scholarly journals Los agaves de las Antillas

2017 ◽  
pp. 37 ◽  
Author(s):  
Alberto Álvarez de Zayas

In this paper an updated list of the 43 Caribbean taxa of Agave, plus nine taxa only know as cultivated plants is given. A comparative study of the main species is done using their most important morphological characters; this allows to separate 12 native species that are different and representative, in such a way that is possible to join the rest of the related species. Aspects of the relationships among the Caribbean species and their continental relatives are discussed. illustrative drawings, tables and a map with the distribution of the taxa are also given.

2014 ◽  
Vol 66 (1) ◽  
pp. 3-15
Author(s):  
Sylwia Ciaglo-Androsiuk

AbstractRelation between morphological traits of the root system and yield related traits is an important issue concerning efforts aiming at improving of ideotype of cultivated plants species, including pea. In this paper, to analyse the dependency between traits describing the root system morphology and yield potential, Person’s andSpearman's_correlations as well as canonical correlations were used.Root system was analyzed in 14 and 21 day-old seedlings growing in blotting-paper cylinders. Yield potential of pea was analysed in a field experiment. Results of Person’s and Spearman's_correlations revealed that number of lateral roots and lateral roots density were correlated witch yield related traits. Correlation between root length and shoot length was observed only for 14 day-old seedlings. The result of canonical correlations revealed that number of lateral roots and lateral roots density had the largest effect on yield related traits. This work highlights, that in order to improve the yield of pea it might become necessary to understand genetic determination of morphological traits of the root system, especially number of lateral roots.


1970 ◽  
Vol 102 (8) ◽  
pp. 1041-1047 ◽  
Author(s):  
S. R. Loschiavo ◽  
L. B. Smith

AbstractA national survey shows that the merchant grain beetle, Oryzaephilus mercator Fauvel, has been present in Canada since at least 1925 and that it has become firmly established as a household pest of processed cereal products preferably of high oil content, but has not been reported from stored grain. A related species, the saw-toothed grain beetle, Oryzaephilus surinamensis (L.), infests both stored grain and processed cereal products. Illustrations are provided to show the morphological characters by which the two species may be recognized and separated.


Zootaxa ◽  
2017 ◽  
Vol 4320 (3) ◽  
pp. 505 ◽  
Author(s):  
ROMANA KALOUSOVA ◽  
LADISLAV BOCAK

Cladophorus Guérin-Méneville, 1830 are endemic Papuan net-winged beetles which take part in highly diverse Müllerian mimicry rings. Available specimens were sequenced for cox1–tRNA-Leu–cox2 mitochondrial DNA fragment and the species delimitations were based on the genetic distance, phylogenetic analysis, and morphology. Three earlier described species were identified in the recently collected material and further 10 species are described: C. pallescens sp. nov., C. bicolor sp. nov., C. craterensis sp. nov., C. motykai sp. nov., C. mindikensis sp. nov., C. kailakiensis sp. nov., C. manokwarensis sp. nov., C. haiaensis sp. nov., C. humeralis sp. nov., and C. boceki sp. nov. DNA-based identifications provided some ambiguous results and closely related species could not be robustly delimited using solely molecular data. Additionally, the species limits were based on clearly defined morphological characters and the morphological differentiation was found unlinked from the genetic divergence. Colour patterns cannot be used for identification because all species available in more specimens were polymorphic and followed various local co-mimics. The Papuan fauna of Cladophorus is very diverse and the closely related species regularly occur in limited regions. Differentiation within restricted ranges is therefore considered as the main speciation mode. 


2003 ◽  
Vol 51 (1) ◽  
pp. 1 ◽  
Author(s):  
B. M. Potts ◽  
R. C. Barbour ◽  
A. B. Hingston ◽  
R. E. Vaillancourt

The contamination of native-eucalypt gene pools via exotic pollen is of concern as (i) pollen dispersal is believed to be much more widespread than seed dispersal, (ii) reproductive barriers are often weak between closely related species, (iii) European settlement has already had a major impact on Australia's eucalypt woodlands and mallee, (iv) there has been a rapid expansion of eucalypt plantations and restoration plantings in Australia and (v) Australia is the custodian of an internationally important genetic resource. Pollen flow between plantation and native eucalypt species has already been reported and implementation of strategies to minimise the risk and consequences of genetic pollution is important if Australian forestry is to be considered sustainable. The risks associated with the introduction of non-native species, provenances and hybrids include direct effects on the gene pool through genetic pollution as well as indirect effects on dependent biodiversity. In many cases, the risk of genetic pollution will be small due to strong barriers to hybridisation between distantly related species, differences in flowering time or poor fitness of hybrids. There is no risk of hybridisation between species from the different major eucalypt genera and/or subgenera (e.g. symphyomyrts, monocalypts, eudesmids, bloodwoods and angophora). The main plantation species are symphyomyrts and within this subgenus, the probability of successful hybridisation generally decreases with increasing taxonomic distance between species. The planting of non-local provenances or improved material within the range of native populations has the potential to have an impact on local gene pools to varying degrees, indicating the requirement for the adoption of management strategies to reduce this risk. Naturally small or remnant populations are at particular risk. A framework for assessment of the risk of genetic pollution is developed herein.


