (2) Guizhou-Hunan-Hubei; (3) central Guangdong; (4) northwestern Guangdong; and (5) the Luoxiao-Nanling-Wuyi -Yangming Mountain. Network analysis showed that the most ancestral haplotypes were located in the first group, i.e., the eastern Yungui Plateau and in eastern Yunnan, which is regarded as a putative glacial refugia for B. sinensis in China. B. sinensis may have expanded its range eastward from these refugia and experienced bottleneck or founder effects in southeastern China. Populations in Liping (Guizhou Province), Longsheng (Guangxi Province), Huizhou (Guangdong Province), Chongyi (Jiangxi Province), Dong-an (Hunan Province), Pingbian (Yunnan Province) and Xinning (Hunan Province) are proposed as the priority protection units.

[DNA barcoding identification of endangered medicinal plants of Orchidaceae].

In this study, DNA barcoding was used to validate the traditional morphological classification of medicinal plants of Orchidaceae. The 163 samples of 135 species belong to 49 genera which have been confirmed by morphological identification were collected. Candidate sequences, including matK, psbA-trnH and ITS2 sequences, were amplified, bidirectionally sequenced, and assembled. All the sequences were blasted to GenBank database at NCBI, then analyzed using Neighbor-joining tree method by MEGA 7.0. The results showed that the DNAs of 163 samples were successfully extracted. The amplification efficiency of matK, psbA-trnH and ITS2 sequences were 100%, 100% and 98.77%, respectively. The 487 sequences were obtained, 345 sequences of which have matched corresponding sequences in the GenBank database and 142 sequences were new sequences. The topology of NJ tree which were constructed with the matK sequences was better than the trees of psbA-trnH and ITS2 sequences. In conclusion, the matK, psbA-trnH and ITS2 sequences were complementary and suitable for identification of medicinal plants of Orchidaceae. DNA barcoding can be used as an auxiliary means for identification of medicinal plants of Orchidaceae.

Comparison of hypoglycemic and antioxidative effects of polysaccharides from four different Dendrobium species.

Four polysaccharides from Dendrobium huoshanense (DHP), D. officinale (DOP), D. nobile (DNP) and D. chrysotoxum (DCP), which had obvious differences in intrinsic viscosities and monosaccharide compositions, were extracted to compare their hypoglycemic and antioxidative activities in alloxan-induced diabetic mice by oral administration. The analysis of fasting blood glucose, glycosylated serum protein and serum insulin levels showed that DHP, DOP and DNP, but not DCP, possessed significant hypoglycemic effect with the decreasing order of DHP>DNP>DOP. Histopathological observation confirmed the capability of DHP, DOP and DNP to intervene the damage in pancreas tissues. The determination of superoxide dismutase, catalase, malonaldehyde and L-glutathione levels in the liver and kidney displayed that DHP, DOP and DNP had protective effects against alloxan-induced oxidative damage and the effect of DHP ranked first. These results suggested that there were significant differences in hypoglycemic and antioxidative activities between four Dendrobium polysaccharides, which may be contributed to their physicochemical properties.

A new orchid genus, Danxiaorchis, and phylogenetic analysis of the tribe Calypsoeae.

BACKGROUND: Orchids have numerous species, and their speciation rates are presumed to be exceptionally high, suggesting that orchids are continuously and actively evolving. The wide diversity of orchids has attracted the interest of evolutionary biologists. In this study, a new orchid was discovered on Danxia Mountain in Guangdong, China. However, the phylogenetic clarification of this new orchid requires further molecular, morphological, and phytogeographic analyses. METHODOLOGY/PRINCIPAL FINDINGS: A new orchid possesses a labellum with a large Y-shaped callus and two sacs at the base, and cylindrical, fleshy seeds, which make it distinct from all known orchid genera. Phylogenetic methods were applied to a matrix of morphological and molecular characters based on the fragments of the nuclear internal transcribed spacer, chloroplast matK, and rbcL genes of Orchidaceae (74 genera) and Calypsoeae (13 genera). The strict consensus Bayesian inference phylogram strongly supports the division of the Calypsoeae alliance (not including Dactylostalix and Ephippianthus) into seven clades with 11 genera. The sequence data of each species and the morphological characters of each genus were combined into a single dataset. The inferred Bayesian phylogram supports the division of the 13 genera of Calypsoeae into four clades with 13 subclades (genera). Based on the results of our phylogenetic analyses, Calypsoeae, under which the new orchid is classified, represents an independent lineage in the Epidendroideae subfamily. CONCLUSIONS: Analyses of the combined datasets using Bayesian methods revealed strong evidence that Calypsoeae is a monophyletic tribe consisting of eight well-supported clades with 13 subclades (genera), which are all in agreement with the phytogeography of Calypsoeae. The Danxia orchid represents an independent lineage under the tribe Calypsoeae of the subfamily Epidendroideae. This lineage should be treated as a new genus, which we have named Danxiaorchis, that is parallel to Yoania. Both genera are placed under the subtribe Yoaniinae.

[A study on chilling injury in medicinal plants region of South China Botanical Garden].

From late January to early February in 2008, Guangzhou suffered from the cold and humid rainy for 20 days, and the daily mean temperature was under 10 degrees C. In 794 species of medicinal plants in South China Botanical Garden, 78 species (9.8%) suffered from chilling injury. The reasons were analyzed and some useful suggestions were made.

Repeated morphine treatment influences operant and spatial learning differentially.

OBJECTIVE: To investigate whether repeated morphine exposure or prolonged withdrawal could influence operant and spatial learning differentially. METHODS: Animals were chronically treated with morphine or subjected to morphine withdrawal. Then, they were subjected to two kinds of learning: operant conditioning and spatial learning. RESULTS: The acquisition of both simple appetitive and cued operant learning was impaired after repeated morphine treatment. Withdrawal for 5 weeks alleviated the impairments. Single morphine exposure disrupted the retrieval of operant memory but had no effect on rats after 5-week withdrawal. Contrarily, neither chronic morphine exposure nor 5-week withdrawal influenced spatial learning task of the Morris water maze. Nevertheless, the retrieval of spatial memory was impaired by repeated morphine exposure but not by 5-week withdrawal. CONCLUSION: These observations suggest that repeated morphine exposure can influence different types of learning at different aspects, implicating that the formation of opiate addiction may usurp memory mechanisms differentially.