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1.
I IntroductionBacterial Blight( Xanthomonas malvacearum,BB) was probably originated in India,althoughthe disease was first reported in the USA byAtkinson( 1 891 ) ,who gave the names angularleaf spot,blackarm and bacterial boll rot to thevarious stages in the syndrome of the disease.The first programme to breed for cultivarresistance to the disease was initiated in Sudanby research officers with the Cotton ResearchCorporation.Methods adopted there were soonimplemented in Uganda and most…  相似文献   

2.
Lily leaf blight,caused by Botrytis elliptica,is an important fungal disease in Taiwan.In order to decrease the disease incidence in Lilium formosanum,the efficacy of application of rhizobacteria for induced systemic resistance(ISR)was examined in this study.Over 300 rhizobacteria were isolated from the rhizosphere of L.formosanum healthy plants and 63 were identified by the analysis of fatty acid profiles.The ability of disease suppression of 13 strains was demonstrated by soil drench application of bacterial suspensions to the rhizosphere of L.formosanum seedlings.Biocontrol experiments were carried out with Bacillus cereus and Pseudomonas putida strains on Lilium Oriental hybrid cultivars Acapulco and Star Gazer besides L.formosanum in the greenhouse and field conditions.The assay with a B.cereus strain good for disease suppression showed that the protection against B.elliptica on L.formosanum could last for at least ten days,consistent with the good association of B.cereus with lily roots.Analysis of the expression of LfGRP1 and LsGRP1,encoding glycine-rich protein of L.formosanum and cv.Star Gazer,respectively,reveals a difference between that in response to the treatment of B.cereus and that singly induced by B.elliptica,suggesting that plant defense responses driven by B.cereus follows a signaling pathway different from that triggered by B.elliptica.According to the results of biocontrol assay and LfGRP1/LsGRP1 gene expression analysis with the culture filtrates of B.cereus strains,we presume that more than one eliciting factor of ISR are generated by B.cereus and some of them exhibit thermostable and autoclave-tolerant traits.This is the first report about ISR-eliciting rhizobacteria and determinants effective for foliar disease suppression on lily.  相似文献   

3.
4.
Based on monitoring data of water quality and river runoff from 2007 to 2008, the dynamics of TN and TP transported into the backwater region of the Linjiang River were investigated and fluxes of TN and TP were also estimated. It was shown that the dynamic changes of TN and TP were significant. The concentration of TP in rainy seasons was higher than that in dry seasons, while the cases for TN was contrary. The fluxes of TN and TP were significantly higher in rainy seasons than those in dry seasons. On average, there were about 4 142 t TN and 455 t TP transported into the backwater region of the Linjiang River every year. And TN flux decreased by 32.7% from 2007 to 2008, while TP flux increased by 34.3%, which was in agreement with the inter annual variation of the concentrations of TN and TP. TN flux was primarily influenced by river runoff, whereas TP flux was affected by both concentration and runoff. Further analyses indicated that TN was mainly caused by point source pollutants(dominated by NH3N, and then DON). On the contrary, TP was mainly caused by plane source pollutants(dominated by PO34P). It was also indicated that it was critical to control the point source pollution in the basin to promote the water quality of the backwater region of the Linjiang River.  相似文献   

5.
Though Ginkgo biloba extract(GBE)and ginsennosides(GS)also have notability bioactivity on cardiovascular disease,there is little literature about applying the compound of them to treat cardiovascular disease.After endothelium cells suffering from oxidative injury were treated with serum containing GBE,GS and the compound of them(GG),respectively,production of NO,ET and MDA in them was observed by applying serum pharmacology.Both GBE and GS up-regulate NO level and down-regulate ET-1 and MDA level in endothelium cells suffering from oxidative injury.Anti-oxidation activity increased after GBE and GS were combined.But the NO up-regulation of GG was inferior to that of GBE and GS,which decreased by 29.9% and 66.7% when compared with that of GBE and GS,respectively.The ET-1 down-regulation of GG was superior to that of GBE, but decreased by 11.6% compared with that of GS.The compatibility of GBE and GS do not show synergic effect on NO and ET-1 regulation in endothelium cells and it is valuable to discuss that the compound of GBE and GS is used to treat cardiovascular diseases.  相似文献   

