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101.
T. Winkel H. D. Bertero P. Bommel J. Bourliaud M. Chevarría Lazo G. Cortes P. Gasselin S. Geerts R. Joffre F. Léger B. Martinez Avisa S. Rambal G. Rivière M. Tichit J. F. Tourrand A. Vassas Toral J. J. Vacher M. Vieira Pak 《Journal of Agronomy and Crop Science》2012,198(4):314-319
Reviewing the situation of quinoa production in southern Bolivia, Jacobsen (2011, J. Agron. Crop Sci. 197: 390) argues that the booming export market has a negative effect on the environment and on the home consumption of quinoa, thereby leading to an environmental disaster in the region. In view of the scarcity of scientific knowledge on the rapid social and environmental dynamics in the region, we consider that Jacobsen’s review misrepresents the situation of quinoa production in southern Bolivia. Specifically, we argue that (i) the data presented by Jacobsen (2011, J. Agron. Crop Sci. 197: 390) do not support any drop in quinoa crop yield supposed to reflect soil degradation and (ii) his demonstration regarding home consumption of quinoa is ill‐founded from both a nutritional and a cultural point of view. We suggest that the diffusion of the arguments exposed by Jacobsen (2011, J. Agron. Crop Sci. 197: 390), because of their flaws, might have strong negative impacts on those concerned with sustainable food production and fair‐trade with developing countries. We conclude that, rather than reinforced agro‐technical controls on local farmers, the rising competition in the international quinoa market requires a shift towards an ethical economy and ethical research cooperation with quinoa producers. 相似文献
102.
Virginia Menzo Angelica Giancaspro Stefania Giove Domenica Nigro Silvana Zacheo Pasqualina Colasuonno Ilaria Marcotuli Ornella Incerti Antonio Blanco Agata Gadaleta 《Euphytica》2013,194(2):151-160
Target region amplification polymorphism (TRAP) is a relatively new PCR-based technique that detects large numbers of loci in a single reaction without extensive pre-PCR processing of samples. The aim of this study was to integrate TRAP markers in an EST-derived SSR linkage map of a RIL mapping population from the cross of the durum wheat cultivars Ciccio and Svevo, for a more general purpose of establishing a high-throughput system for genetic map saturation. Primer combinations producing PCR products with at least 4–5 polymorphic bands were selected and analyzed across the mapping population. The PCR reactions produced a total of 2,881 fragments with an average of 52 peaks per reaction. A total of 142 new TRAP markers were mapped and found to be randomly distributed in the genome. The total length of the map was 2,043.0 cM, with an average chromosome length of 145.9 cM. Homoeologous group one had the highest number of TRAP markers (38 loci) and the longest map length (407.9 cM) for a total of 87 markers, while the homoeologous group five had the lowest TRAP marker number (5 loci) and the shortest map length (232.5 cM). The distribution of markers among the seven homoeologous groups was random. The results indicate that TRAP is highly efficient in genetic mapping, generating a large number of markers scattered across the genome. This closes many existing gaps in marker coverage and may join otherwise separate linkage groups. 相似文献
103.
Glauco Vieira Miranda Leandro Vagno de Souza João Carlos Cardoso Galvão Lauro José Moreira Guimarães Aurélio Vaz de Melo Izabel Cristina dos Santos 《Euphytica》2008,162(3):431-440
The development of successful advanced lines and cultivars in maize is dependent on parental selection and assignment to defined
heterotic groups. So, the objectives of this study were to evaluate genetic variability and identify heterotic groups among
Brazilian popcorn varieties. Thus, diallel crosses of advanced generations of the popcorn hybrids, IAC 112 and Zélia, and
of three open-pollinated popcorn varieties, RS 20, Branco, and SAM were performed. Ten hybrid combinations, the five parents,
and five check treatments were arranged in a block design with four replicates in two tropical-zone locations (CWb climate).
Both additive and non-additive effects were important for grain yield, plant height, ear height, and husk cover. For popping
expansion, only the additive effects were important. Hybrid combinations between the local variety (Branco) and F2 populations (IAC 112 and Zelia) resulted in the third and fourth highest values for popping expansion. The best grain yields
were obtained with hybrid combinations involving SAM. Cultivars Zélia, IAC 112, and RS 20 increased popping expansion, whereas
cultivar Branco increased grain yield of hybrid combinations. The following conclusions may be drawn: Brazilian popcorn populations
have reduced heterosis and genetic variability to popping expansion in relation commercial cultivars; there is genetic variability
among Brazilian popcorn populations that allows the exploitation of additive and non-additive effects for grain yield; it
is possible to increase grain yield by using local varieties; but it would be difficult to obtain commercial hybrids from
local varieties because they have poor performance for popping expansion. 相似文献
104.
