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1.
Stelis duckei, of the Crocodeilanthe group, is described from the state of Ceará, Brazil. The new species is morphologically similar to S. speciosa, but can be distinguished by its longer ramicauls, wider leaves, and obtuse lip with a ridge-like callus at the base. The new combination Stelis speciosa is also provided here.  相似文献   

2.
Gustavia johnclarkii and G. hubbardiorum, two new species from the wet forests of northwestern and Amazonian Ecuador, are described and illustrated. In addition, the two subspecies of both G. speciosa and G. macarenensis are elevated to species, and the new combination Gustavia paucisperma is provided. A justification for these changes is presented.  相似文献   

3.

Key message

Outplanted Polylepis australis seedling growth, survival and mycorrhizal response were not influenced by inoculation with soil from different vegetation types. Seedling inoculation would not be essential for reforestation practices.

Abstract

Polylepis forests are one of the most endangered high mountain ecosystems of South America and reforestation with native Polylepis species has been recommended. To determine whether native soil inoculation could help in reforestation success, a field trial was set up to evaluate the response of outplanted P. australis seedlings to the inoculation with soils from three vegetation types (a grassland, a mature forest and a degraded forest) and a sterile soil, used as control. We evaluated seedlings performance: growth and survival for 18 months, root/shoot ratio, phosphorous content and arbuscular mycorrhizal fungal (AMF) colonization. To interpret performance patterns we evaluated the colonization potential of the three inoculum soils and the changes of the AMF community composition of the seedlings rhizosphere in relation to inoculation treatment and season. Our main results showed no significant differences in seedlings survival and growth between treatments. The colonization potential of grassland and degraded forest soils was ~25 times greater than mature forest soil and specific spore density of some morphospecies varied with season. However, AMF spore community of seedlings rhizosphere became homogenized after outplanting and was similar between treatments after 12 months. Therefore, we conclude that soil inoculation is not essential for outplanted P. australis survival and increase in height, and thus all the tested soils could be used as inocula, including grassland soils which in practice are the easiest to collect.  相似文献   

4.

Key message

The study determined the tolerance of Aloe vera to high temperature, focusing on the expression of hsp70 , hsp100 and ubiquitin genes. These were highly expressed in plants acclimated at 35 °C prior to a heat shock of 45 °C.

Abstract

Aloe barbadensis Miller (Aloe vera), a CAM plant, was introduced into Chile in the semiarid IV and III Regions, which has summer diurnal temperature fluctuations of 25 to 40 °C and annual precipitation of 40 mm (dry years) to 170 mm (rainy years). The aim of this study was to investigate how Aloe vera responds to water and heat stress, focusing on the expression of heat shock genes (hsp70, hsp100) and ubiquitin, which not studied before in Aloe vera. The LT50 of Aloe vera was determined as 53.2 °C. To study gene expression by semi-quantitative RT-PCR, primers were designed against conserved regions of these genes. Sequencing the cDNA fragments for hsp70 and ubiquitin showed a high identity, over 95 %, with the genes from cereals. The protein sequence of hsp70 deduced from the sequence of the cDNA encloses partial domains for binding ATP and the substrate. The protein sequence of ubiquitin deduced from the cDNA encloses a domain for interaction with the enzymes E2, UCH and CUE. The expression increased with temperature and water deficit. Hsp70 expression at 40–45 °C increased 50 % over the controls, while the expression increased by 150 % over the controls under a water deficit of 50 % FC. The expression of all three genes was also studied under 2 h of acclimation at 35 or 40 °C prior to a heat shock at 45 °C. Under these conditions, the plants showed greater expression of all genes than when they were subjected to direct heat stress.  相似文献   

5.
George M. Diggs 《Brittonia》1986,38(4):344-351
Comarostaphylis spinulosa subsp.glandulifera is described from the mountains of Oaxaca and Puebla, Mexico. Four new combinations inComarostaphylis are also made:C. arbutoides subsp.costaricensis, C. discolor subsp.rupestris, C. polifolia subsp.minor, andC. spinulosa.Arctostaphylos glabrata, A. rupestris, andA. spinulosa are lectotypified and the status ofC. polifolia is discussed.  相似文献   