6.
Differential Evolution (DE) was introduced to get the global optimum and overcome the difficulties encountered by coupling two types of design variables in the shape optimization of truss structures with stress, geometry, and local stability constraints. The basic principle of DE algorithm was presented in detail first, and then mathematical model for shape optimization of truss structures was presented, in which two types of design variables, such as the node coordinates and section areas, were considered simultaneously. Several classical problems were solved with DE algorithm, and the results were compared with those using the other optimization methods. It was shown that DE algorithm had good convergence and stability and could be applied for shape optimization of truss structures effectively.  相似文献   

7.
Ecological Stabilization for Sewage Sludge   总被引:2,自引:0,他引:2  
Pilot scale sewage sludge ecological stabilization system was conducted for sludge dewatering,mineralization and stabilization.The study was performed from 2005 to 2008 on a bed with a total area of 80 m 2.Influent total solid,volatile solid and water content were averaged 22.34 g/L,7.76 g/L and 97%.Sludge loading rate was averaged 0.691 kg(TS)/m 2·d.The first two years were sludge loading period and the other two years were natural stabilization period.The percolate COD removals ranged from 60%~80% in the first year,and from 40%~50% in the second year,with 100~200 mg/L of effluent COD concentration.During the first two years,the percolate did not filtrate downwards evenly.Part of percolate filtrated downwards along stems,roots and cracks existing in dried sludge which had lower flow resistance.During the natural stabilization periods,sludge water contents decreased to 34.3% and 30.5%,and organic matter contents decreased to 16.8% and 10.24% in the third and forth years,individually.Total nitrogen and total phosphorus contents of stabilized sludge were averaged to 0.98% and 0.27%.It was found that plant biomass and nutrient components in the system were higher than that of native ones.  相似文献   

8.
Aiming at the fact that parameters in support vector machine(SVM) model were difficult to be identified, a genetic algorithm SVM(GA SVM) was proposed to avoid the blindness in parameter choosing and improve the estimation ability of SVM, in which the parameters in SVM and kernel function were searched by genetic algorithm. And it was then applied to the classification for the swell and shrink grade of expansive soils. Five indexes including liquid limit, total swell shrink ratio, plasticity index, water contents and free expansive ratio were adopted as discriminated factors. And the four grades of the expansive soils were the outputs correspondingly. Classification function was obtained through training a large set of expansive samples. And it was shown that the classification method of GA SVM was effective and with high accuracy.  相似文献   

9.
In the experiment, the denitrifying phosphorus removing bacteria (DPB) was cultivated by high phosphorus and low carbon source influent. It was cultivated successfully by the 2 stage mode for about 100 d. The first stage was about 40 d, which was with the mode of anaerobic/aerobic to enrich the phosphorus accumulating organisms (PAOs). The maximum amounts of the phosphorus release, phosphorus uptake and phosphorus removal were 77.2 mg/L, 89.4 mg/L and 250 mg/L respectively. The second stage was 60 d, which was with the mode of anaerobic/anoxic/aerobic. In this stage, the ratio of denitrifying phosphorus uptake amount to the total phosphorus uptake amount had an ascending tendency. The cultivation of nitrifying activated sludge was about 100 d, with the 50 mg/L ammonia removal amount and more than 98.5% ammonia removal efficiency. Nitrification rate fitted zero order kinetic equation, and the specific nitrification rate constant was 0.002 4 h-1. Phosphorus uptake rates fitted first order absorption kinetic equation. The uptake rate constants under aerobic and anoxic conditions were 0.377 and 0.740 L/(g·h-1). The cultivated DPB sludge and nitrifying activated sludge were used in an anaerobic/anoxic/nitrification sequencing batch reactor(A 2N-SBR) process to remove nitrogen and phosphorus. When the concentrations of influent COD, ammonia and phosphorus were 188.0 mg/L, 54.8 mg/L and 725 mg/L, the removal efficiencies of COD, ammonia and phosphorus were 935%, 76.7% and 94.1% respectively.  相似文献   

