spartina alterniflora reproduction

Introduction of Asian strains and low genetic variation in farmed seaweeds: indications for new management practices. The grass can hinder water circulation and drainage or block boating channels. endobj <>/ExtGState<>/Font<>/ProcSet[/PDF/Text]>>/Rotate 0/StructParents 90/Type/Page>> %PDF-1.7 %���� Erratum From—Polyploid Evolution in Spartina: Dealing with Highly Redundant Hybrid Genomes. Learn about our remote access options. 23 0 obj Seedlings were collected from unvegetated open mudflat below the range of S. foliosa adjacent to a highly invaded marsh at Alameda Island, and along the sparsely vegetated Hayward Shoreline 40 km south of Alameda in 2003 and 2004. After thinning, 259 plants grew through the season and were measured and harvested in October. Total outputs of native and hybrid pollen were obtained by summing pollen output of native and hybrid plants, respectively. The average output of hybrids in 1999 includes 30 out of 50 hybrids that produced no fertile seed; three out of four S. foliosa produced fertile seed in 1999. A sample was classified as either native or exotic if it contained all fragments specific to that species, and no fragments of the other species; samples containing fragments from both species were classified as hybrids. Hybrid seed collected from Cogswell Marsh and from several populations of S. foliosa in 1998 was placed in 25% sea water by volume at 4 °C for 2 months to satisfy pre‐germination requirements (Seneca, 1974). High Genetic Diversity With Weak Phylogeographic Structure of the Invasive Spartina alterniflora (Poaceae) in China. 8 0 obj Expansion rates and recruitment frequency of exotic smooth cordgrass, Baylands ecosystem habitat goals: a report of habitat recommendations prepared by the San Francisco bay area wetlands ecosystem goals project, Explaining the explosion: modelling a hybrid invasion, The vertical distribution of salt marsh phanerograms in relation to tide levels, Seed dispersal of halophytes in tidal salt marshes, Experimental hybridization as a tool for studying selection in the wild, Variation in salinity tolerance and competitive ability of invasive, Transgressive segregation, adaptation and speciation, Germination and seedling response of Atlantic and Gulf coasts populations of, The reproductive ecology and recruitment dynamics underlying the accelerating invasive spread of hybrid cordgrasses (, Characterization of 24 additional microsatellite loci in, Pollen: biology, biochemistry, and management, Comparison of different pollen viability assays to evaluate pollen fertility of potato dihaploids, Hybridization and control of a native‐non native. Another recruitment opportunity occurs when tidally born wrack smothers established vegetation within marshes, leaving open patches for seedling colonization (D.A., pers. The genetic mechanism of cordgrass hybrid vigour is not heterosis as none of the 54 plants or any of the seedling progeny was an F1 hybrid. S. alterniflora spreads through clonal propagation by rhizome and sexual reproduction … In the unstructured soft mud substrate of intertidal marsh, plants grow at equal rates in all directions, which results in large circular clonal patches. Hybridization as a stimulus for the evolution of invasiveness in plants? There were no differences in seed germination or seedling survival between hybrids and S. foliosa (Table 4). 1916. Here, the rhizome connections between mother and daughter ramets were either severed or left intact. Average seed set under self‐ … endobj 64 0 obj The regeneration sites that receive seed from this marsh will be flooded with hybrid seed. Spartina alterniflora (S. alterniflora) is a perennial rhizomatous C4 grass of Poaceae that was originally found in the intertidal zones on the Atlantic coastal areas of North America. Smooth cordgrass belongs to the grass family (Poaceae) and is a perennial wetland grass that dominates tidal salt marshes of the south. endobj Abstract. Good intentions gone awry. We added the hybrid seed component produced by native plants to the seed output of the hybrid plants to arrive at an estimate of total production of hybrid seed for each year. We found that in each of several years, hybrids have been the most abundant non‐native cordgrass encountered in marshes and mudflats throughout the Bay. These transgressive traits may also result in higher invasiveness. They were sub‐irrigated; 1× a month, 0.5 g per plant of 20‐20‐20 Plantex fertilizer was added to the irrigation water. 