Paspalum Species Research Articles

A phylogenetic analysis of the genus Paspalum (Poaceae) based on cpDNA and morphology

With about 350 species, Paspalum is one of the richest genera within the Poaceae. Its species inhabit ecologically diverse areas along the Americas and they are largely responsible for the biodiversity of grassland ecosystems in South America. Despite its size and relevance, no phylogeny of the genus as a whole is currently available and infrageneric relationships remain uncertain. Many Paspalum species consist of sexual-diploid and apomictic-polyploid cytotypes, and several have arisen through hybridization. In this paper we explore the phylogenetic structure of Paspalum using sequence data of four non-coding cpDNA fragments from a wide array of species which were combined with morphological data for a subset of diploid taxa. Our results confirmed the general monophyly of Paspalum if P. inaequivalve is excluded and the small genus Thrasyopsis is included. Only one of the four currently recognized subgenera was monophyletic but nested within the remainder of the genus. Some informal morphological groups were found to be polyphyletic. The placement of known allopolyploid groups is generally congruent with previously stated hypotheses although some species with shared genomic formulae formed paraphyletic arrangements. Other species formed a basal grade including mostly umbrophilous or hygrophilous species. It is hypothesized that the genus may have diversified as a consequence of the expansion of C4 grass-dominated grasslands in South America.

Morphological variation in Paspalum nicorae Parodi accessions, a promising forage

Paspalum nicorae Parodi is a perennial, apomictic tetraploid forage species, native in the state of Rio Grande do Sul, Brazil, with grazing tolerance and adapted to sandy soils and moderate droughts. As a first step to future breeding, a morphological characterization regarding leaf hairiness, sheath, leaf and central venation color, growing habit, plant height, raceme number and length, and leaf length and width was performed in 53 accessions from Rio Grande do Sul that are part of a Paspalum species breeding program. 35.84% of the accessions had completely hairy leaves, 73.58% had green sheath, 54.71% whitish central venation, 50.94% decumbent habit. Leaf color was estimated by two methods, color chart and colorimeter. The accessions were classified as 76.92% green, 13.45% greenish yellow and 9.62% as grayish green by the first, and 59.62% grayish, 32.69% grayish yellow, 5.77% yellow and 1.92% dark grayish by the second method. Raceme length ranged from 9.40 to 1.30 cm, number of racemes from one to six (48.73% of the accessions had four racemes), leaf length and width from 36.13 to 13.06 cm and 0.67 to 0.36 cm, respectively, and plant height from 115.70 to 29.00 cm. Therefore, a large morphological variation among accessions was detected, with no relation to geographical location but indicating a high potential use in plant breeding programs.

Possible Roles of the Leaves of Two Paspalum Species in Salinity Tolerance

Possible Roles of the Leaves of Two Paspalum Species in Salinity Tolerance

Paspalum L. (Poaceae: Panicoideae: Paniceae) no estado de Pernambuco, Brasil

No presente trabalho são tratadas as espécies de Paspalum que ocorrem no Estado de Pernambuco. O estudo foi baseado em trabalho de campo, com duração de dois anos, e em espécimes analisados em 18 herbários do Brasil. Foram registradas 32 espécies do gênero, classificadas em dois subgêneros: Paspalum subg. Paspalum, com 29 espécies e P. subg. Harpostachys (Trin.) S. Denham, com três espécies. Dentre as espécies confirmadas, apenas P. notatum não é nativa de Pernambuco. Dez espécies são novas citações para Pernambuco, sendo o registro de P. calliferum o primeiro para o Brasil. São fornecidas informações sobre relações taxonômicas, distribuição geográfica e uso econômico das espécies.

Padrões de distribuição das espécies de Paspalum L. (Poaceae: Panicoideae: Paniceae) ocorrentes em Pernambuco, Brasil

A fim de contribuir para o conhecimento dos padrões de distribuição de Paspalum, este estudo trata da distribuição das espécies que ocorrem em Pernambuco. Para isto foi realizada uma intensa revisão de literatura, de coleções depositadas em diversos herbários e de bancos de dados disponíveis na internet, além de coletas no estado de Pernambuco. As 31 espécies analisadas foram classificadas em dois padrões de distribuição: amplo, com 29 espécies e restrito, com duas espécies. As espécies do padrão restrito têm sua distribuição na região Nordeste do Brasil, sendo uma endêmica ao domínio do semi-árido e outra, até o momento só registrada para a costa atlântica do Brasil. O padrão de distribuição amplo pode ser subdividido em dois grupos, contínuo e disjunto, os quais por sua vez foram classificados em três subgrupos: americano, centro-sulamericano e sulamericano. Discute-se a importância desta análise para melhor compreender as origens da flora pernambucana.