10.
Under the microwave irradiation, a highly effective adsorptive material zeolitized fly ash (FZ) was made by adding a certain amount of mineralizer in the raw material of the limestone and fly ash. The structure of zeolite and the mechanism of modification were investigated by the analysis of XRD and SEM.The stabilization mechanism was analyzed and the variation of heavy metals and nutrient contents in sewage sludge were investigated through the sludge stabilization experiment by mixing zeolitized fly ash in the municipal sewage sludge. It was indicated that the zeolitized fly ash had obvious stabilization effect to heavy metals (Zn、Cu、Mn) and had apparent retention ability to the nutrients contents of N、P of the municipal sewage sludge. The heavy metals contents of Zn, Cu and Mn were all significant lower than those in the national control standards for pollutants in sludges from Agricultural. After the stabilization treatment of the municipal sewage sludge, the total content of N was lower than that in the national surface water environmental quality standards (10 mg/L), the total content of P was lower than that in Quality Standard of the Sewage discharged into the city sewer system(1 mg/L).  相似文献   

11.
P. E. Abidin    F. A. van  Eeuwijk  P. Stam    P. C. Struik    M. Malosetti    R. O. M. Mwanga    B. Odongo    M. Hermann    E. E. Carey 《Plant Breeding》2005,124(5):491-497
Sixteen sweet potato varieties were evaluated for fresh storage root yield in 20 trials during 2000–2001 for three seasons in four locations in Uganda. Of the 16 varieties, 11 were developed by farmers and five by a central breeding programme. The behaviour of the varieties was quantified in terms of wide adaptation (genotypic mean across trials), specific adaptation (genotypic predictions for specific locations) and stability (Shukla stability variance). With respect to all three aspects of yield behaviour, farmer varieties performed on average better than the official varieties. The results illustrate the potential that farmer varieties can have in the improvement of sweet potato in Uganda and other regions where high diversity of sweet potato landraces exists.  相似文献   

12.
Common beans (Phaseolus vulgaris) are separated into two distinct groups: Andean and Middle American. We identified CAL 143 as the first Andean bean with resistance to angular leaf spot disease caused by Phaeoisariopsis griseola. Angular leaf spot is the most widespread and economically important bean disease in southern and eastern Africa, and it is especially severe on the extensively grown Andean beans. Cal 143 was resistant in Malawi, South Africa, Tanzania, and Zambia, but it was susceptible in Uganda. This was attributed to the presence of races of P. griseola in Uganda not present in the other countries. We identified two additional Andean bean lines, AND 277 and AND 279, with resistance to angular leaf spot in Malawi. We also characterized the virulence diversity of 15 isolates of P. griseola from southern and eastern Africa into nine different races. Five of six isolates from Malawi and two of seven from Uganda, obtained from large-seeded Andean beans, were characterized into four different races considered Andean. These were compatible only or mostly with large-seeded Andean cultivars. The other eight isolates from Uganda, Malawi, and the Democratic Republic of Congo, obtained from a small- or medium-seeded Middle American beans, were characterized into five different Middle American races. These were compatible with Middle American and Andean cultivars. CAL 143 was resistant or intermediate under greenhouse conditions to all but one of the same 15 isolates from southern and eastern Africa, but it was susceptible to an isolate from Uganda obtained from a medium-seeded Middle American bean. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