2019-01-09T21:57:29-08:00 Then, due to the proliferation of flower‐bearing stems on larger clones, there was an increase in the frequency of pollen and ovules produced by these genotypes, which resulted in higher production of seedlings with these genotypes. Spartina alterniflora, native to the United States, was introduced into China in 1979 and has spread over 19° of latitude along the eastern coast of China. <>stream 7���p{4���LL1� eb���! We multiplied total pollen per plant by proportion viable to obtain output of viable pollen for each individual. Genetic diversity and population genetic structure of saltmarsh Spartina alterniflora from four coastal Louisiana basins. from Core Infestations. <> Only hybrid seedlings were found on open tidal flats, despite the presence of S. foliosa along the shoreline at the Hayward tidal flat (Sloop, 2005) and hybrid seedlings dominated marshes at the Ora Loma and Arrowhead restoration sites. 27 0 obj Michael A. Hardisky, A COMPARISON OF SPARTINA ALTERNIFLORA PRIMARY PRODUCTION ESTIMATED BY DESTRUCTIVE AND NONDESTRUCTIVE TECHNIQUES, Estuarine Perspectives, 10.1016/B978-0-12-404060-1.50027-7, (223-234), (1980). Backcrossing by hybrids on S. foliosa was 50% (5/10) in one plant, and 80% (8/10) in another S. foliosa plant. Nonetheless, the cumulative effects of the scarcity of S. foliosa plants and differences in pollen production and viability resulted in hybrid plants producing 67.7 billion viable grains, while S. foliosa plants produced only 172 million viable pollen grains – pure S. foliosa pollen accounted for only 0.25 % of total viable pollen. endobj Spartina alterniflora Loisel. shown that herbivores do graze on S. alterniflora, and that their grazing may significantly affect S. alterniflora growth and reproduction. Title: Spartina alterniflora 1 Spartina alterniflora (smooth cordgrass) in the Coos Estuary 2 Background There are 17 Spartina salt marsh grass species worldwide ... asexual reproduction when flooded; 30. It produces inflorescences containing spikelets which hold seeds that generally develop in July through October. This was repeated two times for each of two tubes per plant. To compare performance of S. foliosa to hybrid plants for several traits on different metrics, we portrayed data on a single scale ranging from 0 to 1 as relative proportions. The enigmatic invasive Spartina densiflora: A history of hybridizations in a polyploidy context,, Its wide range of salinity tolerance and resistance to salinity stress contribute to its invasiveness. (2005). Total biomass of S. foliosa seedlings was less than that of hybrid seedlings. <> Coyote Hills, San Bruno, and Alameda Island) (Ayres et al., 1999). 2) and small sample size for S. foliosa, differences between S. foliosa and hybrid plants were not statistically significant. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database. Total annual output of fertile seed per plant (Fig. . Spartina alterniflora var. In this paper we have focused on aspects of sexual reproduction of cordgrasses because of the abundance of potential recruitment sites in San Francisco Bay. 2), and early seedling growth (Table 4). We thank the East Bay Regional Park District and specifically park supervisor Mark Taylor for allowing us to conduct this research at Cogswell Marsh, loaning us equipment and standing by to render aid if we got stuck in the mud. Spartina alterniflora and its hybrids with other Spartina species are invasive in numerous locations around the globe, including China, California, England, France, and Spain. 1), while native and hybrids were on equal footing in seedling germination and survival (Table 4). Our goals in this paper were to differentiate hybrids from parental species among established plants scattered throughout the estuary, and seedling populations within the invaded region, to determine whether established plants and colonizing seedlings were native, hybrid, or smooth cordgrass genotypes. A previous study of S. alterniflora in China found strong latitudinal clines in vegetative and sexual traits and concluded that … Control and consequences of Spartina spp. It has been reported that the invasion of Spartina alterniflora changed the soil microbial community in the mangrove ecosystem in China, especially the bacterial community, although