78 research outputs found
Genetic diversity and structure of the portuguese pear (Pyrus communis L.) germplasm
A rich heritage of traditional pear varieties is kept in national Portuguese collections. Out
of these varieties, “Rocha” dominates national pear production. Although a noticeable phenotypic
variation among clones of this variety has been reported, little is known about its genetic variability,
as to date molecular studies have been performed on a single “Rocha” clone. Eleven Simple Sequence
Repeats (SSR) markers were used to assess the genetic diversity of 130 local cultivars, 80 of them
being “Rocha” clones. The results allowed the di erentiation of 75 genotypes of which 29 are “Rocha”.
Three synonyms groups and four homonymous groups of other local varieties were confirmed.
A Bayesian model-based clustering approach identified two distinct clusters. Using flow cytometry,
six cultivars were found to be triploids. These results show high genetic variability among “Rocha”
clones. In conclusion, there is a need for di erent “Rocha” clones to be preserved to enable the correct
selection of the multiplication materialinfo:eu-repo/semantics/publishedVersio
Comparison between Four Landraces and a Commercial Variety
Funding Information: Funding: This research was funded by Fundação para a Ciência e a Tecnologia (FCT) and FEDER through ALT20-03-0145-FEDER-029867. Funding Information: This research was funded by Funda??o para a Ci?ncia e a Tecnologia (FCT) and FEDER through ALT20-03-0145-FEDER-029867. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Cowpea (Vigna unguiculata) is a robust legume; nevertheless, yield is always affected by drought, especially when it occurs during reproductive growth and seed filling. Considered a key crop in the effort to attain food security, and a suitable crop for a scenario of climate change, modern disregard for cowpea landraces is particularly detrimental as it causes genetic variability loss, compromising breeding efforts. To contribute to the evaluation of the cowpea germplasm, four Portuguese landraces (L1, L2, L3, L4) were compared with a commercial variety (CV) to evaluate their physiological responses to terminal drought and their inter-variation on productivity, under semi-controlled conditions. Despite no differences in relative water content (RWC) between the CV and the landraces under water deficit (WD), differences in leaf water potential (Ψ) defined the CV as having an isohydric control of stomata in contrast with anisohydric control for landraces. There was an identical decrease in the photosynthetic rate for all plants under stress, caused by both stomatal and non-stomatal limitations, namely, damages at the level of photosystem II as indicated by fluorescence measurements. Instantaneous water use efficiency (iWUE) was improved with stress in L1 and L3. Maintenance of higher relative chlorophyll content for longer periods in the CV revealed a stay-green phenotype. The slim differences observed in terms of stomatal control, iWUE and progression of senescence between the CV and the landraces under WD led to quite important differences in terms of productivity, as inferred from improved yield (number of pods and number of grains per plant). This is a clear result of pragmatic on-farm selection. On one hand it shows that small differences in stomatal responses or water saving strategies under WD may lead to desirable outcomes and should therefore be considered during breeding. On the other hand, it suggests that other traits could be explored in view of drought adaptation. These results highlight the need to preserve and characterize as many genetic pools as possible within a species.publishersversionpublishe
Knowledge Analysis on Logistics Cost Trade-Offs: a Study With Portuguese Food Sector’ Professionals
Logistics is an important area in the economic-financial performance of companies, which makes it necessary to analyse their costs, as well as the trade-offs between them. Thus, the present study, with the objective of analysing the Portuguese food sector logistic professionals’ knowledge regarding to logistics costs trade-offs and their impact on the economic-financial performance of the organizations, showed that there are gaps concerning this subject. Throughout the structured interview and by using the SPSS software, the study shows the existence of flaws in the practical application of the trade-offs’ theory, such as the pressure from the managers for individual cuts in costs; and points out trade-offs of logistical costs relevant to the food sector. These results contribute to the expansion of studies on the subject, besides providing a perspective of the compensatory exchanges that can contribute to the decision making in relation to the costs concerning logistics activities.info:eu-repo/semantics/publishedVersio
Genetic Diversity and Population Structure of Wild Beets (Beta spp.) from the Western Iberian Peninsula and the Azores and Madeira Islands
In this work, using simple sequence repeat (SSR) markers, we present new insights into the
genetic diversity, differentiation, and structure of Beta vulgaris subsp. maritima of western Iberia and
the Azores and Madeira islands and of B. macrocarpa from southern Portugal. B. macrocarpa occurs
only in southern Portugal and frequently in sympatry with B. vulgaris subsp. maritima, showing
genetic introgression. B. macrocarpa has a better-defined structure than B. vulgaris subsp. maritima,
which has a high degree of admixture. A great differentiation (FST ranging from 0.277 to 0.184) was
observed among the northern populations of B. vulgaris subsp. maritima. In contrast, only a small
differentiation (FST ranging from 0.000 to 0.026) was detected among the southern B. vulgaris subsp.
maritima populations. The inland B. vulgaris subsp. maritima populations (“RIO” and “VMT”) are
distinct from each other, which also occurs with the two islands’ populations (“MAD” and “AZO”).
