Differences in allocation patterns in clonal and sexual offspring in a woodland pseudo-annual

We compared the patterns of allocation to reproduction among seed-derived and clonal offspring of a woodland pseudo-annual. Pseudo-annuals are clonal plants which survive the winter only as seeds and hibernacles produced by the rhizome system. Previous studies indicate that flowering is related to the size of these hibernacles. Since seedlings do not have a hibernacle, we did not expect that these plants would reproduce sexually. Assuming a trade-off between sexual and asexual reproduction, and assuming a linear relationship between vegetative plant weight and weight of all reproductive structures (i.e., rhizomes, hibernacles, inflorescences, and seeds), we expected that seed-derived plants would have a stronger biomass allocation to rhizomes and hibernacles. Since resource supply affects plant size, and thus hibernacle and seed production, we also subjected the plants to different levels of shade. At the start of the experiment seed-derived and clonal offspring hardly differed in total fresh weight. At the final harvest in September seed-derived and clonal offspring did not differ in vegetative plant weight (i.e., leaves, stems, and roots). Only light availability significantly affected these plant structures. As predicted, seed-derived plants did not flower in either of the light treatments. Seed-derived plants allocated more biomass to rhizomes and hibernacles, but this was only significant in the highest-light treatment. This result was due only to an increase in the number of hibernacles. Dry weight of single hibernacles was not affected by plant type. The ecological implications of this allocation pattern are discussed. Received: 2 October 1997 / Accepted: 8 March 1998     

The effect of plant size on vegetative reproduction in a pseudo-annual

The relationship between plant size and vegetative reproduction in clonal plants appears complex because vegetative expansion, growth, and reproduction are not clearly separable in such plants. In pseudo-annuals, which are clonal plants surviving the winter only as seeds and hibernacles produced by the rhizome apices, vegetative growth and reproduction are clearly separate processes so that the relationship between vegetative reproduction and plant size can be studied. We used the pseudo-annual Helianthus x laetiflorus Pers. to study the relationship between plant size and total rhizome biomass, rhizome (hibernacle) biomass, and number of hibernacles. We manipulated resource acquisition of the plants by reducing leaf area (leaf-clipping) and by fertilization, thus affecting plant size. Furthermore, we studied the success of thin and thick hibernacles in terms of future growth and reproduction in a separate experiment. The results showed that vegetative reproduction was positively related to plant size. The ratio between the number of hibernacles and mean hibernacle weight was affected by plant size in such a way that in small plants both number of hibernacles and mean hibernacle weight were reduced to the same extent as compared to those in large plants.However, the size distributions of plants of the next generation growing from thin and thick hibernacles did not differ. It remains unclear therefore why this pseudo-annual species produces thick hibernacles at all.     

Clonal Diversity in Differently-Aged Populations of the Pseudo-Annual Clonal Plant Circaea lutetiana L.

Abstract: In many clonal plant species seedling recruitment is restricted to short colonization episodes early in the development of the population, and clonal diversity (i.e., genet diversity) in the population is expected to decrease with increasing population age. In established populations of the pseudo-annual Circaea lutetiana seedling recruitment has previously not been observed. Therefore, we expected established populations to have low clonal diversities. We analysed number and frequency of genets and spatial distribution of genets in six differently-aged C. lutetiana populations with the use of four informative RAPD primers. We found relatively low clonal diversities in young populations but very high clonal diversities in established populations. Therefore, the hypothesis was rejected that seedling recruitment does not occur in established populations. Moreover, we did not find large genet size asymmetries in established populations. Genet size differences can be caused by stochastic processes or by fitness related traits, such as differences in vegetative reproduction. Because vegetative propagation of ramets is dependent on ramet size, and the number of ramets and the size of each ramet determine genet size, we expected that large genets produced, on average, large ramets. However, this was not the case, suggesting that stochastic processes caused genet size differences. Genet size may also be bounded if spatial distribution of genets is affected by micro-habitat differences. For this we expected to find a clumped spatial distribution of ramets of the same genet. However, ramets of large genets were always found intermingled with ramets belonging to other genets.     

Clonal plasticity in response to nutrient availability in the pseudoannual herb,Trientalis europaea L.

