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991.
Juan R. Boyero Raúl Ruiz-López Néstor Rodríguez José M. Vela Ramón Moreno Felipe Pascual 《国际虫害防治杂志》2013,59(3):217-225
Abstract We studied the influence of two orange tree varieties on the fecundity of two hemipteran diaspidid scale insect species: Cornuaspis beckii (Newman) and Parlatoria pergandii Comstock. Samples of females were taken at 7 – 40 day intervals from two orange orchards [Citrus sinensis (L.) Osbeck], one of the Navel Lane Late cultivar and the other of the Valencia Late cultivar. Different categories for the egg stage were considered: preoviposited, oviposited and hatched eggs. Average fecundity in C. beckii was significantly higher than that of P. pergandii. Significant differences between the two orange varieties were evident for some egg categories, with a higher fecundity in Navel Lane Late than in Valencia Late. The temporal pattern of fecundity in relation to accumulated temperature was studied by two methods: (i) comparing the parameter r of a logistic function that related egg-days to accumulated degree-days, and (ii) comparing the parameters b and c of a sinusoidal function that relates the variation egg-days/degree-days to accumulated degree-days. The comparison of such parameters (indicators of changes in the temporal patterns of fecundity) did not show significant differences between orange varieties. Our results suggest that some type of physiological difference between Navel Lane Late and Valencia varieties could be responsible for the differential fecundity of diaspines. Nevertheless, currently we cannot recommend changes in the management of diaspine in citrus orchards. 相似文献
992.
993.
Josângela do Carmo Trezena de Araújo Clístenes Williams Araújo do Nascimento 《Water, air, and soil pollution》2010,211(1-4):113-120
Phytoextraction is a soil remediation technique involving plants that concentrate heavy metals in their shoots, which may be removed from the area by harvest. The application of synthetic chelants to soil increases metal solubility, and therefore enhances phytoextraction. However, synthetic chelants degrade poorly in soil, and metal leaching poses a threat to human and animal health. The aim of this study is to assess the use of two biodegradable chelants (citric acid and nitrilotriacetic acid (NTA)) for Pb phytoextraction by maize from a soil contaminated by battery-casing disposal. In order to assess the behavior of a non-degradable chelant, ethylenediaminetetraacetic acid (EDTA) was also included in the experiment. The chelants NTA and EDTA were applied to soil pots at rates of 0, 3, 5, 7, and 10 mmol kg?1 of soil. The rates used to citric acid were 0, 5, 10, 15, and 30 mmol kg?1. Maize plants were grown for 72 days and chelants were applied 9 days before harvest. Soil samples were extracted with CaCl2 to assess the Pb solubility after chelants application. The results showed that NTA was more efficient than citric acid to solubilize Pb from soil; however, citric acid promoted higher net removal of Pb (120 mg pot?1) than NTA (57 mg pot?1). Thus, the use of citric acid, a biodegradable organic acid, could be feasible for enhancing the phytoextraction of Pb from the site studied with no environmental constraints. 相似文献
994.
Fatima Maria de Souza Moreira Teotonio Soares de Carvalho José Oswaldo Siqueira 《Biology and Fertility of Soils》2010,46(8):771-779
The aim of this study was to evaluate the effects of lime, fertilizers, mycorrhizal fungi, and selected rhizobia strains on the growth of four woody legume species, Albizia lebbeck (L.) Benth., Enterolobium contortisiliquum (Vell.) Morong., Leucaena leucocephala (Lam.) de Wit, and Sesbania virgata (Cav.) Pers. in a low-fertility soil. The experiment was conducted under greenhouse condition in plastic pots (4 kg). Eight treatments and eight replicates per treatment were performed in a completely randomized design. The treatments were: (1) complete treatment (C) (NPK fertilization?+?micronutrients?+?liming?+?MR that is inoculation with mycorrhizal fungi and rhizobia); (2) C minus N (C???N that is as C without the addition of N); (3) C???N???M (as C???N without inoculation with arbuscular mycorrhizal fungi (AMF)); (4) C???N??R (as C???N without inoculation of rhizobia); (5) C???N???liming (as C???N without liming); (6) C???N???micro (as C???N without addition of micronutrients); (7) C???N???P (as C???N without addition of P); (8) control without fertilization, liming, and without inoculation with AMF and rhizobia. After 4 months of growth, we determined the yield of individual plants, nodulation, mycorrhizal colonization, and nutrient contents. Phosphorus was the most limiting nutrient for plant growth, followed by nitrogen. L. leucocephala and S. virgata had the most robust response to the addition of micronutrients and liming, showing an increase in nutrient content, plant height, and root and shoot dry matter. When compared to the single inoculation, the dual inoculation increased growth of all plants, except that of A. lebbeck, which did not respond to either rhizobia or mycorrhizal fungi inoculation. 相似文献
995.
