The soil-resident pathogen, Plasmodiophora brassicae, infects cruciferous crops, causing obligate parasitic clubroot disease and posing a significant threat to the Brassica vegetable industry in China. To learn more a...The soil-resident pathogen, Plasmodiophora brassicae, infects cruciferous crops, causing obligate parasitic clubroot disease and posing a significant threat to the Brassica vegetable industry in China. To learn more about its pathogenesis, we reported a Nanopore sequencing-derived25.3 Mb high-quality genome sequence of P. brassicae pathotype 4 strain(P.b 4). Comparing the P.b 4 genome with that of the published P.brassicae e3 genome(P.b e3) identified single nucleotide polymorphisms, structural variations, and small insertions and deletions. We then carried out RNA-sequencing of root samples from a clubroot-susceptible line at 5, 14, and 28 days after inoculation(DAI), and classified genes into five categories based on their expression patterns. Interestingly, 158 genes were highly expressed at 14 DAI, which were enriched in budding cell isotropic bud growth, ascospore wall assembly, spore wall assembly, spore wall biogenesis, and ascospore wall biogenesis.Subsequently, we bioinformatically predicted 555 secreted effector candidates, among which only 125 were expressed during infection and had amino acid lengths less than 400. The putative effector Pb010018, which was highly expressed at 14 DAI, was validated to have a signal peptide using a yeast secretion system. Luciferase activity and co-immunoprecipitation assays demonstrated that Pb010018 interacts with serine hydroxymethyltransferase BrSHMT1, and expression analysis showed that SHMT1 was upregulated in both Arabidopsis and B. rapa during infection. Furthermore, after infection, the Arabidopsis shmt1 mutant(atshmt1) showed reduced severity of clubroot disease, together with downregulated expression of Pb010018. Our results offer new insights into plant-pathogen interaction mechanisms, and provide the possibility for improving Brassica resistance to clubroot disease.展开更多
[Objective] This study was conducted to investigate the pathogenicity of Plasmodiophora brassicae on cabbage grown under different temperature and soil pH conditions. [Method] The pathogenicity of P. brassicae were te...[Objective] This study was conducted to investigate the pathogenicity of Plasmodiophora brassicae on cabbage grown under different temperature and soil pH conditions. [Method] The pathogenicity of P. brassicae were tested at seven different temperatures and at six different soil pH values with the resting spore concentration of lx108 （spores/g） in the soil. The plant survival rate and incidence rate of clubroot were investigated after 90 d. [Result] The incidence rate of clubroot on cabbage among the different temperature sets varied in a descending order as follows： 30 ℃〉25 ℃〉20 ℃〉35 ℃〉15 ℃〉10 ℃〉5 ℃ at soil pH value of 6, indicating that the pathogenicity of P. brassicae was weak at 5 and 10 ~（3. The incidence rate increased with soil temperature increasing from 15 to 30 ℃, but decreased at 35 ℃. The incidence rates of clubroot were 80.36%, 100%, 65%, 10.77%, 3.23% and 0% at soil pH 4, 5, 6, 7, 8 and 9 at 25 ℃, respectively. The growth of cabbage was inhibited and the survival rate was reduced at pH 4.The incidence rates of clubroot were low at pH value of 7 and 8, and was 0% at pH 9. The Chinese cabbage grew better at pH value of 5 and 6, but had high incidence rates of clubroot. [Conclusion] The results revealed that the incidence rate of clubroot on cabbage was closely related to the temperature and soil pH.展开更多
Research progress was reviewed on the differential systems for physiologic races of Plasmodiophora brassicae Woron,including Williams,differential system and European clubroot differential（ECD） set.The existing prob...Research progress was reviewed on the differential systems for physiologic races of Plasmodiophora brassicae Woron,including Williams,differential system and European clubroot differential（ECD） set.The existing problems and countermeasures of the different differential systems were discussed,and a research status quo on the molecular identification and detection of clubroot pathogen in crucifers were introduced.展开更多
Five commonly-used reference genes： ACT （actin）, UBE （ubiquitin-conjugating enzyme）, RPL2 （ribosomal protein L2）, BRP II （RNA polymerase II subunit）, and NADH （nicotinamide adenine dinucleotide） were examin...Five commonly-used reference genes： ACT （actin）, UBE （ubiquitin-conjugating enzyme）, RPL2 （ribosomal protein L2）, BRP II （RNA polymerase II subunit）, and NADH （nicotinamide adenine dinucleotide） were examined using geNorm software as reference genes for RT-qPCR. Among the tested reference genes, ACT and UBE were the most stable in all samples. In parallel, expression analysis of nitrilases in Brassica juncea var. tumida, was performed to preliminarily investigate the molecular interactions between nitrilase and clubroot development at 10, 15, 20, 25, 30, and 40 d postinoculation （dpi） with a suspension of resting spores of Plasmodiophora brassicae. The results showed that different gene expressions of nitrilases were regulated during the initial periods of clubroot development. The expression level of BjNIT1 increased sharply from 20 to 40 dpi in infected roots while there were no remarkable changes in healthy roots. From 15 to 30 dpi, the expression levels of BjNIT2 and BjNIT4 in infected roots were lower than those in non-infected roots. Finally, BjNIT2 in treatment was down approximately to control at 40 dpi. Our results suggest that BjNIT1, which promoted overproductions of auxin, might be involved in P. brassicae infection of B. juncea.展开更多
