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The life history traits (egg, larva, and pupa stage) of the Lycaenidae butterfly, Luthrodes pandava Horsfield (Lepidoptera: Lycaenidae) observed and trapped on cycad plants are described from the Andaman and Nicobar Islands (ANI), India. The diversity of cycad host plants offered as larval food influences fecundity and conservation status. Zamia furfuracea is recorded for the first time as a cycad host plant and seasonal polyphenism in the ANI, India. [ABSTRACT FROM AUTHOR]

Cycadaceae is regarded as one of the largest cycad families. It is made up of 120 species of the single genus Cycas. Genus Cycas is found only in tropical and subtropical climates. They are dioecious plants with male and female reproductive cones. Members of Cycadaceae family are excellent suppliers of a wide range of beneficial phytochemicals however, only a few numbers of species had undergone phytochemical and pharmacological research. A wide battery of metabolites, including flavonoids, biflavonoids, phenolic acids, sterols, amino acids, lignans, and fatty acids, have been isolated and structurally identified from various Cycas species. Since biflavonoids are a defining trait of all cycads, we focused in this review on the various biflavonoids nuclei found in Cycadaceae and their distribution in distinct Cycas species among other isolated secondary metabolites. Therefore, we outlined the various biflavonoids nuclei found in Cycadaceae and their distribution in distinct Cycas species in this review. Additionally, we highlighted the diverse pharmacological effects of different Cycas species that their biflavonoid content can be credited with. [ABSTRACT FROM AUTHOR]

The type of Cycas debaoensis Y.C.Zhong & C.J.Chen (Y.C.Zhong 8762) consists of nine duplicates in PE. Our new investigation of the type collection suggests that the type includes at least two different gatherings which should be considered as syntypes. For nomenclatural purposes, we lectotypify the name Cycas debaoensis with the herbarium sheet PE00047578 and consider other duplicates in PE and GXMI as isolectotypes. The seeds in the capsule (Y.C.Zhong s.n. collected in Oct 1998) are considered as a syntype. [ABSTRACT FROM AUTHOR]

SUMMARY: Simple telomeric repeats composed of six to seven iterating nucleotide units are important sequences typically found at the ends of chromosomes. Here we analyzed their abundance and homogeneity in 42 gymnosperm (29 newly sequenced), 29 angiosperm (one newly sequenced), and eight bryophytes using bioinformatics, conventional cytogenetic and molecular biology approaches to explore their diversity across land plants. We found more than 10 000‐fold variation in the amounts of telomeric repeats among the investigated taxa. Repeat abundance was positively correlated with increasing intragenomic sequence heterogeneity and occurrence at non‐telomeric positions, but there was no correlation with genome size. The highest abundance/heterogeneity was found in the gymnosperm genus Cycas (Cycadaceae), in which megabase‐sized blocks of telomeric repeats (i.e., billions of copies) were identified. Fluorescent in situ hybridization experiments using variant‐specific probes revealed canonical Arabidopsis‐type telomeric TTTAGGG repeats at chromosome ends, while pericentromeric blocks comprised at least four major telomeric variants with decreasing abundance: TTTAGGG>TTCAGGG >TTTAAGG>TTCAAGG. Such a diversity of repeats was not found in the sister cycad family Zamiaceae or in any other species analyzed. Using immunocytochemistry, we showed that the pericentromeric blocks of telomeric repeats overlapped with histone H3 serine 10 phosphorylation signals. We show that species of Cycas have amplified their telomeric repeats in centromeric and telomeric positions on telocentric chromosomes to extraordinary high levels. The ancestral chromosome number reconstruction suggests their occurrence is unlikely to be the product of ancient Robertsonian chromosome fusions. We speculate as to how the observed chromosome dynamics may be associated with the diversification of cycads. [ABSTRACT FROM AUTHOR]

Toxoplasmosis and cancer are serious worldwide diseases, and the available drugs cause serious side effects. Investigation for new alternative therapies from natural sources is now an increasing concern. Herein, we carried out, for the first time, an in vitro screening of Cycas rumphii Miq. leaves for toxoplasmocidal effect, using Viruluent RH Toxoplasma gondii, and cytotoxic activity against HEPG-2, HCT-116 and HELA cancer cell lines using MTT assay. Among the tested extracts, the ethyl acetate fraction was the most effective against T. gondii, with an EC50 of 3.51 ± 0.2 µg/mL compared to cotrimoxazole (4.18 ± 0.01 µg/mL) and was the most potent against the tested cell lines, especially HEPG-2, with an IC50 of 6.98 ± 0.5 µg/mL compared to doxorubicin (4.50 ± 0.2 µg/mL). Seven compounds were isolated from the ethyl acetate fraction by extensive chromatographic techniques and fully elucidated using different spectroscopies. Compound (7) is an undescribed 4′, 4′′′ biapigenin di-C-glucoside, which showed a strong cytotoxic activity. Four known biflavonoids (1, 2, 4 and 5) in addition to a phenolic acid ester (3) and a flavonoid glycoside (6) were also isolated. Compounds (1, 3 and 6) were reported for the first time from C. rumphii. [ABSTRACT FROM AUTHOR]