Elena L. Peredo M. Ángeles Revilla Barbara M. Reed Branca Javornik Eduardo Cires José Antonio Fernández Prieto Rosa Arroyo-García 《Genetic Resources and Crop Evolution》2010,57(4):575-586
Microsatellite variation at the nuclear and chloroplast genomes was evaluated for wild European and wild American hops, in
order to assess the genetic diversity and origin of cultivated hops. Seven nuclear loci and 32 chloroplast loci were used in the analysis of 182 hop accessions including wild European (68), wild American (48), and cultivars (66). A total
of 116 alleles were identified using 7 nuclear microsatellites showing different averages of polymorphism and distribution
in the wild American and European accessions and cultivars. Two main groups were established as revealed by several statistical
analyses; one including European wild accessions and cultivars and a second group consisting of American wild accessions.
Three polymorphic chloroplast microsatellite loci were detected, six alleles were scored which defined a total of five haplotypes that were exclusive or presented different
distribution between American and European wild accessions. A major influence of the wild European haplotypes was detected
among hop cultivars. To the best of our knowledge, this is the first work reporting the use of chloroplast microsatellites
in hops. 相似文献
996.
Virginia Hernández-Santana José Martínez-Fernández Carlos Morán Ana Cano 《European Journal of Forest Research》2008,127(5):369-378
In the present study, carried out from 2004 to 2006, leaf and stem water potential and stem water content were measured in
Quercus pyrenaica Willd. individuals in an experimental forested catchment located in Central Western Spain under Mediterranean subhumid conditions.
These indicators of tree water status were compared with soil moisture contents measured in the same area from 0 to 1 m depth
and from 0 to 2.5 m depth during the last year of the study. The objectives were to clarify the seasonal and year-to-year
variations in tree water status, to examine applicability of stem water content as useful water stress indicator and to discuss
how deep soil water and root uptake contribute to survival during the long dry summer. Seasonal variations in the tree variables
measured revealed a typical pattern, with maximum values at the end of spring followed by a progressive decline during the
summer drought in response to the decrease in soil water content (almost exhausted at 0–100 cm depth). The relatively high
values and the non-significant variation in predawn leaf water potentials (except for 2005, which was exceptionally dry) indicate
that no clear water stress situations occurred. This may be explained in terms of a progressive absorption of water from the
deeper layers. The results also suggest that the stem water content is a more sensitive indicator of long-term water limitation
than the other variables measured. 相似文献
997.
M. Manuel Robles-González Víctor Manuel Medina-Urrutia José Joaquín Velázquez-Monreal June Simpson 《Euphytica》2008,161(3):401-411
The Mexican lime industry is interested in developing lime cultivars with improved characteristics for fresh and processing
markets. The objective of this study was to determine the field performance and genetic molecular differences among four new
Mexican lime [Citrus aurantifolia (Christm) Swingle] clonal selections compared to traditional thorny Mexican lime under the dry tropical conditions of Mexico.
Tree growth, production, fruit quality, and molecular markers of the traditional thorny Mexican lime (MLT) cultivar were compared to the following lime selections:
thornless Mexican lime (MLTS), seedless Mexican lime (MLS), ML 12-8, and ML 20-3. After 10 years of evaluation MLS showed
the highest and MLTS the lowest tree growth. Most of the genotypes covered the soil surface area assigned to tree growth since
they were 7 years old. Only the less vigorous MLTS required 9 years to cover the same space. MLT was the most productive selection
(165 kg/tree/year, mean of 8 years of evaluation). MLS was the less productive (81 kg/tree in the same period of time). MLTS,
ML 12-8, and ML 20-3 produced intermediate yields. Acidity and total soluble solids among the selections were very similar.
However, MLS had the higher juice content and the lower seed number. The MLS selection is attractive for export market due
to these characteristics. AFLP studies confirmed genetic differences among the five lime selections. Nevertheless, all five
selections shared many bands as expected. 相似文献
998.
Molecular markers linked to the <Emphasis Type="Italic">fin</Emphasis> gene controlling determinate growth habit in common bean 总被引:1,自引:1,他引:0
Astrid Pañeda Cristina Rodríguez-Suárez Ana Campa Juan José Ferreira Ramón Giraldez 《Euphytica》2008,160(2):241-248
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 Rosaceous
S-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: S
9 was 657 bp, S
10 was 266 bp, S
11 was 464 bp, S
12 was 360 bp, S
13 was 401 bp, S
14 was 492 bp, S
15 was 469 bp, S
16 was 481 bp, S
17 was 487 bp, S
18 was 1337 bp, S
19 was 546 bp and S
20 was 1934 bp. S
11–S
20 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
999.
Angustias Márquez-Lema José M. Fernández-Martínez Begoña Pérez-Vich Leonardo Velasco 《Euphytica》2008,164(2):365-375
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
1000.