67 research outputs found
Caracterização de Puccinia hemerocallidis causadora do primeiro surto de ferrugem de lírio-de-um-dia na Europa
Daylily (Hemerocallis spp.) is an ornamental plant widely used in gardens. Daylily rust, caused by the fungus Puccinia
hemerocallidis, has disseminated through all continents only in the 21th century, except in Europe, where it has been
considered a quarantine disease by the European Plant Protection Organisation. In Portugal, since November 2015,
typical rust symptoms were observed in daylily plants in gardens in Lisbon, Alentejo, Algarve and Madeira, attaining
high prevalence, incidence and severity. The causal agent was identified as P. hemerocallidis and the Koch’s postulates
were fulfilled. Phylogenetic data suggest that this fungus may have been introduced from North America. Using
flow cytometry, the genome size of the P. hemerocallidis populations present in Portugal was estimated to be 345 Mbp
(0.3533 pg DNA/1C). For such analysis Rhamnus alaternus was validated as a DNA standard, exhibiting a nuclear content
of 0.680 pg DNA/2C. The identification of this disease in diverse locations in Portugal represents a threat to European
breeding and nursery industries, since there are the appropriate conditions for inoculum maintenance and propagation
from Portugal to the rest of Europeinfo:eu-repo/semantics/publishedVersio
Dynamics of change in a ‘female farming system’, Mbanza Kongo/ Northern Angola
The inhabitants of the Zaire Province of northern Angola, belonging to different
subgroups of the Bakongo, offer an interesting case to study social and agricultural
change in what Boserup would call a traditional ‘female farming system’. Since the
1930s, several factors have produced multiple dynamics of change – sometimes
abrupt and other times gradual – in both livelihoods and the gender relations of
agricultural production. Of these, the paper is going to highlight late colonial
intervention, the anticolonial war, the long civil war, the economic boom after the
end of the war and the recent economic crisis. While colonial interventions reinforced
women’s role as food producers, the wars acted in the opposite direction by
increasing the participation of (non-conscripted into the military) men in agriculture
for those who took refuge in the then Republic of Congo. The economic boom that
followed the end of the civil war opened income-earning opportunities out of
agriculture for young men, but the recent fall in the international oil price reversed
this trend, and agriculture – as a sole occupation or combined with casual off-farm
jobs – became again a way out of hunger and povertyinfo:eu-repo/semantics/publishedVersio
A gafa da oliveira é causada por fungos de diversas espécies, com distinta distribuição geográfica, virulência e preferência pela cultivar
A gafa da oliveira é o principal fator fitopatológico limitante da produção de azeitona em Portugal, ao causar a queda
ou mumificação dos frutos, com consequente quebra de produção e/ou depreciação da qualidade do azeite. Apresenta
incidência a nível nacional entre 30 e 50%, com uma severidade média de 14%. A gafa é causada por diversas espécies
de fungos pertencentes ao género Colletotrichum, sendo C. nymphaeae e C. acutatum sensu stricto as mais virulentas,
enquanto C. godetiae e C. fioriniae apresentam virulência intermédia e C. gloeosporioides (entre outras, pouco frequentes)
se apresenta menos virulenta. No centro e sul de Portugal prevalece C. nymphaeae, enquanto em Trás-os-Montes C.
