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1.
This study aimed to examine the induction of disease resistance, and growth response in chilli plants elicited by plant growth promoting endophytic bacteria [Pseudomonas aeruginosa （UPMP3）, Burkholderia cepacia （UPMB3）, and Serratia marcescens （UPMS3）]. Seed bacterization with UPMP3 and UPMB3 significantly increased peroxidase （PO）, polyphenol oxidase （PPO）, and phenylalanine ammonia-lyase （PAL） activities. This increase corresponded to greater reduction in pre-and post-emergence damping-off caused by Sclerotium rolfsii. UPMS3 alone or as mixture with UPMP3 and UPMB3 did not show any significant reduction in disease incidence. However, all the isolates tested did not inhibit the seed germination and seedling establishment in chilli.  相似文献   

2.
Sugar Baby susceptible to Fusarium axysporum f.sp.niveum was crossed with high resistant male parents D3-1 and D3-2 ,respectively,F1 hybrids showed high resistance,The segregation rations of resistance to susceptibility of F2 and of BC1 hybrid population from Sugar Baby tallied with 3:1 and 1:1 ,respectively,The results indicated that the resistance to Fusarium wilt was a kind of dominant inberitance controlled by mono-gene or mono-segment DNA,Furthermore,5 hybrid combinations with fine character wre bred,Among them,3 were high resistant to Fusarium wilt,and 2 were medium resistant.  相似文献   

3.
Fusarium wilt caused by Fusarium oxysporum f.sp. cucumerinum （Owen） is one of the most devastating diseases in cucumber production worldwide. Recent progresses in the mechanism of resistance to Fusarium wilt in cucumber were reviewed in this paper, including pathogenic mechanism of Fusarium oxysporum, the resistance mechanism of cucumber, the heredity of resistance, and the location of resistance genes. Following works should be the location and cloning of resistance genes with molecular biologic methods.  相似文献   

4.
A halotolerant, gram positive, motile and rod, was isolated from the E1 Gol6a lake of Ghardaia, Alegria and screened for its antimicrobial potential. The strain showed an inhibitory effect to gram positive and gram negative bacteria against Cladosporium spp. and a slight inhibitory effect against C. albicans using chloroform as the extraction solvent and the nutrient broth as production medium. 16S rRNA sequencing showed that the isolate named LMB3981 is a new taxon in the family of Bacillaceae （with 96% similarity）. The strain is close to Filobacillus milosensis and Bacillus haloalkaliphilum with 95% similarity. The phenotypic study showed differences between LMB3981 and two strains that are near and have confirmed the results of 16S rRNA sequencing by specific metabolic properties of the strain.  相似文献   

5.
Late blight caused by Phytophthora infestans is the most serious disease of tomato production in China. Studies on the genetics of resistance and identification of molecular markers are very useful for breeding late blight resistant varieties. The objective of this paper was to study the inheritance of late blight resistance and identify simple sequence repeat （SSR） markers associated with resistance allele in tomato （Lycopersicon esculentum Mill）. The results came from an F2 progeny of 241 plants derived from a cross between 5~ inbred line that is susceptible to late blight and a resistant accession CLN2037E. The late blight responses of F2 plants were tested by artificially inoculation of detached-leaflets in plate and natural infection assayed under greenhouse conditions. Both methods showed that the resistance is dominant and inherited as monogenic trait. Genetic mapping and linkage analysis showed that the late blight resistance gene Ph-ROL was located on chromosome 9 with a genetic distance of 5.7 cM to the SSR marker TOM236.  相似文献   

