Chloroplast-DNA restriction site analysis in the genus Bromus (Poaceae)

Chloroplast DNA (cpDNA) restriction site variation was examined in 32 species, representing five subgenera, of Bromus (Poaceae). Thirty-seven phylogenetically informative restriction sites were detected. Cladistic analysis of the restriction site data produced a single most-parsimonious tree of 50 steps. The cladogram indicated two major clades within the genus. One clade included B. trinii of subgenus Neobromus and species of subgenus Ceratochloa. The other was composed of subgenera Festucaria, Stenobromus, and Bromus. Within the second clade, species of subgenus Festucaria appeared in three lineages. The second clade also contained an assemblage of species belonging to subgenera Stenobromus and Bromus in a separate lineage. There was very little resolution of relationships in this assemblage since several species appeared individually in separate lineages. The cpDNA phylogenetic hypothesis did not separate species of subgenera Stenobromus and Bromus into well-defined clades as circumscribed by morphology and cytogenetics. The cpDNA tree is in agreement with the phylogenetic scheme based on traditional data in that: 1) subgenera Neobromus and Ceratochloa were the first to diverge, while Bromus and Stenobromus diverged later; 2) within the genus Bromus species with small chromosomes are ancestral; and 3) subgenera Bromus and Stenobromus probably originated from similar ancestors as Festucaria. The tree based on cpDNA data does not support that: 1) subgenera Neobromus and Ceratochloa did not have a common origin; 2) subgenus Festucaria is monophyletic; and 3) subgenera Stenobromus and Bromus are distinct entities. The mean nucleotide sequence divergence values between pairs of subgenera ranged from p = 0.0 to 0.9. These values suggest that cpDNA evolution in Bromus is slow.     

Bromus salangensis sp. nov. (Gramineae), a perennial brome grass from Afghanistan

During work on a new synopsis on the genus Bromus L. for the ‘Flora Iranica’ region, an Afghan perennial brome grass previously identified as the Caucasian B. biebersteinii Roem. & Schult., was found to be a new species. It is described here as B. salangensis sp. nov. This discovery rejected the record of B. biebersteinii for Afghanistan.     

Penicillium yugoslavicum sp. nov., isolated from sunflower seeds (Helianthus annuus L.) in Yugoslavia

A new species of Penicillium Link ex Fries is described and illustrated. It was recovered from sunflower seed (Helianthus annuus L.) in Yugoslavia. It clearly differs from all species of the genus described so far and is, therefore, proposed as a new taxon: Penicillium yugoslavicum sp. nov.     

PARTITIONING OF SPACE AND WATER BETWEEN TWO CALIFORNIA ANNUAL GRASSLAND SPECIES

We examined the potential for resource partitioning between two sympatric species with similar phenologies but different rooting morphologies. The annual grass, Bromus diandrus (Roth.), and annual forb, Erodium botrys (Cav.), were grown in monoculture and 50:50 mixed stands at each of three densities (10, 30, 100 seeds/dm²) in a randomized complete block design. Plants were grown outdoors, in 1-m-tall 15-cm-diameter containers. Comparison of seed number produced per plant in mixture and in monoculture indicated greater effects of intraspecific than interspecific competition for Erodium. Such differences were not detected for Bromus seed number, and the converse relationship was suggested from Bromus shoot biomass. Final size inequality of Bromus populations tended to be higher in monoculture than in mixture; no patterns in Erodium size distribution over time or stand composition were evident. Bromus roots were primarily in the upper 10 cm of soil, while Erodium roots were bimodally distributed in the surface and deep soil. Roots of the two species in mixture showed a distribution pattern intermediate between those of the two monocultures. The rate of soil water depletion was higher in the high density than in the low density stands, but was not dependent on stand composition at a given density. Partitioning of belowground space and water resources by groups of species with different root morphologies may partially explain the high species diversity in the grassland.     