Heterogeneous Distribution of Weedy Paspalum Species and Edaphic Variables in Turfgrass

Dallisgrass (Paspalum dilatatum Poir.) and bahiagrass (Paspalum notatum Fluegge) are two of the most troublesome weed species in managed turfgrass. These rhizomatous, perennial grass species affect appearance, texture, and playability of turf in home lawns, golf courses, and athletic fields. The severity and prevalence of these problem species as well as the difficulty of achieving control with herbicide management alone invite the examination of their realized niches for clues to improved management tactics. The distribution of these species was evaluated in both fairways and roughs of three holes on each of two golf courses in North Carolina. Golf courses were selected based on the presence of both weed species. Individual plants were mapped using a high-precision global positioning system unit. This unit was also used to delineate between the rough and fairway height of cut as well as obtain elevation characteristics of each hole. Soil moisture and soil compaction estimates were obtained by sampling on a 9-m grid. Environmental characteristics used for χ2 analysis consisted of mowing height, soil compaction, soil moisture, and elevation. Data were subjected to χ2 analysis to determine if the existing distribution of Paspalum spp. differed from an expected random distribution across all environmental factors. Bahiagrass growth and distribution was more affected by mowing height than dallisgrass. Bahiagrass was predominantly distributed in the rough, whereas dallisgrass occurred at both mowing heights. Similar responses were observed for both species with regard to soil compaction. Higher plant density for both species was observed in moderately compacted soil (40 to 60 N·m−2). Bahiagrass distribution was unaffected by soil moisture. Dallisgrass density was lower in areas with low volumetric soil water content (less than 27%). Although different from an expected uniform distribution on all six holes, the elevation with the highest Paspalum spp. density varied across holes. Results suggest that it may be possible to disadvantage Paspalum spp. in competitive interactions with desirable species through the alteration of landscape attributes. Substrate selection during construction, aeration, and mowing height may help create a landscape that discourages Paspalum spp. infestation.

Duas novas espécies de Paspalum L. (Poaceae: Paniceae) do Brasil

Two new species of Paspalum L. belonging to the informal group Plicatula are described and illustrated. Paspalum laurentii L., from Rio Grande do Sul, southern Brazil, is mainly recognized by the long trichomes on the margins of the rachis and pedicel. Paspalum longipedicellatum L., from Mato Grosso do Sul, west-central Brazil, is flabellate at the base, with short rhizomes covered by velvety cataphylls, the trichomes yellowish, and it has long spikelet pedicels, specially in the proximal portion of each raceme.

Chromosome numbers and ploidy levels of Paspalum species from subtropical South America (Poaceae)

Somatic chromosome numbers of 131 accessions belonging to 55 Paspalum species from subtropical South America have been determined. All species had x = 10 as a basic chromosome number, except P. almum which had x = 6. Six ploidy levels were found among species with tetraploidy as the most frequent condition. New diploid and octoploid counts were reported. For Paspalum lilloi and P. glabrinode (both 2n = 2x = 20), and for P. ellipticum, P. erianthoides, P. ovale and P. remotum (all 2n = 8x = 80) sporophytic chromosome numbers are presented for the first time. Records that differ from previously reported counts are given for the following species: P. paucifolium (2n = 2x = 20), P. ceresia (2n = 6x = 60), P. conjugatum (2n = 6x = 60), P. alcalinum (2n = 6x = 60) and P. aff. arundinellum (2n + 1 = 5x + 1 = 51). These chromosome data are discussed in light of ploidy-level variation and implications for breeding systems within and among species.

Cytogenetic analyses in Paspalum L. reveal new diploid species and accessions

Chromosome numbers were counted in 126 new accessions of 50 Paspalum species from Brazil, Argentina, Paraguay and Bolivia. The chromosome numbers 2n=12, 20, 24, 30, 40, 50, 60, 80 were confirmed. Chromosome numbers for P. arenarium (2n=20), P. barretoi (2n=20), P. aff. ceresia (2n=40), P. corcovadense (2n=20), P. crispulum (2n=20), P. flaccidum (2n=40), P. nummularium (2n=20), P. scalare (2n=20), P. vescum (2n=20) and P. rectum (2n=20) and a diploid cytotype of P. malacophyllum are reported for the first time. The predominance of tetraploid accessions (43.6%) was confirmed, but an unusually high number of diploid species (44%) and accessions (35.7%) was found. These results open new perspectives for breeding programs, phylogenetic studies, and for research on apomixis control, since diploids of Paspalum are typically sexual.