6.
The Neotropical genus Coussarea is species-rich and widely distributed but not well known. Seven new species are described here, documented mainly by recent botanical exploration: C. acrensis is found in western Brazil, C. boliviensis and C. mexiae in the mountains of northwestern Bolivia, and C. camposiana, C. maranonensis, C. pseudopilosula, and C. vasqueziana in Peru. The new combination C. insolita is based on Rudgea insolita from Colombia.  相似文献   

7.
One new name is proposed and eleven new combinations are made inCampomanesia andPimenta. Lectotypes are selected forC. eugenioides var.desertorum, C. phaea, andP. racemosa var.hispaniolensis, var.ouza, and var.terebinthina.  相似文献   

8.
William R. Buck 《Brittonia》1983,35(4):327-330
Three new tropical American species ofSematophyllum are described with relatively broad leaves and short upper leaf cells:S. cubense, S. cataractae, andS. oedophysidium. The Central AmericaS. apaloblastum andS. barnesii are new combinations.Sematophyllum galipense, S. amnigenum, andS. cochleatum are briefly discussed.  相似文献   

9.
Daryl L. Koutnik 《Brittonia》1985,37(4):397-399
Chamaesyce is accepted at the genus level for the Hawaiian taxa. The following new combinations are made:C. celastroides var.laehiensis, C. celastroides var.tomentella, C. rockii var.grandifolia, C. skottsbergii var.vaccinioides, andC. sparsiflora.  相似文献   

10.
11.
A series of naphthoquinone-benzothiazole conjugates were synthesized as algicides, and their efficacies against harmful algal blooming species, such as Chattonella marina, Heterosigma akashiwo and Cochlodinium polykrikoides, were examined. The introduction of substituted benzothiazole at the C2 position of 1,4-naphthoquinone (compounds 19) resulted in higher algicidal activity against C. polykrikoides than the C6 conjugates (compounds 1020). On the other hand, of the C6 conjugates, compounds 11 and 12 exhibited better algicidal activity against H. akashiwo, C. marina, and C. polykrikoides than the C2 conjugates. Further structure-activity analysis indicated that a replacement of the methoxy groups with hydroxyl groups (compounds 2126) decreased the algicidal activity significantly. Among the various synthetic naphthoquinonebezothiazole conjugates tested, compound 12 was found to affect the most significant decrease in the level of C. polykrikoides growth, with an IC50 of 0.19 μM. Compound 11 was found to be the most potent inhibitor against H. akashiwo and C. polykrikoides, with IC50 values of 0.32 and 0.12 μM, respectively. Overall, these results highlight a possible method for controlling and inhibiting red tide forming algae using NQ derivatives.  相似文献   

12.

Key message

QTL mapping in F 2 population [ V. luteola × V. marina subsp. oblonga ] revealed that the salt tolerance in V. marina subsp. oblonga is controlled by a single major QTL.

Abstract

The habitats of beach cowpea (Vigna marina) are sandy beaches in tropical and subtropical regions. As a species that grows closest to the sea, it has potential to be a gene source for breeding salt-tolerant crops. We reported here for the first time, quantitative trait loci (QTLs) mapping for salt tolerance in V. marina. A genetic linkage map was constructed from an F2 population of 120 plants derived from an interspecific cross between V. luteola and V. marina subsp. oblonga. The map comprised 150 SSR markers. The markers were clustered into 11 linkage groups spanning 777.6 cM in length with a mean distance between the adjacent markers of 5.59 cM. The F2:3 population was evaluated for salt tolerance under hydroponic conditions at the seedling and developmental stages. Segregation analysis indicated that salt tolerance in V. marina is controlled by a few genes. Multiple interval mapping consistently identified one major QTL which can explain about 50 % of phenotypic variance. The flanking markers may facilitate transfer of the salt tolerance allele from V. marina subsp. oblonga into related Vigna crops. The QTL for domestication-related traits from V. marina are also discussed.  相似文献   

13.
The following new taxa are recognized inArceuthobium: subgeneraArceuthobium andVaginata; sectionsVaginata, Campylopoda, andMinuta; seriesCampylopoda,Rubra, andStricta; speciesA. apachecum,A. californicum,A. guatemalense,A. hondurense, andA. pini; new formae spécialesA. abietinum f. sp.concoloris,A. abietinum f. sp.magnificae. New combinations:A. abietinum (Engelm.) Hawksworth & Wiens, andA. microcarpum (Engelm.) Hawksworth & Wiens.  相似文献   

