Clonal Plants Research Articles

Contrasting responses of an invasive plant to herbivory of native and introduced insects

BackgroundInteractions between alien plants and insect herbivores in introduced ranges may determine their invasion success. However, few studies have investigated whether alien plants respond differently to native and introduced herbivores in their introduced ranges and whether genotypes of alien plants matter. We conducted a greenhouse experiment to examine the effects of herbivory by a native insect (Spodoptera litura), by an introduced insect (S. frugiperda), and simultaneously by both insect species on growth, morphology, and biomass allocation of 17 genotypes of an invasive alien clonal plant Hydrocotyle verticillata, and used selection gradient analysis to test which herbivory conditions favor selection of a specific leaf or root trait value.ResultsDifferent genotypes of H. verticillata showed significant variation in growth, morphology, and biomass allocation, but their responses to herbivory were relatively consistent. All three herbivory treatments significantly decreased total mass and stolon mass, but herbivory of S. frugiperda increased specific leaf area. Herbivory of S. litura and simultaneous herbivory of both insect species also decreased leaf mass, petiole mass, root mass, and ramet mass. Selection gradient analysis showed that leaf and root traits varied under different herbivory treatments. To achieve greater fitness, as measured by total mass and/or number of ramets, H. verticillata favored larger leaf area under herbivory by S. frugiperda, larger leaf area and lower specific leaf area under herbivory by S. litura, and larger leaf area, lower specific leaf area, and lower root-to-shoot ratio under simultaneous herbivory.ConclusionsH. verticillata demonstrated contrasting responses to herbivory by native and introduced insects, showing a remarkable ability to coordinate leaf trait plasticity and optimize biomass allocation. This strategy allows H. verticillata to achieve greater fitness under various herbivory conditions, potentially contributing to its invasion success. These findings highlight the importance of plant–herbivore interactions in shaping invasion dynamics and underscore the complex adaptive mechanism that enables invasive plants to establish and spread in introduced ranges.

Investigating changes of forest aboveground biomass induced by Moso bamboo expansion with terrestrial laser scanner

As a typical clonal plant, Moso bamboo expands excessively worldwide, causing changes in various aspects of the native forest ecosystem. Among these aspects, aboveground biomass (AGB) is a key indicator characterizing forest productivity and carbon sequestration. However, it is difficult to track AGB changes of a fixed plot in a relatively short period. In this paper, we utilized terrestrial laser scanner (TLS) to investigate AGB changes resulting from the intrusion of Moso bamboo using the space-for-time substitution method. Three sample plots including a China fir stand, a mixed stand and a pure Moso bamboo stand were chosen at an ecotone to represent the different stages of bamboo expansion in Hutou Village, Chongqing, China. Their point clouds were first scanned using TLS, and then segmented into individual plants through refinedly processing the stem intersections. Subsequently, tree and bamboo classification was achieved via combining the structural features, stem texture features, and point distribution features of individual plants. Finally, the compatible biomass models were employed to estimate plant AGBs and analyze the changes. As a result, the overall classification accuracy of trees and bamboos was improved to 92.67 %. The AGB per unit area initially increased and subsequently decreased at three stages of Moso bamboo expansion (5.83 kg/m2, 6.04 kg/m2 and 5.36 kg/m2), and the AGB differences among individual plants showed the similar tendency. Notably, the average AGB of individual China firs in mixed stand (78.97 kg) was higher than that in the pure stand (70.41 kg), so did the average AGB of individual Moso bamboos (21.22 kg vs 18.70 kg). These results indicated that maintaining a certain degree of tree-bamboo mixture was beneficial for improving the gross forest AGB.

Effects of kinship and integration between adjacent/non-adjacent ramets on the growth and feedback with soil biota in a clonal invader.

