Pitcher Plant Species Research Articles

Convergence in carnivorous pitcher plants reveals a mechanism for composite trait evolution.

Composite traits involve multiple components that, only when combined, gain a new synergistic function. Thus, how they evolve remains a puzzle. We combined field experiments, microscopy, chemical analyses, and laser Doppler vibrometry with comparative phylogenetic analyses to show that two carnivorous Nepenthes pitcher plant species independently evolved similar adaptations in three distinct traits to acquire a new, composite trapping mechanism. Comparative analyses suggest that this new trait arose convergently through "spontaneous coincidence" of the required trait combination, rather than directional selection in the component traits. Our results indicate a plausible mechanism for composite trait evolution and highlight the importance of stochastic phenotypic variation as a facilitator of evolutionary novelty.

Shoot regeneration in Nepenthes mirabilis as affected by flurprimidol and GA3 application

Abstract. Dwiati M, Widodo P, Susanto AH. 2023. Shoot regeneration in Nepenthes mirabilis as affected by flurprimidol and GA3 application. Biodiversitas 24: 4168-4174. Nepenthes mirabilis (Lour.) Druce. is a pitcher plant species at a higher risk of extinction mainly due to overexploitation. Previous investigations have shown that in vitro micropropagation can be used as an approach for ex-situ conservation of N. mirabilis. Therefore, this study aimed to assess the new shoot formation of N. mirabilis under in vitro conditions stimulated with the application of flurprimidol and GA3. The three concentrations of flurprimidol and GA3 used as treatments were arranged factorially in a Randomized Complete Block Design (RCBD), with internodes 2, 3, 4, and 5 serving as blocks. Based on the results, F1G0 (flurprimidol of 1 mgL-1 without GA3) had the highest shoot formation, which was not accompanied by sufficiently high contents of chlorophyll, leading to improper shoot development. Despite the smaller number of newly formed shoots in F2G2 (flurprimidol of 2 mgL-1 and GA3 of 2 mgL-1), significantly higher chlorophyll contents were observed, enabling better development of shoot. Leaf length and shoot diameter also showed similar results under F2G2, indicating that higher concentrations of exogenous GA3 were necessary for better shoot development. This indicated that appropriate concentrations of both plant growth regulators should be applied for micropropagation of N. mirabilis in support of ex-situ conservation.

DIVERSITY, ECOLOGY AND CONSERVATION STATUS OF NEPENTHES IN WEST SUMATRA PROVINCE, INDONESIA

Nepenthes is the largest carnivorous plant genus present in Indonesia. There are 39 species of Nepenthes pitcher plants recorded in Sumatra from lowland to montane forests, and 34 of them are endemic; this represents the greatest species diversity of Nepenthes after Borneo. Field studies were conducted in 2021 and 2022 to increase our knowledge of the diversity, habitats and distributions of Nepenthes in West Sumatra province. Twenty-three species of Nepenthes were recorded from the province, consisting of 15 highland species, 4 mid-elevation species and 4 lowland species. Ecophysiological studies conducted at Bukit Malalak showed clumped distributions of N. bongso, N. dubia, N. eustachya and N. rhombicaulis. Foliar and pitcher fluid nutrient concentrations were found to be similar to those cited in other recent studies although growth rates were slightly more rapid than at Gunung Talang. Bukit Malalak is a new locality for two threatened species, namely N. dubia (CR) and N. rhombicaulis (VU), enlarging their extents of occurrence. In total, nine species from West Sumatra are threatened and conservation actions are urgently needed for these and other Nepenthes species remaining on the island.

PROPAGATION OF PITCHER PLANTS (Nepenthes gracilis KORTH. AND Nepenthes reinwardtiana MIQ.) THROUGH CALLUS INDUCTION

