Fungi are often used to induce agarwood inAquilariatrees. This study was conducted to evaluate the effect of several fungi on agarwood formation over time in youngAquilaria malaccensis （Lam.） trees. Typical changes ...Fungi are often used to induce agarwood inAquilariatrees. This study was conducted to evaluate the effect of several fungi on agarwood formation over time in youngAquilaria malaccensis （Lam.） trees. Typical changes in the length and light intensity of the resulting discoloration were observed after three and six month periods following inoculation. Wood samples were observed microscopically and classified into several light intensity groups. The discoloration length was meas-ured longitudinally. The duration after inoculation affected the mean of discoloration length： the 6-month old sample （1.70 cm） had a wider discoloration zone when compared to the 3-month old sample （1.17 cm）. When measuring the discoloration intensity, a positive relationship with time was perceived. Digital images, captured using a camera-equipped microscope, revealed that wood samples collected after six months appeared to be 1.8-times darker than after three months. We concluded that time, not the species of any of the tested fungi, had significant effect on discoloration length and intensity. Gas chromatography/mass spec-trometry （GCMS） analysis of the 6-month old sample yielded some important agarwood compounds such as benzylacetone, anisylacetone, guaiene and palustrol. This demonstrates that the tested fungi have the ability to induce agarwood formation in nurseryA. malaccensis trees.展开更多
In order to map the quantitative trait loci for rice stripe resistance, a molecular linkage map was constructed based on the F2 population derived from a cross between Zhaiyeqing 8 and Wuyujing 3. Reactions of the two...In order to map the quantitative trait loci for rice stripe resistance, a molecular linkage map was constructed based on the F2 population derived from a cross between Zhaiyeqing 8 and Wuyujing 3. Reactions of the two parents, F1 individual and 129 F2：3 lines to, rice stripe were JnvestJgated by both artificial Jnoculation at laboratory and natural infection in the field, and the ratios of disease rating index were scored. The distribution of the ratios of disease rating index in Zhaiyeqing 8/Wuyujing 3 F2：3 population ranged from 0 to 134,08 and from 6.25 to 133.6 under artificial inoculation at laboratory and natural infection in the field, respectively, and showed a marked bias towards resistant parent （Zhaiyeqing 8）, indicating that the resistance to rice stripe was controlled by quantitative trait loci （QTL）. QTL analysis showed that the QTLs detected by the two inoculation methods were completely different. Only one QTL, qSTVT, was detected under artificial inoculation, at which the Zhaiyeqing 8 allele increased the resistance to rice stripe, while two QTLs, qSTV5 and qSTV1, were detected under natural infection, in which resistant alleles came from Zhaiyeqing 8 and Wuyujing 3, respectively. These results showed that resistant parent Zhaiyeqing 8 carried the alleles associated with the resistance to rice stripe virus and the small brown planthopper, and susceptible parent Wuyujing 3 also carried the resistant allele to rice stripe virus. In comparison with the results previously reported, QTLs detected in the study were new resistant genes to rice stripe disease. This will provide a new resistant resource for avoiding genetic vulnerability for single utilization of the resistant gene Stvb-i.展开更多
The resistance of 15 flue-cured tobacco varieties were identified by artificial inoculation of black shank. The results showed that K326, Yunyan 202 and NC102 belonged to resistance variety against black shank, and th...The resistance of 15 flue-cured tobacco varieties were identified by artificial inoculation of black shank. The results showed that K326, Yunyan 202 and NC102 belonged to resistance variety against black shank, and the resistance successively were K326 〉 Yunyan 202 〉 NC102 ; Yunyan 87, Cuibi 5, Yunyan 85, Yunyan 97 and Cuibi 7 belonged to moderate resistance variety against black shank, and the resistance successively were Yunyan 87 ~ Cuibi 5 ~ Yunyan 85 〉 Yunyan 97 〉 Cuibi 7 ; Cuibi 12, NC82, PYH06 and Cuibi 14 belonged to moderate susceptible variety against black shank, and the resistance successively were Cuibi 12 ~ NC82 ~ PVH06 ~ Cuibi 14; Cuibi 1 and Hongda belonged to high susceptible variety against black shank, and the resistance successively were Cuibi 1 〉 09011 〉 Hongda. The disease dynamics of flue-cured tobacco varieties were positively correlated with variety susceptibility, namely the earlier infection in susceptible variety, the faster the disease progression.展开更多
[ Objective ] The paper was to determine the resistance level of the tried and pre-examination wheat cultivars against powdery mildew in Anhui Province of China. [ Method ] By using artificial inoculation and identifi...[ Objective ] The paper was to determine the resistance level of the tried and pre-examination wheat cultivars against powdery mildew in Anhui Province of China. [ Method ] By using artificial inoculation and identification method in fields, the resistance of wheat cultivars was identified in consecutive three years from 2010 to 2012. [ Result] The highly susceptible （HS） cultivar accounted for 30%, 42% and 11% of total tested cultivars in the years of 2010, 2011 and 2012, respectively; moderately susceptible （MS） cultivar accounted for 53% of total tested cuhivars in 2010, which accounted for 47% and 57% in 2011 and 2012, respectively; moderately resistant （MR） cuhivar accounted for 17% of total tested cultivars in 2010, which accounted for 11% and 32% in 2011 and 2012, respectively. [ Conclusion] The paper can guide breeding direction, and also provide scientific basis for variety approval.展开更多