2011 ◽  
Vol 35 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Fernanda Carlota Nery ◽  
Hilton Morbeck de Oliveira ◽  
Amauri Alves de Alvarenga ◽  
Sara Dousseau ◽  
Evaristo Mauro de Castro ◽  
...  

Ecophysiological studies under semi-controlled conditions in nurseries and greenhouses are essential to enable the use of native species to recover degraded areas and for commercial planting. Talisia subalbens (Mart) Radlk, 'cascudo', is a native fruiting species of the Cerrado on the verge of extinction. The ecophysiological performance of this species was evaluated in nursery conditions under different levels of shading (full sunshine, 30%, 50% and 70%). Initial growth, biomass allocation, gas exchange and chlorophyll content of the plants were analyzed. Full sunshine cultivated plants showed a higher accumulation of total, shoot, and root dry biomass. There was no significant difference in the root/shoot ratio among the treatments. Seedlings cultivated under full sunshine and 30% shading showed higher values for height, basal diameter, and leaf area. Differences in stomata conductance and photosynthesis rate were not observed among the different shading levels. Plants cultivated under 70% of shading had higher contents of chlorophyll a, b, and total. During the initial phase with higher levels of radiation were fundamental for the development of T. subalbens seedlings.


1990 ◽  
Vol 105 (2) ◽  
pp. 245-254 ◽  
Author(s):  
E. A. Szabo ◽  
P. M. Desmarchelier

SUMMARYNinety-six isolates of presumptive or confirmedListeria monocytogeneswere obtained from local clinical (30 isolates) or food laboratories (66 isolates). Minimal biochemical analysis identified only 80% of these isolates asL. monocytogenesthe remaining includedL. seeligeri, 1%, or the non-haemolyticL. innocua, 19%. The 27 clinical and 50 food isolates, mainly from meat products, frozen confectionaries, and cheeses, confirmed asL. monocytogeneswere compared biochemically and serologically. Twenty-one isolates, including some strains ofL. innocuaandL. seeligeri, were examined for pathogenicity in immunocompromized mice and 44 typed using bacterial restriction endonuclease DNA analysis (BRENDA). Only isolates ofL. monocytogeneswere found to be pathogenic. Biovar-typing of the isolates was unreliable and provided poor discrimination. Serogroups 1/2 and 4 predominated among clinical and food isolates and BRENDA provided better discrimination among isolates. Ten stable and reproducible restriction patterns were observed among theListeriasp. isolates studied. Overall, a combination of techniques gave the best discrimination and indicated their potential for use as epidemiological tools.


2013 ◽  
Vol 85 (1) ◽  
pp. 307-326 ◽  
Author(s):  
ELIZABETE S. SEKINE ◽  
VAGNER A.A. TOLEDO ◽  
MARCELO G. CAXAMBU ◽  
SUZANE CHMURA ◽  
ELIZA H. TAKASHIBA ◽  
...  

The aim of this study was to carry out a survey of the flora with potential for beekeeping in the counties of Ubiratã and Nova Aurora-PR through the collection of plants and pollen analyses in honey samples collected monthly. 208 species of plants were recorded, distributed in 66 families. The families that showed the major richness of pollen types were: Asteraceae, Myrtaceae and Solanaceae. Approximately 80 pollen types were found in honey samples, most of them were characterized as heterofloral. Cultivated plants, such as Glycine max (soybean) and Eucalyptus spp., were representative in some months of the year. Exotic species, such as Ricinus communis and Melia azedarach, were also frequent. However, over than 50% of the pollen types belong to native species of the region, such as Schinus terebinthifolius, Baccharis spp. Alchornea triplinervia, Parapiptadenia rigida, Hexaclamys edulis, Zanthoxylum sp. and Serjania spp., indicating the importance of the native vegetation for the survival of the colonies.


2014 ◽  
Vol 67 (3-4) ◽  
pp. 275-285 ◽  
Author(s):  
Dorota Wrońska-Pilarek

This paper presents results of studies on pollen morphology of 6 Polish species of the genus Ribes L. (family Grossulariaceae). Observations were carried out with LM and SEM. Pollen diagnoses were illustrated by series of microphotographs. Grains of examined species are small to medium-sized and prolate spheroidal or subprolate in shape, rarely prolate. They represent three pollen classes: zonocolporate, pantoaperturate and pantoporate. Three types of ectoapertures have been observed: colpi, pori and colpoids. Endoapertures are pori, in number (4-) 6-7-8 (-14) per grain. Ornamentation is psilate or fossulate, with the exception of the ectoaperture areas, which are granulate. According to the author, the polarity or apolarity, type of pollen class and ectoaperture, number of endopori and ratio of exine thickness to grain diameter are the main diagnostic features of the pollen grains of the native species of Ribes. The key to Polish species, basing on the morphological characters of grains is given too.


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