A SYBR Green I real-time PCR assay was developed to detect and quantify Plasmodiophora brassicae ribosomal DNA（rDNA） and internal transcribed spacer（ITS）.A pair of primers PBF1/PBR1 was designed based on the conse...A SYBR Green I real-time PCR assay was developed to detect and quantify Plasmodiophora brassicae ribosomal DNA（rDNA） and internal transcribed spacer（ITS）.A pair of primers PBF1/PBR1 was designed based on the conservative region of rDNA-ITS of P.brassicae.The positive plasmid pB12 was obtained and used as the template to create standard curve.The specificity,sensitivity,and reproducibility of real-time PCR were evaluated respectively.Naturally and artificially infested soil samples containing different concentrations of P.brassicae were detected.The results demonstrated that standard curve established by recombinant plasmid was shown a fine linear relationship between threshold cycle and template concentration.The melting curve was specific with the correlation coefficient of 0.995 and that the amplification efficiency was 93.8%.The detection limit of P.brassicae genomic DNA was approximately 40 copies per 25 μL.The sensitivity of the assay was at least 100-fold higher than conventional PCR.Only DNA from P.brassicae could be amplified and detected using this assay,suggesting the highly specific of this assay.The coefficient of variation was less than 3%,indicating the PCR method revealed high reproducibility.The detection limit in soil samples corresponded to 1 000 resting spores g-1soil.Bait plants were used to validate the real-time PCR assay.This developed real-time PCR assay allows for fast and sensitive detection of P.brassicae in soil and should be useful in disease management and pest interception so as to prevent further spread of P.brassicae.展开更多
The efficacy of three seed treating chemicals viz. Provax 200 WP, Brine solution, Rovral 50 WP and one Biofungicide viz. BAU-Biofungicide were evaluated against Alternaria blight of mustard caused by Alternaria brassi...The efficacy of three seed treating chemicals viz. Provax 200 WP, Brine solution, Rovral 50 WP and one Biofungicide viz. BAU-Biofungicide were evaluated against Alternaria blight of mustard caused by Alternaria brassicae and Alternaria brassicicola. Three varieties viz. var. BARI-6, Tori-7 and SAU-Shorisha-1 were used in this study. The field experiment was conducted in the farm of Sher-e-Bangla Agricultural University, Dhaka and laboratory experiment was conducted in the seed health Laboratory, Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka-1207 during the period from November 2008 to July 2009. Among the seed treating chemicals, Rovral 50WP showed the best performance in reducing disease incidence and severity as well as increasing seed yield. Application of Rovral 50 WP gave the best result in increasing the number of pod per plant, pod length (cm), number of branch per plant, 100 siliqua weight (g) and 1000 seed weight (g). BAU-Biofungicide also showed promising performance in controlling Alternaria blight of mustard and reduced 36% and 53% disease incidence and disease severity respectively over untreated control. BAU-Biofungicide may be recommended as an alternative means of chemical fungicide such as Rovral 50 WP for controlling Alternaria blight of mustard.展开更多
Cauliflower is popular vegetable in Pakistan and it is severely attacked by Pieris brassicae (L). There are different cauliflower cultivars available in this area. The aim of this study was to determine the developmen...Cauliflower is popular vegetable in Pakistan and it is severely attacked by Pieris brassicae (L). There are different cauliflower cultivars available in this area. The aim of this study was to determine the developmental response of Pieris brassicae on ten cauliflower cultivars. An experiment was conducted during 2012-13 at the Entomology section of the Agriculture Research Institute Tarnab Peshawar under laboratory conditions of 20°C ± 2°C, 50% ± 5% RH and 12:12h photoperiod. Pieris brassicae eggs were collected from a cauliflower field ARI Tarnab and the larvae placed after hatching on fresh leaves often cauliflower cultivars. The results showed that the larval development of P. brassicae was short (35 days), longer larval length (32.41 mm), larval mortality was low (6.6%) and pupal weight was high (0.50 g) on Clima cultivar. On the other hand, a longer larval developmental period (37 days), higher larval mortality (86.66%), shorter larval length (24.55 mm) and lower pupal weight (0.42 g) were recorded on cultivar AX-2034.展开更多
Chitin is the most widespread amino polysaccharide in nature. Chitin synthase （CHS） plays an important role in chitin formation in the cuticle and the peritrophic membrane （PM） lining the midgut. Total RNA was iso...Chitin is the most widespread amino polysaccharide in nature. Chitin synthase （CHS） plays an important role in chitin formation in the cuticle and the peritrophic membrane （PM） lining the midgut. Total RNA was isolated from the cuticle of Mamestra brassicae （L.） fourth instar larva, cDNA sequence was cloned by RT-PCR and Rapid Amplification of cDNA Ends （RACE）. cDNA 5 220 bp in length, contained an open reading frame of 4 704 bp coding for a polypeptide of 1 567 amino acid residues with a predicted molecular weight of 178.3 ku and its pI was 6.42. The deduced amino acid sequence from Mi brassicae （L.） shared the high level of identity with chitin synthase sequences from other insects, especially lepidopteran insects, cDNA sequence has been deposited with GenBank under accession No. GQ281761展开更多