Pseudomonas syringae is the most frequently emerging group of plant pathogenic bacteria.Because this bacterium is ubiquitous as an epiphyte and on various substrates in non-agricultural settings,there are many questio...Pseudomonas syringae is the most frequently emerging group of plant pathogenic bacteria.Because this bacterium is ubiquitous as an epiphyte and on various substrates in non-agricultural settings,there are many questions about how to assess the risk for plant disease posed by strains in the environment.Although P.syringae is considered to have discrete host ranges in defined pathovars,there have been few reports of comprehensive comparisons of host range potential.Here we present results of host range tests for 134 strains,representing eight phylogroups,from epidemics and environmental reservoirs on 15 to 22 plant species per test conducted in four separate tests to determine the patterns and extent of host range.We sought to identify trends that are indicative of distinct pathotypes and to assess if strains in the P.syringae complex are indeed restricted in their host range.We show that for each test,strains display a diversity of host ranges from very restricted to very broad regardless of the gamut of phylogroups used in the test.Overall,strains form an overlapping continuum of host range potential with equal representation of narrow,moderate and broad host ranges.Groups of distinct pathotypes,including strains with currently the same pathovar name,could not be identified.The absence of groupings was validated with statistical tests for pattern recognition.The extent of host range was positively correlated with the capacity of strains to swarm on semi-solid agar medium and with the abundance of genes in biosynthetic clusters and was inversely correlated with the abundance of genes for proteins with transmembrane domains in their genomes.Our results are consistent with the current paradigm that disease symptoms are the result of multiple molecular interactions between P.syringae and its plant host that are modulated by abiotic and biotic conditions.This leads us to propose that pathovar denominations do not correspond to the underlying biology of P.syringae.A new concept of pathogenicity that accounts for the continuum of pathogenic potential in P.syringae would open new perspectives to understand the evolution of pathogenicity in this bacterium and new insights to anticipate disease and to manage plant health.展开更多
基金supported by the Universiti Putra Malaysia Research University Grant Scheme(Project No.03-03-11-1438RU)
文摘Fungi are often used to induce agarwood inAquilariatrees. This study was conducted to evaluate the effect of several fungi on agarwood formation over time in youngAquilaria malaccensis （Lam.） trees. Typical changes in the length and light intensity of the resulting discoloration were observed after three and six month periods following inoculation. Wood samples were observed microscopically and classified into several light intensity groups. The discoloration length was meas-ured longitudinally. The duration after inoculation affected the mean of discoloration length： the 6-month old sample （1.70 cm） had a wider discoloration zone when compared to the 3-month old sample （1.17 cm）. When measuring the discoloration intensity, a positive relationship with time was perceived. Digital images, captured using a camera-equipped microscope, revealed that wood samples collected after six months appeared to be 1.8-times darker than after three months. We concluded that time, not the species of any of the tested fungi, had significant effect on discoloration length and intensity. Gas chromatography/mass spec-trometry （GCMS） analysis of the 6-month old sample yielded some important agarwood compounds such as benzylacetone, anisylacetone, guaiene and palustrol. This demonstrates that the tested fungi have the ability to induce agarwood formation in nurseryA. malaccensis trees.
文摘In order to map the quantitative trait loci for rice stripe resistance, a molecular linkage map was constructed based on the F2 population derived from a cross between Zhaiyeqing 8 and Wuyujing 3. Reactions of the two parents, F1 individual and 129 F2：3 lines to, rice stripe were JnvestJgated by both artificial Jnoculation at laboratory and natural infection in the field, and the ratios of disease rating index were scored. The distribution of the ratios of disease rating index in Zhaiyeqing 8/Wuyujing 3 F2：3 population ranged from 0 to 134,08 and from 6.25 to 133.6 under artificial inoculation at laboratory and natural infection in the field, respectively, and showed a marked bias towards resistant parent （Zhaiyeqing 8）, indicating that the resistance to rice stripe was controlled by quantitative trait loci （QTL）. QTL analysis showed that the QTLs detected by the two inoculation methods were completely different. Only one QTL, qSTVT, was detected under artificial inoculation, at which the Zhaiyeqing 8 allele increased the resistance to rice stripe, while two QTLs, qSTV5 and qSTV1, were detected under natural infection, in which resistant alleles came from Zhaiyeqing 8 and Wuyujing 3, respectively. These results showed that resistant parent Zhaiyeqing 8 carried the alleles associated with the resistance to rice stripe virus and the small brown planthopper, and susceptible parent Wuyujing 3 also carried the resistant allele to rice stripe virus. In comparison with the results previously reported, QTLs detected in the study were new resistant genes to rice stripe disease. This will provide a new resistant resource for avoiding genetic vulnerability for single utilization of the resistant gene Stvb-i.