Pedro Radi Belícuas Aurélio Mendes Aguiar Dyeme Antonio Vieira Bento Tassiano Marinho Maxwell Câmara Cláudio Lopes de Souza Junior 《Euphytica》2014,198(2):163-173
Stay-green maize genotypes have been associated with tolerance to biotic and abiotic stresses, including tolerance to drought, and to stalk and root lodging, but there is limited information on its inheritance. Thus, this research was conducted to study the inheritance of the stay-green trait using both conventional analysis and QTL mapping of the Design III in a tropical maize population developed from two inbred lines genetically divergent for this trait. Two-hundred and fifty F2 plants were genotyped with 177 microsatellite markers, and their backcrossed progenies to both parental inbreds were evaluated at three locations. Ten plants per plot were assessed 120 days after sowing and the plot means scores for stay-green, adjusted for days to silking emergence, were used for analysis. The additive variance was larger than the dominance variance, the genetic by location interaction variance presented a high magnitude, and the heritability coefficient on a plant-basis a low magnitude. Seventeen QTL were mapped, most of them were clustered on four chromosomes and accounted for by 73.08 % of the genetic variance. About half of the QTL interacted with location, and the average level of dominance was partial dominance. The additive effects were larger than the dominance effects; the latter were not unidirectional, so that heterosis could not be exploited in crosses. Procedures for marker-assisted selection to increase the level of stay-green are discussed and an approach is suggested for using both stable and non-stable QTL in a marker-assisted backcross program. 相似文献
105.
Carlos Alberto Scapim Cleso Antônio Patto Pacheco Antônio Teixeira do Amaral Júnior Rafael Augusto Vieira Ronald José Barth Pinto Thiago Vincenzi Conrado 《Euphytica》2010,174(2):209-218
In plant breeding, correlations between the statistics of stability and adaptability of popcorn cultivars are not yet well
understood. Therefore, the objectives of the present experiment was to investigate the correlations between sdi2 \sigma_{\rm di}^{2} and bi \beta_{\rm i} from Eberhart and Russell, ωi from Wricke,
\textS\texti(1) {\text{S}}_{\text{i}}^{(1)} ,
\textS\texti(2) {\text{S}}_{\text{i}}^{(2)} and
\textS\texti(3) {\text{S}}_{\text{i}}^{(3)} from Huehn, Pi from Lin and Binns and the rank-sum from Kang, and indicate the most reliable method for selecting popcorn cultivars. These
statistics were estimated by data of crop yield from 19 Brazilian genotypes under 21 environments and popping expansion under
16 environments. The ωi,
\textS\texti(1) {\text{S}}_{\text{i}}^{(1)} ,
\textS\texti(2) {\text{S}}_{\text{i}}^{(2)} ,
\textS\texti(3) {\text{S}}_{\text{i}}^{(3)} and sdi2 \sigma_{\rm di}^{2} were positively and significantly correlated indicating that just one in these five statistics is sufficient for selecting
stable genotypes although they were not correlated with the means of crop yield and popping expansion. The bi \beta_{\rm i} was negatively and significantly correlated with Pi for crop yield indicating that the most adaptable genotypes tend to have the lowest estimates of Pi. Although Pi was not correlated with ωi,
\textS\texti(1) {\text{S}}_{\text{i}}^{(1)} ,
\textS\texti(2) {\text{S}}_{\text{i}}^{(2)} ,
\textS\texti(3) {\text{S}}_{\text{i}}^{(3)} , or sdi2 \sigma_{\rm di}^{2} statistics, it displayed positive correlation with the Index 1 (crop yield and popping expansion +
\textS\texti(1) {\text{S}}_{\text{i}}^{(1)} rank) and Index 2 (crop yield and popping expansion + Wi) indicating that superior popcorn genotypes are also stable. Finally, both Pi and the rank-sum are useful statistics in breeding programmes where crop yield, popping expansion and stability are essential
traits for selecting genotypes. 相似文献
106.
Luis García Esteban Paloma de Palacios Francisco García Fernández Juan Antonio Martín Mar Génova Juan Ignacio Fernández-Golfín 《Wood Science and Technology》2009,43(7-8):679-690
The hygroscopicity and thermodynamic properties of buried juvenile Pinus sylvestris L. wood with an age of 1,170 ± 40 BP were compared with the corresponding values of juvenile wood of the same species from recently cut trees. The 35 and 50°C isotherms were plotted following the saturated salts method and subsequently fitted in accordance with the GAB model. The isotherms were then compared by means of the hysteresis coefficients. X-ray diffractograms were used to analyse the crystal structure of the cellulose. The effect of time on the buried wood caused hemicelluloses degradation and a decrease in the crystallinity index and the crystallite length, resulting in an increase in the proportion of amorphous zones. Because of this, the equilibrium moisture contents of the buried wood are higher than of the recent wood, both in adsorption and desorption. In terms of the thermodynamic properties, the heat involved is greater in the buried wood than in the recent wood. 相似文献
107.