Trientalis europaea plants were subjected to four levels of nutrient availability to test two hypotheses: (1) Clonal morphology of pseudoannuals with short-lived rhizomes is responsive to nutrient availability in terms of spacer length (a negative correlation expected) and branching intensity (a positive correlation expected), and (2) the size of the hibernacles of T. europaea shows a positive correlation with nutrient availability. The results support the first hypothesis, since the primary spacers of T. europaea were longer at lower nutrient levels while the branching intensity of the primary rhizomes increased at increasing nutrient supply. The second hypothesis was not confirmed, however; the plants produced fewer, but bigger hibernacles at lower levels of nutrient availability. The ecological significance of the results is discussed in the context of foraging for essential resources and habitat-related effects of hibernacle size on survival and establishment chances of daughter ramets.     

The relative importance of sexual and clonal reproduction for population growth in the perennial herb Fragaria vesca

The relative importance of sexual and clonal reproduction for population growth in clonal plants is highly variable. Clonal reproduction is often more important than sexual reproduction but there is considerable interspecific variation and the importance of the two reproductive modes can change with environmental conditions. We carried out a demographic study on the woodland strawberry (Fragaria vesca), a widespread clonal herb, at 12 sites in Switzerland during 2 years. Study sites were selected in two different habitats, i.e., forest and forest edge. We used periodic matrix models to estimate annual population growth rates and carried out prospective analyses to identify life cycle components that influence population growth rates most. Retrospective analyses were applied to study how the two different habitats affected population dynamics. Furthermore, we tested whether trade-offs between sexual and clonal reproduction occurred. There were large differences in annual population growth rates between sites and large within-site differences between years. Results of the prospective analyses clearly indicate that clonal reproduction is the dominant reproductive pathway whereas sexual reproduction is rather insignificant for population growth. Compared to forest habitats, forest edge habitats had higher population growth rates in the first year but smaller growth rates in the second year. We attribute these differing habitat effects to different water availabilities during consecutive years. No trade-offs between sexual and clonal reproduction were found. In conclusion, population growth of F. vesca relies heavily on clonal reproduction. Furthermore, reproduction and survival rates of F. vesca depend highly on spatio-temporal variation of environmental conditions.     

Estimation of the relative importance of sexual and vegetative reproduction in the clonal woodland herb Anemone nemorosa

Anemone nemorosa is a perennial rhizomatous plant of European woodlands. The “probability of clonal identity” method estimated the relative proportion of sexual to vegetative reproduction in this species to be 4.4% from allozyme genotype distributions. This result is congruent with investigations on the germination, short-term demography, population genetics, and breeding system of this species, and supports the hypothesis that even low levels of seedling recruitment can maintain considerable intrapopulational genetic diversity. Received: 2 March 1998 / Accepted: 24 July 1998     

Partner limitation and restoration of sexual reproduction in the clonal dwarf shrubLinnaea borealis L. (Caprifoliaceae)

Summary Reports suggest that there is widespread reproductive failure inLinnaea borealis in Britain, Scandinavia, and North America. Our investigations of Scottish populations of this clonal dwarf shrub indicate that, although visited by a number of different insects, pollen transfer in this species is highly effective and principally occurs by small flies (Muscidae). However, natural levels of fruit set varied between populations (from 0% to 25.1%) and reproductive failure was most severe in populations which were composed of single clones. Microscopic examination of stigmas showed that there is no barrier to pollen flow since at least 85% of stigmas have sufficient germinating pollen to effect seed set. Fluorescence microscopy of germinating pollen grains indicates high levels of pollen rejection in the style and only a small proportion of the pollen tubes were able to reach the ovary. It was concluded that lack of xenogamous pollination limits fruit formation in populations ofL. borealis. Reproductive success in an isolated population with extreme reproductive failure was restored by experimental field pollination with viable pollen imported from plants from another population. In Scotland,L. borealis occurs in small, isolated populations and restoration of reproduction can be achieved by the reintroduction of compatible mating partners. This is an important consideration for the conservation management of isolated populations since their long-term recovery may only be possible by translocation of different genotypes from elsewhere into the population. Habitat fragmentation in any part of the species range may impose a potential reproductive bottleneck by causing loss of population diversity and this could explain the low levels of seed set recorded for this species in other parts of its range.     