In vitro propagation of pitcher plants is still limited only using seeds, while the other in vitro methods using leaf explants such as embryogenesis, organogenesis, and callus culture has not been widely reported. The research aims to study the growth response of leaf explants in two species of pitcher plants (Nepenthes gracilis and Nepenthes reinwardtiana), which formed callus in several treatment media combinations. Leaf pieces were taken from a 4-month pitcher plant culture were grown on the treatment media, namely modified media of Murashige & Skoog with a half concentration (½ MS) added 2.4-Dichlorophenoxoxyacetate (2.4-D) with a concentration of 0, 0.5, 1, 1.5, and 2 mg L-1 and kinetin (0.5 mg L-1). The treatment was then stored in a dark environment to induce callus formation. The observation for 12 weeks showed that the time of callus formation in two species of pitcher plant observed was not significantly different. Both species of pitcher plants begin to form callus in the fourth week after treatment. None of the leaf explants were planted on the control medium without hormones formed callus. The best medium for callus induction in N. gracilis is ½ MS medium added with 2 mg L-1 2,4-D and 0.5 mg L-1 kinetin, with callus morphology brownish-white with friable texture. In comparison, the optimum callus media from leaf explant of N. reinwardtiana has not been obtained yet. Thus further research is still needed.

Sex identification in Nepenthes adrianii from Baturraden Botanical Garden: Genetic analysis using RAPD Markers

Nepenthes adrianii is one of pitcher plant species that grows endemically in Mount Slamet, Central Java. At present, it is one of pitcher plant collections of Baturraden Botanical Garden. Since N. adrianii is dioecious and both sexes are difficult to distinguish morphologically, early sex determination supporting its conservation at Baturraden Botanical Garden is needed. One approach can be performed with the use of RAPD molecular markers. Hence, this study aims to know whether differences in RAPD pattern between male and female N. adrianii exist or not and also to find out what the differences are. Genomic DNAs were extracted from leaves of 4 males, 2 females, and 2 sexually unidentified individuals. The extracted DNAs were then used to analyze DNA variation between male and female N. adrianii employing RAPD technique. As many as five oligonucleotide primers (OPA-15, OPK-16, OPP-15, OPP-08, and OPO-08) were used to amplify N. adrianii DNA. The results showed that one primer, i.e. OPK-16 (5’-GAGCGTCGAA-3’), produces a specific band of approximately 290 bp which is only found in female plants. It is assumed that this band is related to gene(s) controlling sex determination in N. adrianii. The RAPD marker can be used for the sex determination of young N. adrianii seedlings.

UPLC-TOF-MS/MS-Based Metabolomics Analysis Reveals Species-Specific Metabolite Compositions in Pitchers of Nepenthes ampullaria, Nepenthes rafflesiana, and Their Hybrid Nepenthes × hookeriana.

Hybridization is key to the evolution and diversity of plants in nature. Nepenthaceae comprises a family of diverse tropical carnivorous pitcher plant species with extensive hybridization. However, there is no study to date on the metabolite expression of hybrids in this family. We performed a non-targeted metabolomics analysis of the pitchers of two Nepenthes species with different dietary habits, namely, the semi-detritivorous N. ampullaria and carnivorous N. rafflesiana with their hybrid (N. × hookeriana) for a comparative study. The whole-pitcher samples were extracted in methanol:chloroform:water (3:1:1) via sonication-assisted extraction and analyzed using ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOF-MS) followed by data analysis to profile chemical compositions. A total of 1,441 metabolite features were profiled from the three species in which 43.3% of features in the hybrid samples were not found in either of its parents. The partial least squares discriminant analysis (PLS-DA) found 324 metabolite features with variable in projection (VIP) values greater than one in which 55 features were statistically significant. This showed that the hybrid is closer to N. rafflesiana, which is consistent to the previous study on gene and protein expressions. A total of 105 metabolites were putatively identified with manual searches using public metabolite databases. Phenols were detected to be the most abundant secondary metabolites due to a high flavonoid content, especially in N. rafflesiana. The most abundant feature 476.3s:449.102 was found to be the most significant VIP for distinguishing between the three species as a chemical marker. This is the first study comparing metabolites in the carnivory organs of different Nepenthes species with comprehensive profiling and putative identification. The differential metabolite compositions in the pitchers of different species might have ecological implications with the hybrid showing intermediate phenotype between the parents as well as manifesting unique metabolites. However, there is no clear evidence of metabolites related to the differences in dietary habits between the hybrid and the two parent species.