Cytokinins are a class of phytohormones that promote cell division and differentiation and are thought to affect plant immunity to multiple pathogens.However,a comprehensive analysis of cytokinin dehydrogenase/oxidase...Cytokinins are a class of phytohormones that promote cell division and differentiation and are thought to affect plant immunity to multiple pathogens.However,a comprehensive analysis of cytokinin dehydrogenase/oxidase(CKX)family genes in cabbage has not been reported.In this study,a total of 36 CKX genes were identified using a genome-wide search method.Phylogenetic analysis classified these genes into three groups.They were distributed unevenly across nine chromosomes in B.oleracea,and 15 of them did not contain any introns.The results of colinearity analysis showed that 36 CKX gene in Arabidopsis was present in several copies in the Brassica oleracea genome.An analysis of cisacting elements indicated that all genes possessed at least one stress or hormone responsive cis-acting element.A heatmap of CKX gene expression showed the patterns of expression of these genes in various tissues and organs.Three genes(Bol028363,Bol031036 and Bol018140)were relatively highly expressed in all of the investigated tissues under normal conditions,showing the expression profile of housekeeping genes.Generally,the expression patterns of CKX genes in Jingfeng 1 and Xiangan 336 were quite different under the same treatment.Notably,three genes(Bol020547,Bol028392 and Bol045724)were significantly down-regulated and up-regulated in the susceptible and resistant material,respectively,after inoculation,which may indicate their crucial roles in resistance to clubroot disease.The results provide insights for better understanding the roles of CKX genes in the B.oleracea–P.brassicae interaction.展开更多
Brassica clubroot caused by Plasmodiophora brassicae has been identified as a severe soil-borne disease that poses a significant threat to plants root systems.The disease results in the formation of tumorous enlargeme...Brassica clubroot caused by Plasmodiophora brassicae has been identified as a severe soil-borne disease that poses a significant threat to plants root systems.The disease results in the formation of tumorous enlargements in the roots,leading to wilting and eventual plant death.Consequently,crop yield is drastically reduced,causing substantial economic losses in agriculture.The current study aims to provide a comprehensive overview of recent research process on Brassica clubroot,focusing on the biological characteristics,physiological race identification,and pathogenic mechanism of P.brassicae.Furthermore,it covers the latest advancements in the comprehensive prevention and clubroot control.The insights gained from this study are expected to contribute to the future research on clubroot and the development of resistance breeding strategies.展开更多
Efficiency of imidacloprid and pymetrozine on population growth parameters of cabbage aphid, Brevicoryne brassicae L. （Homoptera： Aphididae） was determined using demographic toxicology by leaf dip method. At first,...Efficiency of imidacloprid and pymetrozine on population growth parameters of cabbage aphid, Brevicoryne brassicae L. （Homoptera： Aphididae） was determined using demographic toxicology by leaf dip method. At first, bioassay tests were performed. The LC50 value and confidence limit for imidacloprid and pymetrozine were 1.61 × 10^-5 mol/L （0.74 × 10^-5-2.66 × 10^-5） and 2.14 × 10^-4 mol/L （1.24 × 10^-4-3.40 × 10^-4）, respectively. To evaluate the sublethal effect of two insecticides on population growth parameters of cabbage aphid, LC30 concentrations of imidacloprid and pymetrozine were used at 5 mol/L and 30 mol/L. The experiments were carried out in a incubator at 20±1℃, 60% ± 5% RH and 16：8 （L：D） photoperiod on canola seedlings, Brassica napus L. var. ＇PF＇. Net fecundity rate decreased in both insecticide-treated populations. Intrinsic rates of increase （rm） were lower in imidacloprid and pymetrozine treatments than in controls. Intrinsic birth rates also decreased in treated populations. There was a relative increase in intrinsic death rates of treated populations. The mean generation times and doubling time were also lower in populations treated with insecticides than in controls. There was a considerable reduction in the average numbers of nymphs reproduced per female as compared with the control. The average longevity of female adults in the control was significantly different from those treated with imidacloprid and pymetrozine. However, there was no significant differences in aphid life-table parameters between the two insecticide-treated populations （P 〉 0.01）.展开更多