Many invasive plants can reproduce through both seeds and clonal growth. In habitats, interacting seedlings may originate from the same mother, and interacting ramets originating from the same plant may not be adjacent to each other in the stolon, particularly for vines that can show curved growth. However, in a homogeneous environment, how kinship and integration between adjacent/non-adjacent ramets affect plant growth and feedback with soil biota has been less studied. We address these questions using an invasive stoloniferous vine Mikania micrantha. We found that sibling groups and stranger groups did not differ in biomass production, root allocation and feedback with soil biota, indicating that kin recognition is unlikely in M. micrantha. For two-ramet stolon fragments in which interacting ramets were adjacent to each other, older ramets allocated more biomass to roots than younger ramets when integrated, particularly in comparison with disconnected ramets from different genotypes, indicating that a division of labor was induced. For four-ramet stolon fragments in which there were two unrooted ramets between the two rooted, interacting ramets, integration increased biomass allocation to roots, possibly because only two of the four ramets could absorb belowground resources and a lower shoot allocation decreased aboveground light competition. When inoculated with soil biota conditioned by the four-ramet integrated fragments, plants of M. micrantha also increased biomass allocation to roots. These results indicate that the distance between interacting ramets in the stolon may affect the integration effect and feedback with soil biota in clonal plants.

Strategies of resource sharing in clonal plants: A conceptual model and an example of contrasting strategies in two closely related species.

Clonal growth is widespread among herbaceous plants, and helps them to cope with environmental heterogeneity through resource integration via connecting clonal organs. Such integration is considered to balance heterogeneity by translocation of resources from rich to poor patches. However, such an 'equalisation' strategy is only one of several possible strategies. Under certain conditions, a strategy emphasising acropetal movement and exploration of new areas or a strategy of accumulating resources in older ramets may be preferred. The optimal strategy may be determined by environmental conditions, such as resource availability and level of light competition. We aimed to summarise possible translocation strategies in a conceptual analysis and to examine translocation in two species from different habitats. Resource translocation was compared between two closely related species from different habitats with contrasting productivity. The study examined the bidirectional translocation of carbon and nitrogen in pairs of mother and daughter ramets grown under light heterogeneity (one ramet shaded) at two developmental stages using stable-isotope labelling. At the early developmental stage, both species translocated resources toward daughters and the translocation was modified by shading. Later, the species of low-productivity habitats, Fragaria viridis, translocated carbon to shaded ramets (both mother and daughter), according to the 'equalisation' strategy. In contrast, the species of high-productivity habitats, Potentilla reptans, did not support shaded mother ramets. Nitrogen translocation remained mainly acropetal in both species. The two studied species exhibited different translocation strategies, which may be linked to the habitat conditions experienced by each species. The results indicate that we need to consider different possible strategies. We emphasise the importance of bidirectional tracing in translocation studies and the need for further studies to investigate the translocation patterns in species from contrasting habitats using a comparative approach.

Anatomical and physiological responses of roots and rhizomes in Oryza longistaminata to soil water gradients.

Roots and rhizomes are critical for the adaptation of clonal plants to soil water gradients. Oryza longistaminata, a rhizomatous wild rice, is of particular interest for perennial rice breeding due to its resilience under abiotic stress conditions. While root responses to soil flooding are well-studied, rhizome responses to water gradients remain underexplored. We hypothesize that physiological integration of Oryza longistaminata mitigates heterogeneous water deficit stress through interconnected rhizomes, and both roots and rhizomes respond to contrasting water conditions. We investigated the physiological integration between mother plants and ramets, measuring key photosynthetic parameters (photosynthetic and transpiration rate, and stomatal conductance) using an Infrared Gas Analyzer. Moreover, root and rhizome responses to three water regimes (flooding, well-watered, and water deficit) were examined by measuring radial water loss and apparent permeance to O2, along with histochemical and anatomical characterization. Our experiment highlights the role of physiological integration via interconnected rhizomes in mitigating water deficit stress. Severing rhizome connections from mother plants or ramets exposed to water deficit conditions led to significant decreases in key photosynthetic parameters, underscoring the importance of rhizome connections in bidirectional stress mitigation. Additionally, O. longistaminata rhizomes exhibited constitutive suberized and lignified apoplastic barriers, while such barriers were induced in roots under water stress. Anatomically, both rhizomes and roots respond similarly to water gradients, showing thinner diameters under water deficit conditions and larger diameters under flooding conditions. Our findings indicate that physiological integration through interconnected rhizomes helps alleviate water deficit stress when either the mother plant or the ramet is experiencing water deficit, while the counterpart is in control conditions. Moreover, O. longistaminata can adapt to various soil water regimes by regulating anatomical and physiological traits of roots and rhizomes.

