共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
Alberto E. Areces-Mallea 《Brittonia》1993,45(3):226-230
Leptocereus scopulophilus is newly described as endemic to the limestone summits and rocky hillsides of Somorrostro Hill, 25 km southeast of La Habana, Cuba. Since being discovered in 1923, it has been confused withLeptocereus leonii, from which it can be easily distinguished by its erect, ascending, branches which are greater in diameter and often 4–5 ribbed, by the more prominent and less crenate ribs bearing more widely spaced areoles and longer spines, and by its larger flowers with exserted stigma lobes and nearly tubular, green, spiny receptacles. The fruits also differ in being larger and in bearing clusters of persistent spines at maturity. Areces-Mallea, Alberto E. (museo Nacional de Historia Natural, Capitolio Nacional, La Habana 2, Ciudad de La Habana 10200, Cuba).Leptocereus scopulophilus (Cactaceae) a new species from western Cuba. Brittonia 45: 226–230. 1993.—Leptocereus scopulophilus es descrito como especie nueva, endémica de las cumbres calizas y paredones rocosos de la loma de Somorrostro, 25 km al sureste de La Habana, Cuba. Habiéndosela descubierto en 1923, siempre se la confundió conLeptocereus leonii, de la que fácilmente se distingue por sus ramas erectas, ascendentes, más anchas que las de esta especie y comúnmente 4–5-acostilladas; sus costillas más prominentes y menos crenadas, provistas de areolas más separadas y mayores espinas, y sus flores más grandes, con lóbulos estigmáticos exsertos receptáculos casi tubulosos, verdes, espinosos. Los frutos también se diferencian por ser mayores y llevar grupos de espinas persistentes en la madurez. 相似文献
3.
Résumé A Cuba, les oeufs h?tes parasités parTrichogramma fuentesi Torre (Hymenoptera: Trichogrammatidae) deviennent soit noirs, soit marrons. Une série de croisements entre Trichogrammes
a permis de montrer que le déterminisme de ce caractère est sous la dépendance d'un locus portant deux allèles: Bh, dominant,
confère une couleur noire à l'h?te; bh, récessif, confère une couleur marron. L'allèle bh étant plus fréquent dans la région
orientale de Cuba, la plus chaude, nous avons suivi l'évolution des fréquences des deux allèles dans des populations expérimentales
polymorphes placées à 23 °C et 30 °C. Dans toutes les conditions testées, bh a été désavantagé par rapport à Bh, sauf à 30
°C lorsque sa fréquence initiale était élevée (90%). La température n'explique donc certainement pas à elle seule le maintien
du polymorphisme à Cuba.
In Cuba, during its larval development inside its host egg,Trichogramma fuentesi turns its host egg either black or brown. Crossings carried out between the two forms ofT. fuentesi allowed to show that this character is determined by one locus with two alleles: Bh, dominant, colours the host black; and bh, recessive, colours the host brown. The bh allele is more frequent in the eastern region of Cuba which is also the warmest, than in the western region. We studied the evolution of frequencies of the two alleles in different experimental polymorphic populations at 23 °C and at 30 °C. In all tested conditions, bh was at a disadvantage by comparison with Bh, except at 30 °C when its initial frequency was high (90%). Thus, temperature alone should certainly not explain the maintenance of the observed polymorphism in Cuba.相似文献
4.
As a contribution to the taxonomic study of Asplenium L. for the new "Flora de la República de Cuba", the spore morphology was studied into three complexes of hardly delimited species. Twenty-two collections have been studied by SEM and eighty-nine by LM. Shape, number of spores per sporangium and perispore ornamentation, specially fine details revealed by scanning electron microscopy, were the most valuable characters in the recognition of taxa. Irregularities in spore shape and size, unusual development of perispore wall surface elements, and collapsed protoplast characterize aborted spores and suggest the occurrence of a possible hybrid species. 相似文献
5.
Laura Weber Patricia González-Díaz Maickel Armenteros Víctor M. Ferrer Fernando Bretos Erich Bartels Alyson E. Santoro Amy Apprill 《Environmental microbiology》2020,22(1):499-519
There are a few baseline reef-systems available for understanding the microbiology of healthy coral reefs and their surrounding seawater. Here, we examined the seawater microbial ecology of 25 Northern Caribbean reefs varying in human impact and protection in Cuba and the Florida Keys, USA, by measuring nutrient concentrations, microbial abundances, and respiration rates as well as sequencing bacterial and archaeal amplicons and community functional genes. Overall, seawater microbial composition and biogeochemistry were influenced by reef location and hydrogeography. Seawater from the highly protected ‘crown jewel’ offshore reefs in Jardines de la Reina, Cuba had low concentrations of nutrients and organic carbon, abundant Prochlorococcus, and high microbial community alpha diversity. Seawater from the less protected system of Los Canarreos, Cuba had elevated microbial community beta-diversity whereas waters from the most impacted nearshore reefs in the Florida Keys contained high organic carbon and nitrogen concentrations and potential microbial functions characteristic of microbialized reefs. Each reef system had distinct microbial signatures and within this context, we propose that the protection and offshore nature of Jardines de la Reina may preserve the oligotrophic paradigm and the metabolic dependence of the community on primary production by picocyanobacteria. 相似文献
6.