13.
Summary Cassava (Manihot esculenta) is a tropical crop that is grown in Africa, Latin America and Southeast Asia. Cassava was introduced from Latin America into West and East Africa at two independent events. In Uganda a serious threat to cassava's survival is the cassava mosaic disease (CMD). Uganda has had two notable CMD epidemics since the introduction of cassava in the 1850s causing severe losses. SSR markers were used to study the effect of CMD on the genetic diversity in five agroecologies in Uganda with high and low incidence of CMD. Surprisingly, high gene diversity was detected. Most of the diversity was found within populations, while the diversity was very small among agroecological zones and the high and low CMD incidence areas. The high genetic diversity suggests a mechanism by which diversity is maintained by the active involvement of the Ugandan farmer in continuously testing and adopting new genotypes that will serve their diverse needs. However, in spite of the high genetic diversity we found a loss of rare alleles in areas with high CMD incidence. To study the effect of the introgression history on the gene pool the genetic differentiation between East and West Africa was also studied. Genetic similarities were found between the varieties in Uganda and Tanzania in East Africa and Ghana in West Africa. Thus, there is no evidence for a differentiation of the cassava gene pool into a western and an eastern genetic lineage. However, a possible difference in the genetic constitution of the introduced cassava into East and West Africa may have been diminished by germplasm movement.  相似文献   

14.
Rust caused by Uromyces appendiculatus (Pers., Pers.) Unger is one of the major foliar diseases of common bean (Phaseolus vulgaris) in Uganda. The use of host resistance remains the best option in managing this disease. The objective of this study was to identify sources of broad-spectrum rust resistance in common bean germplasm including landraces, commercial cultivars and introduced genotypes using a combination of phenotypic and genotypic screening with 22 simple sequence repeat (SSR) markers located on chromosome Pv04. A total of 138 genotypes were field screened from 2014 and 2015 using an alpha lattice design. The variance and correlation of disease incidence, area under the disease progression curve (AUDPC) and total grain yield were computed using GenStat. The polymorphism information content of the genotypes was determined, and the association of the markers and the disease resistance traits were analyzed using PowerMarker and TASSEL respectively. Resistance of each genotype was compared to the presence and absence of amplified markers. There were highly significant differences (P < 0.001) among the genotypes for disease incidence, AUDPC and total grain yield and a strong correlation (P < 0.001) between disease incidence and AUDPC in both years. The SSR markers, BARC_PV_SSR04725, bean_ssr_0778 and bean_ssr_2892 were associated (P ≤ 0.05) with rust resistance. Fifteen 15 genotypes which included the landraces Nabufumbo, and Kapchorwa white, and the commercial cultivar NABE 2 were identified as new sources of rust resistance that would be useful in future bean breeding programmes in Uganda.  相似文献   

15.
猪肺炎支原体净化检测程序研究进展   总被引:1,自引:1,他引:0  
猪支原体肺炎(猪气喘病)是由猪肺炎支原体引起的一种严重危害全球养猪业生产的传染病之一。很多国家,特别是西欧各国和北美,均通过彻底净化病原的方式来控制该病的爆发。实行净化程序必须对净化后的猪群进行各项检测以确定净化成功与否。然而,每个猪场采用的检测方案都不一样,也没有形成一个统一的阴性群标准。本研究就国外猪肺炎支原体净化后阴性群的检测方法和不同检测方案做一综述,给国内猪场实施气喘病净化后检测方案的制定提供依据。  相似文献   

16.
In this study, field experiments have been conducted over three growing seasons to evaluate the effect of fungicides (triazoles and strobilurins) and a foliar fertilizer application to winter wheat at anthesis on flag leaf senescence, grain yield, bread-making quality, Fusarium head blight (FHB) disease and deoxynivalenol (DON) contamination.Flag leaf greenness was significantly influenced by the fungicide application. A delay in flag leaf senescence following triazole use did not increase grain yield. No effects of fungicide application on protein concentration were recorded. The application of strobilurin to a triazole programme did not significantly delay senescence of the flag leaf or increased yield, compared to the triazole-only application, while a consistent benefit was observed for dough strength (W). The triazole application led to significantly lower FHB symptoms and DON contamination, while the triazole-strobilurin fungicides programme led to an increase in DON contents, that were often higher than the untreated controls.Grain yield and quality were improved when a foliar feed containing macro- and micro-nutrients was added to a triazole fungicide programme, with no additional risk for DON contamination. Compared to the strobilurin fungicide application, the foliar fertilizer led to a longer delay of the flag leaf senescence and higher bread-making quality.  相似文献   