godetiae é mais frequente. As variações na virulência dependem no entanto da interação com a cultivar. Por exemplo,
em ‘Cobrançosa’, C. godetiae apresenta maior virulência do que C. acutatum s.s., contrariando a média geral. As variações
na virulência destes agentes patogénicos, a sua interação com as cultivares de oliveira, a sua distribuição geográfica e
as recentes dinâmicas populacionais deverão ser tidas em conta e compreendidas para a implementação de medidas
de proteção do olivalinfo:eu-repo/semantics/publishedVersio
The use of flow cytometry for fungal nuclear DNA quantification
Genome size information is sparse across fungi, with information being available for less
than 2000 species. So far, most records have been obtained using static, microscopebased
cytometry methods or derived from genome sequencing projects. Flow cytometry
is now considered the state-of-the-art method for obtaining genome size measurements,
and appropriate methods and DNA standards are available, enabling the analysis of most
genome size ranges in a rapid, robust and inexpensive way. The average fungal genome
size is 60 Mbp, but sizes vary across phylogeny, ranging from 2.2 (Encephalitozoon
romaleae) to 3706 Mbp (Jafnea semitosta). In several fungal clades, genome size expansion
seems to accompany evolution either to plant mutualism or to plant parasitism (particularly
biotrophy), and fungi that interact with plants seem to have larger genomes
than saprobes and those that interact with animals. Whereas flow cytometry for nuclear
DNA quantification is routinely employed in plant sciences for genome size and ploidy
studies, its use in fungal biology is still infrequent. Appropriate standards, methods and
best practices are described here, with the aim of stimulating a more generalized and
widespread use of flow cytometry for fungal genome size measurementinfo:eu-repo/semantics/publishedVersio
Response to anthracnose in a tarwi (Lupinus muyabilis) collection is influenced by anthocyanin pigmentation
Anthracnose, caused by Colletotrichum lupini, is a major limiting factor for lupin production.
Tarwi or Andean Lupin (Lupinus mutabilis) is generally regarded as susceptible to anthracnose, but the
high protein and oil content of its seeds raise interest in promoting its cultivation in Europe. In this
study we evaluated the response to anthracnose of 10 tarwi accessions contrasting in anthocyanin
pigmentation, by comparison to white lupin (Lupinus albus), using a contemporary Portuguese fungal
isolate. A severity rating scale was optimized, including weighted parameters considering the type
of symptoms and organs a ected. All tarwi accessions were classified as susceptible, exhibiting
sporulating necroses on the main stem from seven days after inoculation. Anthracnose severity was
lower on anthocyanin-rich tarwi plants, with accession LM34 standing out as the less susceptible.
Accession I82 better combines anthracnose response and yield. In global terms, disease severity was
lower on white lupin than on tarwi. Although based on a limited collection, the results of the study
show the existence of genetic variability among L. mutabilis towards anthracnose response relatable
with anthocyanin pigmentation, providing insights for more detailed and thorough characterization
of tarwi resistance to anthracnoseinfo:eu-repo/semantics/publishedVersio
Genetic and genomic diversity in a Tarwi (Lupinus mutabilis Sweet) germplasm collection and adaptability to Mediterranean climate conditions
Lupinus mutabilis (tarwi) is a species of Andean origin with high protein and oil content
and regarded as a potential crop in Europe. The success in the introduction of this crop depends in
part on in depth knowledge of the intra-specific genetic variability of the collections, enabling the
establishment of breeding and conservation programs. In this study, we used morphological traits,
Inter-Simple Sequence Repeat markers and genome size to assess genetic and genomic diversity
of 23 tarwi accessions under Mediterranean conditions. Phenotypic analyses and yield component
studies point out accession LM268 as that achieving the highest seed production, producing large
seeds and e ciently using primary branches as an important component of total yield, similar to the
L. albus cultivars used as controls. By contrast, accession JKI-L295 presents high yield concentrated on
the main stem, suggesting a semi-determinate development pattern. Genetic and genomic analyses
revealed important levels of diversity, however not relatable to phenotypic diversity, reflecting the
recent domestication of this crop. This is the first study of genome size diversity within L. mutabilis,
revealing an average size of 2.05 pg/2C (2001 Mbp) with 9.2% variation (1897–2003 Mbp), prompting
further studies for the exploitation of this diversityinfo:eu-repo/semantics/publishedVersio