6.
Downy mildew （DM）, caused by the fungus Peronospora parasitica, is a destructive disease of radish （Raphanus sativus L.） worldwide. Host resistance has been considered as an attractive and environmentally friendly approach to control the disease. However, the genetic mechanisms of resistance in radish to the pathogen remain unknown. To determine the inheritance of resistance to DM, F1, F2 and BC1F1 populations derived from reciprocal crosses between a resistant line NAU-dhp08 and a susceptible line NAU-qtbjq-06 were evaluated for their responses to DM at seedling stage. All F1 hybrid plants showed high resistance to DM and maternal effect was not detected. The segregation for resistant to susceptible individuals statistically iftted a 3：1 ratio in two F2 populations （F2（SR） and F2（RS））, and 1：1 ratio in two BC1F1 populations, indicating that resistance to DM at seedling stage in radish was controlled by a single dominant locus designated as RsDmR. A total of 1 972 primer pairs （1 036 SRAP, 628 RAPD, 126 RGA, 110 EST-SSR and 72 ISSR） were screened, and 36 were polymorphic between the resistant and susceptible bulks, and consequently used for genotyping individuals in the F2 population. Three markers （Em9/ga24370, NAUISSR826700 and Me7/em10400） linked to the RsDmR locus within a 10.0 cM distance were identiifed using bulked segregant analysis （BSA）. The SRAP marker Em9/ga24370 was the most tightly linked one with a distance of 2.3 cM to RsDmR. These markers tightly linked to the RsDmR locus would facilitate marker-assisted selection and resistance gene pyramiding in radish breeding programs.  相似文献   

7.
The objective of this paper was to investigate the mode of heredity for resistance in oats （Avena sp.） to crown rust caused by Puccinia coronata Cda. f. sp. avenae Eriks, Eight generations of 2 crosses were used to estimate genetic effects and narrow-sense heritability （NSH）. Separate generation means analysis （GMA） indicated a complex gene action controlling this trait with additive, dominance, epistatic and maternal effects （ME）. The genetic model which assumed no epistasis and no ME did not accurately describe the resistance to P. coronata. In both crosses, the digenic epistatic model with ME was sufficient to explain variation in generation means for isolate CRec58 and isolate CRec46. Additive dominance and epistatic components were negative in most cases, suggesting that gene effects contributed more to the resistance than to the susceptibility. The estimated values of NSH were 15-99% depending upon the cross and isolates. The results indicated that appropriate choice of maternal parent and recurrent selection would increase resistance to crown rust in oats.  相似文献   

8.
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9.
Tribenuron-Methyl Resistant Flixweed （Descurainia sophia）   总被引：2，自引：0，他引：2  
Flixweed seeds were collected from suspected winter wheat fields and remote hillside in Shaanxi Province, China, their sensitivities to tribenuron-methyl were evaluated in the greenhouse. Results revealed that biotype S was susceptible to tribenuron, and its GRs0 was 0.23 g a.i. ha^-1, whereas biotypes R1, R2, R3, and R4 were resistant to the tribenuron, and their GR50 were 161.99, 79.70, 439.80, and 312.30, respectively. Biotypes R1 and R2 showed moderate resistance with resistant indices （RI） of 615.23 and 302.7, respectively. Whereas biotypes R3 and R4 showed high resistance to the herbicide with RI values as high as 1 670.34 and 1 186.10, respectively.  相似文献   

10.
[Objective] The experiment studied on insecticidal and antifeedant action of on Portulaca oleracea L.to provide theoretical basis for developing a new botanical insecticide by taking Portulaca oleracea L.as a raw material.[Method] The insecticidal activities of the ethanol extracts and 5 kinds of extracts with petroleum ether,chloroform,ethyl acetate,n-butanol,water from Portulaca oleracea L..against Aphis sp.was studied;Leaves are using drug treatments of 5 extracts anti-feedant activity of Aphis sp.[Result] The results showed that 95% ethanol extract displayed high contact activity to Aphis sp.The corrected mortality after 48 h reached 95.4 % under the concentration of 50.00 mg·ml-1 and the insecticidal activities of 5 extracts against Aphis sp.was in the order that petroleum ether > chloroform > n-butanol > ethyl acetate >water.Five kinds of anti-feeding activity in the extract of the order for the water> ethyl acetate> n-butanol > chloroform >petroleum ether.[Conclusion] The extract from Portulaca oleracea L.has a strong contact toxicity of pesticide active on Aphis sp.substances and for a small polar compounds,the strong anti-feeding activity is a kind of larger polar compounds.  相似文献   