Evaluation of Differences in Capacity of Nutrient Content Accumulation between two Ecotypes of Lotus (Nelumbo Nucifera) due to Environmental Difference in Tropical and Temperate Regions

Environmental fluctuations can amplify variations even in clonal plants. However, it is unclear whether these differences in environmental conditions can alter physiological activities of two different ecotypes of lotus. We intended to evaluate whether the difference in nutrient content accumulation capability between two ecotypes is different because of the different geographical distribution. The present study revealed us a substantial difference in capacity of nutrient accumulation of lotus (Nelumbo nucifera) due to environmental difference in tropical and temperate zone. The moisture content of lotus in the tropical region was 8.25%, whereas the temperate region was 86.04%.Maintaining a low moisture content might extend the shelf life of the seed. Crude protein and crude fibres levels were found to be high in tropical lotus (24.4% and 3.15%, respectively) and low in temperate lotus (17.50% and 2.00%). Growth amplifying environmental conditions leads to increase in production of protein content. The tropical lotus has the largest crude lipid content (3.68%), whereas the temperate lotus had the lowest (1.90%).Because of the presence of big rhizomes in temperate lotus, the amount of Ash content produced (8.00%) was about double that of tropical lotus (4.03%). Overall, the tropical lotus ecotype had the highest nutrient content accumulation for crude protein, crude fibres and crude lipids. However, temperate lotus has the highest moisture and ash content.

Alpine grassland community productivity and diversity differences influence significantly plant sexual reproduction strategies.

Whether and how community structure variation affects plant sexual reproduction is crucial for understanding species' local adaptation and plant community assembly, but remains unrevealed. In Qinghai-Tibetan grassland communities that differed in aboveground biomass (AGB) and species diversity, we found significant influence of AGB on both species' reproductive biomass allocation (RBA) and flowering and fruiting time, but of species diversity only on species' reproductive time. In high-AGB or high-diversity communities, smaller and earlier flowering species generally advanced their reproductive phenology and increased their reproductive allocation for maximizing their reproductive success, whereas larger and later flowering species delayed their reproductive phenology and decreased their reproductive allocation for maximizing their vegetative growth and resource competition. This change in reproductive allocation with the variation in community structures was more pronounced in nonclonal as compared to clonal plant species. Thus, we evidence an important influence of community structure on plant sexual reproduction strategies, and the pattern of the influence depends largely on species biological attributes.

Origin and Persistence of Lycopodium clavatum and Lycopodium annotinum (Lycopodiaceae) in Scots Pine Forests.

Understanding the growth dynamics of spore-bearing clonal plant sporophytes and the influence of abiotic and biotic factors is crucial for predicting the persistence of club moss populations and implementing effective habitat management techniques. Despite this, the longevity and development of club-moss populations are rarely studied. This study adopted an integrated approach to assess the probability of repetitive young sporophyte recruitment via sexual propagation in Lycopodium annotinum L. and Lycopodium clavatum L. The size-age problem of clonal spore-bearing forest plants and their niche segregation were addressed. The canopy characteristics, insolation, small-scale disturbance, and genetic polymorphism were studied in temperate semi-natural Scots pine forests in Lithuania. Based on the size of the clones discovered, we hypothesize that initial sporophyte emergence occurred in 20-year-old pine stands, with subsequent sporophyte emergence continuing over time. The emergence was related to small-scale disturbances. High genetic polymorphism indicates that all sporophyte stands studied likely emerged via sexual reproduction. According to Ellenberg values, L. annotinum is related to shady habitats, but our findings show both species coexisting abundantly in the more open habitat, supposedly more suitable for L. clavatum.No significant differences in vegetation relevés and light availability was detected using hemispheric images.