Luthrodes pandava Horsfield (Lepidoptera: Lycaenidae) has been reported as a pest of cycad plants in the Andaman and Nicobar Islands, India for the first time. Its impact on host species is assessed. Compared to introduced species, endemic cycads appear to be most susceptible to damage by its larvae, feeding on the plant and affecting growth. Larvae damage all above‐ground plant parts. C. dharmrajii L. J. Singh and C. pschannae R.C. Srivast. & L. J. Singh, endemic to the Andaman and Nicobar Islands, are recorded here for the first time as new host plants. [ABSTRACT FROM AUTHOR]

Background and Aims We conducted a comprehensive analysis of the functional traits of leaves (leaflets) of cycads. The aim of this study was to clarify the functional divergence between the earlier origin Cycadaceae and the later differentiated Zamiaceae, and the differences in trait associations between cycads and angiosperms. Methods We selected 20 Cycadaceae species and 21 Zamiaceae species from the same cycad garden in South China, and measured their leaf structure, economic traits, mechanical resistance (F p) and leaf water potential at the turgor loss point (π tlp). In addition, we compiled a dataset of geographical distribution along with climatic variables for these cycad species, and some leaf traits of tropical–sub-tropical angiosperm woody species from the literature for comparison. Key Results The results showed significantly contrasting leaf trait syndromes between the two families, with Zamiaceae species exhibiting thicker leaves, higher carbon investments and greater F p than Cycadaceae species. Leaf thickness (LT) and π tlp were correlated with mean climatic variables in their native distribution ranges, indicating their evolutionary adaptation to environmental conditions. Compared with the leaves of angiosperms, the cycad leaves were thicker and tougher, and more tolerant to desiccation. Greater F p was associated with a higher structural investment in both angiosperms and cycads; however, cycads showed lower F p at a given leaf mass per area or LT than angiosperms. Enhancement of F p led to more negative π tlp in angiosperms, but the opposite trend was observed in cycads. Conclusions Our results reveal that variations in leaf traits of cycads are mainly influenced by taxonomy and the environment of their native range. We also demonstrate similar leaf functional associations in terms of economics, but different relationships with regard to mechanics and drought tolerance between cycads and angiosperms. This study expands our understanding of the ecological strategies and likely responses of cycads to future climate change. [ABSTRACT FROM AUTHOR]

Understanding the genetic diversity of wild populations is fundamental to conserving species in-situ and ex-situ. To aid conservation plans and to inform ex-situ conservation, we examined the genetic diversity of the cycad Cycas calcicola (Cycadaceae). Samples were collected from wild populations in the Litchfield National Park and Katherine regions in the Northern Territory, Australia. Additional samples were obtained from botanic garden plants that were originally collected in the Katherine region, Daly River and Spirit Hills in the Northern Territory, Australia. Using RADseq we recovered 2271 informative genome-wide SNPs, revealing low to moderate levels of gene diversity (uHe = 0.037 to 0.135), very low levels of gene flow, and significant levels of inbreeding (mean FIS = 0.491). Population structure and multivariate analysis showed that populations fall into two genetic groups (Katherine vs Litchfield + Daly River + Spirit Hills). Genetic differentiation was twice as high between populations of the Katherine and Litchfield regions (FST ~ 0.1) compared to within these two regions (FST ~ 0.05). Increasing population fragmentation together with high levels of inbreeding and very little gene flow are concerning for the future adaptability of this species. The results indicated that the ex-situ collections (1) had significantly lower genetic diversity than the wild populations, and (2) only partly capture the genetic diversity present, particularly because the Litchfield National Park populations are not represented. We recommend that ex-situ collections be expanded to incorporate the genetic diversity found in Litchfield National Park and to increase the number of representatives from Daly River/Spirit Hills, and that in-situ populations from the Katherine and Greater Litchfield regions be conserved as separate management units. [ABSTRACT FROM AUTHOR]