Effects of perennial neighbors and nitrogen pulses on growth and nitrogen uptake by Bromus tectorum

An experiment was conducted to determine if growth and biomass responsesof the annual grass Bromus tectorum are affected by themagnitude and timing of nitrogen (N) pulses and if these responses areinfluenced by different perennial neighbor species. Nitrogen(NH₄:NO₃) was applied in three pulse treatments of varyinginterpulse length (3-d, 9-d, or 21-d between N additions). The total amount of Nadded was the same among treatments; hence, both the frequency and magnitude ofN pulses varied (i.e., the longer the interpulse period,the greater the amount of N added for a single pulse).Bromus showed little response to the different N-pulsetreatments. The only characteristic that varied among pulse treatments wasspecific leaf area (SLA), which was significantly greater whenBromus was grown under the 21-d N pulse than when grownunder the 3-d or 9-d N pulses. Bromus height, leaf andtiller numbers, leaf area and aboveground biomass were not affected by theN-pulse treatments nor were tissue-N contents and concentrations. However,Bromus production and tissue-N were significantly differentwhen Bromus was grown with different perennial neighborspecies. Tiller production, aboveground biomass, and seed numbers ofBromus were lowest when the perennial neighbor was thetussock grass Agropyron desertorum, intermediate when theneighbor was the evergreen shrub Artemisia tridentata, andgreatest when the neighbor was the deciduous shrub Chrysothamnusnauseosus. N contents of Bromus leaves were alsolowest when the neighbor was Agropyron. In contrast, root Nuptake capacities were greatest for Agropyron-Bromus rootmixes and lowest for Chrysothamnus-Bromus root mixes. Theseresults suggest that perennial neighbors affect growth, seed production, and Nuptake of Bromus to a greater extent than the timing andmagnitude of N pulses.     

The effect of rodent seed predation on four species of California annual grasses

Summary The effect of seed predation by Microtus californicus and Mus musculus on plant numbers of four species of California annual grasses was investigated for one year period on a grassland near Davis, California. In winter, mice utilized dead star thistle plants for cover when grasses in open areas were short, but moved into open areas when grass grew tall in spring.Using exclosures and plots sown with known quantities of seed, it was estimated that a mouse population (approximate density 120/acre) consumed 75% of Avena fatua seed, 44% of Hordeum leporinum seed, and 37% of Bromus diandrus seed. Mice showed a strong preference for Avena seed.Plant numbers of Avena and Hordeum were reduced by 62% and 30%, respectively. Hordeum, Lolium, and to a lesser extent, Bromus responded to a competitive release from Avena by increases in plant size and reproductive output. In addition, seed predation markedly increased seed to adult plant survivorship of Avena, Hordeum, and Bromus.Vertebrate seed predation is discussed as a potentially important factor in the yearly patterns of plant population regulation in California annual grasslands.     

REPRODUCTIVE BIOLOGY OF SEVERAL BROMEGRASSES (BROMUS): BREEDING SYSTEM,PATTERN OF FRUIT MATURATION,AND SEED SET

Five species of Bromus were tested for self-fertility when bagged. Bromus inermis was self-incompatible. Bromus tectorum, B. kalmii, B. ciliatus, and B. latiglumis were capable of self-fertilization. Further evidence from flowering behavior suggested that B. tectorum almost always self-pollinated and that the remaining self-fertile species sometimes outcrossed. Florets in different positions on a spikelet varied in the proportion that set seed. Open-pollinated B. inermis plants had lower seed set than the self-fertile species, in agreement with the pattern in a variety of hermaphroditic plants.     

Variation in the establishment of a non-native annual grass influences competitive interactions with Mojave Desert perennials

Competition between native and non-native species can change the composition and structure of plant communities, but in deserts, the highly variable timing of resource availability also influences non-native plant establishment, thus modulating their impacts on native species. In a field experiment, we varied densities of the non-native annual grass Bromus madritensis ssp. rubens around individuals of three native Mojave Desert perennials—Larrea tridentata, Achnatherum hymenoides, and Pleuraphis rigida—in either winter or spring. For comparison, additional plots were prepared for the same perennial species and seasons, but with a mixture of native annual species as neighbors. Growth of perennials declined when Bromus was established in winter because Bromus stands had 2–3 months of growth and high water use before perennial growth began. However, water potentials for the perennials were not significantly reduced, suggesting that direct competition for water may not be the major mechanism driving reduced perennial growth. The impact of Bromus on Larrea was lower than for the two perennial grasses, likely because Larrea maintains low growth rates throughout the year, even after Bromus has completed its life cycle. This result contrasts with the perennial grasses, whose phenology completely overlaps with (Achnatherum) or closely follows (Pleuraphis) that of Bromus. In comparison, Bromus plants established in spring were smaller than those established in winter and thus did not effectively reduce growth of the perennials. Growth of perennials with mixed annuals as neighbors also did not differ from those with Bromus neighbors of equivalent biomass, but stands of these native annuals did not achieve the high biomass of Bromus stands that were necessary to reduce perennial growth. Seed dormancy and narrow requirements for seedling survivorship of native annuals produce densities and biomass lower than those achieved by Bromus; thus, impacts of native Mojave Desert annuals on perennials are expected to be lower than those of Bromus.     