14.
Hibiscus sectionFurcaria includes more than 60 known taxa. The section has a mainly tropical distribution, but a few species penetrate subtropical and temperate regions. Seven taxa are recognized that occur in the islands of the Pacific Basin, five of which are endemic.Hibiscus fijiensis is described and a new combination,Hibiscus brackenridgei subsp.molokaianus, is proposed.  相似文献   

15.
Steven R. Hill 《Brittonia》1980,32(4):464-483
The genusMalvastrum A. Gray is interpreted to include 22 taxa in 14 species. Seven taxa are here described as new, namely:M. americanum var.stellatum,M. tomentosum subsp.pautense,M. bicuspidatum subsp.campanulatum,M. bicuspidatum subsp.oaxacanum, M. bicuspidatum subsp.tumidum var.tumidum, M. bicuspidatum subsp.tumidum var.glabrum, andM. coromandelianum subsp.fryxellii. In addition, two new combinations are proposed, namely:M. tomentosum andM. coromandelianum subsp.capitato-spicatum.  相似文献   

16.
Local vibrational modes can be directly derived from normal vibrational modes using the method of Konkoli and Cremer (Int J Quant Chem 67:29, 1998). This implies the calculation of the harmonic force constant matrix F q (expressed in internal coordinates q) from the corresponding Cartesian force constant matrix f x with the help of the transformation matrix U?=?WB ?(BWB ?)?1 (B: Wilson’s B-matrix). It is proven that the local vibrational modes are independent of the choice of the matrix W. However, the choice W?=?M ?1 (M: mass matrix) has numerical advantages with regard to the choice W?=?I (I: identity matrix), where the latter is frequently used in spectroscopy. The local vibrational modes can be related to the normal vibrational modes in the form of an adiabatic connection scheme (ACS) after rewriting the Wilson equation with the help of the compliance matrix. The ACSs of benzene and naphthalene based on experimental vibrational frequencies are discussed as nontrivial examples. It is demonstrated that the local-mode stretching force constants provide a quantitative measure for the C–H and C–C bond strength.  相似文献   

17.
18.
Roy E. Halling 《Brittonia》1996,48(4):487-494
Five species of Gymnopus section Levipedes are reported for tropical South America. Two of these, Gymnopus macropus and G. nubicola, are newly described. Collybia laccata is considered synonymous with G. mucubajiensis comb. nov. now known from Andean Ecuador; both were originally described from the Venezuelan páramo. Gymnopus alkalivirens and G. semihirtipes are compared to G. mucubajiensis. Gymnopus spongiosus, previously known from the eastern United States, is newly reported from Colombian Quercus forests and is proposed as a new combination. Gymnopus dryophilus is, at present, not known from tropical South America, but extralimital material from nearby Costa Rica is described for comparison. No known species of Collybia s.str. have been identified from tropical South America.  相似文献   

19.
Two new monotypic genera,Didonica andUtleya, are described, withD. pendula from Panama andU. costaricensis from Costa Rica.Disterigma trimera (Panama),D. utleyorum (Costa Rica, Panama, Colombia, and Ecuador),Lateropora santafeensis (Panama),Lysiclesia panamensis (Panama),Macleania talamancensis (Costa Rica),Themistoclesia costaricensis (Costa Rica) andT. horquetensis (Panama),Vaccinium costaricense andV. orosiense (both from Costa Rica) and V.jefense (Panama) are all described as new. New combinations are provided for the PanamanianVaccinium floccosum (=Symphysia floccosa) and the West IndianVaccinium racemosum (=Symphysia racemosa). Keys are provided for the Central American species ofDisterigma andThemistoclesia, the species ofLateropora andLysiclesia, and the Costa Rican and Panamanian species ofVaccinium. Six new species are illustrated.  相似文献   

20.
Orthologs and paralogs - we need to get it right   总被引:1,自引:0,他引:1  
Jensen RA 《Genome biology》2001,2(8):interactions1002.1-interactions10023
A response to Homologuephobia, by Gregory A Petsko, Genome Biology 2001 2:comment1002.1-1002.2, to An apology for orthologs - or brave new memes by Eugene V Koonin, Genome Biology 2001, 2:comment1005.1-1005.2, and to Can sequence determine function? by John A Gerlt and Patricia C Babbitt, Genome Biology 2000, 1:reviews0005.1-0005.10.  相似文献   

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