Background and Aims Previous molecular dating studies revealed historical mass extinctions and recent radiations of extant cycads, but debates still exist between palaeobotanists and evolutionary biologists regarding the origin and evolution of Cycadaceae. Methods Using whole plastomic data, we revisited the phylogeny of this family and found the Palawan endemic Cycas clade was strongly related to all lineages from Southeast Eurasia, coinciding with a plate drift event occurring in the Early Oligocene. By integrating fossil and biogeographical calibrations as well as molecular data from protein-coding genes, we established different calibration schemes and tested competing evolutionary timelines of Cycadaceae. Key Results We found recent dispersal cannot explain the distribution of Palawan Cycas , yet the scenario including the tectonic calibration yielded a mean crown age of extant Cycadaceae of ~69–43 million years ago by different tree priors, consistent with multiple Palaeogene fossils assigned to this family. Biogeographical analyses incorporating fossil distributions revealed East Asia as the ancestral area of Cycadaceae. Conclusions Our findings challenge the previously proposed Middle–Late Miocene diversification of cycads and an Indochina origin for Cycadaceae and highlight the importance of combining phylogenetic clades, tectonic events and fossils for rebuilding the evolutionary history of lineages that have undergone massive extinctions. [ABSTRACT FROM AUTHOR]

The paleotropics harbor many biodiversity hotspots and show many different species richness patterns. However, it remains unclear which factors are the most important in directly shaping richness patterns among regions in the paleotropics (i.e. diversification rates, colonization times, and dispersal frequency). Here we used Cycadaceae as a model system to test the causes of regional richness patterns in the paleotropics. Specifically, we tested the roles of dispersal frequency, colonization time, diversification rates, and their combined role in explaining richness patterns among regions. We generated a well‐sampled, time‐calibrated phylogeny and then used this to estimate dispersal events, colonization times, and diversification rates. Richness patterns were significantly associated with the timing of the first colonization of each region and were best explained by the combined effects of colonization time and diversification rates. The number of dispersal events into each region and the diversification rates of species in each region were not significantly related to richness. Ancestral‐area reconstructions showed frequent migrations across Wallace's line, with a higher diversification rate east of Wallace's line than west of it. Overall, our study shows that colonization time can be an important factor for explaining regional richness patterns in the paleotropics. [ABSTRACT FROM AUTHOR]

Toxoplasmosis and cancer are serious worldwide diseases, and the available drugs cause serious side effects. Investigation for new alternative therapies from natural sources is now an increasing concern. Herein, we carried out, for the first time, an in vitro screening of Cycas rumphii Miq. leaves for toxoplasmocidal effect, using Viruluent RH Toxoplasma gondii, and cytotoxic activity against HEPG-2, HCT-116 and HELA cancer cell lines using MTT assay. Among the tested extracts, the ethyl acetate fraction was the most effective against T. gondii, with an EC50 of 3.51 ± 0.2 µg/mL compared to cotrimoxazole (4.18 ± 0.01 µg/mL) and was the most potent against the tested cell lines, especially HEPG-2, with an IC50 of 6.98 ± 0.5 µg/mL compared to doxorubicin (4.50 ± 0.2 µg/mL). Seven compounds were isolated from the ethyl acetate fraction by extensive chromatographic techniques and fully elucidated using different spectroscopies. Compound (7) is an undescribed 4′, 4′′′ biapigenin di-C-glucoside, which showed a strong cytotoxic activity. Four known biflavonoids (1, 2, 4 and 5) in addition to a phenolic acid ester (3) and a flavonoid glycoside (6) were also isolated. Compounds (1, 3 and 6) were reported for the first time from C. rumphii.

Background and Aims: Research required to clarify leaf nutrient relations of cycad species has been inadequate. Common garden studies are useful for determining the influence of genetics on leaf traits because of the homogeneous environment among experimental units. To date, there have been no common garden studies which included all ten genera of cycads. The full phylogenetic breadth has, therefore, not been included in this important area of study. Methods: We examined macronutrient and micronutrient content of leaves from one representative species from each of the ten cycad genera at Nong Nooch Tropical Botanical Garden in Thailand. Nitrogen content was determined by dry combustion, and the remaining nutrients were quantified by spectrometry. Results: The least variable elements were nitrogen and phosphorus, and the most variable elements were boron and sodium. Nutrient content based on leaflet area was more variable than based on leaflet mass, reflecting species differences in specific leaf area. There were no universal macronutrient or micronutrient signals indicating clear phylogenetic distinctions. Implications for Conservation: Active management of threatened cycad taxa requires research to develop the knowledge to enable evidence-based decisions. This common garden study inclusive of all 10 cycad genera creates a foundation to determine leaf nutrient sufficiency ranges to inform management decisions. [ABSTRACT FROM AUTHOR]

