Ectinogonia buquetti (Spin.) (Coleoptera, Buprestidae) was identified as the agent causing damage on a Eucalyptus camaldulensis (Dehnh.) bioenergy plantation. Damage affected the principal apex and upper lateral branches and loss of lateral branches on E. camaldulensis due to complete ring-barking. E. buquetti is a coleopteron native to Chile, it preferably feeds on the wood of native species. A total of 205 individuals, all adults were found; 45% of the plants presented some type of damage. 相似文献
Taxus globosa (Mexican yew) is a conifer endemic to México and Central America. It produces a substance known as taxol, which is useful
in treatment of ovarian cancer. Because seed production for this dioecious tree is limited, and seed germination is extremely
difficult, the use of cuttings could facilitate propagation of this species. With the intention of massively propagating individuals
selected for taxol content, two trials were established in which the effect of substrate temperature (average temperatures
18 and 23°C), age (i.e., young vs. old shoots) and management of cuttings, as well as clone variation in rooting capacity,
were evaluated. Low temperature favored rooting (53 vs. 34% on average for the two trials); younger shoots rooted three times
(61 vs. 23%) more than mature ones, while basal wounding did not affect rooting capacity. A wide variation was found in rooting
capacity of clones (8–76%), which could be associated with genetic or physiological differences among donor trees. 相似文献
Changing biotic and abiotic stress mediate in plant–plant interactions resulting in positive to neutral or negative effects,
and these effects can change with gradients of stress or through plant dynamics. Here we studied the variability in annual
grass production and composition induced by gradients of intercepted light by trees in years of contrasting precipitation
in Mediterranean holm oak open woodlands. Although trees reduce the light radiance received by the pasture community, the
presence of trees generally had a positive effect on pasture production in average climatic years where soil fertility was
low. However, the interaction changed with increasing abiotic water stress. In a dry year, the increase in fertility could
not be utilized and the effect of the crown was neutral. The effect of shade turned out to be beneficial for growth, contrary
to the situation in an average climatic year. Light insolation was positive for legume biomass. There was high variability
in functional components over the course of the growing period and from 1 year to another. Under low levels of other biotic
stresses such as livestock grazing or root competition, the limiting factor among light, soil moisture or soil nutrients may
determine whether facilitation or competition occurs. 相似文献
The new eremophilanolide 1, the known eremophilane derivatives 2 and 3, already described as part of mixtures, the known compounds hyperin, 2'-acetylhyperin and two calenduladiol esters were isolated from Roldana lineolata. Their structures were determined by spectroscopic methods. Compounds 1 and 2 as well as their acetylated and oxidized derivatives were tested against several fungi strains. Eremophilanolide 1 showed a mild activity against Trichophyton mentagrophytes. 相似文献
? The physical properties of wood and the associated variations within and between trees were evaluated by analysing 770 small specimens of clear wood from 11 Pinus sylvestris L. trees thinned from 3 plantations.
? Within-tree variations in basic density or volumetric shrinkage increased with cambial age and decreased with increasing ring width. The effect of the height in the stem on wood properties was considered indirect and height was not included as an explanatory variable in the mixed models proposed to estimate basic density and volumetric shrinkage.
? The models had random components for the intercept parameter and explained 52.5% of the total variance in basic density and 56% of the total variance in volumetric shrinkage. Linear shrinkage in the direction of the grain was extremely variable.
? Between-tree variation and between-plot variation in the physical properties of wood were high, considering that all trees sampled were growing in similar sites and stands. It would then be desirable to predict physical properties of wood on living trees in order to use the quality of wood as a criterion for timber tree selection in thinnings.
Many of the best management practices (BMPs) that are recommended for agricultural producers have not been scientifically
evaluated for their conservation benefits considering the soil, climate, and hydrology of the proposed application location.
The goal of this study was to compare royal palm (Roystonea elata) production in south Florida, USA, using tensiometer automated irrigation and reduced soil applications of nitrogen (N) and
phosphorus (P), to that of traditional grower practices considering water savings, nutrient inputs, crop yield, crop nutrient
status, soil nutrient status, and economic analyses. The study consisted of six treatments: (1) control (i.e., a grower irrigation
rate and N and P fertilizer rates); (2) irrigation system automated to irrigate when soil water suction exceeded 5 kPa and
the grower N and P rates; (3) irrigation system automated to irrigate when soil water suction exceeded 15 kPa and the grower
N and P rates; (4) irrigation system automated to irrigate when soil water suction exceeded 15 kPa and 50% of the grower N
and P rates; (5) the grower irrigation rate and 75% of the grower N and P rates; and (6) the grower irrigation rate and 50%
of the grower N and P rates. Irrigation water volume applied, plant diameters, and plant heights were measured periodically
throughout the study and plant tissue samples and soil samples were collected periodically for analysis of N and P content.