Increasing evidence has revealed that micro RNAs play a pivotal role in the post transcriptional regulation of gene expression in response to pathogens in plants. However, there is little information available about t...Increasing evidence has revealed that micro RNAs play a pivotal role in the post transcriptional regulation of gene expression in response to pathogens in plants. However, there is little information available about the expression patterns of mi RNAs and their targets in Chinese cabbage(Brassica rapa ssp. pekinensis) under Plasmodiophora brassicae stress. In the present study, using deep sequencing and degradome analysis, a genome-wide identification of mi RNAs and their targets during P. brassicae stress was performed. A total of 221 known and 93 potentially novel mi RNAs were successfully identified from two root libraries of one control(635-10CK) and P. brassicae-treated Chinese cabbage samples(635-10T). Of these, 14 known and 10 potentially novel mi RNAs were found to be differentially expressed after P. brassicae treatment. Degradome analysis revealed that the 223 target genes of the 75 mi RNAs could be potentially cleaved. KEGG(Kyoto Encyclopedia of Genes and Genomes)pathway analysis suggested that the putative target genes of the mi RNAs were predominately involved in selenocompound metabolism and plant hormone signal transduction. Then the expression of 12 mi RNAs was validated by quantitative real-time PCR(q RT-PCR). These results provide insights into the mi RNA-mediated regulatory networks underlying the stress response to the plant pathogen P. brassicae.展开更多
Trichogramma brassicae(Bezdenko)is an important biological control agent that has been used widely against many lepidopteran pests.Commonly,colonies of Trichogramma are mass reared on factitious hosts such as Sitotrog...Trichogramma brassicae(Bezdenko)is an important biological control agent that has been used widely against many lepidopteran pests.Commonly,colonies of Trichogramma are mass reared on factitious hosts such as Sitotroga cerealella(Olivier)over many generations.In this study,we evaluated the quality and performance of a colony of T.brassicae that had been reared for over 45 generations(G)using two-sex life table parameters and parasitism capacity.We found that female adult longevity was significantly different among sequential generations,ranging from 5.58±2.5 d(at G5)to 3.75±1.42 d(at G45).However,no significant difference was found in male adult longevity among different generations.Although female wasps survived longer until the 15th gener・ation,they allocated more days for egg laying at G5 and GIO.The highest values of gross reproductive rate(GRR),net reproductive rate(7.),intrinsic rate of increase(r),finite rate of increase(λ)and mean generation time(T)were found in G5 and GIO,which also showed significantly higher cq.No significant difference in the finite parasitism rate(co)was found among generations up to G15.These results suggest that T.brassicae wasps held under continuous laboratory rearing can be used successfully in biological control programs until the 15th generation without any loss of quality or performance.However,laboratory mass rearing colonies declined in quality after 15 generations and we suggest that they should be rejuvenated regularly by adding field-collected parasitoids periodically.展开更多
When, how often and for how long organisms mate can have strong consequences for individual fitness and are crucial aspects of evolutionary ecology. Such determinants are likely to be of even greater importance in mon...When, how often and for how long organisms mate can have strong consequences for individual fitness and are crucial aspects of evolutionary ecology. Such determinants are likely to be of even greater importance in monandrous species and species with short adult life stages. Previous work suggests that mobility, a key dispersal? related trait, may affect the dynamics of copulations, but few studies have investigated the impact of individual mobility on mating latency, copulation duration and oviposition latency simultaneously. In this paper, we monitored the copulation dynamics of 40 males and 40 females, as well as the oviposition dynamics of the females of the Large White butterfly Pieris brassicae, a facultative long-distance disperser butterfly. Individuals from a breeding were selected to create a uniform distribution of mobility and we recorded the timing, number and duration of all copulations in a semiexperimental system. We showed that mobility, measured as the time spent in flight under stressful conditions (a proxy of dispersal tendency), correlates with all aspects of copulation dynamics: mobile males and females mated earlier and for shorter periods than less mobile individuals. In turn, late mating females increased the time between copulation and oviposition. These results feed the previously described mobility syndrome of R brassicae, involving morphological and physiological characters, with life-history traits. We suggest that the reduction of mating latency and copulation duration has an adaptive value in dispersing individuals, as their life expectancy might be shorter than that of sedentary individuals.展开更多
基金supported by the Youth Foundation of Beijing Academy of Agriculture and Forestry Sciences[Grant No.QNJJ202242]the Excellent Young Scholars of Beijing Academy of Agriculture and Forestry Sciences[Grant No.YXQN202205]+3 种基金the Beijing Nova Program[Grant No.20220484052]the National Natural Science Foundation of China[Grant No.31801852]the Collaborative Innovation Center of Beijing Academy of Agriculture and Forestry Sciences[Grant No.KJCX201907-2]the Earmarked Fund for China Agriculture Research System[Grant No.CARS-23-A-05].