Molecular evidence for host-adapted races of the fungal endophyte Epichloë bromicola after presumed host shifts

Abstract.— Host shifts of plant‐feeding insects and parasites promote adaptational changes that may result in the formation of host races, an assumed intermediate stage in sympatric speciation. Here, we report on genetically differentiated and host‐adapted races of the fungal endophyte Epichloë bromicola, which presumably emerged after a shift from the grass Bromus erectus to other Bromus hosts. Fungi of the genus Epichloë (Ascomycota) and related anamorphs of Neotyphodium are widespread endophytes of cool‐season grasses. Sexually reproducing strains sterilize the host by formation of external fruiting structures (stromata), whereas asexual strains are asymptomatic and transmitted via seeds. In E. bromicola, strains infecting B. erectus are sexual, and strains from two woodland species, B. benekenii and B. ramosus, are asexual and seed transmitted. Analyses of amplified fragment length polymorphism fingerprinting and of intron sequences of the tub2 and tef1 genes of 26 isolates from the three Bromus hosts collected at natural sites in Switzerland and nearby France demonstrated that isolates are genetically differentiated according to their host, indicating that E. bromicola does not form a single, randomly mating population. Phylogenetic analyses of sequence data did not unambiguously resolve the exact origin of asexual E. bromicola strains, but it is likely they arose from within sexual populations on B. erectus. Incongruence of trees derived from different genes may have resulted from recombination at some time in the recent history of host strains. Reciprocal inoculations of host plant seedlings showed that asexual isolates from B. benekenii and B. ramosus were incapable of infecting B. erectus, whereas the sexual isolates from B. erectus retained the assumed ancestral trait of broad compatibility with Bromus host seedlings. Because all isolates were interfertile in experimental crosses, asexual strains may not be considered independent biological species. We suggest that isolates infecting B. benekenii and B. ramosus represent long‐standing host races or incipient species that emerged after host shifts and that may evolve through host‐mediated reproductive isolation toward independent species.     

Evolvability of between‐year seed dormancy in populations along an aridity gradient

Under global climate change, adaptation to new conditions is crucial for plant species persistence. This requires the ability to evolve in traits that are correlated with changing climatic variables. We studied between‐year seed dormancy, which correlates with environmental variability, and tested for clinal trends in its evolvability along an aridity gradient in Israel. We conducted a germination experiment under five irrigation levels with two dryland winter annuals (Biscutella didyma, Bromus fasciculatus) from four sites along the gradient. Species differed in means and evolvability of dormancy. Biscutella had high dormancy, which significantly increased with aridity but decreased with higher irrigation. In Bromus, dormancy was low, similar among populations, and only marginally affected by irrigation. Evolvability in Biscutella was high and varied among populations, without a clinal trend along the gradient. Conversely, in Bromus, trait evolvability was low and declined with increasing aridity. We argue that changes in evolvability along climatic gradients depend on the relative intensity of stabilizing selection. This may be high in Bromus and not only depends on environmental stress, but also on variability. Our findings point to the importance of measuring evolvability of climate‐related traits across different natural and artificial environments and for many coexisting species. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 924–934.     

Competitive outcomes between two exotic invaders are modified by direct and indirect effects of a native conifer

When organisms interact in multi‐species groups, the direct effects of facilitation and competition can be modified by indirect interactions. We explored multispecies interactions among the native Pinus ponderosa, the invasive annual grass Bromus tectorum, and the invasive forb Centaurea stoebe in intermountain prairie of the northern Rocky Mountains. Centaurea is much less abundant under Pinus than in surrounding open grassland and Bromus is more abundant under Pinus. We found that the more fertile soil associated with Pinus facilitated both invasive species and did not alter competitive outcomes. Pinus litter and litter leachate inhibited both species, but litter also shifted competitive outcomes in favor of Bromus and against Centaurea. The effects of Pinus litter leachate were also strong and leachate eliminated the competitive effect of Centaurea on Bromus while not changing the competitive effect of Bromus on Centaurea. There are many other ways that Pinus may affect understory composition, but by altering the competitive playing field through leaf litter Pinus appears to indirectly facilitate Bromus by more strongly inhibiting Centaurea chemically, an unusual case of a native inhibiting an invader through allelopathy. Our results also provide an unexpected and novel perspective on indirect interactions among competitors, but not through intransitive competitive relationships. Instead, one species (Pinus) strongly ‘modified’ interactions between two other species in addition to disproportionately affecting one species more than another.     