The existence of two distinct Atlantic Sea currents can explain the fact that Madeira is related to the
southern populations, while the Azores is related to the northern populations. We consider that
understanding the relationships existing within Beta spp. is key to future genetic studies and for the
establishment of conservation measures. Our results show that the southern coastal areas of Portugal
should be considered as a potential site for in situ conservation of the beet wild relatives. Special
attention is needed in what concerns B. macrocarpa because this is a rare species that also occurs in a
sympatric relationship with B. vulgaris subsp. maritimainfo:eu-repo/semantics/publishedVersio
Genetic diversity assessment of portuguese cultivated Vicia faba L. through IRAP markers
Faba bean have been grown in Portugal for a long time and locally adapted populations are
still maintained on farm. The genetic diversity of four Portuguese faba bean populations that are still
cultivated in some regions of the country was evaluated using the Inter Retrotransposons Amplified
Polymorphism (IRAP) technique. It was shown that molecular markers based on retrotransposons
previously identified in other species can be efficiently used in the genetic variability assessment
of Vicia faba. The IRAP experiment targeting Athila yielded the most informative banding patterns.
Cluster analysis using the neighbor-joining algorithm generated a dendrogram that clearly shows the
distribution pattern of V. faba samples. The four equina accessions are separated from each other and
form two distinct clades while the two major faba bean accessions are not unequivocally separated
by the IRAP. Fluorescent In Situ Hybridization (FISH) analysis of sequences amplified by IRAP
Athila revealed a wide distribution throughout V. faba chromosomes, confirming the whole-genome
coverage of this molecular marker. Morphological characteristics were also assessed through cluster
analysis of seed characters using the unweighted pair group method arithmetic average (UPGMA)
and principal component analysis (PCA), showing a clear discrimination between faba bean major
and equina groups. It was also found that the seed character most relevant to distinguish accessions
was 100 seed weight. Seed morphological traits and IRAP evaluation give similar results supporting
the potential of IRAP analysis for genetic diversity studiesinfo:eu-repo/semantics/publishedVersio
Use of repetitive sequences for molecular and cytogenetic characterization of Avena species from Portugal
Genomic diversity of Portuguese accessions of Avena species—diploid A. strigosa and
hexaploids A. sativa and A. sterilis—was evaluated through molecular and cytological analysis of
45S rDNA, and other repetitive sequences previously studied in cereal species—rye subtelomeric
sequence (pSc200) and cereal centromeric sequence (CCS1). Additionally, retrotransposons and
microsatellites targeting methodologies—IRAP (inter-retrotransposon amplified polymorphism) and
REMAP (retrotransposon-microsatellite amplified polymorphism)—were performed. A very high
homology was detected for ribosomal internal transcribed sequences (ITS1 and ITS2) between the
species analyzed, although nucleolar organizing regions (NOR) fluorescent in situ hybridization
(FISH) analysis revealed distinct number of Nor loci between diploid and hexaploid species.
Moreover, morphological diversity, evidenced by FISH signals with different sizes, was observed
between distinct accessions within each species. pSc200 sequences were for the first time isolated
from Avena species but proven to be highly similar in all genotypes analyzed. The use of
primers designed for CCS1 unraveled a sequence homologous to the Ty3/gypsy retrotransposon
Cereba, that was mapped to centromeric regions of diploid and hexaploid species, being however
restricted to the more related A and D haplomes. Retrotransposon-based methodologies disclosed
species- and accessions-specific bands essential for the accurate discrimination of all genotypes
studied. Centromeric, IRAP and REMAP profiles therefore allowed accurate assessment of inter
and intraspecific variability, demonstrating the potential of these molecular markers on future oat
breeding programs
Population structure in Quercus suber L. revealed by nuclear microsatellite markers
Quercus suber L. is a sclerophyllous tree species native to the western Mediterranean,
a region that is considered highly vulnerable to increased temperatures and severe dry
conditions due to environmental changes. Understanding the population structure
and demographics of Q. suber is essential in order to anticipate whether populations at
greater risk and the species as a whole have the genetic background and reproductive
dynamics to enable rapid adaptation. The genetic diversity of Q. suber has been subject
to different studies using both chloroplast and nuclear data, but population structure
patterns remain unclear. Here, we perform genetic analyses on Q. suber using 13
nuclear microsatellite markers, and analysed 17 distinct locations across the entire
range of the species. Structure analyses revealed that Q. suber may contain three major
genetic clusters that likely result from isolation in refugia combined with posterior
admixture and putative introgression from other Quercus species. Our results show a
more complex structure scenario than previously inferred for Q. suber using nuclear
markers and suggest that different southern populations contain high levels of genetic
variation that may contribute to the resilience of Q. suber in a context of environmental
change and adaptive pressureinfo:eu-repo/semantics/publishedVersio
Haplotype diversity patterns in Quercus suber (Fagaceae) inferred from cpDNA sequence data
Chloroplast genome diversity in cork oak (Quercus suber) is characterised by the occurrence of haplotypes that are akin
to those found in other Mediterranean oak species, particularly in Q. ilex and Q. rotundifolia, suggesting the possible presence
of an introgressed chloroplast lineage. To further investigate this pattern, we reconstructed chloroplast haplotypes by
sequencing four chloroplast markers (cpDNA), sampled across 181 individuals and 10 taxa. Our analyses resulted in the
identification of two diversified chloroplast haplogroups in Q. suber, corresponding to a geographically widespread lineage
and an Afro-Iberian lineage. Time-calibrated phylogenetic analyses of cpDNA point to a Miocene origin of the two haplogroups
in Q. suber, suggesting that the Afro-Iberian lineage was present in cork oak before the onset of glaciation periods.
The persistence of the two haplogroups in the western part of the species distribution range may be a consequence of either
ancient introgression events or chloroplast lineage sorting, combined with different fixation in refugia through glaciation
periods. Our results provide a comprehensive insight on the origins of chloroplast diversity in these ecologically and economically
important Mediterranean oaks.info:eu-repo/semantics/publishedVersio
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