Diversity and volume of international trade in Old World pitcher plants

In global trade analyses, plants are neglected in comparison to animals. Controlling and monitoring international trade in threatened species contributes to their overall conservation. Here, an in-depth look at the dynamics of the international trade in attractive and widely traded carnivorous Old World pitcher plants (Nepenthes spp.) from their first appearance in the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES) Trade Database in 1983 until 2017 is presented. The current trade of Nepenthes is rapidly growing in terms of the total volume traded and the number of both species and importing countries. Most of pitcher plants are globally traded as artificially propagated live plants. The share of wild-originated live plants was only 0.09%. Hybrids and Nepenthes spp. dominated the trade, representing 61 and 15% of the total traded volume respectively, followed by N. alata and N. mirabilis. The latter species was also the most traded species from the wild. Sri Lanka is a hotspot, exporting the highest volume and number of species of live pitcher plants. Monitoring of the trade is complicated by (1) the absence of a permit obligation for seeds, seedlings and in vitro cultures, and (2) the outdated list of valid species in the CITES Checklist. Using a holistic approach with a focus on the permanent monitoring, recording and assessing of international trade is desirable.

Characterization of endophytic bacterial communities within greenhouse and field-grown rhizomes of three rare pitcher plant species (Sarracenia oreophila, S. leucophylla, and S. purpurea spp. venosa) with an emphasis on nitrogen-fixing bacteria

Several Sarracenia species are endangered due to habitat destruction. Knowledge of their microbiomes may better inform reintroduction efforts. We characterized bacterial communities within rhizomes of three species with an emphasis on diazotrophs. Microbiomes of wild and greenhouse-grown Sarracenia were characterized using cultivation-independent and cultivation-dependent methods, including Illumina MiSeq, 16S rRNA and nifH qPCR, colony identification via 16S rRNA sequencing, and nifH colony PCR. Rhizomes were tested for biological nitrogen fixation using acetylene reduction assays. Diazotrophs make up a notable proportion of the S. oreophila microbiome according to qPCR. Microbiomes of greenhouse S. oreophila varied from wild ones by having greater proportions of diazotrophs as indicated by qPCR. Wild and greenhouse plant microbiomes also differed with respect to several phylogenetic groups. Acetylene reduction assays indicated that nitrogen fixation occurred in some rhizomes. Multiple colonies from S. leucophylla and S. purpurea were nifH+, and 16S rRNA sequencing likewise revealed dissimilarities between wild and greenhouse-grown plant microbiomes. Our study is the first to characterize bacterial communities within Sarracenia rhizomes and demonstrates that substantial differences exist between wild and greenhouse plants. We provide evidence that Sarracenia can contain large populations of diazotrophs that may help explain how these plants survive in oligotrophic environments.

The Sarracenia alata pitcher plant system and obligate arthropod inquilines should be considered an evolutionary community

AbstractAimThe Sarracenia alata pitcher plant and inquiline species comprise an ecological community. These inquilines span the continuum in their ecological association with the host pitcher plant, from species that contain little‐to‐no interaction with the plant to species that are completely dependent on the plant for their entire life cycle. We are interested in testing if degree of ecological dependence is positively correlated with a shared evolutionary history, and in identifying members of this community that display concordant phylogeographic structure.LocationSoutheastern United States.MethodsWe collected genome‐wide sequence data from a set of arthropods that are ecologically associated with the plant to estimate comparative phylogeographic patterns among the species. We estimated species tree distributions from biallelic unlinked SNP data and used phylogeographic concordance factors (PCFs) to test degree of phylogeographic concordance among community members. In addition, for each species we conducted an analysis of molecular variance and calculated FST values to identify population genetic structure across the landscape, and compared these traditional values to the tree‐based approach.ResultsObligate members of the pitcher plant community display concordant phylogeographic patterns, suggesting their ecological dependence has manifested itself into a shared evolutionary history. In contrast, two spider species do not contain significant population genetic structure or similar phylogeographic histories, highlighting their loose association with the host pitcher plant.Main conclusionThe S. alata pitcher plant system should be considered an evolutionary community, where multiple members sharing strong ecological interactions also display concordant phylogeographic structure. This work demonstrates that PCFs provide an important quantitative measure into assessing community structure and illustrates how simulations can be used to assess significance of shared patterns of phylogeographic structure across the landscape.

