RESUMEN
Knowledge of the evolution of fungicide resistance is important in securing sustainable disease management in agricultural systems. In this study, we analyzed and compared the spatial distribution of genetic variation in azoxystrobin sensitivity and SSR markers in 140 Phytophthora infestans isolates sampled from seven geographic locations in China. Sensitivity to azoxystrobin and its genetic variation in the pathogen populations was measured by the relative growth rate (RGR) at four fungicide concentrations and determination of the effective concentration for 50% inhibition (EC50). We found that all isolates in the current study were sensitive to azoxystrobin and their EC50 was similar to that detected from a European population about 20 years ago, suggesting the risk of developing azoxystrobin resistance in P. infestans populations is low. Further analyses indicate that reduced genetic variation and high fitness cost in resistant mutations are the likely causes for the low evolutionary likelihood of developing azoxystrobin resistance in the pathogen. We also found a negative correlation between azoxystrobin tolerance in P. infestans populations and the mean annual temperature of collection sites, suggesting that global warming may increase the efficiency of using the fungicide to control the late blight.
Asunto(s)
Fungicidas Industriales/farmacología , Metacrilatos/farmacología , Repeticiones de Microsatélite/genética , Phytophthora infestans/efectos de los fármacos , Pirimidinas/farmacología , China , Resistencia a Medicamentos/efectos de los fármacos , Variación Genética , Phytophthora infestans/genética , Phytophthora infestans/crecimiento & desarrollo , Hojas de la Planta/parasitología , Solanum tuberosum/parasitología , Estrobilurinas , TemperaturaRESUMEN
OBJECTIVE: To investigate the single nucleotide polymorphism (SNP), the distribution of their haplotypes and linkage disequilibrium of hepatic lipase (HL) gene promoter 250G/A, 514C/T, 710T/C and 763A/G in cerebral infarction patients of Shanghai. METHODS: Peripheral blood sample were collected from 133 patients with cerebral infarction and 112 healthy controls in Shanghai. The HL gene polymorphism was analyzed by polymerase chain reaction- restriction fragment length polymorphism. RESULTS: There were statistically significant differences in genotype and allele frequencies between the healthy controls and the patients with cerebral infarction in -250G/A and -514C/T genotypes and allele frequencies (all P < 0.05). However, there were no significant differences in genotype and allele frequencies in -710T/C and -763A/G between the healthy controls and the patients with cerebral infarction (all P > 0.05). Besides, there was a strong linkage disequilibrium between -250G/A and -514C/T, -710T/C, and -763A/G respectively, between -514C/T and -710T/C and -763A/G respectively, and between -710T/C and -763A/G. When the haplotypes were -250G/-514C, -250G/-710C, -250G/-763G, -514C/-710C, and 514C/-763G respectively, the frequencies in the cerebral infarction group were significantly lower than that in the healthy controls. When the haplotype was -250A/-514T, -250A/-710T, -250A/-710C, -250A/-763G, -514T/-710C, -514T/-763G, and -710T/-763G respectively, the frequencies in the cerebral infarction group were significantly higher than those in the healthy controls. CONCLUSION: There are significant haplotypes and linkage disequilibrium among the four SNPs of HL gene in the cerebral infarction patients of Shanghai. The haplotypes GC, GG, and CC lower the incidence rate of cerebral infarction, while the haplotypes AT, AC, AG, TC, and TG increase the incidence rate of cerebral infarction.