Genus Cycas, Cycadaceae family, contains about 117 species. Nevertheless, few species have been phytochemically and pharmacologically studied. To date Eighty-eight secondary metabolites, including flavonoids, terpenoids, lignans, aromatic acids and sterols were isolated and identified from nineteen Cycas species. Among the isolated compounds flavonoids are the most prevalent metabolites. The extracts as well as pure compounds isolated from Cycas species were reported to exhibit a wide range of biological activities including; antimicrobial, anti-oxidant, antidiabetic, cytotoxic, anthelmintic, analgesic, anti-arthritic, anti-inflammatory and thrombolytic activities. The present review highlights the reported phytochemical content as well as the pharmacological potential of Cycas species. Interestingly, it indicates that; almost all the previous investigation of the biological activity of pure compounds isolated from this genus was directed towards its flavonoid content. Accordingly, more biological studies are needed to figure out the possible role of other isolated compounds in the observed biological activities and/or the reported traditional uses of different Cycas species. Moreover, further studies are required to investigate other unexplored species. [ABSTRACT FROM AUTHOR]

The literature containing which chemical elements are found in cycad leaves was reviewed to determine the range in values of concentrations reported for essential and beneficial elements. We found 46 of the 358 described cycad species had at least one element reported to date. The only genus that was missing from the data was Microcycas. Many of the species reports contained concentrations of one to several macronutrients and no other elements. The cycad leaves contained greater nitrogen and phosphorus concentrations than the reported means for plants throughout the world. Magnesium was identified as the macronutrient that has been least studied. Only 14 of the species were represented by data from in situ locations, with most of the data obtained from managed plants in botanic gardens. Leaf element concentrations were influenced by biotic factors such as plant size, leaf age, and leaflet position on the rachis. Leaf element concentrations were influenced by environmental factors such as incident light and soil nutrient concentrations within the root zone. These influential factors were missing from many of the reports, rendering the results ambiguous and comparisons among studies difficult. Future research should include the addition of more taxa, more in situ locations, the influence of season, and the influence of herbivory to more fully understand leaf nutrition for cycads. [ABSTRACT FROM AUTHOR]

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Cycas micronesica is a foundation species in several Micronesian islands and its seeds have been a historical source of starch for the island residents. The species has become endangered by invasive specialist insect herbivores and conservationists struggle with the inability to estimate the age of observed seeds. To inform this agenda, we evaluated numerous Cycas micronesica seed traits to determine if any exhibited a relationship with age and a substantial change in absolute value. Of the 30 direct and derived seed traits that we evaluated, most of them were non-linear and exhibited minimal change after about 12 months in age. The only traits that emerged as unambiguous estimators of age were the quotients derived as gametophyte fresh weight/total seed fresh weight and sarcotesta dry weight/sclerotesta dry weight. These two simple metrics can be used to accurately estimate seed age for this arborescent cycad species. [ABSTRACT FROM AUTHOR]

Invasions of non-native species can threaten native biodiversity, and island ecosystems are ideal for studying these phenomena. In this article, first, we report on the invasive species that combine to threaten the island cycad Cycas micronesica by reviewing the history of previously reported invasions and providing an update of recent invasions. Then, we prioritize the threat status of each herbivore and the interactions among them. Plant damage was initiated in 2003─2005 by the non-native Aulacaspis yasumatsui Takagi armored scale, Erechthias sp. Meyrick leaf miner, and Luthrodes pandava Horsfield butterfly, which elicited unprecedented irruptions of the native Acalolepta marianarum Aurivillius stem borer and increased herbivory by feral pigs (Sus scrofa L.). The combined impact of these five consumers represents the greatest sustained threat to the cycad tree species. Mitigation of the damage caused by phytophagous non-native species is urgently needed to conserve this unique gymnosperm tree.

The literature containing which chemical elements are found in cycad leaves was reviewed to determine the range in values of concentrations reported for essential and beneficial elements. We found 46 of the 358 described cycad species had at least one element reported to date. The only genus that was missing from the data was Microcycas. Many of the species reports contained concentrations of one to several macronutrients and no other elements. The cycad leaves contained greater nitrogen and phosphorus concentrations than the reported means for plants throughout the world. Magnesium was identified as the macronutrient that has been least studied. Only 14 of the species were represented by data from in situ locations, with most of the data obtained from managed plants in botanic gardens. Leaf element concentrations were influenced by biotic factors such as plant size, leaf age, and leaflet position on the rachis. Leaf element concentrations were influenced by environmental factors such as incident light and soil nutrient concentrations within the root zone. These influential factors were missing from many of the reports, rendering the results ambiguous and comparisons among studies difficult. Future research should include the addition of more taxa, more in situ locations, the influence of season, and the influence of herbivory to more fully understand leaf nutrition for cycads.

The United States is currently home to five native cycad species. We provide a discussion on these five cycad species to illuminate how evolutionary and geopolitical processes influence phytogeography and published checklists of threatened plants. The number of threatened species in need of protection within any given country is a product of speciation that is contingent with evolutionary processes. However, this number may change instantaneously along with shifting of geopolitical boundaries brought about by armed conflict between rival states and multilateral negotiations. There are five contemporary cycad species within the United States, and the various historical bilateral and multilateral agreements that have generated this list are reviewed. Three of these five cycad species are threatened and in need of urgent protection. A discussion on the history of United States cycads as a microcosm of worldwide conservation issues is presented, with a focus on how federal conservation endeavors of individual nations may influence the world’s biodiversity crisis.