Common Antigen(s) in Cotton to Fusarium oxysporum f. sp. vasinfectum

Antigen-antibody reactions in agar gel, as demonstrated by the double diffusion technique, between cotton seed globulins and the antisera specific to each of the tested Fusarium oxysporum f. sp. vasinfectum isolates as well as the antiserum of F. moniliforme revealed that all the tested antisera of F. oxysporum f. sp. vasinfectum reacted with seed globulins except the Menoufi cultivar globulins. No precipitin lines were detected in the reaction between the antigenof the cotton cultivar Acala SJ2 versus the antiserum of P10 isolate. The 5 cultivars behaved differently with each fungal antiserum to the extent that they could be distinguished accordingly. When the seed globulins of the susceptible cultivars (Giza 74, and Bahtim 110) reacted with antiserum of the tested F. oxysporum f. sp. vasinfectum isolates, more precipitin lines were formed than the resistant cultivars. On the other hand, no obvious reaction was detected in case of F. moniliforme antiserum.     

Notes and lectotypification of names based on Brazilian collections of Prince Maximilian of Wied

In the course of reconstructing the Brazilian herbarium of Prince Maximilian of Wied, several species were found in the literature which need either correction or clarification. Problems include priority considerations, authority of species names, conflicting typifications and other errors. This paper reports 12 currently accepted species collected by Prince Maximilian in Brazil, commenting on their taxonomic status and nomenclature. Included are type specimens of Andromeda ambigua Schrad. (lecto and isolectotypes; = Agarista revoluta (Spreng.) Hook. f. ex Nied.), Andromeda crassifolia Nees (lecto and isolectotypes; = Agarista revoluta), Aphelandra marginata Nees & Mart. (lecto and isolectotypes), Aphelandra maximiliana (Nees) Benth. (lecto and isolectotypes), Ceiba ventricosa (Nees & Mart.) Ravenna (lectotype), Cinnamodendron axillare (Nees) Endl. ex Walp. (lecto and isolectotypes), Croton gnaphaloides Schrad. (lecto and isolectotype), C. klaenzei Müll. Arg. (holotype), Geissomeria nitida (Nees & Mart.) Nees & Mart. (lecto and isolectotypes), Nectandra squarrosa Nees var. pyrifolia Nees (lecto and isolectotypes; = Ocotea squarrosa (Nees) Mez), Ocotea squarrosa (lecto and isolectotypes), Pavonia semiserrata (Schrad.) Steud. (lecto and isolectotypes), Stenandrium serpens Nees (lecto and isolectotypes), Zollernia falcata Wied-Neuw. & Nees (lecto and isolectotypes; = Z. glabra (Spreng.) Yakovlev) and Z. splendens Wied-Neuw. & Nees (lectotype; = Z. glabra). Additionally, a new name, Aphelandra verrugensis P. L. R. Moraes, is proposed to replace Synandra amoena Schrad., which is the oldest name of the taxon currently known as Aphelandra ignea Nees.     

Study of the Characters of the Genus Malcolmia R. Br. in Aiton Part 3 With 8 figures and 1 table

Malcolmia meyeri Boiss. subsumes according to the anatomical structure of the dissepiment under the genus Maresia Pomel. The species represents an evolutional link from which ancestors there proceeds on one hand the genus Maresia Pomel with other nine species, on the other hand a shorter evolutional line with two species subsumed so far under the genus Malcolmia R. Br. in Aiton: Malcolmia crenulata (DC.) Boiss., Malcolmia exacoides (DC.) Spreng.     

The yeast genus Yarrowia gen. nov.

The ascigerous teleomorph of Candida lipolytica (Harrison) Diddens et Lodder, previously classified as Endomycopsis lipolytica Wickerham et al. and as Saccharomycopsis lipolytica (Wickerham et al.) Yarrow, has been assigned to the new genus Yarrowia. Yarrowia lipolytica (Wickerham et al.) comb. nov. is the type species for the genus.The remaining species of Saccharomycopsis are revised.     