11.
G.  K.  N.  Chhetry  H.  C.  Mangang 《农业科学与技术》2011,(1):68-72
The rationale behind the use of soil amendments by traditional marginal farmers against soil borne pathogen is an area of interest. The present work ascertain the effect of certain soil amendments against pre emergent and post emergent rot of French bean in the agro climatic condition of Manipur, Four soil amendments： cow dung （COD）, sawdust （SD） ＋ paddy husk （PH）, decomposed floating phytomat （DFP） was tried in field conditions in four different combinations. These have been often used by the traditional farmers. A locally available commonly cultivated pole type of French bean has been used for the study. Disease incidences in plots treated with these amendments were then compared with that of control plots where no amendments were made. The plots with a combined treatment of the soil amendments showed maximum seed germination and least post emergent rot against sclerotinia rot. But DFP showed effectiveness against rhizoctonia rot with maximum seed germination while saw dust showed maximum decrease in post emergent rot against rhizoctonia rot. The plots treated with organic soil amendments showed statistically significant positive effect against the pathogens as compared with untreated control plots.  相似文献   

12.
番茄内生细菌的分离及其促生活性研究(英文)   总被引：5，自引：1，他引：4  
[Objective] The study aimed to investigate the growth-promoting activities of endophytic bacteria from tomato plants.[Method]The endophytic bacteria isolated from different tissues of tomato plants were analyzed for the effects of their growth-promoting activities on the germination and growth of tomato plants.The bacteria with growth-promoting activity were preliminarily identified.[Result]Totally 59 endophytic bacterial strains were isolated from roots and stems of tomatoes,of which 4 showed significantly growth-promoting activity to germination and growth of tomato.The results suggest that these strains are endowed with the potential capability of growth-promoting.[Conclusion]The endophytic bacteria with growth-promoting activity were found among the isolates from tomato plants.This provided a good foundation for utilization of these bacteria with growth-promoting activity.  相似文献   

13.
番茄内生细菌的分离及其促生活性研究(英文)   总被引：4，自引：0，他引：4  
[Objective] The study aimed to investigate the growth-promoting activities of endophytic bacteria from tomato plants.[Method]The endophytic bacteria isolated from different tissues of tomato plants were analyzed for the effects of their growth-promoting activities on the germination and growth of tomato plants.The bacteria with growth-promoting activity were preliminarily identified.[Result]Totally 59 endophytic bacterial strains were isolated from roots and stems of tomatoes,of which 4 showed significantly growth-promoting activity to germination and growth of tomato.The results suggest that these strains are endowed with the potential capability of growth-promoting.[Conclusion]The endophytic bacteria with growth-promoting activity were found among the isolates from tomato plants.This provided a good foundation for utilization of these bacteria with growth-promoting activity.  相似文献   

14.
To investigate the gene expression profile of endosperm development, a cDNA library was constructed and characterized from the pulp of coconut at different developmental stages. The constructed cDNA library incorporated approximately 1 × 10^7 clones in total, and the size of the insertion fragments ranged from 800 to 2 000 bp. Sequencing results of 100 randomly picked clones showed that the recombination rate was 96%. In subsequent sequence analysis, 41 clones （41%） were homologous to known function proteins, and 23 clones showed high amino acid identity （more than 80%） with the corresponding genes of different plants. Semi-quantitative RT-PCR indicated that oleosin and globulin genes are pulpspecific expression, and have differential expression level in different developmental stage. Clone 29, recognized as homologous to KIAA1239 protein （Homo sapiens）, was observed to occur nine times, indicating that this gene may be over-expressed during the endosperm development stage. However, the homologous protein was found only in mammals, and the detailed function is still unknown. Elucidation of the functional characterization of these genes will be carried out immediately.  相似文献   

15.
Expression profiles of ten pathogenesis-related （PR） genes during plant defense against Fusarium, Yellow dwarf virus （YDV） aphid-transmitted and Hessian fly （Hf） were compared temporally in both resistant and susceptible genotypes following pathogen infection or insect infestation. Quantitative real-time PCR （qRT-PCR） revealed that PR1, PR2, PR3, PR5, PR6, PR8, PR9, and PR15 appeared to be induced or suppressed independently in response to Fusarium, YDV aphid-transmitted or Hf during the interactions. The PR gene（s） essential to defense against one organism may play little or no role in defense against another pathogen or pest, suggesting the alternative mechanisms may be involved in different interactions of wheat- Fusarium, wheat-YDV aphid-transmitted and wheat-Hf. However, strong up- or down-regulation of PRl2 and PR14 encoding low molecular membrane acting protein, defensin and lipid transfer protein （LTP）, respectively, had been detected after either pathogen infection or insect infestation, therefore showed broad responses to pathogens and insects. It was postulated that low molecular proteins such as defensins and LTPs might play a role in the early stages of pathogenesis in the signaling process that informs plants about the attack from biotic stresses. In addition, a synergistic action between different PR genes might exist in plants to defense certain pathogens and insects on the basis of comprehensive expression profiling of various pathogenesis-related genes revealed by qRT-PCR in this study.  相似文献   