Sexuality, apomixis, ploidy levels, and genomic relationships among four Paspalum species of the subgenus Anachyris (Poaceae)

The subgenus Anachyris of the genus Paspalum comprises six species, all native to the New World. Cytology, embryology, fertility, and hybridization experiments were examined in four of the six species and different chromosome races. Meiotic chromosome behavior supported autoploid origin for tetraploid P. procurrens and tetraploid P. usterii, and also corroborates autoploidy for P. malacophyllum. Meiosis of the three species was compared with the meiotic chromosome behavior of a tetraploid P. simplex strain acquired by artificial autopolyploidization. Moreover, chromosome associations observed in tetraploid interspecific hybrids of P. simplex× procurrens and P. simplex× usterii, in triploid hybrids of P. simplex× malacophyllum, and in diploid hybrids of P. simplex× malacophyllum, indicate that the four species share the same basic genome, and that the polyploid races are autoploids. Facultative apomixis of the aposporous type is reported for the first time in tetraploid strains of P. procurrens and P. usterii. It is also confirmed for tetraploid P. malacophyllum, a species whose diploid representative is here reported to reproduce sexually, though embryological analyses demonstrated some potential for apospory. Our results suggest that the whole subgenus Anachyris of Paspalum is basically an agamic complex. At least three species: P. simplex, P. procurrens, and P. malacophyllum involve sexual self-incompatible diploid races as well as apomictic polyploid (mainly tetraploid) representatives.

Moths that Vector a Plant Pathogen also Transport Endophytic Fungi and Mycoparasitic Antagonists

Claviceps paspali, a common fungal pathogen of Paspalum grasses, attracts moth vectors by producing sugary exudates in the grass florets it infects. These exudates also support mycoparasitic Fusarium species that may negatively influence C. paspali fitness. We examined the potential for moths on which C. paspali depends to also transmit mycoparasitic Fusarium and fungal endophytes, which inhabit asymptomatic plant tissue and may influence host susceptibility to pathogens. We quantified infections by C. paspali, Fusarium spp., and endophytic fungi associated with Paspalum spp. at focal sites in the southeastern USA and used data from the nuclear internal transcribed spacer (ITS rDNA) to compare communities of plant-associated and moth-borne fungi. ITS sequences of moth-borne fungi were identical to reference sequences of mycoparasitic Fusarium heterosporum and to three distinct endophytic fungi isolated from Paspalum species. Our results demonstrate an unexpected overlap of fungal communities between disparate locations and among plant species and plant tissues, and suggest an unexpected role of moths, which vector a plant pathogen, to transmit other guilds of fungi. In turn, the potential for insects to transmit plant pathogens as well as mycoparasites and endophytic fungi suggests complex interactions underlying a commonly observed grass-pathogen system.

Produção e valor nutritivo de dez gramíneas forrageiras na região Noroeste do Estado de São Paulo

Avaliaram-se a produção e o valor nutritivo da forragem das seguintes espécies: Cynodon spp (Tifton 68, Tifton 78, Tifton 85, Florakirk, Florico e Florona), Paspalum notatum (Tifton 9), Brachiaria brizantha (Marandu) e Panicum maximum (Tanzânia) na região de Araçatuba, Estado de São Paulo. Utilizou-se o delineamento de blocos completos casualizados com parcelas subdivididas e quatro repetições. A produção de massa seca (PMS) acumulada não diferiu entre as espécies forrageiras. Teores mais elevados de PB (125 a 145 g . kg-1) foram observados nos cultivares do gênero Cynodon na estação das águas. Teores mais elevados de FDN foram observados nos capins dos gêneros Cynodon e Paspalum na estação das águas e seca. Os valores de DIVMS variaram de 436 a 699 g . kg-1, sendo o menor valor observado no capim-Tifton 9, na estação das águas, e o maior valor no capim-Tifton 68, na época da seca. A diferença estacional na PMS foi mais pronunciada no capim-Tifton 85, que apresentou somente 9% da produção anual na estação seca

Four New Species of <I>Paspalum</I> (Poaceae, Paniceae) from Central Brazil, and Resurrection of an Old One