Cycas micronesica is a foundation species in several Micronesian islands and its seeds have been a historical source of starch for the island residents. The species has become endangered by invasive specialist insect herbivores and conservationists struggle with the inability to estimate the age of observed seeds. To inform this agenda, we evaluated numerous Cycas micronesica seed traits to determine if any exhibited a relationship with age and a substantial change in absolute value. Of the 30 direct and derived seed traits that we evaluated, most of them were non-linear and exhibited minimal change after about 12 months in age. The only traits that emerged as unambiguous estimators of age were the quotients derived as gametophyte fresh weight/total seed fresh weight and sarcotesta dry weight/sclerotesta dry weight. These two simple metrics can be used to accurately estimate seed age for this arborescent cycad species.

The gymnosperm genus Cycas is the sole member of Cycadaceae, and is the largest genus of extant cycads. There are about 115 accepted Cycas species mainly distributed in the paleotropics. Based on morphology, the genus has been divided into six sections and eight subsections, but this taxonomy has not yet been tested in a molecular phylogenetic framework. Although the monophyly of Cycas is broadly accepted, the intrageneric relationships inferred from previous molecular phylogenetic analyses are unclear due to insufficient sampling or uninformative DNA sequence data. In this study, we reconstructed a phylogeny of Cycas using four chloroplast intergenic spacers and seven low-copy nuclear genes and sampling 90% of extant Cycas species. The maximum likelihood and Bayesian inference phylogenies suggest: (1) matrices of either concatenated cpDNA markers or of concatenated nDNA lack sufficient informative sites to resolve the phylogeny alone, however, the phylogeny from the combined cpDNA-nDNA dataset suggests the genus can be roughly divided into 13 clades and six sections that are in agreement with the current classification of the genus; (2) although with partial support, a clade combining sections Panzhihuaenses  +  Asiorientales is resolved as the earliest diverging branch; (3) section Stangerioides is not monophyletic because the species resolve as a grade; (4) section Indosinenses is not monophyletic as it includes Cycas macrocarpa and C. pranburiensis from section Cycas ; (5) section Cycas is the most derived group and its subgroups correspond with geography. [ABSTRACT FROM AUTHOR]

Premise of research. The armored scale Aulacaspis yasumatsui Takagi has invaded numerous geographic regions to devastate cultivated populations of Cycas L. and the native population of Cycas micronesica K.D. Hill on the islands of Guam and Rota. Questions remain as to how this small hemipteran insect can so rapidly kill a large cycad tree. One possibility is depletion of nonstructural carbohydrates (NSCs) until the storage pool can no longer sustain plant viability.Methodology. We infested Cycas revoluta Thunberg plants with A. yasumatsui and harvested whole plants periodically until plant mortality at week 60. Harvested plants were separated into leaves, stems, and roots, and tissue was frozen and then lyophilized. The dry mass of each organ was measured, and then fructose, glucose, maltose, starch, and sucrose were quantified. Concentration and total pool size within each organ were calculated for each NSC.Pivotal results. Concentration and total pool of all five NSCs were greatest in stems. Concentrations exhibited linear or quadratic declines with time of infestation for all NSCs and organs, with the exception of glucose in stems and maltose in leaves. The total pool of all five NSCs declined linearly or quadratically in all three organs, with the exception of maltose in leaves. Initial plant dry mass of 152 g was 23% NSC, and ending plant dry mass of 59 g was 26% NSC. Carbohydrate stoichiometry shifted in favor of sugars over starch, and sugar stoichiometry shifted in favor of hexoses over disaccharides as time of infestation progressed.Conclusions. These results are consistent with carbohydrate depletion as the mechanism that explains rapid Cycas tree mortality during chronic A. yasumatsui infestation. This is the first demonstration of stress-induced expenditures of carbohydrates by cycads. [ABSTRACT FROM AUTHOR]