The role of protective understorey in the regeneration system of a heavily browsed woodland

The paper tests an apparent relationship between young understorey of Ilex aquifolium and the presence of seedlings of the canopy species Fagus sylvatica and Quercus species, in heavily browsed woodland in the New Forest, southern England. A small block of woodland was searched and mapped, and the information collected subject to graphical and statistical analyses.Regeneration, though of low frequency, is present and shows non-random patterns of distribution. Older seedlings appear to be located in or near areas of understorey, or near fallen branches, logs, etc. Principal components analysis of woodland characteristics suggests six main habitat types are available to seedlings, and predictions are made about likely regeneration patterns associated with these habitats, according to a model based on the hypothesis of a protective understorey and heavy browsing pressure. Chi-square tests of actual seedling occurrences versus habitat types demonstrate marked associations of regeneration with non-trampled areas, including young Ilex understorey but also other forms of protective barrier. The association is more marked for larger seedlings.The implications for a wider understanding of regeneration processes and community dynamics in heavily browsed forest are discussed. It is concluded that regeneration theories appropriate to such forests are required, since the dominant gap-phase theories are not successful in predicting regeneration patterns when browsing is a major factor.     

松嫩平原光稃茅香无性系种群的营养繁殖特征

光稃茅香是典型的无性系禾草 .分蘖节可繁殖 2个世代 ,最多存活 3个年度 .根茎最多存活 2个年度 .无性系种群的分蘖株和根茎均有 2个龄级 ,并均以 1龄级占较大比重 .无性系潜在种群由冬性苗和根茎芽所组成 .以潜在种群的数量估计 ,在割草场混生群落中将保持现有的地位和作用 ,在放牧场的优势种群落中将增强其地位和作用 .     

Sexual vs. vegetative reproduction in relation to forest dynamics in the understorey shrub,Hydrangea paniculata (Saxifragaceae)

In the forest understorey, shrubs usually reproduce vegetatively rather than sexually, but the relative contribution of these two reproductive modes may vary with temporal changes in environmental conditions (e.g., light, substrates of forest floor) that are closely related to forest dynamics. To evaluate the occasional changes in reproductive modes of the clonal understorey shrub Hydrangea paniculata, the reproductive characteristics (i.e., flowering, seedling establishment, vegetative propagation, reproductive size and age) were investigated in four different developmental stages in a Japanese beech forest (early gap, EG; late gap, LG; building, BU; mature, MA). Flowering individuals occurred only in EG and LG, and a much greater number of seedlings was observed in both EG and LG than in BU and MA, mainly because canopy gaps provided sufficient light for flowering and suitable substrates (fallen trees and exposed mineral-soil) for seedling establishment. The flowering individuals originated from plants that had persisted in the shaded understorey until gap formation. In contrast to sexual reproduction, clonal fragmentation increased with forest development in the order LG, EG, BU, MA. This is because, in later stages of forest dynamics (BU and MA), large individuals, some of which had previously flowered in gap stages, were layered on the forest floor and subsequently produced a substantial number of clonal fragments by separation of the buried branches from the main stems which had decayed. This resulted in a large number of clonal fragments originating from a single mother plant. These results suggest that the reproductive modes of H. paniculata is strongly influenced by the changes in environmental conditions with respect to the dynamics of canopy trees. Reproduction from seed in gap stages, despite their short period, provide new genets in established populations, whereas vegetative propagation via fragmentation in closed-canopy stages enhance the stability of the population until the next disturbance.     

Effects of salinity and clonal integration on growth and sexual reproduction of the invasive grass Spartina alterniflora

The purpose of this study was to explore clonal integration of Spartina alterniflora under gradually changing substrate salinity conditions. We hypothesized that there might be a trade-off between growth and sexual reproduction influenced by soil salinity and, that clonal integration would change this trade-off. The experiment consisted of three levels of substrate salinity (5‰, 20‰ and 35‰), two clonal integration treatments (rhizomes severed or not), and three growth stages of daughter ramets (21, 40 and 60 cm tall). Both growth and sexual reproduction of S. alterniflora greatly decreased with increasing salinity. Clonal integration enhanced the survival, growth and sexual reproduction of daughter ramets experiencing salt stress, especially for young ramets, whereas the performance of mother ramets was reduced by clonal integration. Therefore, clonal integration did not affect performance of the whole clones. Contrary to expectations, there was no evidence for a trade-off between growth and sexual reproduction associated with salinity. In addition, clonal integration did not change the effect of salinity on the growth and sexual reproduction of mother and daughter ramets nor of the whole clones.     

An efficient in vitro method for mass propagation of a woody ornamentalIxora coccinea L.