文摘The soil-resident pathogen, Plasmodiophora brassicae, infects cruciferous crops, causing obligate parasitic clubroot disease and posing a significant threat to the Brassica vegetable industry in China. To learn more about its pathogenesis, we reported a Nanopore sequencing-derived25.3 Mb high-quality genome sequence of P. brassicae pathotype 4 strain(P.b 4). Comparing the P.b 4 genome with that of the published P.brassicae e3 genome(P.b e3) identified single nucleotide polymorphisms, structural variations, and small insertions and deletions. We then carried out RNA-sequencing of root samples from a clubroot-susceptible line at 5, 14, and 28 days after inoculation(DAI), and classified genes into five categories based on their expression patterns. Interestingly, 158 genes were highly expressed at 14 DAI, which were enriched in budding cell isotropic bud growth, ascospore wall assembly, spore wall assembly, spore wall biogenesis, and ascospore wall biogenesis.Subsequently, we bioinformatically predicted 555 secreted effector candidates, among which only 125 were expressed during infection and had amino acid lengths less than 400. The putative effector Pb010018, which was highly expressed at 14 DAI, was validated to have a signal peptide using a yeast secretion system. Luciferase activity and co-immunoprecipitation assays demonstrated that Pb010018 interacts with serine hydroxymethyltransferase BrSHMT1, and expression analysis showed that SHMT1 was upregulated in both Arabidopsis and B. rapa during infection. Furthermore, after infection, the Arabidopsis shmt1 mutant(atshmt1) showed reduced severity of clubroot disease, together with downregulated expression of Pb010018. Our results offer new insights into plant-pathogen interaction mechanisms, and provide the possibility for improving Brassica resistance to clubroot disease.
基金Supported by Science and Technology Project of Yunnan Province(2014RA061)Special Fund for Modern Agriculture Research System for Rape of Yunnan Province~~
文摘[Objective] This study was conducted to investigate the pathogenicity of Plasmodiophora brassicae on cabbage grown under different temperature and soil pH conditions. [Method] The pathogenicity of P. brassicae were tested at seven different temperatures and at six different soil pH values with the resting spore concentration of lx108 （spores/g） in the soil. The plant survival rate and incidence rate of clubroot were investigated after 90 d. [Result] The incidence rate of clubroot on cabbage among the different temperature sets varied in a descending order as follows： 30 ℃〉25 ℃〉20 ℃〉35 ℃〉15 ℃〉10 ℃〉5 ℃ at soil pH value of 6, indicating that the pathogenicity of P. brassicae was weak at 5 and 10 ~（3. The incidence rate increased with soil temperature increasing from 15 to 30 ℃, but decreased at 35 ℃. The incidence rates of clubroot were 80.36%, 100%, 65%, 10.77%, 3.23% and 0% at soil pH 4, 5, 6, 7, 8 and 9 at 25 ℃, respectively. The growth of cabbage was inhibited and the survival rate was reduced at pH 4.The incidence rates of clubroot were low at pH value of 7 and 8, and was 0% at pH 9. The Chinese cabbage grew better at pH value of 5 and 6, but had high incidence rates of clubroot. [Conclusion] The results revealed that the incidence rate of clubroot on cabbage was closely related to the temperature and soil pH.
基金Supported by the National Science and Technology Program of the Ministry of Science and Technology of China(2010BAD01B04)Research Fund of Department of Science and Technology of Sichuan Province(2008NG0003)the Genetic Engineering Fund of Department of Finance of Sichuan Province(2011JYGC06)~~
文摘Research progress was reviewed on the differential systems for physiologic races of Plasmodiophora brassicae Woron,including Williams,differential system and European clubroot differential（ECD） set.The existing problems and countermeasures of the different differential systems were discussed,and a research status quo on the molecular identification and detection of clubroot pathogen in crucifers were introduced.