Javier Francisco-Ortega Iralys Ventosa Ramona Oviedo Francisco Jiménez Pedro Herrera Michael Maunder José L. Panero 《The Botanical review》2008,74(1):112-131
The Caribbean Islands are one of the ten insular biodiversity hotspots that are defined based on endemicity, massive habitat
loss and vulnerability to extinction. Asteraceae genera endemic to islands have provided well known examples of plant radiation
worldwide and illustrate the importance of these insular systems for evolutionary and conservation studies. A review of known
patterns of taxonomic diversity and molecular cladistics is provided for Asteraceae genera and species endemic in the Caribbean
Island biodiversity hotspot. We found that when compared with other island systems worldwide the Caribbean Islands have the
highest number of endemic genera (41), have endemic genera in the highest number of tribes, and harbor the only Asteraceae
tribe endemic to an island system, the Feddeeae which is restricted to Cuba. These unique patterns identify the Caribbean
Islands as the most important insular area of endemism for this major plant family. Molecular cladistic studies are limited
to only seven species in seven endemic genera and six endemic species in five non-endemic genera. These few studies are however
relevant as: (1) they confirm the tribal status of the Feddeeae, (2) suggest colonization events from the highlands of Cuba
toward low elevation and geologically recent areas of the Bahamas and South Florida, (3) provide evidence for biogeographical
links to remote regions of the Pacific Basin, and (4) identify sister relationships with continental taxa, mostly from North
America.
Resumen Las Islas del Caribe son uno de los diez “punto calientes” insulares de biodiversidad, los cuales vienen definidos por sus niveles de endemicidad, masiva pérdida de habitat y vulnerabilidad y extinción. Asteráceas endémicas de islas han proporcionado ejemplos muy bien conocidos de radiación vegetal a nivel mundial, éstos ilustran la importancia de los sistemas insulares en estudios evolutivos y de conservación. Se presenta una revisión de las pautas de diversidad taxonómica y de cladismo molecular en Asteráceas de las Islas del Caribe. Hemos encontrado que comparadas con otros sistemas insulares, las Islas del Caribe tienen el mayor número de géneros endémicos (41), tienen géneros endémicos en el mayor número de tribus y poseen la única tribu de la familia endémica en islas, Feddeeae es endémica de Cuba. Estas pautas de diversidad exclusivas de las Islas del Caribe hacen que éstas sean el área de endemismos insulares más importante para las Asteráceas. Estudios de cladismo molecular se limitan solamente a siete especies en siete géneros endémicos y a seis especies en cinco géneros no endémicos. Este reducido número de estudios son de todas formas relevantes debido a que: (1) confirman el estatus a nivel de tribu de Feddeeae, (2) sugieren una ruta de colonización desde zonas altas de Cuba hacia áreas de baja elevación de las Bahamas y el sur de la Florida, (3) proporcionan evidencia de conexiones biogeográficas con regions remotas del Océano Pacífico, y (4) identifican relaciones de hermandad con táxones continentales, principalmente de América del Norte.相似文献
7.
A new alkaloid, N(1)-acetyl-N(1)-deoxymayfoline was isolated from Maytenus buxifolia growing in the vicinity of Santiago de Cuba. Plants of 相似文献
8.
Genesis is an HNF-3/fkh homologous protein. By using multi-dimensional NMR techniques, we have obtained the solution structure and backbone dynamics of Genesis complexed with a 17 base-pair DNA. Our results indicate that both the local folding and dynamic properties of Genesis are perturbed when it binds to the DNA site. Our data show that a conserved flexible amino acid sequence (wing 1) makes dynamic contacts to DNA in the complex and a short helix is induced by Genesis-DNA interactions. Our data indicate that, unlike the HNF-3gamma/DNA complex, a magnesium ion is not required in forming the stable Genesis-DNA complex. 相似文献
9.