Various factors that affect culture establishment, shoot growth, proliferation and rooting ofIxora coccinea L., a woody shrub, were studied. Stem cuttings (decapitated shoot, three nodes) were the most suitable explants for multiple-shoot proliferation, and when cultured on a woody plant medium (WPM) containing 2.5 M BA produced axillary shoots which branched repeatedly, yielding an average of 27 shoots per explant after 6 weeks in culture. Kinetin, 2-iP, zeatin and thidiazuron all induced multiple-shoot formation, but were less effective than BA. While the presence of IAA in the multiplication medium was detrimental to shoot proliferation, shoot growth was not affected by IAA. The production of large amounts of basal callus and vitrification of shoots were the major problems to be avoided in proliferating shoot cultures. Addition of TIBA to the multiplication medium markedly reduced basal callusing, while sealing the culture vessels with a fluorocarbon polymer (tetrafluoroethyleneperfluoroalkyl vinyl ether) film (Neoflon PFA film) almost completely eliminated vitrification. A reduction in the number of vitrified shoots was also achieved with AVG treatment. Following this protocol of using BA-supplemented WPM and Neoflon film, it would be possible to produce more than 100,000 plants from a single stem cutting in 1 year.Abbreviations AVG Aminoethoxyvinylglycine - BA N⁶-benzyladenine - BM basal medium - IAA indole-3-acetic acid - IBA indole-3-butyric acid - 2-tiP N⁶-(2-isopentenyl)adenine - KIN kinetin - MS Murashige and Skoog medium - NAA -naphthaleneacetic acid - SRM shoot regeneration medium - TDZ thidiazuron - TIBA 2,3,5-triiodobenzoic acid - WPM woody plant medium - ZEA zeatin     

Timing of sexual reproduction and reproductive success in the high-mountain plant Saxifraga bryoides L

SAXIFRAGA BRYOIDES L. is one of the plant species reaching the upper limits of distribution for flowering plants in the European Alps. Because of its abundance in the subnival and nival zones, we expected S. BRYOIDES to reproduce efficiently in the highly stochastic climate at higher altitudes. Investigations were carried out at two subnival sites (2650 m and 2880 m a.s.l.) in the Austrian Alps. We studied flowering phenology, dynamics of seed development, and reproductive success in the climatically different years from 2001 - 2004. For a nival plant species, S. BRYOIDES showed a particularly long prefloration period (6 - 9 weeks). From onset of anthesis until seed maturity took an individual flower another 6 - 7 weeks and all individuals at a site 9 - 10 weeks. The length of the prefloration period and seed histogenesis was temperature-dependent, whereas seed maturation seemed to be endogenously controlled. Only in the exceptionally long and warm growing season of 2003 did all fruits mature at a site. In the other years, the onset of winter conditions halted development in many fruits before maturity. The seed/ovule ratio of mature fruits was around 0.7 in all years. The relative reproductive success (RRS) ranged from zero to 0.7, depending on the site and year. In conclusion, S. BRYOIDES needs an unexpectedly long time to undergo reproductive development. Though fruit maturation is uncertain, the high S/O ratio of single intact fruits results in at least a small seed crop in most years. This seems to be sufficient to assure the spread and maintenance of S. BRYOIDES at higher altitudes. As a seed-risk strategist (Molau,1993), S. BRYOIDES would clearly benefit from a prolonged growing season, which might occur more often if climate warming continues.     

苦豆子营养器官的发育解剖学及组织化学研究

采用石蜡切片法对苦豆子(Sophora alopecuroides L.)根、茎、横走茎及叶的发育过程进行了研究,并利用组织化学的方法对生物碱在苦豆子各营养器官中的分布规律进行了测定.苦豆子根、茎及横走茎的初生生长与一般双子叶植物的发育规律一致,但在次生生长时,部分维管形成层细胞平周分裂只形成薄壁组织,从而将次生维管组织也分离成束.茎与横走茎的功能及生活环境不同,所以在结构上也存在一定的差异.叶是等面叶,上下表皮内都有栅栏组织的分布,其组织分化和发育过程与双子叶植物叶的发育规律一致.在茎、横走茎及叶主脉中,韧皮部的外侧都包围有纤维束,其来源都是原生韧皮部.应用硅钨酸、碘化铋钾及I-KI溶液进行沉淀反应,测定出生物总碱在苦豆子根、茎、横走茎及叶的薄壁组织细胞中均存在.     