16.
Leafhopper Cicadulina bipunctata is represented the main insect as a pathogen for phytoplasma disease occurring by insect-transmitted plant viruses in date palm orchards. Therefore, it is important to investigate the potential effect of some insecticides against such insect. The adults of leafhopper C. bipunctata were collected from date palm orchards in Alhasa, Eastern province, Saudi Arabia. Three insecticides from different classes--beta-cyfluthrin （pyrethroids）, imidacloprid （neonicotinoids） and abamectin （natural compounds）--have been evaluated in vivo against adults C. bipunctata. This stage was exposed to residual film of various concentrations of each insecticide on transparent plastic cups using a Potter precision laboratory spray tower. Bioassay test showed that both beta-cyfluthrin and imidacloprid caused 100% mortality by 500 ppm at 24 h after treatment, whereas abamectin gave the same mortality by 50 ppm at the same time. Toxicity values revealed that abameetin was the most potent insecticide compared with beta-cyfluthrin and imidacloprid, where the lethal concentrations LC50 and LC95 were 24.58 ppm and 116.73 ppm at 3 h after treatment, respectively. Therefore, abamectin can be a possible candidate to be applied on date palm or ground grass by the Ministry of Agriculture after successful field experiments.  相似文献   

17.
The objective of this study was to technically and economically assess the effect of biopesticides on the serious plant parasitic nematode Radopholus similis on banana in Costa Rica. The following treatments were evaluated： a mixture of nematode trapping fungi-Arthrobotrys oligospora, A. botryospora, Dactylella brochophaga and Drechmeria coniospora; DiTera DF which consist of a ＂dead＂ fungus Myrothecium spp. and its fermentation substrate; Savitan produced from desert plant extracts; QL Agri which contain Quillaja saponaria extracts; Japanese-style compost called Bokashi; two application of a chemical nematicide; and an absolute control. Results of root sampling on a six month basis showed that the biopesticides had lower nematode population densities than the control with the nematode trapping-fungi having statistically significant differences over the other treatments. Chemical control was highly effective and produced the lowest nematode density. However, there were no significant differences between the chemical treatment and the trapping-fungi treatment. The functional root weight and bunch weight showed no significant differences between treatments. Conversely, economic analyses indicated that using nematode trapping-fungi, chemical nematieide, or the QL Agri treatments gave a detectable profit. The land expectation value （LEV） of the banana plantation was higher than the price of banana land which indicated that under normal conditions in the banana sector, production is economically sustainable / profitable. Other results confirm that profit in banana production is affected by the price of a banana box, production and discount rate. The optimal production cycle was obtained in year ten after farm establishment, which refers to the year with the highest profit following plantation renewal. Finally, economical results highlighted the importance of nematodes control, since profitability indexes were sensitive to the efficiency and cost of nematode management technology adopted by the banana company.  相似文献   