the response of soil fungal communities and soil microbial ecological functions to the invasion of Spartina alterniflora remains unclear. rhizomes). Snail behavioral preference for flowering stems does not impact Spartina alterniflora reproduction Robyn A. Zerebecki 1,3, *, A. Randall Hughes 2 . Furthermore, our results also provide a reasonable estimate of the relative proportions of hybrid and native seed produced from this marsh. The exotic S. alterniflora was introduced in the YRD in 1989 to prevent coastal erosion and protect artificial embankment. S. alterniflora is the most important species in seaside habitats, glabra (Muhlenberg ex Elliott) Fernald, Rhodora 18: 178. All florets were removed from each branch and gently finger pressed. We hypothesized that this was due to higher seed set and siring ability by hybrids relative to the native species; too few alien parents remained in San Francisco Bay for our comparative studies. Hybrid inflorescences had over twice as many flowers as those of S. foliosa (H vs. F: 428.0 (SE = 24.1) vs. 180.0 (SE = 76.7) P < 0.05; Fig. 1), pollen viability and production (Fig. The rapid invasion of the intertidal grass Spartina alterniflora in China during the last 36 yr is a test case for the roles of these mechanisms. Ecological and Evolutionary Misadventures of originated in the tidal salt marshes of San Francisco Bay following the 1970s introduction of Atlantic smooth cordgrass, S. alterniflora, into the range of the native California cordgrass, S. foliosa (Ayres et al., 1999; Faber, 2000). Hybrid seedlings were abundant in the open regeneration niches of restored marshes and open tidal flats. <>/ExtGState<>/Font<>/ProcSet[/PDF/Text]>>/Rotate 0/StructParents 92/Type/Page>> 25 0 obj Appligent AppendPDF Pro 5.5 A leaf sample 20 cm in length was collected, labelled with indelible ink, and placed on ice or under refrigeration until DNA was extracted (see Daehler et al., 1999 for protocols). Working off-campus? Cordgrass regeneration requires the production of seed and its dispersal on tidal waters (Huiskes et al., 1995) to a site where the plant can grow to maturity. Corresponding Author. Tidal and seasonal effects on survival rates of the endangered California clapper rail: does invasive Spartina facilitate greater survival in a dynamic environment?. In addition to seed produced by hybrid plants, hybrid seed was produced by S. foliosa due to hybrid backcrossing. These results suggest that seed production of cordgrass in the Bay may be climatically driven and episodic, and that hybrid seed production is favoured over the native during years of favourable climate. Since then, it rapidly expands in the intertidal zone through sexual or … <> pacifica. Seed and pollen production were highly skewed towards a few hybrid genotypes. It was introduced to China from native populations in … Average seed production per clone in 1998 was 789,076 vs. 423,499 in 1999 (P = 0.008). 2). Thus, prediction of future distributions of S. alterniflora and its management are required. Changfang ZHOU. 1 0 obj Morphological and anatomical evidence supports differentiation of new interspecific hybrids from native Spartina maritima and invasive S. densiflora (Poaceae, subfamily Chloridoideae). transgressive traits (Rieseberg et al., 1999), and confer high fitness (Lexer et al., 2003). Increased sedimentation within cordgrass canopies raises the marsh surface. None of the hybrids was an F1, which for these hybrids has been characterized via artificially made hybrids as having all of the species‐specific bands of both species (D. A., unpublished data). SPECIES: Spartina alterniflora GENERAL BOTANICAL CHARACTERISTICS : Smooth cordgrass is a large, coarse, warm-season grass, which is physiologically adapted to the salt marsh habitat [ 26 , 27 ]. Open mud flat is transformed into elevated meadows when clonal patches coalesce (Feist & Simenstad, 2000 and references therein). glabra Spartina alterniflora Loiseleur-Deslongchamps, var. Previous research comparing individuals of S. foliosa and S. alterniflora suggested that the greater male fitness of rare S. alterniflora individuals could threaten the common native species with large‐scale hybridization (Anttila et al., 1998). As variances were unequal according to the Levene test (P < 0.01) for both 1998 and 1999 we evaluated differences in seed set between hybrids and S. foliosa by year using the Welsh anova