Adaptation of epiphytic bryophytes in the understorey attributing to the correlations and trade-offs between functional traits

This study explores adaptive strategies of epiphytic bryophytes in the understorey by investigating the photosynthetic characteristics, pigment concentrations and nutrient stoichiometry, as well as other functional traits of three trunk-dwelling bryophytes in a subtropical montane cloud forest in SW China. The results showed that their light-saturated net photosynthetic rate (A_nmax?L), light saturation point (I_sat), light compensation point (I_c) and dark respiration rate (R_d) were ca 0.55, 106.72, 4.17 and 0.25?μmol?m^?2?s^?1, respectively. Furthermore, the samples demonstrated photosynthetic down-regulation under high irradiance. These photosynthetic characteristics can be explained by higher total chlorophyll concentrations, specific leaf area, chlorophyll per unit leaf N (Chl/N), lower ratio of chlorophyll a to chlorophyll b (Chl a/b) and photosynthetic nitrogen-use efficiency. We suggest that the bryophytes adapted to the shaded understorey microhabitats through a series of correlations and trade-offs between functional traits.     

Recovery and succession in a multi-species tropical seagrass meadow following experimental disturbance: the role of sexual and asexual reproduction

Recolonisation and succession in a multi-species tropical seagrass meadow was examined by creating gaps (50×50 cm) in the meadow and manipulating the supply of sexual and asexual propagules. Measurements of leaf shoot density and estimates of above-ground biomass were conducted monthly to measure recovery of gaps between September 1995 and November 1997. Measurements of the seeds stored in the sediment (seed bank) and horizontal rhizome growth of colonising species were also conducted to determine their role in the recovery process.Asexual colonisation through horizontal rhizome growth from the surrounding meadow was the main mechanism for colonisation of gaps created in the meadow. The seed bank played no role in recolonisation of cleared plots. Total shoot density and above-ground biomass (all species pooled) of cleared plots recovered asexually to the level of the undisturbed controls in 10 and 7 months, respectively. There was some sexual recruitment into cleared plots where asexual colonisation was prevented but seagrass abundance (shoot density and biomass) did not reach the level of unmanipulated controls. Seagrass species did not appear to form seed banks despite some species being capable of producing long-lived seeds.The species composition of cleared plots remained different to the undisturbed controls throughout the 26-month experiment. Syringodium isoetifolium was a rapid asexual coloniser of disturbed plots and remained at higher abundances than in the control treatments for the duration of the study. S. isoetifolium had the fastest horizontal rhizome growth of species asexually colonising cleared plots (6.9 mm day⁻¹). Halophila ovalis was the most successful sexual coloniser but was displaced by asexually colonising species. H. ovalis was the only species observed to produce fruits during the study.Small disturbances in the meadow led to long-term (>2 years) changes in community composition. This study demonstrated that succession in tropical seagrass communities was not a deterministic process. Variations in recovery observed for different tropical seagrass communities highlighted the importance of understanding life history characteristics of species within individual communities to effectively predict their response to disturbance. A reproductive strategy involving clonal growth and production of long-lived, locally dispersed seeds is suggested which may provide an evolutionary advantage to plants growing in tropical environments subject to temporally unpredictable major disturbances such as cyclones.     

Some observations of phenology and ecophysiology ofDaphne kamtschatica Maxim.var.jezoensis (Maxim.) Ohwi, a shade deciduous shrub, in the forest of northern Japan

The phenology and leaf traits ofDaphne kamtschatica Maxim. var.jezoensis (Maxim.) Ohwi, the only summer deciduous shrub (20–40 cm) in the temperate forest of northern Japan, are examined. This plant carries through the winter mature leaves and well formed flower buds. It flowers in early spring during snowmelt and begins photosynthesis under relatively high irradiance under an open forest canopy. Our results show that there is significant carbon gain during the period when new leaves and fruit maturation also take place. Beginning in June, as the forest canopy closes, leaves onDaphne shoots senesce acropetally and the plants become completely bare in mid-July. After a period of 20-day dormancy, the shoots begin to resprout. Leaves become mature in early October and remain on the stem over winter. Leaf traits and photosynthesis measurements suggest as follows. 1) By becoming summer deciduous,D. kamtschatica avoids the cost of maintaining leaves inefficient under deep shade. 2) The onset and breaking of the summer dormancy is triggered by photoperiod since plants at the forest edge also become dormant even when light remained relatively high. However, the decreased duration of dormancy with higher light levels suggests that there is a tendency towards shorter dormancy where summer shade is absent and this could eventually lead to an evergreen habit such as that found in the alpine speciesDaphne miyabeana.     