18.
Fusarium wilt （FW） is one of the most common cotton diseases in the world. Identification of QTLs conferring resistance to FW is key for the incorporation of resistance genes into elite cultivars. Two intraspecific （cross between Gossypium hirsuturn L.） and one interspecific （cross between Gossypium hirsutum L. and Gossypium bardence L.） F2 populations were constructed by using a highly resistant cultivar and crossing it to a susceptible cultivar with 154, 79, and 148 offsprings, respectively. Simple sequence repeats （SSR） were used to screen genomic regions closely linked to FW resistance. The results showed that five QTLs associated with FW resistance were detected in two intraspecific populations using a composite interval mapping method under four different conditions. Four of these loci located on Chr. 2/Chr. 17 neighboring markers JESPR304 or CIR305 which explained 13.1 to 45.9% of the phenotypic effect. Furthermore, JESPR304 and CIR305 were previously testified and found to be tightly linked. It is possible that these four QTLs detected under different conditions were the same resistance QTL/gene. We consider that there is the possibility of a major FW resistant gene in intraspecific populations. In the interspecific mapping populations two QTLs were detected on Chr. 9 and Chr. 12/26 which explained great phenotypic variance of 49.4 and 45.7%. As the location of QTLs for FW resistance among the intraspecific and the interspecfic populations were totally different, it is suggested that there may be different resistance mechanisms between G. bardence L. and G. hursutum L. Thus, the present research provides an opportunity to understand the genetic control of resistance to FW in Gossypium hirsutum and Gossypium bardence and to conduct MAS in breeding programs to develop FW resistant cultivars.  相似文献   

19.
The insecticide chlorantraniliprole exhibits good efifcacy and plays an important role in controlling the diamondback moth, Plutella xylostella Linnaeus. However, resistance to chlorantraniliprole has been observed recently in some ifeld populations. At present study, diamondback moths with resistance to chlorantraniliprole （resistant ratio （RR） was 82.18） for biochemical assays were selected. The assays were performed to determine potential resistance mechanisms. The results showed that the selected resistant moths （GDLZ-R） and susceptible moth could be synergized by known metabolic inhibitors such as piperonyl butoxide （PBO）, triphenyl phosphate （TPP） and diethyl-maleate （DEM） at different levels （1.68-5.50-fold and 2.20-2.89-fold, respectively）, and DEM showed the maximum synergism in both strains. In enzymes assays, a high level of glutathione-S-transferase （GST） was observed in the resistant moth, in contrast, moths that are susceptible to the insecticide had only 1/3 the GST activity of the resistant moths. The analysis of short-term exposure of chlorantraniliprole on biochemical response in the resistant strain also showed that GST activity was signiifcantly elevated after exposure to a sub-lethal concentration of chlorantraniliprole （about 1/3 LC50, 12 mg L-1） 12 and 24 h, respectively. The results show that there is a strong correlation between the enzyme activity and resistance, and GST is likely the main detoxiifcation mechanism responsible for resistance to chlorantraniliprole in P. xylostella L., cytochrome P450 monooxygenase （P450） and carboxy-lesterase （CarE） are involved in to some extent.  相似文献   

20.
Exotic plant invasion presents a serious threat to native ecosystem structure and function. Little is known about the role of soil microbial communities in facilitating or resisting the spread of invasive plants into native communities. The purpose of this research is to understand how the invasive annual plant Ambrosia artemisiifolia L. facilitates its competition capacity through changing the structure and function of soil microbial communities. The soil characteristics of different areas invaded by A. artemisiifolia were examined. Greenhouse experiments were designed to assess the effect of A. artemisiifolia invasion-induced changes of soil biota on co-occurring plant growth, and on the interactions between A. artemisiifolia and three co-occurring plant species. The results showed that the soil organic C content was the highest in heavily invaded sites, the lowest in native plant sites, and intermediate in newly invaded sites. Soil available N, P and K concentrations in heavily invaded site were 2.4, 1.9 and 1.7 times higher than those in native plant soil, respectively. Soil pH decreased as A. artemisiifolia invasion intensity increased, and was lower in invaded sites（heavily invaded and newly invaded） than in native plant sites. The soil microbial community structure was clearly separated in the three types of sites, and A. artemisiifolia invasion increased anaerobe, sulfate-reducing bacteria and actinomycete abundance. Soil biota of invaded sites inhibits growth of co-occurring plants（Galinsoga parvifloraCav., Medicago sativa L. and Setaria plicata（Lam.） T. Cooke.） compared to soil biota from un-invaded sites, but facilitates A. artemisiifolia growth and competition with co-occurring plants. A. artemisiifolia biomass was 50-130% greater when competing with three co-occurring plants, compared to single-species competition only（invasion by A. artemisiifolia alone）, in heavily invaded soil. Results of the present study indicated that A. artemisiifolia invasion alters the soil microbial communit  相似文献   

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