The extent of genetic diversity within a species is an important determinant of successful adaptation to adverse environmental conditions. Assessment of extent of genetic diversity/variability is also important to monitor genetic erosion within a species. In threatened plant species, genetic diversity assessment helps in selection of genetically diverse populations to enrich the genetically impoverished populations, thus minimizing the probability of genetic drift. Confirming taxonomic identity of threatened species, particularly those belonging to species complexes with dispute identity, is another essential task in the conservation of threatened species, which is best resolved through molecular approaches. The present study estimated the genetic variability within and among the populations of four threatened species, viz. Justicia beddomei (C.B. Clarke) Bennet (Acanthaceae), Embelia ribes Burm. f. (Myrsinaceae), Madhuca insignis (Radlk.) H.J. Lam (Sapotaceae) and Cycas beddomei Dyer (Cycadaceae) using Inter Simple Sequence Repeat (ISSR) and Simple Sequence Repeat (SSR) markers for selecting the genetically diverse populations. The phylogeny was analysed through ITS (nrDNA) and matK (cpDNA) sequences to confirm the species identity. The phylogenetic analyses confirmed four distinct species of Justicia, which also revealed that J. beddomei and J. adhatoda were sister groups with a common ancestor showing rapid parallel speciation with J. gendarussa in one clade and J. betonica in another. Madhuca insignis with extremely small population in the Western Ghats (Karnataka to Kerala) might have undergone either extensive hybridization or incipient speciation. In case of Embelia species, a greater evolutionary closeness between E. subcoraceae and E. floribunda was revealed, while E. ribes had a distinct clad. Both ISSR and SSR markers distinguished various genotypes of Cycas beddomei. [ABSTRACT FROM AUTHOR]

Climate change, species dispersal ability and habitat fragmentation are major factors influencing species distribution and genetic diversity, especially for the range-restricted and threatened taxa. Here, using four sequences of chloroplast DNAs (cpDNAs), three nuclear genes (nDNAs) and 12 nuclear microsatellites (SSRs), we investigated the genetic diversity, genetic structure, divergence time and population dynamics of Cycas segmentifida D. Y. Wang and C. Y. Deng, a threatened cycad species endemic to Southwest China. High levels of genetic diversity and genetic differentiation were revealed in C. segmentifida. Haplotypes of networks showed two evolutionary units in C. segmentifida, with the exception of the nuclear gene GTP network. Meanwhile, the UPGMA tree, structure and PCoA analyses suggested that 14 populations of C. segmentifida were divided into two clades. There was significant effect of isolation by distance (IBD) in this species. However, this species did not display a significant phylogeographic structure. The divergence time estimation suggested that its haplotypes diverged during the Middle Pleistocene. Additionally, the population dynamics inferred from different DNA sequences analyses were discordant. Bottleneck analysis showed that populations of C. segmentifida did not experience any recent bottleneck effect, but rather pointed to a contraction of its effective population size over time. Furthermore, our results suggested that the population BM which held an intact population structure and occupied undisturbed habitat was at the Hardy-Weinberg equilibrium, implying that this population is a free-mating system. These genetic features provide important information for the sustainable management of C. segmentifida. [ABSTRACT FROM AUTHOR]

Cycas dharmrajii L.J.Singh (Cycadaceae), a new species from the Andaman Islands, India is described and illustrated, and its conservation status is assessed. An abnormal branching habit of the giant trunk, its swollen base, often branched, polymorphic aerial roots, medium-sized leaves, megasporophylls with well-defined 10-28 paired lateral hook-like structures and 1-3 pairs of ovules, 2-schizo-lysigenous mucilage canals in leaflet, and characteristic pitting on the periclinal walls of the epidermal cells of the leaflets distinguishes it from all previously known species. A key to the species of Cycas from the Andaman and Nicobar Islands is also provided. [ABSTRACT FROM AUTHOR]

Chilades pandava (Lepidoptera: Lycaenidae) larval food quality was studied to determine its influence on adult life history traits. A wild population from Cycas nongnoochiae (Cycadales: Cycadaceae) endemic habitat behaved similarly to the population collected from a garden setting. Cycas micronesica, Cycas revoluta, and Cycas seemannii leaves were used as high-quality food, whereas C nongnoochiae, Cycas taitungensis, and Cycas condaoensis leaves were used as low-quality food. The daily oviposition rate was not influenced by food quality, but longevity and lifetime fecundity of females were increased by high-quality larval food. These results indicate that in situ Cycas species impose a physiological constraint on the genetic capacity to produce offspring by C pandava. The removal of that constraint by high-quality novel Cycas species may be one reason this butterfly can increase in population rapidly after an invasion event and express greater herbivory of Cycas species within invaded regions. [ABSTRACT FROM AUTHOR]