Introduction to Documentation of Nepenthes Species in Bako National Park, Sarawak

In order to accomplish the learning objectives of ecology, biodiversity and environment course, in situ activities remain the finest key to complement by conducting real fieldwork experiments. The specific objectives of the fieldwork are to ensure sustainable learning, adopting best practice in scientific documentation, and implementing holistic and integrated learning approach in the course. Therefore, related field topic was given to the students and resulted with the following attributes. Four different species of pitcher plants were identified and classified throughout the study. The recent biology educational trip to Bako National Park had documented various well-known species of Nepenthes. Information on Nepenthes species present in the parks is useful for educational and research purposes, developing a conservation plan and management and also helps in promoting ecotourism. The trip was conducted to introduce a comprehensive learning experience to the students in biodiversity-related discipline.

Evidence for pitcher trait-mediated coexistence between sympatric Nepenthes pitcher plant species across geographical scales

ABSTRACTBackground: According to modern coexistence theory, ecologically similar species can coexist if fitness differences between them are small, or niche differences between them are large. However, these predictions have not been tested extensively in real systems and are difficult to examine in traits-based studies.Aims: The aim of our study was, by using the carnivorous pitcher plant genus Nepenthes as a model system, to examine (1) species growth ranks as a proxy for fitness; (2) modern coexistence theory at a geographical scale; (3) evidence for pitcher trait-mediated resource partitioning between sympatric Nepenthes species.Methods: We used growth ranks, obtained from a survey of experienced Nepenthes nursery owners, as a proxy for fitness. Multivariate pitcher-, vegetative- or combined-trait distances, computed from morphometric-trait data from the literature were used as proxies for niche differences. Data on global Nepenthes species-pair sympatry was modelled against these fitness and niche differences.Results: Niche and growth rate differences were positively and negatively correlated with sympatry, respectively, as expected from theory.Conclusion: Our results agree with theory and suggest that fitness differences can be approximated from average species growth. Prey- and microhabitat-resource partitioning, operating through divergent pitcher and vegetative traits respectively, are likely mechanisms that stabilise the coexistence of sympatric Nepenthes species.

Fauna Diversity in Pitcher Plants at Setiam Hill, Bintulu, Sarawak, Malaysia

A study was carried out to determine the diversity and enumerate the fauna species related to five pitcher plant species at a selected area in Bukit Setiam Forest, Tatau, Bintulu, Sarawak, Malaysia. At the end of the study, six insect orders together with nematodes and Araneae were detected with different existence abundances and diversity. From the 901 total fauna trapped, 58.82% belonged to the order Hymenoptera, mainly of the ant species, followed by nematodes (21.64%), Diptera (15.87%), Coleoptera (1.66%), Hemiptera (0.89%), Blattaria (0.44%) and finally, Lepidoptera (0.33%) and Araneae (0.33%). Significant differences (p<0.05) in the composition of insect trapped in pitcher plants were observed for the order Hymenoptera, Diptera, Lepidoptera, Hemiptera and even nematodes. Meanwhile, no significant difference was observed for Coleoptera, Blattaria and Araneae. There is a strong relationship between fauna and Nepenthes pitcher either as a prey, predator, a mutualistic relationship or parasites or also for a habitat to live or to reproduce.

Pitcher plant facilitates prey capture in a sympatric congener

Carnivorous plants avoid below-ground competition for nitrogen by utilizing an alternative nitrogen resource—invertebrate prey, but it remains unclear if sympatric carnivorous plants compete for prey resources. The aim of this study was to investigate if exploitative prey-resource competition occurs between the two sympatric pitcher plant species, Nepenthes rafflesiana and N. gracilis in Singapore. We first investigated if prey-resource partitioning occurs between these two species, and then investigated niche shift in N. gracilis by examining its pitcher contents along an in situ gradient of N. rafflesiana interspecific competition. Our results showed clear evidence of resource partitioning between the two species, but contrary to the expectation of competition, proximity to N. rafflesiana pitchers correlated with higher total prey numbers in N. gracilis pitchers. Our multivariate model of prey assemblages further suggested that N. rafflesiana facilitates N. gracilis prey capture, especially in several ant taxa that are trapped by both species. Concurrently, we found strong evidence for intraspecific competition between N. gracilis pitchers, suggesting that prey resources are exhaustible by pitcher-predation. Our results show that resource partitioning can be associated with facilitative interactions, instead of competition as is usually assumed. Facilitation is more typically expected between phylogenetically distant species, but divergences in resource acquisition strategies can permit facilitation between congeners.