Significant differences among treatments were only observed for the irrigation water volume applied. Automating the irrigation
system to irrigate at soil suction exceeding 5 and 15 kPa resulted in 75 and 96% less water applied, respectively, than traditional
irrigation scheduling practices used by a grower. Economic analyses suggested that all treatments would result in financial
savings ranging from 7 to 34% per ha considering a 5-year, 2 ha investment. Thus, automating irrigation based on soil water
suction for palm production in southern Florida, USA and similar locations will result in more sustainable agricultural production
systems by benefiting the environment (less nutrients and water applied) and the grower (lower cost). 相似文献
The S-genotypes of 16 apricot (Prunus armeniaca L.) cultivars native to China were determined by the S-allele PCR approach and the results were confirmed by cross-pollination tests among these cultivars. Primer combination EM-PC2consFD + EM-PC3consR,
based on the conserved regions C2 and C3 of RosaceousS-RNase genes, was the most useful primer combination for identifying Chinese apricot S-alleles. Twelve S-RNase alleles were identified using this primer combination, and they were defined as follows: S9 was 657 bp, S10 was 266 bp, S11 was 464 bp, S12 was 360 bp, S13 was 401 bp, S14 was 492 bp, S15 was 469 bp, S16 was 481 bp, S17 was 487 bp, S18 was 1337 bp, S19 was 546 bp and S20 was 1934 bp. S11–S20 were new S-RNase genes deposited in GenBank under accession numbers DQ868316, DQ870628-DQ870634, EF133689 and EF160078, respectively.
Our findings contribute to a more efficient breeding program of Chinese apricot and further studies on the S-RNase genes. 相似文献
The presence of high levels of sinigrin in the seeds represents a serious constraint for the commercial utilisation of Ethiopian
mustard (Brassica carinata A. Braun) meal. The objective of this research was the introgression of genes for low glucosinolate content from B. juncea into B. carinata. BC1F1 seed from crosses between double zero B. juncea line Heera and B. carinata line N2-142 was produced. Simultaneous selection for B. carinata phenotype and low glucosinolate content was conducted from BC1F2 to BC1F4 plant generations. Forty-three BC1F4 derived lines were selected and subject to a detailed phenotypic and molecular evaluation to identify lines with low glucosinolate
content and genetic proximity to B. carinata. Sixteen phenotypic traits and 80 SSR markers were used. Eight BC1F4 derived lines were very close to N2-142 both at the phenotypic and molecular level. Three of them, with average glucosinolate
contents from 52 to 61 micromoles g−1, compared to 35 micromoles g−1 for Heera and 86 micromoles g−1 for N2-142, were selected and evaluated in two additional environments, resulting in average glucosinolate contents from
43 to 56 micromoles g−1, compared to 29 micromoles g−1 for Heera and 84 micromoles g−1 for N2-142. The best line (BCH-1773), with a glucosinolate profile made up of sinigrin (>95%) and a chromosome number of
2n = 34, was further evaluated in two environments (field and pots in open-air conditions). Average glucosinolate contents over
the four environments included in this research were 42, 31 and 74 micromoles g−1 for BCH-1773, Heera and N2-142, respectively. These are the lowest stable levels of glucosinolates reported so far in B. carinata. 相似文献
Antiproliferative effect of Amaranthus mantegazzianus proteins and peptides released after simulated gastrointestinal digestion (DH% 37.8?±?3.8) was investigated on human colon cancer cell line HT-29. Inhibition of proliferation of HT-29 cells was exhibited after a 24 h treatment with different concentrations of amaranth protein isolate (API) and the peptides released after digestion (DGS), presenting IC50 values of 1.35?±?0.12 and 0.30?±?0.07 mg soluble protein/mL, respectively. Lactate dehydrogenase assay indicated that both samples caused the loss of membrane integrity and cell lysis over HT-29 cells, and DAPI fluorescence microscopies evidenced typical apoptotic features. Moreover, Annexin V-FITC flow cytometry showed a significant increase of early apoptotic and late apoptotic/necrotic HT-29 cells compared to untreated ones, and caspase-3 assay confirmed the apoptosis induction with a 43.0?±?10.3 and 65.8?±?12.7% increase of caspase-3 activity produced by a 2 mg/mL treatment of API and DGS, respectively. In conclusion, amaranth peptides successfully released after simulated gastrointestinal digestion would exert a potential antiproliferative activity over HT-29 tumor cells. This effect was linked to the induction of cell necrosis and apoptosis, supporting the idea of using amaranth proteins as a potential food alternative ingredient for functional foods.
Mexican landrace avocados are naturally distributed mainly in high areas of central Mexico, where they have been produced and consumed since pre-Hispanic times. However, trees of these species are being replaced by improved varieties with greater global demand, and many species have been lost due to the destruction of their natural habitats. Many people in Mexico like to consume the pulp and peel of these fruits and have done so since pre-Hispanic times. This is because the peel of Mexican landrace avocados, unlike the peel of Hass avocados, is very thin and flavorful. The peel color may be bluish-purple or dark reddish due to the presence of anthocyanins, which are compounds with antioxidant activity. The objective of this study was to assess the oil and anthocyanin contents and to evaluate the antioxidant activity in fruits of 11 accessions collected from producing-regions of Mexico. The oil content was 16.2 to 32.3 g 100 g?1 in pulp, and the main unsaturated fatty acids were oleic, linoleic and palmitoleic acids, depending on the accession. The anthocyanin contents in peels ranged from 0.64 to 47 mg g?1 fresh weight. The highest antioxidant activity was found in the peel (53.3–307.3 mmol g?1 fresh weight). The results confirm that the pulp and peel of dark-peel Mexican landrace avocados could be important nutraceuticals for humans.