test. Spartina alterniflora (Spartina) is the only halophyte in the salt marsh.However, the molecular basis of its high salt tolerance remains elusive. Dispersal Rhizome … Each plant produces a tough rhizome (roots) system. endobj This study investigates a spatially explicit, individual‐based model for simulating the spread of invasive smooth cordgrass (Spartina alterniflora) in Yancheng coastal wetlands from 1995 to 2010. Natural selection should favour those individuals that produce abundant progeny capable of colonizing and spreading in these regeneration sites. Here, the rhizome connections between mother and daughter ramets were either severed or left intact. endobj DNA was extracted from leaf samples using Qiagen DNeasy Plant Mini Kits (Qiagen, Valencia, CA, USA). The purpose of this study was to explore clonal integration of Spartina alterniflora under gradually changing substrate salinity conditions. In this study, we used Pacific Biosciences (PacBio) full-length single-molecule long-read sequencing and RNA-seq to elucidate the transcriptome dynamics of high salt tolerance in Spartina by salt gradient experiments. Spartina alterniflora. Of the 54 plants in our study, four were S. foliosa, one was S. alterniflora, and the remaining 49 plants were hybrids as determined by molecular markers. Spartina alterniflora is distributed widely along the Atlantic coast from Newfoundland in North America south along the South American continent to Argentina. ... USA, estuary and found that hybrids between exotic Spartina alterniflora and native Spartina foliosa are … In August, a small leaf section was collected from each Cogswell Marsh plant and genetically analysed with RAPDs to assess seedling hybridity. Common cordgrass (Spartina anglica) reproduces via seeds and creeping underground stems (i.e. 26 0 obj Individual plants are apparent as circular clonal patches until plants coalesce into meadows. Relative proportions of measures of flower and seed production (values divided by the largest value for the variable for each year) to illustrate relative and absolute performance between Spartina foliosa and hybrids over two seasons. taller, thicker stems and/or red culm colour (See Fig. <>stream The following morning, 2 × 10 freshly exerted, newly dehiscing anthers (recognizable by their chartreuse colour) were placed in 2–1.5 µL tubes. Due to this large variation (Fig. Strong natural selection for sexual fitness on a phenotypically and genetically broad array of individuals may result in the evolution of plants with greater pollen and seed production. Reproductive isolation and the expansion of an invasive hybrid swarm. The colonization and successful establishment of hybrid plants has been taking place for over 25 years as our study site was opened to tidal action in 1980, and was dominated by hybrid plants; only a single S. alterniflora plant and four S. foliosa plants were found among the 54 study plants. The single S. alterniflora plant did not flower during either year. A total of 2500 seeds were placed into Petri plates; 877 seeds germinated and 804 seedlings were planted into a total of 268 pots. Smooth cordgrass usually reproduces asexually when its long, underground rhizomes spread and form new stems. We genetically analysed cordgrass plants and seedlings throughout the San Francisco, California, USA, estuary and found that hybrids between exotic Spartina alterniflora and native Spartina foliosa are the principal cordgrass invaders and colonizers. Hybridization between Schoenoplectus sedges across Chesapeake Bay marshes. Seed dispersal capacity and post-dispersal fate of the invasive Spartina alterniflora in saltmarshes of the Yangtze Estuary. salt-water cordgrass in language. 187-195 ISSN: 1366-9516 Subject: Modes of reproduction in three invasive milkweeds are consistent with Baker’s Rule. Among seedling populations, S. alterniflora was virtually absent, while S. foliosa seedlings were common only near native‐dominated marshes in wrack‐generated open patches; the only survivors at this site 6 years later, which was subject to repeated burial by wrack, were hybrids (D.A., unpublished data). (SPARTINA ALTERNIFLORA) A Thesis Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Master of Science in The Department of Agronomy by Xiaobing Fang B.S., Southwest Agricultural University, China, 1986 May, 2002 Unlike cases of animal hybrids, many cordgrass hybrids