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101.
M. F. Moura M. C. Picanço R. N. C. Guedes E. C. Barros M. Chediak E. G. F. Morais 《Journal of Applied Entomology》2007,131(3):215-220
Abstract: A conventional sampling plan for the leafhopper Empoasca kraemeri Ross & Moore (Auchenorrhyncha: Cicadellidae) in common beans (Phaseolus vulgaris L.) is presented based on samples from 51 commercial fields. The research encompassed three phases. The first phase had the objective of determining the most suitable leaf to be used as a precise and representative sampling unit. In the second phase of the project, the available sampling methods for E. kraemeri were compared, including the approach identified in the first phase. In the third phase, the theoretical frequency distribution of the sampling data was assessed and the number of samples necessary for the sampling plan was established. The best leaves to sample adult leafhoppers were the fourth and the fifth from the apex, while the best leaf for sampling nymphs was the fifth from the apex. The best sampling technique for nymphs and adults was the beating of the apical leaves against a plastic tray. The sampling data obtained with this technique were fit to a negative binomial distribution with common aggregation parameter for adults ( K common = 1.04) and nymphs ( K common = 0.47). This sampling plan required 16.8 and 31.2 min to be carried out at an expense of US$ 0.31 and US$ 0.54 for sampling adults and nymphs in a field, respectively. 相似文献
102.
Using hygromycin B resistance as a marker for selection, we have established the conditions required for the transformation
of Chlorella vulgaris. The exponentially grown C. vulgaris cells were transformed by electroporation with plasmid pIG121-Hm, and transformants were selected with hygromycin B at a
concentration of 50 μg/ml. Cell extracts prepared from the late-log cultures of the transformants exhibited glucuronidase
activities as conferred by the gus gene on pIG121-Hm. The maintenance of plasmid in the algal cells seemed to be transient as many cultures derived from the
hygromycin B-resistant colonies gradually lost the hygromycin resistance upon prolonged growth. The result of Southern blotting
of the genomic DNAs prepared from transformant cultures exhibiting persistent hygromycin resistance showed that integration
of part of the plasmid DNA into the host chromosome had taken place.
Received: 19 December 1997 / Revision received: 5 October 1998 / Accepted: 27 October 1998 相似文献
103.
杏愈伤组织的超低温保存 总被引:11,自引:1,他引:10
杏茎段在附加1.0mg/L 2,4-D和0.1mg/L BA的改良MS培养基中诱导出愈伤组织,放入10%DMSO+0.5mol/L山梨醇或葡萄糖的冰冻保护剂中,以1C/min的降温速度降至-40℃,停留2h后投入液氮保存,在40℃水浴中化冻。继代培养8次生长15-20d的愈伤组织保存后的相对存活率最高,不同品种基因型保存效果差异很大,保存后的愈伤组织生长量比对照减少,但经过2次继代培养后不再表现差 相似文献
104.
植物激素在小球藻异养培养中的作用 总被引:8,自引:0,他引:8
本文研究了几种植物激素对小球藻异养培养的影响。结果表明 ,IAA、IBA及 6_BA三种植物激素均不同程度地促进了小球藻的异养生长 ,培养≤ 36h时 ,IAA或IBA以 2 0mg/L的促进小球藻异养生长的效应最大 ,1 0 0mg/LIAA或IBA则抑制了藻的生长 ;>36h时 ,1 0 0mg/LIAA或IBA表现出促进小球藻生长的效应 ,并最终获最大净A540 增长量 ;6_BA以 0 1mg/L的促进作用最大。IBA与 6_BA组合同样表现出促进小球藻异养生长的效应 ,但并非IBA和 6_BA简单的加合效应 ,5mg/LIBA与 6_BA组合的效应维持 6_BA单因子的作用趋势 ,2 0mg/LIBA与 1mg/L 6_BA组合的效应大于与 0 .1mg/L 6_BA组合的 ,1 0 0mg/LIBA与 0 .1mg/L 6_BA组合的效应在≤ 36h时大于与 1mg/L 6_BA组合的 ,>36h时则相反。另外 ,高浓度IBA(≥ 2 0mg/L)与 6_BA组合抑制了前中期异养藻对葡萄糖的吸收 ,但加速了中后期葡萄的吸收。再者 ,IBA与 6_BA组合加速了异养小球藻对NO_3 的吸收。 相似文献
105.