Abstract Four new Brazilian species from the genus Paspalum are described and illustrated:P. phaeotrichum, P. vexillarium, P. veredense, and P. clipeum Paspalum phaeotrichum is an annual with no obvious affinity to any known species of Paspalum, although it shares several characters with species of both P. subg. Ceresia and the ‘Bertoniana’ group. Paspalum vexillarium is presumably related to P. ceresia, with which it has been confused. Paspalum veredense shows affinities with both P. ellipticum and P. erianthoides. Paspalum clipeum is probably related to annual species of the ‘Plicatula’ group, although it lacks the dark brown upper florets typical of that group. Moreover, P. spissum, a species currently considered as a synonym under P. carinatum, is recognized on the basis of vegetative morphology, phenology and habitat. Keys to the treated species are provided when relevant, as well as a distribution map. Resumo—Quatro novas especies de Paspalum do Brasil sao descritas e ilustradas:P. phaeotrichum, P. ...

Unusual chromosome numbers in Paspalum L. (Poaceae: Paniceae) from Brazil

Somatic chromosome numbers were determined for 20 new germplasm accessions of Paspalum, belonging to 17 species collected in Brazil. Chromosome number is reported for the first time for P. reduncum (2n = 18), P. cinerascens (2n = 20), P. cordatum (2n = 20), P. filgueirasii (2n = 24), P. ammodes (2n = 36), P. bicilium (2n = 40), P. heterotrichon (2n = 40), and P. burmanii (2n = 48). New cytotypes were confirmed for two germplasm accessions of P. carinatum (2n = 30) and P. trachycoleon (2n = 36), one of P. clavuliferum (2n = 40) and one of P. lanciflorum (2n = 40), indicating variability in these species. The remaining chromosome numbers reported here confirm previous counts. The unexpected chromosome numbers 2n = 18, 24, 36, and 48 in Paspalum species, which are usually shown to be multiples of 10, suggest that much more collection and cytogenetic characterization are necessary to assess the whole chromosomal and genomic multiplicity present in the genus, which seems to be much more diverse than currently thought to be.

Cytogenetic data for Paspalum notatum Flügge accessions

Several species of the genus Paspalum L. are important forages, due their to quality, productivity and tolerance to environmental stresses. Chromosome numbers, meiotic configurations and pollen fertility were evaluated in a collection of 85 accessions of Paspalum notatum Flügge and in seven accessions of Pensacola (P. notatum var saurae). All P. notatum accessions were tetraploid, with 2n = 4x = 40, except one diploid accession, considered as an escape of Pensacola. All Pensacola plants had 2n = 2x = 20. Meiotic configurations at diakinesis and metaphase I varied among tetraploid accessions, from plants with only bivalents to plants with high frequency of quadrivalents. Pollen fertility varied from 82.5 to 95.9% among diploid accessions and from 72.4 to 97.9% among the tetraploids. Due to the apomictic mode of reproduction of tetraploid P. notatum, meiotic irregularities can be maintained by plants without harming their propagation. At the same time, pollen fertility should be high enough to assure endosperm development, since the species is pseudogamous. Wild diploid P. notatum populations, apart from the endemic P. notatum var saurae, are very rare. From a plant breeding point of view, all the examined tetraploid accessions are potentially male-fertile and could be used as males in crosses.

Studies in the genus Paspalum (paniceae, poaceae) in Europe — 1. Paspalum distichum subsp. Paucispicatum, an overlooked taxon in France

Verloove, F. & Reynders, M.: Studies in the genus Paspalum (Paniceae, Poaceae) in Europe — 1. Paspalum distichum subsp. paucispicatum, an overlooked taxon in France. — Willdenowia 37: 199–204. — ISSN 0511-9618; © 2007 BGBM Berlin-Dahlem. doi:10.3372/wi.37.37109 (available via http://dx.doi.org/)The present paper reports about the naturalization of the Mexican grass species Paspalum paucispicatum in the Loire valley in France. The species has long been confused with and erroneously referred to as P. dilatatum, P. distichum, P. longipilum or P. pubiflorum. A revision of several relevant herbaria enabled us to reconstruct the species' invasion history in France. Main diacritic features are given and an identification key for Paspalum in France is presented. P. paucispicatum, of a debated taxonomic rank in its area of origin but clearly delimited in France, is probably better treated as a subspecies of P. distichum; hence the new combination at subspecific level is validated.

Genome rearrangements derived from autopolyploidization in Paspalum sp.