Advancements in the techniques for rescue and vegetative propagation of adult Mimosa caesalpiniifolia Benth. trees

ABSTRACT This study focused on the method known as air layering to facilitate the growth of new plants from Mimosa caesalpiniifolia Benth. a technique relatively unexplored for this species. The primary goal was to ascertain whether air layering could effectively produce new clonal (genetically identical) plants. Additionally, the study aimed to establish and enhance a small-scale nursery for clonal plants. To this end, trials were conducted on segments of branches from six adult trees in a special setup which stimulates root growth using various indole-3-butyric acid (IBA) concentrations. Root development was monitored biweekly. Based on these experiments, a clonal mini-garden was established to observe the growth and health of these new plants, assessing the number of new shoots and mini-cuttings generated and their survival rates. The findings indicate that root development occurred under all conditions, although the IBA concentration did not significantly affect the outcome. The success of plant growth within the clonal mini-garden appeared to be linked to the quality of root development during the air layering process. Therefore, employing air layering to cultivate new Mimosa caesalpiniifolia plants is viable and can support the creation of a clonal mini-garden for subsequent propagation.

Advances In Tissue Culture And Somatic Embryogenesis In Fruit Crops

In modern era, traditional propagation techniques are overpowered by the advanced in vitro culture, that offers the highest commercial value of the plants, due to its rapid generation of clonal plants.

Clonal integration facilitates the expansion of Hydrocotyle vulgaris from a limited space to a larger area

AbstractClonal integration is an important ecological advantage of clonal plants. To ask whether clonal integration can help invasive plants escape space limitations, we tested the hypothesis that it can promote the growth of apical ramets when their connected basal ramets grow in limited space. We conducted a greenhouse experiment on the common perennial herb Hydrocotyle vulgaris. Clonal fragments consisting of pairs of connected ramets grew with basal ramets in three different sizes of pots (small, medium, and large) and apical ramets in large pots, and the connection between ramets was either severed or left intact. Pot size significantly affected the growth of basal ramets such that the biomass, number of leaves and flowers, and stolon length were in general greater in medium pots than in large and small pots when stolons were intact and were greater in medium and large pots than in small pots when stolons were severed. Furthermore, pot size interacted with severance to affect the performance of H. vulgaris. When the basal ramets grew in small pots, the intact stolon resulted in a significant promotion of apical ramet growth, but such positive effect was not found when the basal ramets grew in medium and large pots. Our results suggest that H. vulgaris is able to promote the growth of apical ramets to occupy the surrounding areas through clonal integration when the space where basal ramets grow is limited.

Interactions between developmental phenology, carbon movement, and storage constrain demography in the understory clonal herb Podophyllum peltatum L.