基金financially supported by the Natural Science Foundation of Chongqing Science and Technology Commission,China (2008BB1370)Fuling Agricultural Science Institute of Chongqing,China
文摘Five commonly-used reference genes： ACT （actin）, UBE （ubiquitin-conjugating enzyme）, RPL2 （ribosomal protein L2）, BRP II （RNA polymerase II subunit）, and NADH （nicotinamide adenine dinucleotide） were examined using geNorm software as reference genes for RT-qPCR. Among the tested reference genes, ACT and UBE were the most stable in all samples. In parallel, expression analysis of nitrilases in Brassica juncea var. tumida, was performed to preliminarily investigate the molecular interactions between nitrilase and clubroot development at 10, 15, 20, 25, 30, and 40 d postinoculation （dpi） with a suspension of resting spores of Plasmodiophora brassicae. The results showed that different gene expressions of nitrilases were regulated during the initial periods of clubroot development. The expression level of BjNIT1 increased sharply from 20 to 40 dpi in infected roots while there were no remarkable changes in healthy roots. From 15 to 30 dpi, the expression levels of BjNIT2 and BjNIT4 in infected roots were lower than those in non-infected roots. Finally, BjNIT2 in treatment was down approximately to control at 40 dpi. Our results suggest that BjNIT1, which promoted overproductions of auxin, might be involved in P. brassicae infection of B. juncea.
基金supported by the emarked fund for Moden Agro-Industry Technology Research System, China (CARS25)the National Natural Science Foundation of China (31201473)the Key Laboratory of Biology and Genetic Improvement of Horticulture Crops, Ministry of Agriculture, China
文摘A SYBR Green I real-time PCR assay was developed to detect and quantify Plasmodiophora brassicae ribosomal DNA（rDNA） and internal transcribed spacer（ITS）.A pair of primers PBF1/PBR1 was designed based on the conservative region of rDNA-ITS of P.brassicae.The positive plasmid pB12 was obtained and used as the template to create standard curve.The specificity,sensitivity,and reproducibility of real-time PCR were evaluated respectively.Naturally and artificially infested soil samples containing different concentrations of P.brassicae were detected.The results demonstrated that standard curve established by recombinant plasmid was shown a fine linear relationship between threshold cycle and template concentration.The melting curve was specific with the correlation coefficient of 0.995 and that the amplification efficiency was 93.8%.The detection limit of P.brassicae genomic DNA was approximately 40 copies per 25 μL.The sensitivity of the assay was at least 100-fold higher than conventional PCR.Only DNA from P.brassicae could be amplified and detected using this assay,suggesting the highly specific of this assay.The coefficient of variation was less than 3%,indicating the PCR method revealed high reproducibility.The detection limit in soil samples corresponded to 1 000 resting spores g-1soil.Bait plants were used to validate the real-time PCR assay.This developed real-time PCR assay allows for fast and sensitive detection of P.brassicae in soil and should be useful in disease management and pest interception so as to prevent further spread of P.brassicae.
文摘The efficacy of three seed treating chemicals viz. Provax 200 WP, Brine solution, Rovral 50 WP and one Biofungicide viz. BAU-Biofungicide were evaluated against Alternaria blight of mustard caused by Alternaria brassicae and Alternaria brassicicola. Three varieties viz. var. BARI-6, Tori-7 and SAU-Shorisha-1 were used in this study. The field experiment was conducted in the farm of Sher-e-Bangla Agricultural University, Dhaka and laboratory experiment was conducted in the seed health Laboratory, Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka-1207 during the period from November 2008 to July 2009. Among the seed treating chemicals, Rovral 50WP showed the best performance in reducing disease incidence and severity as well as increasing seed yield. Application of Rovral 50 WP gave the best result in increasing the number of pod per plant, pod length (cm), number of branch per plant, 100 siliqua weight (g) and 1000 seed weight (g). BAU-Biofungicide also showed promising performance in controlling Alternaria blight of mustard and reduced 36% and 53% disease incidence and disease severity respectively over untreated control. BAU-Biofungicide may be recommended as an alternative means of chemical fungicide such as Rovral 50 WP for controlling Alternaria blight of mustard.
文摘Cauliflower is popular vegetable in Pakistan and it is severely attacked by Pieris brassicae (L). There are different cauliflower cultivars available in this area. The aim of this study was to determine the developmental response of Pieris brassicae on ten cauliflower cultivars. An experiment was conducted during 2012-13 at the Entomology section of the Agriculture Research Institute Tarnab Peshawar under laboratory conditions of 20°C ± 2°C, 50% ± 5% RH and 12:12h photoperiod. Pieris brassicae eggs were collected from a cauliflower field ARI Tarnab and the larvae placed after hatching on fresh leaves often cauliflower cultivars. The results showed that the larval development of P. brassicae was short (35 days), longer larval length (32.41 mm), larval mortality was low (6.6%) and pupal weight was high (0.50 g) on Clima cultivar. On the other hand, a longer larval developmental period (37 days), higher larval mortality (86.66%), shorter larval length (24.55 mm) and lower pupal weight (0.42 g) were recorded on cultivar AX-2034.