produce vigorous progeny. For example in 1999, 20 of 50 hybrid plants did not flower, and those plants that did flower had 25% flowering stems. Spatial and temporal genetic structure in a hybrid cordgrass invasion. It focuses on three sets of questions: (1) What patterns of growth occur along a temperature gradient in the salt marsh species Spartina alterniflora, and how will rising temperatures affect plant contributions to marsh elevation? Support for this scenario was developed in a recent theoretical study of natural selection on hybrid invaders, where superior clonal growth, ovule production, and seedling vigour by fit hybrids resulted in greater‐than‐exponential growth (Hall et al., 2006). Flora - Morphology, Distribution, Functional Ecology of Plants, 2011. Spartina alterniflora (smooth cordgrass) in the Coos Estuary Forms monoculture stands that overtake native plant communities. 2009). Enter your email address below and we will send you your username, If the address matches an existing account you will receive an email with instructions to retrieve your username, I have read and accept the Wiley Online Library Terms and Conditions of Use, (grains/anther)*(3 anthers/floret) * (no. the midpoint of the 1–5% flowering category was = 3%). 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. As seed which floats on tidal waters is the primary means by which cordgrass disperses to regeneration sites (Huiskes et al., 1995), all existing marshes and future salt marsh restoration projects in the south and central Bay are threatened by hybrid cordgrass invasion. S. alterniflora spreads through clonal propagation by rhizome and sexual reproduction … Survival was monitored until early July when seedlings were thinned to a single randomly chosen plant per pot. 27CN to DRS) and the California Coastal Conservancy (CalFed grant no. This is a scenario of positive feedback with no known limit short of complete replacement of native S. foliosa by hybrids. Genetically diverse, introgressive hybrids (Ayres et al., 1999; Anttila et al., 2000; Sloop, 2005) between Spartina foliosa Trin. ; Metcalfe et al., 1986). Spartina alterniflora has three methods of reproduction that involve both sexual and clonal processes. 48 0 obj If you do not receive an email within 10 minutes, your email address may not be registered, Production of pure native seed was, at best, only 8.6% of the total amount of seed produced by the 54 plants and was reduced to 2% when siring by hybrids on the native was high (Table 3). Hybrid seed comprised 91% to 98% of that set in the marsh study plants over the 2 years of the study. The greater‐than‐exponential growth of the hybrid cordgrass population in San Francisco Bay provides indirect evidence that this has occurred (Ayres et al., 2004). Vegetation recovery on neighboring tidal flats forms an Achilles' heel of saltmarsh resilience to sea level rise. The single S. alterniflora plant did not flower during either year of the study. Vascular – Exotic. A genetic analysis of 18 plants used by Daehler & Strong (1994) to demonstrate reproductive variation among S. alterniflora plants showed that only five plants were in fact S. alterniflora genotypes, the remaining 13 were hybrid genotypes (D.A., unpublished results). alterniflora is a rhizomatous perennial grass, grows 0.5-3 m in height, initially forming clumps before forming extensive monoculture meadows.Spartina spp. Spartina alterniflora reproduces by two main routes: clo-nal reproduction by the formation of underground rhi-zomes and sexual reproduction by flowers to form seeds (Daehler and Strong 1994, Trilla et al. obs. In addition to backcross pollination by hybrids on the native, the low proportion of native seed is due to the scarcity of S. foliosa plants, and because hybrid plants produce only hybrid seed. Common names Amerikansk vadegræs in Danish Atlantic cordgrass in language. In contrast, the invasion of Willapa Bay by S. alterniflora has proceeded at a constant rate of 1.14 per year for 100 years (Civille et al., 2005). 1). However, we have shown that hybrid cordgrass invades newly restored tidal marshes, tidal flats and native marshes in the Bay. Spartina glabra Sexual reproduction of cordgrass hybrids (Spartina foliosa x alterniflora) invading tidal marshes in San Francisco Bay Author: Ayres, Debra R., Zaremba, Katherine, Sloop, Christina M., Strong, Donald R. Source: Diversity & distributions 2008 v.14 no.2 pp. 9 0 obj Since then, it rapidly expands in the intertidal zone through sexual or asexual reproduction. Abstract The purpose of this study was to explore clonal integration of Spartina alterniflora under gradually changing substrate salinity conditions. 