基金Supported by General Project of Panzhihua Branch of Sichuan Tobacco Company"Breeding and Application of Cuibi Series Varieties"(PZHYC20130016)
文摘The resistance of 15 flue-cured tobacco varieties were identified by artificial inoculation of black shank. The results showed that K326, Yunyan 202 and NC102 belonged to resistance variety against black shank, and the resistance successively were K326 〉 Yunyan 202 〉 NC102 ; Yunyan 87, Cuibi 5, Yunyan 85, Yunyan 97 and Cuibi 7 belonged to moderate resistance variety against black shank, and the resistance successively were Yunyan 87 ~ Cuibi 5 ~ Yunyan 85 〉 Yunyan 97 〉 Cuibi 7 ; Cuibi 12, NC82, PYH06 and Cuibi 14 belonged to moderate susceptible variety against black shank, and the resistance successively were Cuibi 12 ~ NC82 ~ PVH06 ~ Cuibi 14; Cuibi 1 and Hongda belonged to high susceptible variety against black shank, and the resistance successively were Cuibi 1 〉 09011 〉 Hongda. The disease dynamics of flue-cured tobacco varieties were positively correlated with variety susceptibility, namely the earlier infection in susceptible variety, the faster the disease progression.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(3-15)
文摘[ Objective ] The paper was to determine the resistance level of the tried and pre-examination wheat cultivars against powdery mildew in Anhui Province of China. [ Method ] By using artificial inoculation and identification method in fields, the resistance of wheat cultivars was identified in consecutive three years from 2010 to 2012. [ Result] The highly susceptible （HS） cultivar accounted for 30%, 42% and 11% of total tested cultivars in the years of 2010, 2011 and 2012, respectively; moderately susceptible （MS） cultivar accounted for 53% of total tested cuhivars in 2010, which accounted for 47% and 57% in 2011 and 2012, respectively; moderately resistant （MR） cuhivar accounted for 17% of total tested cultivars in 2010, which accounted for 11% and 32% in 2011 and 2012, respectively. [ Conclusion] The paper can guide breeding direction, and also provide scientific basis for variety approval.
基金supported by in-house funding from INRA and from the Ministry of Education,Science and Technological Development of Serbia,grant No.173026The salary of JRL was supported by DAFNE,University of TusciaThe sojourn of IN to conduct pathogenicity tests in Avignon was supported by a Research Grant from the Federation of European Microbiology Societies.
文摘Pseudomonas syringae is the most frequently emerging group of plant pathogenic bacteria.Because this bacterium is ubiquitous as an epiphyte and on various substrates in non-agricultural settings,there are many questions about how to assess the risk for plant disease posed by strains in the environment.Although P.syringae is considered to have discrete host ranges in defined pathovars,there have been few reports of comprehensive comparisons of host range potential.Here we present results of host range tests for 134 strains,representing eight phylogroups,from epidemics and environmental reservoirs on 15 to 22 plant species per test conducted in four separate tests to determine the patterns and extent of host range.We sought to identify trends that are indicative of distinct pathotypes and to assess if strains in the P.syringae complex are indeed restricted in their host range.We show that for each test,strains display a diversity of host ranges from very restricted to very broad regardless of the gamut of phylogroups used in the test.Overall,strains form an overlapping continuum of host range potential with equal representation of narrow,moderate and broad host ranges.Groups of distinct pathotypes,including strains with currently the same pathovar name,could not be identified.The absence of groupings was validated with statistical tests for pattern recognition.The extent of host range was positively correlated with the capacity of strains to swarm on semi-solid agar medium and with the abundance of genes in biosynthetic clusters and was inversely correlated with the abundance of genes for proteins with transmembrane domains in their genomes.Our results are consistent with the current paradigm that disease symptoms are the result of multiple molecular interactions between P.syringae and its plant host that are modulated by abiotic and biotic conditions.This leads us to propose that pathovar denominations do not correspond to the underlying biology of P.syringae.A new concept of pathogenicity that accounts for the continuum of pathogenic potential in P.syringae would open new perspectives to understand the evolution of pathogenicity in this bacterium and new insights to anticipate disease and to manage plant health.