The dynamic properties of a winged helix protein, Genesis, and its DNA complex at different temperatures were studied. Due to the complexity of motions, the commonly used model-free formalism could not be used to reflect the dynamic properties. The reduced spectral density function mapping approach was proven to be a useful tool to describe the overall and internal motion of molecules on the picosecond to nanosecond time-scale, and conformational exchanges on the microsecond to millisecond time-scale. The local motions in DNA-free Genesis showed strong temperature dependence and the backbone dynamics of each secondary structural element responds to the temperature change differently, while the Genesis-DNA complex showed more stability with changing the temperatures. Furthermore, each DNA contact sequence of Genesis showed distinct dynamic perturbation after Genesis binds to DNA. 相似文献
10.
Alberto E. Areces-Mallea 《Brittonia》1996,48(2):224-236
The ranges ofConsolea nashii andC. moniliformis were found to extend from the Bahamas and Hispaniola, respectively, into Cuba. Two new subspecies are now recognized on the basis of morphological and geographical discontinuities of populations:Consolea nashii subsp.gibarensis from the coastal thickets between Manatí and Maisí, northeastern Cuba, andC. moniliformis subsp.guantanamana from the cacti thorn-woodlands and thickets of Guantánamo and Santiago de Cuba Provinces, on the southern coast and adjacent dry plains of eastern Cuba. A key to the Cuban species ofConsolea is provided. 相似文献
11.
Lixophaga diatraeae (Townsend) parasitized 20 to 78% ofDiatraea saccharalis (F) larval populations within 3 weeks after release. The flies (4 to 6 days old) did not migrate from the release area, but
the progeny dispersed as much as 3 km into adjacent untreated areas within 5 generations. Progeny dispersal, apparently during
the prelarviposition period, resulted in 100% parasitization ofD. saccharalis larvae in some plots.
In 2 of the 3 tests, the host population decreased after the releases. Percentage damaged internodes increased with distance
from the release site.
Résumé Des lachers de la mouche parasite, appelée vulgairement mouche de Cuba, dans les champs de anne, en Floride, ont limité les populations du foreur de la canne. La tachinaire a parasité 20 à 78% des foreurs. En outre, la descendance des parasites a été retrouvée à plus de 3 km des points de lacher. Les dégats aux cannes à sucre furent moindres dans les champs où les lachers ont été effectués que dans les champs voisins.相似文献
12.
E. A. Gorokhovskaya 《Entomological Review》2015,95(8):972-983
In his book The Genesis of Hymenoptera and Phases of Their Evolution, S.I. Malyshev not only examined the evolution of the behavior of Hymenoptera but also implicitly presented an original theoretical approach to the evolution of species-specific behavior in general. This article suggests a reconstruction of this theoretical approach. The phases of evolution of the Hymenoptera singled out by Malyshev do not conform to specific taxa. They are regular phases of evolution of behavior as a integral functional system. In the same way, Malyshev develops his hypothesis of the origin of ants and bees, distinguishing transitional behavior phases from the solitary life of the Hymenoptera to the social organization of bees and ants. 相似文献
13.
Dhillon B. S. Singh J. 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1977,49(3):117-122
Summary The present investigation involved crosses among 20 elite yellow maize populations. These were evaluated in four environments in a randomized block design with four replications in each environment. Variety Cuba was observed to be the best general combiner for grain yield, followed by St Croix and Prolific. No clear association could be discerned between general combining ability (GCA) effects for grain yield and its components, and mean grain yield performance and GCA effects. Heterosis was observed in general and all the crosses involving Cuba yielded better than the midparent. The five hybrids, Kisan × Cuba, Antigua 3D × St Croix, Prolific × St Croix, Vijay × Antigua Gr. I and A 23 × Cuba, yielded more than the standard check. Significant yield superiority of these varietal hybrids over the best commercial composite (Jawahar) suggested the possibility of their commercial exploitation.Part of the thesis submitted by the senior author in the partial fulfilment of the requirements for the Ph.D. degree 相似文献
14.
The authors give the known distribution ofBidens pilosa L. in Cuba, discuss some features of its ecology, its diaspore production, and enumerate its parasites known in Cuba. 相似文献
15.
《Journal of bryology》2013,35(2):95-97
AbstractThe new species Omphalanthus baracoensis, from the Yunque de Baracoa plateau, southeastern Cuba, is described and illustrated. The species is related to the widely distributed Omphalanthus filiformis, but differs in the presence of a large tooth at the lobule apex. 相似文献
16.