Ramet phenology and clonal architectures of the clonal sedge <Emphasis Type="Italic">Schoenoplectus americanus</Emphasis> (Pers.) Volk. ex Schinz &; R. Keller

The clonal plant Schoenoplectus americanus shows variable belowground clonal architecture as a result of producing two types of ramets: those with very long rhizomes (long rhizome ramet, LRR) and those with very short ones (short rhizome ramet, SRR). In a previous study we demonstrated that the two types of ramets are functionally specialised. The production of SRRs results in the formation of consolidated clonal patches with densely packed shoots, while the production of LRRs results in a more diffuse network of connected rhizomes with widely spaced shoots. We hypothesised that the two types of ramets would be produced at different times during the growing season because of their functional differences. The production of LRRs throughout the growing season would enable the species to continuously explore new habitats while the production of SRRs early in the growing season would enable the species to occupy and consolidate resources in available open patches. We evaluated this hypothesis through field observations in different communities with S. americanus and indeed found that SRRs were produced early in the growing season while LRRs tended to be produced over an extended period of time. Plants in high-quality environments (i.e. higher light conditions) produced more SRRs, and these were formed early in the growing season. In contrast, plants in low-quality environments produced more LRRs, and these were formed continuously over the growing season. We also observed that the shoot longevity was greater for SRR. In high-quality patches, the production of the lower cost SRRs results in a more rapid occupancy of open spaces; in lower quality patches, the production of LRRs throughout the growing season enables plants to explore the immediate environment for higher quality patches.     

Rapid clonal propagation of Saccharum officinarum L. Vars. CO-6907 and CO-86249 and to assess the genetic uniformity through molecular markers

Abstract

An efficient protocol was developed for in vitro clonal propagation of Saccharum officinarum Vars. CO-6907 and CO-86249 through axillary meristem culture. Maximum meristem elongation was achieved on Murashige and Skoog's (MS) medium supplemented with 0.5 mg/L 6-benzyladenine (BA) and 0.5 mg/L kinetin (Kn) within 15 days of culture. Multiple shoots were induced from meristems on MS basal medium supplemented with 1.0 mg/L BA, 0.5 mg/L Kn, 0.25 mg/L 1-napthaleneacetic acid (NAA) and 3% (w/v) sucrose. Addition of 0.1–0.25 mg/L gibberellic acid into the multiplication medium found the better shoot elongation. Repeated subculture on multiplication medium induces higher rate of shoot multiplication. The root induction from excised microshoots was achieved on half-strength MS medium supplemented with 1.0–2.0 mg/L NAA or indole-3-butyric acid and 6% (w/v) sucrose. While either decreasing or increasing of sucrose concentration in the rooting medium, the percentage of rooting was reduced. Maximum percentage of rooting was achieved on medium having 2.0 mg/L NAA with 6% (w/v) sucrose. About 80% of micropropagated plantlets were hardened in the greenhouse and successfully established in the soil. Random Amplified Polymorphic DNA marker was used to detect the variability among the micropropagated plants developed through in vitro. The results showed that there was no polymorphism among the micropropagated plants. This study will help for propagation of quality planting material of high-yielding variety of sugarcane for commercialization.     

Vegetative multiplication and patch colonisation of Asarum europaeum subsp. europaeum L. (Aristolochiaceae) inferred by a combined morphological and molecular study

Asarum europaeum subsp. europaeum (Aristolochiaceae) is a rhizomatous herb forming distinct patches in calcareous broadleaved forests. Within natural stands, patches were mapped. In two regions, at least four patches were dug out, and connections between leaf modules through rhizomatous spacers were checked for signs of clonal reproduction (decay, breaking). Modules were sampled for amplified fragment length polymorphism (AFLP) fingerprinting to test whether they represent unique genets or are merigenets of a larger genet (split up by clonal reproduction), respectively.Morphologically, merigenet-relationships were only revealed in few cases with disrupted spacers between modules. With the obtained AFLP profiles for two primer combinations, the samples could be assigned to genets; clonal descendants of the same genet were readily identified. In one patch analysed in detail, 18 samples from 17 unconnected “plants” belonged to only two genets, which were morphologically divided into two and 15 merigenets, respectively. These two genets probably belonged to different maternal lineages and came into contact after lateral spread from the established clones. They showed divergent affinities to samples from adjacent patches (which all represented unique genets).The findings support the suitability of the combined morpho-ecological and molecular approach: compared to either method alone, it allows a more detailed analysis and interpretation of the fine-scale clonal structure, patch colonisation and especially of vegetative multiplication (with morpho-ecological studies to discern clonal growth and clonal reproduction and AFLP fingerprinting for genet and merigenet identification, respectively).