Potential effects of climate change on members of the Palaeotropical pitcher plant family Nepenthaceae.

Anthropogenic climate change is predicted to have profound effects on species distributions over the coming decades. In this paper, we used maximum entropy modelling (Maxent) to estimate the effects of projected changes in climate on extent of climatically-suitable habitat for two Nepenthes pitcher plant species in Borneo. The model results predicted an increase in area of climatically-suitable habitat for the lowland species Nepenthes rafflesiana by 2100; in contrast, the highland species Nepenthes tentaculata was predicted to undergo significant loss of climatically-suitable habitat over the same period. Based on the results of the models, we recommend that research be undertaken into practical mitigation strategies, as approximately two-thirds of Nepenthes are restricted to montane habitats. Highland species with narrow elevational ranges will be at particularly high risk, and investigation into possible mitigation strategies should be focused on them.

Shrew poo and deranged hamsters

Pitcher plant potties for tree shrews on the go Carnivorous plants derive key nutrients by beckoning, trapping, and digesting insects. One class of these plants, pitcher plants, typically ensnares its prey in a slippery, inescapable, pitcher-shaped leaf full of sticky digestive fluid. But for at least three species of Nepenthes pitcher plants found in northern Borneo, the pitcher acts more like a bowl—specifically, a toilet bowl. In the fog-enshrouded mountain forests where these plants grow, insects are relatively scarce compared with other pitcher plant habitats such as lowland swamps. So the mountain-dwelling plants have repurposed their pitchers as potties, luring mouselike tree shrews, Tupaia montana, with tasty secretions. While licking the plants’ upper rims, the shrews perch with their derrieres hung over the bowl. Some of the shrews then defecate into the pitcher, giving the plants a source of needed nitrogen. Botanist Charles M. Clarke of Monash University first reported

Exploring the predation of UK bumblebees (Apidae, Bombus spp.) by the invasive pitcher plant Sarracenia purpurea: examining the effects of annual variation, seasonal variation, plant density and bumblebee gender

Invasive carnivorous plant species can impact the native invertebrate communities on which they prey. This article explores the predation of native UK bumblebees (Bombus spp.) by the invasive pitcher plant species Sarracenia purpurea and discusses the potential effect of S. purpurea on native bumblebees. Specifically, it evaluates whether the extent to which bumblebees are captured varies (i) over successive years, (ii) across June and July, (iii) with density of distribution of pitchers or (iv) with bumblebee gender. Pitcher contents were examined from an established population of Sarracenia purpurea growing in Dorset, UK. Results show that the total extent to which bumblebees were captured differed over the years 2012–2014 inclusive. A 1-year study in 2013 showed that more bumblebees were caught in July than in June and more bumblebees were captured when pitchers grew at high density. Results from 2013 also showed that more pitchers caught more than one bumblebee than would be expected based on a normal probability distribution and that this phenomenon affects female and male bumblebees equally. We discuss possible reasons for these results including that the bumblebees may be using S. purpurea as a resource. Further work is required to establish the exact underpinning mechanisms and the relative roles of plant and bumblebee behaviour within the relationship. Such interaction complexity may have consequences for consideration in invasive carnivorous plant management.

Phylogenetic analysis of niche divergence reveals distinct evolutionary histories and climate change implications for tropical carnivorous pitcher plants

AbstractAimTo analyse the underpinnings of historical drivers of diversity and their contributions to current distributions and future roles in a changing climate, we studied the relationship between ecological niche divergence and phylogenetic signal in tropical carnivorous pitcher plants.LocationSoutheast Asia.MethodsEstimates of realized ecological niches were reconstructed and plotted along a newly created multilocus molecular phylogeny. Phylogenetic signal was analysed by comparisons of calculated phylogenetic relatedness with ecological niche divergence. Current and projected future potentially suitable habitats were mapped for several species of plants with variable evolutionary histories and distributions.ResultsHighland and lowland species had distinct phylogenetic signals. Higher altitude species had significantly lower molecular divergence as compared with the lowland species, yet ecological niches with less overlap. When projected onto a future climate scenario, highland species lose a greater amount of potentially suitable habitat compared to lower altitude species, and the majority of studied higher altitude species will face an overall loss of future suitable habitat.Main conclusionWe conclude that distinct phylogenetic signals not only unravel differing evolutionary histories but also show that the implications of species' tolerances to future changing climate vary. Over the past million years, historical climate change shaped the differing evolution and ecological niches of highland and lowland tropical pitcher plant species. Rapid, recent radiations of the higher altitude species are reflected in limited molecular divergence, which is in sharp contrast with the more gradually evolved and genetically distinct lower altitude species in our study. Our projections for future potentially suitable habitats show that on‐going climate shifts will have detrimental effects on especially the higher altitude species due to a narrower niche tolerance and dramatic loss of potentially suitable habitat.