Alan W. Meerow Carl Lewis Ramona Oviedo Javier Francisco‐Ortega 《Plant Species Biology》2014,29(1):2-15
Ipomoea microdactyla Griseb. (Convolvulaceae) is restricted to the Bahamian archipelago, Cuba, and southeastern Florida. The species is listed as a state endangered species in Florida, where it is mostly restricted to the hyperfragmented pine rockland of Miami‐Dade County. Using seven DNA microsatellite loci, we assessed levels of genetic diversity for 12 populations of this species from Andros Island in the Bahamas (six sites), Cuba (one site), and Florida (five sites). We found significantly greater mean numbers of alleles, and higher mean values for both observed and expected heterozygosity in populations from the continuous forest on Andros than those from the habitat fragments in Florida. It is unknown if these patterns of genetic diversity in the Florida populations are the result of habitat fragmentation or founder effects. The population from Cuba exhibited relatively high levels of genetic variation, suggesting that this island is a major center of diversity and dispersal for this species. It appears that hybrid introgression for I. carolina alleles within I. microdactyla individuals occurred at a single site on Andros Island. Overall, the mean inbreeding coefficient value was 0.089, suggesting low levels of inbreeding. The highest inbreeding coefficient values were mostly recorded in Florida. Two groups were revealed, one containing the populations from Florida, and the second one encompassing those from the Bahamas and Cuba. Our results highlight the negative genetic consequences of habitat fragmentation and support initiatives recently established to establish corridors to connect the remnants of the pine forest of the Miami‐Dade County. 相似文献
17.
Illicium hottense, a new species, is here described from the floristically diverse Massif de la Hotte of southern Haiti. It is compared to
related species, especiallyI. ekmanii, with which it has previously been confused.Illicium hottense andI. ekmanii are members ofIllicium subsectionParviflora, a group that comprises four species, all endemic to peninsular Florida (I. parviflorum) or the Greater Antilles: Cuba (I. cubense) and Hispaniola (I. ekmanii, andI. hottense). The subsection is characterized by its distinctive laminar-carnose, ovoid stamens; all have trisyncolpate pollen.Illicium hottense is similar toI. ekmanii andI. parviflorum in having flowers with ten to thirteen carpels and six to less commonly eight stamens, but differs from both in its strongly
papillose outer tepals and consistently acute leaves. In addition, its leaves lack the strong anise fragrance ofI. parviflorum. Finally, molecular data provide support for recognizingI. hottense as a species distinct fromI. ekmanii. 相似文献
18.
Robert W. Hefner 《American anthropologist》2002,104(4):1242-1242
From Cosmogony to Exorcism in. Javanese Genesis. Stephen C. Headley. New York: Oxford University Press, 2000. 250 pp. 相似文献
19.
An assemblage of 46 fossil pollen and spore types is described from a core drilled through the middle Eocene Saramaguacán Formation, Camagüey Province, eastern Cuba. Many of the specimens represent unidentified or extinct taxa but several can be identified to family (Palmae, Bombacaceae, Gramineae, Moraceae, Myrtaceae) and some to genus (Pteris, Crudia, Lymingtonia?). The paleoclimate was warm-temperate to subtropical which is consistent with other floras in the region of comparable age and with the global paleotemperature curve. Older plate tectonic models show a variety of locations for proto-Cuba during Late Cretaceous and later times, including along the norther coast of South America. More recent models depict western and central Cuba as two separate parts until the Eocene, and eastern Cuba (joined to northern Hispaniola) docking to central Cuba also in the Eocene. All fragments are part of the North American Plate and none were directly connected with northern South America in late Mesozoic or Cenozoic time. The Saramaguacán flora supports this model because the assemblage is distinctly North American in affinities, with only one type (Retimonocolpites type 1) found elsewhere only in South America. 相似文献
20.
C Menéndez-Sainz A González-Quevedo S González-García M Peña-Sánchez R Giugliani 《Genetics and molecular research : GMR》2012,11(3):2352-2359
Although lysosomal storage disorders (LSDs) are considered individually rare, as a group they present a non-negligible frequency. Few studies have been made of populational occurrence of LSDs; they have been conducted predominantly on Caucasian populations. We studied the occurrence of LSDs in Cuba. Data from individuals who had been referred to the Institute of Neurology and Neurosurgery in Havana from hospitals all over the country between January 1990 and December 2005 were analyzed. This institute was the only laboratory to provide enzyme-based diagnostic testing for 19 LSDs in Cuba during this period. Occurrence rates were calculated by dividing the number of postnatal diagnoses by the number of births during the study period. The combined occurrence of LSDs in Cuba was 5.6 per 100,000, lower than that reported in other studies conducted on Caucasian populations. The most frequent individual LSDs were: mucopolysaccharidosis type I (1.01 per 100,000) and, surprisingly, alpha-mannosidosis (0.72 per 100,000) and fucosidosis (0.62 per 100,000). These findings may be related to specific genetic characteristics and admixture of the Cuban population. This is the first comprehensive study of the occurrence of LSDs in Cuba. We conclude that the epidemiology of these diseases can vary regionally, and we stress the need for similar surveys in other Latin American countries. 相似文献