Rapid sequence rearrangements along with alterations in cytosine-directed methylation patterns follow allopolyploid formation in several plant species. The occurrence of similar changes is yet to be examined in detail during the generation of autopolyploids. The objective of this work was to investigate the presence of nascent variation in genome sequence after autopolyploidization in two Paspalum species. The increments of ploidy level were produced either by hybridization involving unreduced gametes or colchicine treatment. Genetic modifications affected 15–23% and 9.55% of the genomic loci in Paspalum rufum and Paspalum notatum, respectively. In all cases the frequency of band loss from the progenitors was significantly higher than that of novel band gain. In random amplified polymorphic DNA (RAPD) experiments the majority of polymorphisms were detected by particular sets of primers, suggesting that repetitive domains were preferentially targeted. Several P. notatum polymorphic fragments were cloned, sequenced and used as probes in genomic hybridization analyses. Some of them corresponded to interspersed middle-repetitive sequences with unknown function. Methylation-sensitive genomic hybridization showed that sequence modifications occurred invariably in cytosine-methylated regions, which remained methylated after polyploidization.

Characterization of Seashore Paspalum (Paspalum vaginatum Swartz) Germplasm by Transferred SSRs from Wheat, Maize and Sorghum

One hundred and thirty SSR markers from wheat, maize and sorghum were screened for the transferability to Paspalum. The transfer rate was 67.5, 49.0 and 66.8% respectively. This would be a very efficient approach for DNA marker development for species which are not well studied molecularly. The polymorphism level for transferred SSR markers was 51.5% within species (Paspalum vaginatum) and 87.1% among Paspalum species. The high level of polymorphism is directly related to the high degree of heterozygosity maintained by its way of reproduction, i.e. self-incompatibility. Forty transferred polymorphic SSR markers were selected and used for characterization and evaluation of seventy-three Paspalum accessions. In total, 209 polymorphic bands were detected from these 40 SSR markers, with an average of five polymorphic bands per marker. The Paspalum accessions clustered into three major groups. Two very similar dendrograms can be generated from either 109 or 209 polymorphic bands. This led us to determine that 18 of the transferred SSR markers were sufficient for genetically differentiating the investigated germplasm accessions. The number of SSR markers required for germplasm characterization and evaluation is discussed. This is the first report of the transfer of SSR markers from major field crops to newly emerged environmental turfgrasses.

A Preliminary Approach to the Phylogeny of the Genus Paspalum (Poaceae)

The present work intends to clarify the phylogenetic relationships among the species of Paspalum L. belonging to the informal groups Notata/Linearia and Dilatata, and to raise some preliminary hypotheses on the phylogeny of the genus as a whole. A combined dataset including morphological and molecular characters was used to analyze 28 species of Paspalum plus some representatives of related genera of the tribe Paniceae. Analyses were performed using both parsimony and maximum likelihood. The monophyly of Paspalum is not supported nor contradicted. The circumscription of informal groups of Paspalum is discussed, as well as the cladistic treatment of allopolyploid taxa, especially those comprising the Dilatata group. The relationships of members of the Dilatata with their putative progenitors is confirmed, but the monophyly of the group as a whole is not. A close relationship between P. dilatatum Poir. and P. lividum Trin. ex Schltdl. is shown. Our analysis is consistent with the monophyly of a group comprising Notata+Linearia, with a monophyletic Notata group nested within it. The delimitation of the core Notata is proposed by including P. conduplicatum Canto-Dorow, Valls and Longhi-Wagner, P. notatum Flüggé, P. minus E. Fourn., P. pumilum Nees and P. subciliatum Chase.

Estructura, dimensiones y producción de propágulos sexuales de malezas del trópico húmedo.

The objectives of this study were to determine the average dimensions, to describe the external structure of seeds, fruits or spikelets and to estimate the number produced per plant and per gram of twelve weed species. Propagules sketchs were elaborated. The number of seeds per plant varied from 1290 in Asclepias curassavica to 195.008 in Ludwigia sp within the dycotyledoneae. The second specie with the highest average number of seeds per plant was Sida rhombifolia (7962) followed by Ipomoea sp.(2876). Hyptis capitata showed a higher number of heads per plant (341) than Bidens pilosa (106). Mimosa pudica produced an average of 3.3 seeds per fruit. In relation to Poaceae species Paspalum conjugatum y P. Virgatum produced a larger number of spikelets per floral branch (381 y 1185 respectively) than Ischaemum indicum (81) and Rottboellia cochinchinensis (14). Anemocory, hydrocory and zoocory are mentioned as mechanisms contributing to dispersal of these species.