Carnivorous pitcher plant species (Sarracenia purpurea) increases root growth in response to nitrogen addition

Nitrogen (N) deposition from anthropogenic sources can facilitate the encroachment of plant species with high-N demands into nutrient-poor ecosystems such as sphagnum bogs. Prior research has demonstrated that altered leaf morphology of the carnivorous pitcher plant Sarracenia purpurea L. can serve as a biological indicator of increased bog nitrification. Our objective was to assess the effect of N addition on the root morphology of S. purpurea. To make this assessment, nine S. purpurea plants were grown in microcosms with their roots positioned on transparent acrylic tubes so that root growth could be monitored. Three replicate microcosms received either a high-N treatment (1.0 mg NH4-N·L−1), low-N treatment (0.1 mg NH4-N·L−1), or no additional N. After 7 weeks, we scanned the roots with WinRhizo Pro software, recorded leaf dimensions, and measured the dry mass of the roots and leaves. The high-N treatment had significantly greater root length, surface area, and dry biomass than the controls. In contrast, we found no difference in leaf dimensions or aboveground biomass among treatments. The results of this study support our hypothesis that S. purpurea increases root growth to uptake nutrients from the soil under conditions of increased N deposition.

Bacterial communities associated with the pitcher fluids of three Nepenthes (Nepenthaceae) pitcher plant species growing in the wild.

Nepenthes pitcher plants produce modified jug-shaped leaves to attract, trap and digest insect prey. We used 16S rDNA cloning and sequencing to compare bacterial communities in pitcher fluids of each of three species, namely Nepenthes ampullaria, Nepenthes gracilis and Nepenthes mirabilis, growing in the wild. In contrast to previous greenhouse-based studies, we found that both opened and unopened pitchers harbored bacterial DNA. Pitchers of N. mirabilis had higher bacterial diversity as compared to other Nepenthes species. The composition of the bacterial communities could be different between pitcher types for N. mirabilis (ANOSIM: R = 0.340, p < 0.05). Other Nepenthes species had similar bacterial composition between pitcher types. SIMPER showed that more than 50 % of the bacterial taxa identified from the open pitchers of N. mirabilis were not found in other groups. Our study suggests that bacteria in N. mirabilis are divided into native and nonnative groups.

Genetic diversity in three endangered pitcher plant species (Sarracenia; Sarraceniaceae) is lower than widespread congeners

Narrow-ranging, rare species often exhibit levels of genetic diversity lower than more common or widespread congeners. These taxa are at increased risk of extinction due to threats associated with natural as well as anthropogenic events. We assessed genetic variation in three federally endangered Sarracenia species. We discuss maintenance of genetic diversity and evolutionary implications of rarity. • We analyzed three noncoding chloroplast regions and nine microsatellite loci in populations spanning the geographic ranges of S. oreophila, S. alabamensis, and S. jonesii. The same microsatellite loci were used to examine a single field site of three more widespread species (S. alata, S. leucophylla, and S. rubra subsp. wherryi). • All three endangered species have experienced reductions in population size and numbers. All show considerably less variation than more widespread members of the genus. Sarracenia alabamensis maintains the greatest microsatellite variation but has the fewest remaining populations and may be under the greatest threat. More widespread S. oreophila maintains surprising chloroplast diversity, yet exhibits little microsatellite diversity. Sarracenia jonesii lacks chloroplast diversity, yet maintains greater microsatellite diversity than S. oreophila. • The three endangered species differ in levels and structure of diversity, yet not in predictable ways, emphasizing that unique demographic and ecological histories, rather than current distribution and population size, best explain present patterns of genetic variation. Maintenance of remaining genetic variation is important, but preventing further habitat loss and degradation is critical.