Fernando Silla Álvaro Camisón Andrea Solana Héctor Hernández Guillermo Ríos Miguel Cabrera Dámaris López Albert Morera-Beita 《Annals of Forest Science》2018,75(4):95
Key message
Quercus secondary forests show a gradual transition toward mixed forests, with sweet chestnut ( Castanea sativa ) becoming increasingly abundant in the western Spanish Central System. Additionally, in chestnut-dominated stands, it shows a certain resistance to competitive displacement by Quercus pyrenaica . Our results partially refute the traditional view that C. sativa is unable to recruit in the absence of cultural inputs.Context
Sweet chestnut, Castanea sativa, is a component of European broadleaf forests and is one of the most managed trees. Due to a reduction in cultural inputs, chestnut-dominated stands tend to be invaded by other species, and it is unclear how chestnut is able to persist in natural mixed forests.Aims
Our work aimed to identity the main factors that limit the establishment of C. sativa and to analyze the recruitment and mortality processes of C. sativa trees.Methods
The age, growth ring patterns, regeneration density, and the spatial structure of trees and saplings in 11 plots in the Spanish Central System were analyzed.Results
Chestnut seedling density increased with C. sativa basal area, but transition toward the sapling stage appeared limited owing to light availability. In Quercus pyrenaica secondary forests, sparse canopies did not constrain chestnut regeneration, and in old chestnut stands, C. sativa showed a certain resistance to competitive displacement. By contrast, mixed young coppices showed a high mortality, most likely due to competition with other vigorous resprouters.Conclusion
Quercus secondary forests showed a gradual transition toward mixed forests with sweet chestnut becoming increasingly more abundant. In old stands, C. sativa is likely to persist under a gap-phase mode of regeneration. Our results partially refute the traditional view that C. sativa is unable to recruit in the absence of cultural inputs.108.
Reyes Tárrega Leonor Calvo Ángela Taboada Elena Marcos José Antonio Marcos 《European Journal of Forest Research》2011,130(6):949-957
We compared the structure of the arboreal layer and the diversity and species composition of the understory vegetation of
three types of mature forest communities: oak (Quercus pyrenaica) and beech (Fagus sylvatica) forests and Scots pine (Pinus sylvestris) plantations. Our main aim was to determine whether differences in these variables existed and were due to the identity of
the dominant tree species. We selected four stands or replicates per forest type located geographically close and with relatively
similar conditions. We found no differences in the arboreal structure of oak and beech forests, which were characterised by
great variability in tree size, while in case of plantations, this variability was lower at both the intra-stand (estimated
by the coefficient of variation) and inter-stand (i.e. the four replicates harboured trees of similar sizes) scales. However,
the highest variability in the canopy layer of natural forests was not consistently linked to greater understory species richness.
Indeed, the lowest plant species richness was found in beech forests, while oak forests harboured the highest value at either
the sampling unit (per m2) or stand scales. The greatest negative correlation between plant diversity and the environmental variables measured was
found for litter depth, which was the highest in beech forests. The results obtained by the CCA indicated that the four replicates
of each forest type clustered together, due to the presence of characteristic species. We concluded that pine plantations
did not approach the environmental conditions of native forests, as plantations were characterised by singular understory
species composition and low arboreal layer variability, compared to natural woodlands. 相似文献
109.
Serena Santolamazza-Carbone Montserrat Pestaña José Antonio Vega 《Journal of pest science》2011,84(3):343-353
The spectrum and dynamics of xylophagous insects infesting Pinus pinaster after a fire event were studied from November 2007 to December 2008 at Sierra de Outes (Galicia, NW Spain). Insects were
collected within and outside the fire area. Relationships among species status, species abundance, tree parameters and tree
injury were assessed. Mortality of injured trees was also recorded. Insect colonization built up consistently during the first
year after the fire, although the pests did not colonize unburned trees in nearby areas. Thirteen insect species from six
xylophagous families were collected. Tomicus spp., Buprestis novenmaculata, Anobium punctatum and Pissodes castaneus were the first species detected. Tomicus spp. (29%) and Ips sexdentatus (23%) were the dominant taxa. Bole char height and soil burn severity were positively correlated with insect presence. Trees
with short stem diameter and thinner bark were also preferred. B. novenmaculata presence was positively correlated with crown scorch. Loss of cambium hydration was negatively related to the occurrence
of pests, likely because sapwood desiccation and loss of nutrient impede brood development. About 33.3% of the fire-scorched
pines died. The results recommend the removal of injured and dying pines after fire, to avoid the rise of pest population
threatening recovering trees in the burned areas. 相似文献
110.
In this paper, an experimental procedure is proposed, in order to evaluate the machinability of different particleboards. A dedicated test stand has been built to measure the power consumption during the process for different typologies of particleboards. This methodology could constitute a quick particleboard grading system, in order to maximise the feeding rate during the working process, and, at the same time, minimise the tool wear and the loads on the shaft of the electrical spindle, with a considerable improvement in the overall production costs. 相似文献