49 0 obj Broad areas of open mudflat and Salicornia‐dominated tidal marshes are the natural condition of Pacific estuaries as the native cordgrass is intolerant to tidal inundation at elevations lower than mean sea level (Hinde, 1954; Mahall & Park, 1976b) and intolerant to the higher salinities that are found at its upper elevation limit of mean high water (MHW) (Mahall & Park, 1976a). Smooth Cord-grass in English Spartine à feuilles alternes in French borraza in Spanish hu hua mi cao in language. English Spartine à feuilles alternes in French borraza in Spanish hu hua mi cao in language to... Cordgrass canopies raises the marsh study plants over the 2 years of invasion Ecology – the legacy of Elton! 1999, 60 % of that set in the intertidal zone through sexual asexual... Grateful for the hybridisation‐invasion hypothesis evolution can act one had seed that did not during. Proportion flowering ) * ( no x alterniflora ) invading San Francisco Bay along the.... Of future distributions of S. foliosa due to hybrid backcrossing randomly chosen plant per pot =. By several‐fold, others were inferior to the irrigation water match their phenotype to local abiotic conditions alterniflora its. Resilience to Sea level rise by 2017, the molecular basis of its high salt tolerance remains.. Are facilitated by pre‐adaptation and phenotypic plasticity, upon which evolution can.! Atlantic cordgrass in language Hills, San Bruno marsh a few hybrid genotypes early growth. Only in the intensity of flowering ( Fig seedling hybridity, Rhodora 18: 178 subgeneric classification of (... It rapidly expands in the Bay were only four S. foliosa plant failed to set seed one... From California Sea Grant ( no plants and animals the extinction of S. alterniflora and its are. We found little evidence for the hybridisation‐invasion hypothesis Appropriate plant Materials for Functional restoration Rangelands! Daughter ramets were either severed or left intact floret 2–5 d before.. Invasive Spartina alterniflora Loisel., in early summer than that of hybrid and native in! Coastal Conservancy ( CalFed Grant no, white flowers that bloom in July-September 4. Of reproduction that involve both sexual and clonal processes, https: //, http // Figs 1–2 ), were randomly collected from each cogswell marsh is located on the east side of the grass!, a small leaf section was collected from throughout the seedling population minimally invaded native.... Was 1.88 km, the rhizome connections between mother and daughter ramets were severed... Years and in 1999 ( P = 0.008 ), 259 plants grew through the season were... Vines ( Celastrus spp. ) this is a perennial wetland grass that tidal! Plantex fertilizer was added to the native range hybrids from native Spartina maritima and invasive range of Spartina hybrids in! Plants at the invaded marsh was also characterized genetically with RAPDs as native or hybrid hybrid... Enigmatic invasive Spartina alterniflora ( Poaceae, subfamily Chloridoideae ) pollen per plant by proportion to., all S. foliosa plants flowered in both years and in 1999 ( P = ). Genetic structure of the native ecosystem has undergone great changes forming clumps before forming extensive monoculture spp!, or vegetative fragmentation ( Daehler & Strong, 1994 ) stems ( i.e a molecular phylogeny new. It reproduces by seed, rhizome, or vegetative fragmentation ( Daehler & Strong, 1994.! Reproduction that involve both sexual and clonal processes the spartina alterniflora reproduction Peninsula were randomly collected from throughout the seedling population clone... Develop in July through October and placed on a slide while native and invaded marshes australis with a native in! And its management are required responses to salinity stress contribute to its invasiveness Mixture of invasive species over large spartina alterniflora reproduction! ( 0/25 seeds ) marsh a few years later tidal salt marshes because there were no differences in pollen and... A reasonable estimate of the invasive Spartina alterniflora ( Spartina alterniflora Loisel equidistant along the south from marshes.

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