17.
Forty-five Musa clones, including endemic and introduced cultivars plus hybrids, were evaluated for resistance against the banana weevil, Cosmopolites sordidus, in a field trial in Uganda. The predominant groups of staple crops, East African highland bananas (Musa spp. AAA) and plantains (Musaspp. AAB), as well as plantain-derived hybrids (AAB × AA), showed the highest levels of susceptibility to this pest. These were followed by dessert bananas (Musa spp. AAA), exotic bananas (Musa spp. ABB) and finally diploids of M. acuminata (AA). Hybrids of banana origin were highly resistant. Some East African highland cultivars, especially brewing types (e.g., Kabula, Bagandeseza, Ediirira), showed intermediate levels of resistance. Among the non-highland bananas, high levels of resistance were observed in Yangambi-Km5 (AAA), Cavendish (AAA), Gros Michel (AAA), Kayinja (ABB, Pisang Awak subgroup), Ndiizi (AB, Ney Poovan subgroup)and Kisubi (Ney Poovan subgroup). The highest resistance was observed in banana hybrids TMB2×7197-2, TMB2×8075-7 and the wild banana Calcutta-4 (AA). These were considered the best sources of resistance for a weevil resistance-breeding programme with the two hybrids commonly used as improved male parents. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

18.
Z. P. Yang    X. Y. Yang  D. C. Huang 《Plant Breeding》1999,118(4):289-292
The objectives of this study were to compare efficiency of evaluation for resistance to Fusarium head blight (FHB) under two inoculation methods in a recurrent selection programme. Fifty selected homozygous F5 fertile lines, from each of five cycles (C0, C1, C2, C3 and C4) of recurrent selection, and two control cultivars were evaluated in a split-plot design in 1995 and 1996 under the soil-surface inoculation with Fusarium graminearum-colonized kernels and the single-floret inoculation with ascospore suspension. Comparison of the two inoculation methods using means, ranges, coefficients of variation, heritabilities and correlations among infected spikelet rate (ISR), reaction index (RI) and disease index (DI) indicated that FHB resistance could be evaluated with similar accuracy and precision using either of the two inoculation methods. Regressions of disease scores in the soil-surface inoculation on disease scores in the single-surface inoculation were positive and highly significant, showing a strong relationship between both inoculation methods for FHB resistance. The percentage of lines with similar performance for FHB disease scores in both inoculation methods was high. The soil-surface inoculation and single-floret inoculation appear to be useful techniques for evaluating numerous individuals of segregating population and screening advanced homozygous lines for FHB resistance in a recurrent selection programme in wheat, respectively.  相似文献   

19.
高粱空间诱变效应研究   总被引:8,自引:0,他引:8  
1996年利用我国第17颗返回式卫星对高粱唐恢28恢复系种子进行搭载处理后,对其变异后代进行了田间鉴定和同工酶及RAPD分析。主要结果如下:(1)SP1代获得一个特大穗型突变体(MTR28),其后代性状分离广泛,变异类型丰富,从中获得了遗传性状稳定且具有不同特点的高产、抗病优良变异选系;(2)优良变异选系组配的杂交种产量明显高于对照,可应用于生产上组配高产、抗病杂交种;(3)空间诱变后代性状稳定时间比常规杂交后代稳定快2—4个世代,可缩短育种进程;(4)变异选系在酯酶同工酶和细胞色素氧化酶同工酶酶带种类及酶活性上存在着较大的遗传差异;(5)RAPD分析结果显示,空间诱变选系在基因组水平上发生了明显的变化。  相似文献   

20.
Quantitative trait locus (QTL) analyses for combustion‐related traits including calcium, phosphorus and sulphur content have been carried out using two years of field trial data. Nine putative QTLs were detected using the Multiple QTL Model approach and the programme MapQTL 4.0. Two QTLs were found for calcium, two for sulphur and five for phosphorus. Out of the QTLs for phosphorus, P1 is probably the same locus as P3, and P2 as P4, although their confidence intervals do not agree. Ca1 was also consistently detected. These results may constitute the first step in developing a Marker‐Assisted Selection programme in Miscanthus for combustion‐related traits.  相似文献   

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