Little is known about how carbon integration and storage dynamics affect and are affected by demography in field populations. We sought to elucidate this link by examining dynamic patterns of carbon integration relative to the timing of demographically significant developmental decisions regarding shoot type determination in mayapple, Podophyllum peltatum, a clonal plant with large and persistent rhizomes. Individual rhizome systems growing in natural populations were fed 14CO2 either in late-April, early-May, or mid-June, then harvested at intervals throughout the current season and into the next. When distribution of label was examined we found that carbon fixed at different times in the growing season is used differently: April-fixed assimilate remained in the labeled shoot or was moved into the old rhizome, May-fixed assimilate was found predominantly in the old rhizome, while early-June fixed assimilate moved into the old rhizome and the extending new ramet. Movement of assimilate into the old rhizome appeared to have precedence over formation of additional new ramets. Despite significant within season changes in location of dominant sinks within rhizome systems, there was little redistribution of labeled assimilate: early fixed assimilate was not used to fuel later within season growth, however, assimilate was redistributed between seasons. Vegetative and sexual systems differed in the distribution only of April-fixed assimilate. This was observed even though early labeling occurred prior to anthesis. Sexual systems retained a greater proportion of assimilate in the stem than did vegetative ones, which exported more to the old rhizome. 14C-distribution patterns did not vary between systems differing in future demographic status suggesting that the developmental decision regarding shoot type is based on resources acquired in prior years. We explore the hypothesis that preformation and storage are functionally linked traits that permit plants to coordinate the developmental determination of structures differing in cost and demographic function with known resource status. We conclude that demography influences and is influenced by integrative physiology and that physiological restrictions on within season redistribution of assimilates constrain plants' capacities to respond to short-term environmental variation. Such constraints may affect plants' abilities to respond to rapid environmental change in the Anthropocene.

Growth Characteristics of Ramet System in Phyllostachys praecox Forest under Mulch Management.

The ramet system is a typical structural type in the life history of clonal plants. This massive structure is formed by many similar ramets connected by underground rhizomes, which are independent and mutually influential. Therefore, the ramet system is unique to bamboo forests, and its role in the construction, maintenance, and productivity of bamboo populations is irreplaceable. Mulch management is a high-level cultivation model for bamboo forests that is used to cultivate bamboo shoots. However, the basic conditions of bamboo ramet systems in this managed model are poorly understood. This study analyzed the underground rhizome morphology, bud bank, and branching of bamboo ramets in a Phyllostachys praecox C.D. Chu et C.S. Chao 'Prevernalis' forest to explore the growth patterns of bamboo ramets in high-level management fields. In mulched bamboo forests, the bamboo rhizomes, distributed in intermediate positions of the bamboo ramet system, were long with many lateral buds and branches, and those at the initial and distal ends were short with few lateral buds and branches. The initial end of the ramet system reduced the ramet system, the intermediate part expanded the ramet system, and the distal end promoted ramet system regeneration. Owing to the continuous reduction, expansion, and renewal of ramet systems, the bamboo rhizome system demonstrates mobility and adaptability. This study found that a higher level of bamboo forest management increased the possibility of artificial fragmentation of the ramet system and that improving the efficiency of the ramet system was beneficial for maintaining its high vitality. Thus, this study provides a crucial reference for guiding the precise regulation of bamboo ramet systems in artificial bamboo forests.

Genotypic richness affects inorganic N uptake and N form preference of a clonal plant via altering soil N pools

Genotypic richness affects inorganic N uptake and N form preference of a clonal plant via altering soil N pools

Caloric restriction extends lifespan in a clonal plant.

When subjected to dietary caloric restriction (CR), individual animals often outlive well-fed conspecifics. Here, we address whether CR also extends lifespan in plants. Whereas caloric intake in animals comes from ingestion, in plants it derives from photosynthesis. Thus, factors that reduce photosynthesis, such as reduced light intensity, can induce CR. In two lab experiments investigating the aquatic macrophyte Lemna minor, we tracked hundreds of individuals longitudinally, with light intensity-and hence, CR-manipulated using neutral-density filters. In both experiments, CR dramatically increased lifespan through a process of temporal scaling. Moreover, the magnitude of lifespan extension accorded with the assumptions that (a) light intensity positively relates to photosynthesis following Michaelis-Menten kinetics, and (b) photosynthesis negatively relates to lifespan via a power law. Our results emphasize that CR-mediated lifespan extension applies to autotrophs as well as heterotrophs, and suggest that variation in light intensity has quantitatively predictable effects on plant aging trajectories.