基金Supported by Natural Science Foundation of Heilongjiang Province (C2007-7)Scientific and Technical Innovation Fund of Harbin (RC2006QN002027)Northeast Agricultural University Research Fund (2005)
文摘Chitin is the most widespread amino polysaccharide in nature. Chitin synthase （CHS） plays an important role in chitin formation in the cuticle and the peritrophic membrane （PM） lining the midgut. Total RNA was isolated from the cuticle of Mamestra brassicae （L.） fourth instar larva, cDNA sequence was cloned by RT-PCR and Rapid Amplification of cDNA Ends （RACE）. cDNA 5 220 bp in length, contained an open reading frame of 4 704 bp coding for a polypeptide of 1 567 amino acid residues with a predicted molecular weight of 178.3 ku and its pI was 6.42. The deduced amino acid sequence from Mi brassicae （L.） shared the high level of identity with chitin synthase sequences from other insects, especially lepidopteran insects, cDNA sequence has been deposited with GenBank under accession No. GQ281761
基金supported by the Youth Science Fund Project(Grant No. 31801876)。
文摘Cytokinins are a class of phytohormones that promote cell division and differentiation and are thought to affect plant immunity to multiple pathogens.However,a comprehensive analysis of cytokinin dehydrogenase/oxidase(CKX)family genes in cabbage has not been reported.In this study,a total of 36 CKX genes were identified using a genome-wide search method.Phylogenetic analysis classified these genes into three groups.They were distributed unevenly across nine chromosomes in B.oleracea,and 15 of them did not contain any introns.The results of colinearity analysis showed that 36 CKX gene in Arabidopsis was present in several copies in the Brassica oleracea genome.An analysis of cisacting elements indicated that all genes possessed at least one stress or hormone responsive cis-acting element.A heatmap of CKX gene expression showed the patterns of expression of these genes in various tissues and organs.Three genes(Bol028363,Bol031036 and Bol018140)were relatively highly expressed in all of the investigated tissues under normal conditions,showing the expression profile of housekeeping genes.Generally,the expression patterns of CKX genes in Jingfeng 1 and Xiangan 336 were quite different under the same treatment.Notably,three genes(Bol020547,Bol028392 and Bol045724)were significantly down-regulated and up-regulated in the susceptible and resistant material,respectively,after inoculation,which may indicate their crucial roles in resistance to clubroot disease.The results provide insights for better understanding the roles of CKX genes in the B.oleracea–P.brassicae interaction.
基金supported by the Science and Technology Talent Promotion Project(2023TJ-Z09)Innovation Program(2023RC1077,2023JJ40279)of Hunan Province,China.
文摘Brassica clubroot caused by Plasmodiophora brassicae has been identified as a severe soil-borne disease that poses a significant threat to plants root systems.The disease results in the formation of tumorous enlargements in the roots,leading to wilting and eventual plant death.Consequently,crop yield is drastically reduced,causing substantial economic losses in agriculture.The current study aims to provide a comprehensive overview of recent research process on Brassica clubroot,focusing on the biological characteristics,physiological race identification,and pathogenic mechanism of P.brassicae.Furthermore,it covers the latest advancements in the comprehensive prevention and clubroot control.The insights gained from this study are expected to contribute to the future research on clubroot and the development of resistance breeding strategies.
文摘Efficiency of imidacloprid and pymetrozine on population growth parameters of cabbage aphid, Brevicoryne brassicae L. （Homoptera： Aphididae） was determined using demographic toxicology by leaf dip method. At first, bioassay tests were performed. The LC50 value and confidence limit for imidacloprid and pymetrozine were 1.61 × 10^-5 mol/L （0.74 × 10^-5-2.66 × 10^-5） and 2.14 × 10^-4 mol/L （1.24 × 10^-4-3.40 × 10^-4）, respectively. To evaluate the sublethal effect of two insecticides on population growth parameters of cabbage aphid, LC30 concentrations of imidacloprid and pymetrozine were used at 5 mol/L and 30 mol/L. The experiments were carried out in a incubator at 20±1℃, 60% ± 5% RH and 16：8 （L：D） photoperiod on canola seedlings, Brassica napus L. var. ＇PF＇. Net fecundity rate decreased in both insecticide-treated populations. Intrinsic rates of increase （rm） were lower in imidacloprid and pymetrozine treatments than in controls. Intrinsic birth rates also decreased in treated populations. There was a relative increase in intrinsic death rates of treated populations. The mean generation times and doubling time were also lower in populations treated with insecticides than in controls. There was a considerable reduction in the average numbers of nymphs reproduced per female as compared with the control. The average longevity of female adults in the control was significantly different from those treated with imidacloprid and pymetrozine. However, there was no significant differences in aphid life-table parameters between the two insecticide-treated populations （P 〉 0.01）.
