[Objective] This study aimed to explore the pathotype structure of Magnaporthe grisea in Chongyang and Yuan'an in Hubei Province,China.[Method] From the rice-growing fields of Chongyang and Yuan'an in Hubei Pr...[Objective] This study aimed to explore the pathotype structure of Magnaporthe grisea in Chongyang and Yuan'an in Hubei Province,China.[Method] From the rice-growing fields of Chongyang and Yuan'an in Hubei Province where rice blast occurs frequently,60 isolates which were pathotyped against two sets of host differentials:Chinese host differentials and CO39 NILs,were obtained.Then,20 pathotypes with the six indica host differentials(CO39 NILs) were observed,while 13 pathotypes in four race groups were observed out of the same single spore isolates with Chinese host differentials which consists of three indica cultivars and four japonica cultivars.The diversity of the pathotypes of M.grisea populations tested by CO39 NILs was 2.54 and the pathotype 137.1 occurred at predominantly high frequency(21.67%).The diversity of physiological races of M.grisea populations tested by Chinese host differentials was 1.22 and the race group ZA occurred at predominantly high frequency(73.33%).The diversity of physiological races of M.grisea in Chongyang and Yuan'an were also calculated.Overall,the diversity of pathotypes of M.grisea in Yuan'an was higher than that in Chongyang with the two sets of the host differentials.[Conclusion] This study provided current information on the pathotype spectrum of M.grisea populations in the rice fields of Hubei Province to allow the formulation of viable strategies for blast resistance breeding programs in Hubei Province.展开更多
Intestinal microflora possesses both beneficial and pathogenic properties with respect to host health and well being. Three procedures are usually proposed for its modulation： probiotic, prebiotic and their combinati...Intestinal microflora possesses both beneficial and pathogenic properties with respect to host health and well being. Three procedures are usually proposed for its modulation： probiotic, prebiotic and their combination on symbiotic. In this in vitro study the authors assess the effect of a symbiotic combination between cellobiose and two probiotic strains （L. rhamnosus, S. thermophilus） toward two pathogenic bacteria （S. aureus and E. colO. In addition, we evaluate the influence of this fiber either on the localization of the lactic inhibiting substances and their extracelluler polymer substances （EPS） production. The results showed that the prebiotic candidate noticeably elongated the adaptation phase of the target pathogens to up than 12 hours, while stimulate the probiotic growth till 2 Log CFU/mL in favor of L. rhamnosus and to approximately 3 Log CFU/mL for S. thermophilus compared with control substrate （glucose）. The inhibiting effect was more important toward S. aureus （2.54 and 1.09 Log CFU/mL against 4.99 and 7.75 in co-culture with L. rhamnosus and S. thermophilus respectively at the 4th hour of incubation） and lesser for E. coli compared with the control substrate. And the results suggested that S thermophilus inhibited both target strains mainly by bacteriocins, whilst L. rharnnosus rather inhibited S. aureus growth by bacteriocins and E. coli ones by acids production. We also observed a significant stimulation of the exopolysaccahrids production by this fiber, which may allow a better adhesion of the probiotic candidates in the intestinal tract.展开更多
基金Supported by the Key Project of the National 11th Five-Year Plan of China (2006BADO8A04-06)
文摘[Objective] This study aimed to explore the pathotype structure of Magnaporthe grisea in Chongyang and Yuan'an in Hubei Province,China.[Method] From the rice-growing fields of Chongyang and Yuan'an in Hubei Province where rice blast occurs frequently,60 isolates which were pathotyped against two sets of host differentials:Chinese host differentials and CO39 NILs,were obtained.Then,20 pathotypes with the six indica host differentials(CO39 NILs) were observed,while 13 pathotypes in four race groups were observed out of the same single spore isolates with Chinese host differentials which consists of three indica cultivars and four japonica cultivars.The diversity of the pathotypes of M.grisea populations tested by CO39 NILs was 2.54 and the pathotype 137.1 occurred at predominantly high frequency(21.67%).The diversity of physiological races of M.grisea populations tested by Chinese host differentials was 1.22 and the race group ZA occurred at predominantly high frequency(73.33%).The diversity of physiological races of M.grisea in Chongyang and Yuan'an were also calculated.Overall,the diversity of pathotypes of M.grisea in Yuan'an was higher than that in Chongyang with the two sets of the host differentials.[Conclusion] This study provided current information on the pathotype spectrum of M.grisea populations in the rice fields of Hubei Province to allow the formulation of viable strategies for blast resistance breeding programs in Hubei Province.
文摘Intestinal microflora possesses both beneficial and pathogenic properties with respect to host health and well being. Three procedures are usually proposed for its modulation： probiotic, prebiotic and their combination on symbiotic. In this in vitro study the authors assess the effect of a symbiotic combination between cellobiose and two probiotic strains （L. rhamnosus, S. thermophilus） toward two pathogenic bacteria （S. aureus and E. colO. In addition, we evaluate the influence of this fiber either on the localization of the lactic inhibiting substances and their extracelluler polymer substances （EPS） production. The results showed that the prebiotic candidate noticeably elongated the adaptation phase of the target pathogens to up than 12 hours, while stimulate the probiotic growth till 2 Log CFU/mL in favor of L. rhamnosus and to approximately 3 Log CFU/mL for S. thermophilus compared with control substrate （glucose）. The inhibiting effect was more important toward S. aureus （2.54 and 1.09 Log CFU/mL against 4.99 and 7.75 in co-culture with L. rhamnosus and S. thermophilus respectively at the 4th hour of incubation） and lesser for E. coli compared with the control substrate. And the results suggested that S thermophilus inhibited both target strains mainly by bacteriocins, whilst L. rharnnosus rather inhibited S. aureus growth by bacteriocins and E. coli ones by acids production. We also observed a significant stimulation of the exopolysaccahrids production by this fiber, which may allow a better adhesion of the probiotic candidates in the intestinal tract.