Urban and rural household energy consumption and deforestation patterns in Zaire province, Northern Angola: A landscape approach
Angola has been labelled a “petro-state”, since independence, due to its oil-wealth and the country’s economic
dependence on its revenues. Considering that oil availability and price could be a factor reducing deforestation
and forest degradation through accelerating energy-transition, our objective was to study the energy consumption
patterns and the role of woody biomass as a source of income of rural villagers and urban poor dwellers
practicing agriculture, living in one of the oil-rich provinces. We used a “people and pixels” approach, combining
interviews with households’ heads with remote sensing analysis of land use/cover change. Our findings revealed
that while kerosene is the main energy source for cooking and lighting in the city, in rural areas it is firewood and
flashlights, respectively, and that the selling of firewood and/or charcoal is practiced by few households. Contrary
to what has been reported about other Angolan regions and African countries, satellite imagery analysis
showed that deforestation around Zaire province capital city and surrounding rural villages is comparatively
small. Bearing in mind that the consumption of biomass for domestic household needs is reduced, other drivers of
deforestation/forest degradation must be considered. Nonetheless, the high domestic use of kerosene contributes
to the exhaustion of its limited global supplies and to increasing greenhouse gas emissions, disregarding the
country’s potential to produce renewable energyinfo:eu-repo/semantics/publishedVersio
Petro-Landscapes: Urban Expansion and Energy Consumption in Mbanza Kongo City, Northern Angola
Original ResearchAngola is a resource-rich country, which experienced a major urban concentration of the population owing to a long civil war
followed by an oil-related economic boom. The majority of the population, however, remains without access to basic services
such as potable water, sanitation or electricity. Despite the economic and social exclusion of the majority of the citizens, how does
its oil wealth translate into the energy consumption patterns of poor urban households in the capital city of one of its oil-rich
provinces? Research conducted in around 300 households of Mbanza Kongo city of Zaire province—whose livelihoods relied on
odd jobs and/or peri-urban agriculture—showed that contrary to much received wisdom most of the poor urbanites do not use
either fuelwood or charcoal as their main source of energy, and thus do not contribute to deforestation or forest degradation.
Unexpectedly, a major impetus for deforestation is house construction. Attention must be paid to diverse drivers of deforestation
and greenhouse gas emissions. The major expansion of urban areas is an important factor; here we mapped one World Heritage
city in Angola through remote sensinginfo:eu-repo/semantics/publishedVersio
Yield and seed chemical composition of Lupinus mutabilis in Portugal
Lupinus mutabilis Sweet (tarwi), being cultivated for thousands of years in the Andean region, is regarded as a
potential crop for Europe, especially because of its high protein and oil content. The objective of this study was to
revise the productivity and seed composition analyses of several tarwi accessions conducted over several years, in a
Mediterranean environment (Lisbon, Portugal), in order to select more suitable lines. The productivity, although low
(bellow 2 t/ha, in average), and variable (ranging from 0.26 to 6.0 t/ha), indicates that it should be possible to obtain lines
with productivity levels high enough to make of this species a non-irrigated autumn-sown legume crop. These results
are more encouraging when compared with the lower yields obtained in central Europe, where indeterminate growth
also often causes unsurpassed difficulties. The chemical composition of tarwi seeds obtained in this Mediterranean
environment reaches very high levels both in the protein content (up to 50%) and in oil (up to 19%). It is possible to
select plants for higher oil levels with little reduction on the protein content. Seeds seem to have a slightly lower protein
content than when obtained under central European conditions, but with oil contents consistently higher. Presently,
the main obstacles to be transposed in order to make tarwi a crop for the Mediterranean area are: to increase cold and
frost tolerance, in order to adapt it to colder winters than those in coastal areas; to increase seed yield and oil content
(without reducing protein); to increase resistance to pests and diseases and a better competition against weeds; and to
optimise the plant architecture in order to maximise pod and seed set without compromising productive flexibility (so
much necessary to face the typical Mediterranean climate interanual variability)info:eu-repo/semantics/publishedVersio
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