The Cycas segmentifida complex consists of eight species whose distributions overlap in a narrow region in Southwest China. These eight taxa are also morphologically similar and are difficult to be distinguished. Consequently, their taxonomic status has been a matter of discussion in recent years. To study this species complex, we sequenced four plastid intergenic spacers (cpDNA), three nuclear genes and genotyped 12 microsatellites for the eight taxa from 19 different localities. DNA sequences were analyzed using Maximum Likelihood (ML) method and Bayesian Inference (BI), and microsatellites were analyzed using the Neighbor-joining (NJ) and structure inference methods. Results of cpDNA, nuclear gene GTP and microsatellites all rejected the hypotheses that this complex consisted of eight taxa or one distinct lineage (species) but two previously described species were adopted: Cycas guizhouensis K. M. Lan et R. F. Zou and Cycas segmentifida D. Y.Wang et C. Y. Deng. Cycas longlinensis H. T. Chang et Y. C. Zhong was included in C. guizhouensis and the other five taxa were included in C. segmentifida. Our species delimitation inferred from molecular data largely corresponds to morphological differentiation. However, the other two nuclear genes were unable to resolve species boundaries for this complex independently. This study offered evidences from different genomes for dealing with the species boundaries and taxonomical treatment of the C. segmentifida complex in an integrated perspective. [ABSTRACT FROM AUTHOR]

We compiled Red List data from all listed cycad taxa to determine the current status of the world's most threatened plant group. Each Red List threat category had different proportions of genera, and the genera comprised different proportions of threat categories. Each Red List threat category consisted of different proportions of Red List criteria. Each genus was composed of different proportions of Red List criteria, and every genus was represented by different proportions of listed versus non-listed species. Differences among the genera and categories were substantial, revealing no canonical characteristics that define the members of this plant group. Species that are missing from the Red List or Data Deficient deserve high priority for completion of assessment and listing. Cycas is the genus that may change the most as taxonomy and Red List threat assessments continue to be modified. Distinctive overviews of the Red List data such as this one provide a unique snapshot of the conservation status of the world's cycads, and should be repeated as trends evolve. [ABSTRACT FROM AUTHOR]

A new sub-population of Cycas beddomei Dyer (Cycadaceae), hitherto believed to be endemic to the Seshachalam Hills (Tirupati-Kadapa Hills) of Andhra Pradesh is discovered from Velikonda Hills (Nellore-Kadapa districts) of Andhra Pradesh. Hence its global distribution status is hereby revised endemic to Seshachalam and Velikonda hills of Eastern Ghats of Andhra Pradesh. Combined datasets of our earlier studies with the latest indicated no change in its 'Endangered' status. [ABSTRACT FROM AUTHOR]

An outbreak of poisoning by Cycas revoluta in cattle is reported in the municipality of Pesqueira, in the semiarid region of Pernambuco. During a severe draught on the year 2013, a farmer fed its cattle with Cycas revoluta mixed with roughage (Pennisetum purpureum). The animals presented anorexia, ruminal atony, mild jaundice, petechial hemorrhages in the ocular and vulvar mucosa, ascitis, blackish feces with mucus, and recumbence. Serum activities of aspartate amino transferase and gamma glutamyl transferase were increased and total serum proteins and albumin were decreased. All the 12 cows that ingested the plant were affected and five died showing diffuse centrilobular necrosis of the liver. During severe draughts, feeding animals with plants that the farmers do not known their toxicity is one of the main causes of poisoning in the semiarid northeastern region of Brazil. [ABSTRACT FROM AUTHOR]

Mature zygotic embryos of Cycas revoluta Thunb. were used as explants to investigate direct and indirect organogenesis. Explants were incubated on half-strength Murashige and Skoog (½ MS) basal medium supplemented with various plant growth regulators, singly or in combination (all at 0.5 mg l-1): 6-benzyladenine (BA), kinetin (Kin), 2,4-dichlorophenoxyacetic acid (2,4-D), Kin × 2,4-D, BA×Kin and BA × 2,4-D. Cultures were placed at a low light intensity (4 μmol m-2 s-1 PPFD). Adventitious shoot regeneration was observed in the presence of 0.5 mg l-1 BA after 35 days. The highest number of direct and indirect shoots per zygotic embryo was 3.67 and 29.67, respectively. Roots were induced on indirect shoots by continuous culture on rooting medium (½ MS,þ 0.1 mg l-1 1-naphthaleneacetic acid) and hardened successfully in perlite. Each rooted plantlet with pinnate leaves and a primary tap root was individually isolated and acclimatized 185 days after the beginning of culture, with a 10% success rate. [ABSTRACT FROM AUTHOR]

Cycas is the most widespread and diverse genus among the ancient cycads, but the extant species could be the product of late Miocene rapid radiations. Taxonomic treatments to date for this genus are quite controversial, which makes it difficult to elucidate its evolutionary history. We cloned 161 genomic ITS sequences from 31 species representing all sections of Cycas. The divergent ITS paralogs were examined within each species and identified as putative pseudogenes, recombinants and functional paralogs. Functional paralogs were used to reconstruct phylogenetic relationships with pseudogene sequences as molecular outgroups, since an unambiguous ITS sequence alignment with their closest relatives, the Zamiaceae, is unachievable. A fully resolved and highly supported tree topology was obtained at the section level, with two major clades including six minor clades. The results fully supported the classification scheme proposed by Hill (2004) at the section level, with the minor clades representing his six sections. The two major clades could be recognised as two subgenera. The obtained pattern of phylogenetic relationships, combined with the different seed dispersal capabilities and paleogeography, allowed us to propose a late Miocene rapid radiation of Cycas that might have been promoted by vicariant events associated with the complex topography and orogeny of South China and adjacent regions. In contrast, transoceanic dispersals might have played an important role in the rapid diversification of sect. Cycas, whose members have evolved a spongy layer in their seeds aiding water dispersals. [ABSTRACT FROM AUTHOR]