106.
UWE MOHR JÜRG LANGE THOMAS BOLLER RES WIEMKEN & REGINA VÖGELI-LANGE 《The New phytologist》1998,138(4):589-598
107.
Rodolfo FaríasRodríguez Robert B. Mellor Carlos Arias Juan José PeñaCabriales 《Physiologia plantarum》1998,102(3):353-359
Nine cultivars of common bean were grown in the presence of a natural microflora without exogenous rhizobial inoculation. Nodules were harvested 30 days post planting (early flowering stage) and the presence of trehalose determined. Amounts present varied according to cultivar and were between 0.20 and 1.63 mg g−1 nodule dry weight. Rhizobial strains were isolated from the nodules of three selected cultivars (Canario 101, Flor de Mayo Bajio and Flor de Mayo 38). Trehalose levels in nodules produced after either mixed strain reinfection, or after axenic homologous reinfection or after axenic cross‐reinfection could be manipulated by applying drought stress. Mixed reinfection nodules from stressed plants accumulated between two and six times the trehalose concentration found in non‐stressed control plants. After axenic cross‐reinfection up to 48‐fold increases in nodule trehalose content were recorded during drought stress. Those cultivars exhibiting high nodule trehalose levels and/or a high degree of trehalose stimulation in response to drought stress also exhibited a high leaf relative water content and were also the most drought resistant. During drought stress nodule trehalase levels rose only slightly. 相似文献
108.
T. Schmidt S. Kubis A. Katsiotis C. Jung J. S. Heslop-Harrison 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(5-6):696-704
In a search for repetitive DNA sequences in the sugar beet genome, two sequences with repeat unit lengths of 143 and 434 bp
were isolated and characterized. The pSV family showed an unusual conservation of restriction sites reflecting homogenization
of the analyzed repeats. Members of the family are organized as tandem repeats as revealed by PCR and sequencing of dimeric
units. The pSV satellite occurs in large intercalary arrays which are present on all chromosome arms of sugar beet. The pSV
sequence family is present in different abundance in the sections Beta, Corollinae and Nanae but is not detectable by Southern hybridization in the section Procumbentes. The pDRV family is characterized by an interspersed genomic organization. The sequence is detectable in all sections of
the genus and is amplified in species of the section Beta but was also detected, although at lower abundance, in the remaining three sections. Fluorescent in situ hybridization has
shown that the pDRV sequence family is dispersed over all chromosomes of the sugar beet complement with some regions of clustering
and centromeric depletion.
Received: 18 March 1998 / Accepted: 31 March 1998 相似文献
109.
Relative importance of osmotic-stress and ion-specific effects on ABA-mediated inhibition of leaf expansion growth in Phaseolus vulgaris 总被引:2,自引:1,他引:1
The osmotic and ion-specific components of salt-induced inhibition of leaf expansion growth were investigated in beans grown from 12 h to several days in either NaCl-containing solution cultures, an isosmotic concentrated macronutrient solution, or a vermiculite–compost mixture with low Na+ but high Cl– availability. Inhibition of leaf expansion and leaf ABA increase was more intense in the NaCl than in the isosmotic macronutrient treatment. Root Na+ was highly correlated to inhibition of leaf expansion and leaf or xylem sap ABA. When Na+ was sequestered in soil, salinized plants showed no reduction in leaf expansion or ABA increase, regardless of the presence of high leaf Cl– concentrations. Stomatal conductance exhibited an exponential relationship with the reciprocal value of xylem sap ABA. Our results indicate that an ion-specific effect caused by Na+ in roots may account for an ABA-mediated reponse of both stomatal closure and leaf expansion inhibition. 相似文献
110.