基金supported by the Excellent Young Scientist Foundation of Henan Academy of Agricultural Sciences(2016YQ11)the National Key Technology R&D Program(2012BAD02B01-3)+1 种基金the Specialized Scientific Research Fund of Henan Academy of Agricultural Sciences(20157805)the Excellent Technology Innovation Team of Henan Province
文摘Increasing evidence has revealed that micro RNAs play a pivotal role in the post transcriptional regulation of gene expression in response to pathogens in plants. However, there is little information available about the expression patterns of mi RNAs and their targets in Chinese cabbage(Brassica rapa ssp. pekinensis) under Plasmodiophora brassicae stress. In the present study, using deep sequencing and degradome analysis, a genome-wide identification of mi RNAs and their targets during P. brassicae stress was performed. A total of 221 known and 93 potentially novel mi RNAs were successfully identified from two root libraries of one control(635-10CK) and P. brassicae-treated Chinese cabbage samples(635-10T). Of these, 14 known and 10 potentially novel mi RNAs were found to be differentially expressed after P. brassicae treatment. Degradome analysis revealed that the 223 target genes of the 75 mi RNAs could be potentially cleaved. KEGG(Kyoto Encyclopedia of Genes and Genomes)pathway analysis suggested that the putative target genes of the mi RNAs were predominately involved in selenocompound metabolism and plant hormone signal transduction. Then the expression of 12 mi RNAs was validated by quantitative real-time PCR(q RT-PCR). These results provide insights into the mi RNA-mediated regulatory networks underlying the stress response to the plant pathogen P. brassicae.
文摘Trichogramma brassicae(Bezdenko)is an important biological control agent that has been used widely against many lepidopteran pests.Commonly,colonies of Trichogramma are mass reared on factitious hosts such as Sitotroga cerealella(Olivier)over many generations.In this study,we evaluated the quality and performance of a colony of T.brassicae that had been reared for over 45 generations(G)using two-sex life table parameters and parasitism capacity.We found that female adult longevity was significantly different among sequential generations,ranging from 5.58±2.5 d(at G5)to 3.75±1.42 d(at G45).However,no significant difference was found in male adult longevity among different generations.Although female wasps survived longer until the 15th gener・ation,they allocated more days for egg laying at G5 and GIO.The highest values of gross reproductive rate(GRR),net reproductive rate(7.),intrinsic rate of increase(r),finite rate of increase(λ)and mean generation time(T)were found in G5 and GIO,which also showed significantly higher cq.No significant difference in the finite parasitism rate(co)was found among generations up to G15.These results suggest that T.brassicae wasps held under continuous laboratory rearing can be used successfully in biological control programs until the 15th generation without any loss of quality or performance.However,laboratory mass rearing colonies declined in quality after 15 generations and we suggest that they should be rejuvenated regularly by adding field-collected parasitoids periodically.
文摘When, how often and for how long organisms mate can have strong consequences for individual fitness and are crucial aspects of evolutionary ecology. Such determinants are likely to be of even greater importance in monandrous species and species with short adult life stages. Previous work suggests that mobility, a key dispersal? related trait, may affect the dynamics of copulations, but few studies have investigated the impact of individual mobility on mating latency, copulation duration and oviposition latency simultaneously. In this paper, we monitored the copulation dynamics of 40 males and 40 females, as well as the oviposition dynamics of the females of the Large White butterfly Pieris brassicae, a facultative long-distance disperser butterfly. Individuals from a breeding were selected to create a uniform distribution of mobility and we recorded the timing, number and duration of all copulations in a semiexperimental system. We showed that mobility, measured as the time spent in flight under stressful conditions (a proxy of dispersal tendency), correlates with all aspects of copulation dynamics: mobile males and females mated earlier and for shorter periods than less mobile individuals. In turn, late mating females increased the time between copulation and oviposition. These results feed the previously described mobility syndrome of R brassicae, involving morphological and physiological characters, with life-history traits. We suggest that the reduction of mating latency and copulation duration has an adaptive value in dispersing individuals, as their life expectancy might be shorter than that of sedentary individuals.