Abstract: A new cycad species, Cycas fushunensis sp. nov., is described from the Lutetian Jijuntun Formation at Fushun Coalmine, Liaoning Province, northeast China, based on a well-preserved partial frond containing about 15 leaflets. The fossil is characterized by a single strong vein per leaflet, decurrent leaflet base and haplocheilic stomata, suggesting that the fossil is attributed to the genus Cycas of Cycadaceae. Epidermal anatomical comparisons between the fossil and 17 selected modern Cycas species further indicate that C. fushunensis sp. nov. closely resembles Cycas panzhihuaensis Zhou et Yang, an endemic cycad to southwest China, due to characters shared, such as the straight anticlinal walls of both adaxial and abaxial epidermal cells and granular to striate cuticular characters on the internal surface of guard cell periclinal walls. The occurrence of close-to-modern Cycas from the early Cenozoic largely casts doubt on a hypothesis of the late Miocene differentiation of modern cycads, suggested by a recent molecular phylogenetic study. [Copyright &y& Elsevier]

Premise of research. Cycas is the earliest-diverging extant lineage in the ancient order Cycadales, well separated phyletically from the other nine extant genera. Despite the ancient status of Cycas, all extant species are no more than 12 Myr old, and many extant species have become known only in recent decades. Given this context, a broad survey of variation in Cycas leaflet structure may show structural diversity that corresponds with and informs phylogeny and biogeography. Methodology. We investigated the leaflet anatomy of 48 Cycas species grown in a common garden to ascertain the variation of anatomical traits and compared this to available phylogenetic and geographic information to determine patterns in this variation. Pivotal results. We find a very strict anatomical bauplan within the genus and only limited qualitative variation in such features as epidermal cell type, stomatal structure, and extent of hypodermal specialization. Conclusions. Our findings thus sustain the well-accepted monophyly of the genus with a consistent series of synapomorphic features. The most distinctive character is the existence of pits within the outer wall of the epidermis, a feature almost unique for gymnosperms. Unlignified midrib fibers appear to be a unique synapomorphy for Australian and Papuan members of section Cycas. Encrypted stomata and epidermal cell shape confirm a close relationship between sections Asiorientales and Panzhihuaenses and suggest a distinction from section Stangerioides but do not show a clear geographic relationship. Mucilage canals are found only within section Stangerioides. No unique synapomorphy exists for section Indosinenses, but variation in epidermal cell shape appears correlated to the presence of an adaxial hypodermis in section Indosinenses. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of the ethyl acetate extract ofCycas revolutaThunb. leaflets afforded five compounds including two new dihydroamentoflavone glucosides, (2S)-I-(2,3)-dihydro-I-7-O-β-d-glucopyranosylamentoflavone (1) and (2S)-I-(2,3)-dihydro-I-7,II-7-di-O-β-d-glucopyranosylamentoflavone (2), in addition to the known compounds prunin (3), vitexin-2″-rhamnoside (4) and protocatechuic acid (5). Compounds (3) and (4) being reported for the first time in this plant. The structures of these compounds were established by the detailed analysis of their spectroscopic data, mainly 1D NMR, 2D NMR, CD and HR-MSD-TOF. The ethyl acetate extract showed weak cytotoxicity against HepG2 (IC50 = 207.6 μg/mL) and RAW 264.2 cells (IC50 = 160.8 μg/mL). Compound4showed significant activity towardsLeishmania donavani(IC50 = 13.8 μM, IC90 = 34.6 μM). The isolated compounds showed weak antimicrobial activity (IC50>10 μg/mL). [ABSTRACT FROM PUBLISHER]

The type of Cycasdebaoensis Y.C.Zhong & C.J.Chen ( Y.C.Zhong 8762 ) consists of nine duplicates in PE. Our new investigation of the type collection suggests that the type includes at least two different gatherings which should be considered as syntypes. For nomenclatural purposes, we lectotypify the name Cycasdebaoensis with the herbarium sheet PE00047578 and consider other duplicates in PE and GXMI as isolectotypes. The seeds in the capsule ( Y.C.Zhong s.n. collected in Oct 1998) are considered as a syntype., (Yong Yang, David K. Ferguson.)