Stem elongation and gibberellin response to submergence depth in clonal plant Alternanthera philoxeroides

Clonal plants are widely distributed in the riparian zone and play a very important role in the maintenance of wetland ecosystem function. Flooding is an environmental stress for plants in the riparian zone, and the response of plants varies according to the depth and duration of flooding. However, there is a lack of research on the growth response of clonal plants during flooding, and the endogenous hormone response mechanism of clonal plants is still unclear. In the present study, Alternanthera philoxeroides, a clonal plant in the riparian zone, was used to investigate the time-dependent stem elongation, the elongation of different part of the immature internodes, and the relationship between growth elongation and the phytohormone gibberellin (GA) under a series of submergence depths (0 m, 2 m, 5 m, and 9 m). The results showed that stem elongation occurred under all treatments, however, compared to 0 m (control), plants grew more under 2 m and 5 m submergence depth, while grew less under 9 m water depth. Additionally, basal part elongation of the immature internode was the predominant factor contributing to the stem growth of A. philoxeroides under different submergence depths. The phytohormone contents in basal part of the mature and immature internodes showed that GA induced the differential elongation of internode. Plant submerged at depth of 2 m had the highest GA accumulation, but plant submerged at depth of 9 m had the lowest GA concentration. These data suggested that GA biosynthesis are essential for stem elongation in A. philoxeroides, and the basal part of the immature internode was the main position of the GA biosynthesis. This study provided new information about the rapid growth and invasion of the clonal plant A. philoxeroides around the world, further clarified the effects of submergence depth and duration on the elongation of the stem, and deepened our understanding of the growth response of terrestrial plants in deeply flooded environments.

Growth regulators on shooting and adventitious rooting of Mimosa caesalpiniifolia adult stem cuttings

Mimosa caesalpiniifolia, crucial for fencing and firewood in Brazil's Caatinga dry forest, presents a promising avenue for commercial propagation. The challenges faced in seed propagation, such as the scarcity of inputs and the difficulties in overcoming dormancy, highlight the advantages of vegetative methods. These methods emerge as a viable alternative, enabling uniform and large-scale production of clonal plantlets. This technique ensures consistent plant quality, which is crucial given the wide variety of uses for this species. Additionally, the use of plant growth regulators is critical to enhance the success of vegetative propagation, promoting the formation of robust roots and overall development of plants from cuttings of adult trees. Recognizing the significance of creating clonal forests of M. caesalpiniifolia and the necessity for understanding methods to expedite this endeavor, this study was designed to assess the shooting and adventitious rooting of stem cuttings sourced from adult M. caesalpiniifolia trees, examining the effects of auxinic agents. M. caesalpiniifolia cuttings were harvested through vegetative rescue from six randomly selected adult trees, treated with indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA) at concentrations of 0, 1,000, 2,000, and 4000 mg L−1, using a completely randomized design in a 2 × 4 factorial arrangement. The evaluations included assessing root presence, number of shoots, vigor of clonal plantlets and plant survival under greenhouse conditions, shade house conditions, and full sun exposure. The study did not reveal any significant interaction between growth regulators and their concentrations under these conditions. IBA at intermediate concentrations enhanced root growth, while cuttings without growth regulators exhibited superior aerial development. A decrease in survival percentages with increasing concentrations of regulators was observed, while cuttings without regulators demonstrated better morphological development. The study suggests for large-scale nurseries, natural rooting and shoot formation in M. caesalpiniifolia cuttings may suffice for successful propagation without IBA or IAA.