Effects of Nutrient Manipulations and Grass Removal on Cover,Species Composition,and Invasibility of a Novel Grassland in Colorado

Cover and richness of a 5‐year revegetation effort were studied with ,respect to small‐scale disturbance and nutrient manipulations. The site, originally a relict tallgrass prairie mined for gravel, was replanted to native grasses using a seed mixture of tall‐, mixed‐, and short‐grass species. Following one wet and three relatively dry years, a community emerged, dominated by species common in saline soils not found along the Colorado Front Range. A single species, Alkali sacaton (Sporobolus airoides), composed nearly 50% of relative vegetation cover in control plots exhibiting a negative relationship between cover and richness. Seeded species composed approximately 92% of vegetation cover. The remaining 8% was composed of weeds from nearby areas, seed bank survivors, or mix contaminants. Three years of soil nutrient amendments, which lowered plant‐available nitrogen and phosphorus, significantly increased relative cover of seeded species to 97.5%. Fertilizer additions of phosphate enhanced abundance of introduced annual grasses (Bromus spp.) but did not significantly alter cover in control plots. Unmanipulated 4‐m² plots contained an average of 4.7 planted species and 3.9 nonplanted species during the 5‐year period, whereas plots that received grass herbicide averaged 5.4 nonplanted species. Species richness ranged from an average 6.9 species in low‐nutrient, undisturbed plots to 10.9 species in the relatively high‐nutrient, disturbed plots. The use of stockpiled soils, applied sparingly, in conjunction with a native seed mix containing species uncommon to the preexisting community generated a species‐depauperate, novel plant community that appears resistant to invasion by ruderal species.     

Dendromyza hiepkoana sp. nov. from Irian Jaya and D. staufferi sp. nov. from Papua New Guinea (Amphorogynaceae)

The genus Dendromyza (Amphorogynaceae) comprises approximately 21 species with a distribution from the Malay Archipelago to southern Australia. Two new hemiparasitic species in this genus: D. hiepkoana from Irian Jaya and D. staufferi from Papua New Guinea are here described, illustrated and compared. Dendromyza hiepkoiana is similar to members of the genus Phacellaria (Benth.) where the leaves are very small and bract‐like, but differs in its separate stigmas and chambered fruits that possess a crown of fibers on the endocarp. Dendromyza staufferi is allied to D. reinwardtiana (Bl. ex Korth.) Danser but differs from this species by broader, ovate rather than narrower, spathulate leaves and sessile inflorescences. Dendromyza staufferi also has an ovoid rather than elliptical endocarp and the crown of fibres at the apex of the endocarp are pilose. Due to their hemiparasitic nature and aerial habitat, species of Dendromyza are generally considered to be vulnerable in terms of conservation status. Based on the information available to us, however, the species described here are categorised as locally common or near threatened.     

A tribute to Dr Royce E. Longton

Abstract

The relationships within the Bryaceae, with emphasis on the genus Bryum, were studied based on morphological and anatomical characters and using cladistic methods. The analysis was performed with thirty-six species representing the different parts of the family, and with Funaria hygrometrica Hedw., Mnium hornum (Dicks.) Lindb., and Tayloria lingulata Hedw. as outgroups. The Bryaceae, and the subfamilies Bryoideae, Mielichhoferioideae, and Pohlioideae, as defined by several earlier authors appear to be paraphyletic. The genus Bryum seems to be paraphyletic, because Leptobryum pyriforme (Hedw.) Wils., Osculatia columbica De Not., and Rhodobryum giganteum (Schwaegr.) Paris, appear as ingroups within this genus when the tree is rooted with Funaria. Mnium hornum came out as the sister taxon of a clade including Pohlia cruda (Hedw.) Lindb. and P. longicollis (Hedw.) Lindb., whereas P. drummondii (Müll. Hall.) A.L. Andrews, appears not to be closely related to the other two Pohlia species studied here, making this genus paraphyletic. Mielichhoferia mielichhoferiana (Funck.) Loeske, appears as the sister taxon of Schizymenium bryoides Harv., suggesting that both these genera are paraphyletic. Overall, the stabilities of the clades are low and it is suggested that combined analyses of morphological, anatomical, and molecular data are needed to get better resolved and more stable trees.     

Two new species of the genus <Emphasis Type="Italic">Quadroppia</Emphasis> (Acari: Oribatida: Quadroppiidae) from Turkey

Two new species of the genus Quadroppia Jacot, 1939, Quadroppia (Coronoquadroppia) squarrosa sp. n. and Quadroppia (Quadroppia) foveolata sp. n. are described and illustrated from Turkey. They were collected from soil and litter under pear trees (Pyrus communis) and moss on rock, respectively.