Clonal integration benefits Calystegia soldanella in heterogeneous habitats

Abstract Land-use change and tourism development have seriously threatened the ecosystems of coastal protection forests and beaches. Light and nutrients are spatially heterogeneously distributed between the two ecosystems. Clonal plants, such as Calystegia soldanella, which play a crucial role in maintaining the ecological stability of coast habitats, are likely to encounter diverse environments. In this study, we investigated clonal integration and the division of labor in C. soldanella under heterogeneous (high nutrient and low light [HNLL]; low nutrient and high light [LNHL]) and homogeneous habitats. We cultivated pairs of connected and severed ramets of C. soldanella in these environments. Our results showed the total biomass (TB) of connected ramets was higher than that of severed ramets in heterogeneous environments, suggesting clonal integration enhances growth in heterogeneous habitats. The root shoot ratio was significantly lower in HNLL than in LNHL conditions for connected ramets, demonstrating a division of labor in growth under heterogeneous conditions. However, parameters of clonal propagation of C. soldanella did not significantly differ between connected and severed ramets in heterogeneous environments, indicating no division of labor in clonal propagation. In homogeneous environments, the growth of C. soldanella did not benefit from clonal integration. Connected ramets in heterogeneous habitats exhibited higher TB than in homogeneous habitats. The TB of one ramet in HNLL was consistently higher than that in LNHL, irrespective of ramet’s states, which suggests that high soil nutrients may enhance the growth. We conclude that C. soldanella has the capability of clonal integration to achieve high biomass in heterogeneous but not in homogeneous conditions, and the establishment of coastal protection forests (high nutrient and low light) may foster the growth of C. soldanella.

Changes induced by parental neighboring touch in the clonal plant Glechoma longituba depend on the light environment.

Touch by neighboring plants is a common but overlooked environmental variable for plants, especially in dense vegetation. In addition, shade is inevitable for understory plants. The growth performance of clonal plant to the interaction between thigmomorphogenesis and shade response, and their impact on light adaptability is still unknown. At the present study, parental ramets of Glechoma longituba were exposed to two conditions (neighboring touch and shade), and their offspring ramets were in ambient or shaded environment. The phenotype and growth of parental and offspring ramets were analyzed. The results showed that neighboring touch of parental ramets regulated the performance of offspring ramets, while the effect depended on the light environment. The parental neighboring touch occurring in ambient environment suppressed the expansion of leaf organ, showed as a shorter petiole and smaller leaf area. Moreover, G. longituba exhibited both shade avoidance and shade tolerance characters to shaded environment, such as increased leaf area ratio and leaf mass ratio, longer specific petiole length and specific stolon length. It was notable that these characters of shade response could be promoted by parental neighboring touch to some extent. Additionally, parental light environment plays an important role in offspring growth, parent with ambient light always had well-grown offspring whatever the light condition of offspring, but the growth of offspring whose parent in shaded environment was inhibited. Finally, for the offspring with shaded environment, the touch between parental ramets in shade environment showed a disadvantage on their growth, but the influence of the touch between parental ramets in ambient environment was slight. Overall, the interaction of parental neighboring touch and shade environment complicate the growth of understory plants, the performance of plants is the integrated effect of both. These findings are conducive to an in-depth understanding of the environmental adaptation of plants.

The complete chloroplast genome sequence of Hydrocotyle vulgaris L. (Araliaceae)

Hydrocotyle vulgaris is a perennial wetland clonal plant in the Araliaceae family, which was introduced to China as an ornamental plant in the 1990s. Although H. vulgaris is now considered a potential invasiveness species in China, it also plays a significant role in the remediation of water pollution. Here, we reported its complete chloroplast genome and analyzed the basic characteristics. The chloroplast genome was 153,165 bp in length, including a pair of inverted repeat (IR) regions of 25,072 bp separated by a large single-copy (LSC) region of 84,291 bp and a small single-copy (SSC) region of 18,730 bp. The H. vulgaris chloroplast genome contained 132 predicted genes, and its overall GC content was 37.60%. Phylogenetic analysis revealed that H. vulgaris was closely related to H. verticillata. The H. vulgaris chloroplast genome presented in this study will lay a foundation for further genetic and genomic studies of the genus Hydrocotyle.