Azoxystrobin acts as an inhibitor of electron transport by binding to the Qo center of cytochrome b （cyt b）. Resistance to azoxystrobin was usually caused by the point mutation of cyt b gene or by the induction of a...Azoxystrobin acts as an inhibitor of electron transport by binding to the Qo center of cytochrome b （cyt b）. Resistance to azoxystrobin was usually caused by the point mutation of cyt b gene or by the induction of alternative respiration. Oxygen consumption test for mycelia of Colletotrichum capsici showed that azoxystrobin inhibited mycelial respiration within 12 h; however, as time went on, the respiration of the mycelia recovered when the mycelia were treated with azoxystrobin and salicylhydroxamic acid （SHAM, a known inhibitor of alternative respiration）, and the oxygen consumption of the mycelia could not be inhibited. Meanwhile, cytochrome b （cyt b） gene expression increased with the recovery of mycelial respiration. The increased cyt b gene expression might play a role in the development of resistance to azoxystrobin in C. capsici.展开更多
Powdery mildew, caused by Erysiph necator, is a common and severe fungal disease of grapevine all over the world. The disease costs millions of dollars to vine growers, due to intensive use of fungicides and yield los...Powdery mildew, caused by Erysiph necator, is a common and severe fungal disease of grapevine all over the world. The disease costs millions of dollars to vine growers, due to intensive use of fungicides and yield losses. Recently in population of E. necator two genetic groups have been described, the two groups seem to occupy different temporal niches, with a temporal alternation that is clear-cut in vineyards intensively treated with chemical fungicides. QoI-STAR (Quinol Outside Inhibitors-Strobilurin Type of Action and Resistance) fungicides are widely used to control the disease, and generally carry a high risk of pathogen resistance development. To clarify the behaviors of the biotrophic fungus when treated with azoxystrobin as a representative of QoI-STAR, baseline sensitivity of laboratory isolates were determined. A leaf bioassay and the primers RSCBF1 and RSCBR2 designed on the highly conserved regions of cytb gene in fungi were used. Partial sequence of E. necator cytb gene were obtained. Attempts to obtain a laboratory mutant were not totally successful. The sensitivity to azoxystrobin (EC50) in isolates of genetic group B was significantly higher than in isolates of group A, to which all the isolates collected later in the season belonged. The higher sensitivity to azoxystrobin fungicides observed in group B isolates can be at the basis of their precocious disappearance in vineyards, and can have important implications for powdery mildew control strategies.展开更多
[目的]吡唑醚菌酯是巴斯夫公司开发的一种高活性的具有保健作用的QoI类杀菌剂。主要研究了吡唑醚菌酯对大豆炭疽病的田间防效及其对大豆的保健增产作用。[结果]田间防效试验结果表明:25%吡唑醚菌酯EC 67.5、100、135 g a.i./hm2对大豆...[目的]吡唑醚菌酯是巴斯夫公司开发的一种高活性的具有保健作用的QoI类杀菌剂。主要研究了吡唑醚菌酯对大豆炭疽病的田间防效及其对大豆的保健增产作用。[结果]田间防效试验结果表明:25%吡唑醚菌酯EC 67.5、100、135 g a.i./hm2对大豆炭疽病的防效分别为58.5%7、5.8%和85.7%1;8.3%Opera SC 90、110 g a.i./hm2的防效分别为69.6%和82.5%;对照药剂25%丙环唑EC 169 g a.i./hm2的防效为61.2%。在使用吡唑醚菌酯处理后的田块,大豆的产量、株高、底荚高度和百粒质量显著提高,但对大豆植株的有效分枝数、主茎节数、每株结荚数并未产生影响。[结论]用吡唑醚菌酯处理后,大豆豆荚的颜色更为鲜亮美观,颗粒饱满,提高了大豆的品质。展开更多
基金sponsored by the National 973 Program of China (2006CB101907)the National 863 Program of China (2006AA10A211, 2008AA10Z414)the National Natural Science Foundation of China(30671048, 30671384)
文摘Azoxystrobin acts as an inhibitor of electron transport by binding to the Qo center of cytochrome b （cyt b）. Resistance to azoxystrobin was usually caused by the point mutation of cyt b gene or by the induction of alternative respiration. Oxygen consumption test for mycelia of Colletotrichum capsici showed that azoxystrobin inhibited mycelial respiration within 12 h; however, as time went on, the respiration of the mycelia recovered when the mycelia were treated with azoxystrobin and salicylhydroxamic acid （SHAM, a known inhibitor of alternative respiration）, and the oxygen consumption of the mycelia could not be inhibited. Meanwhile, cytochrome b （cyt b） gene expression increased with the recovery of mycelial respiration. The increased cyt b gene expression might play a role in the development of resistance to azoxystrobin in C. capsici.
文摘Powdery mildew, caused by Erysiph necator, is a common and severe fungal disease of grapevine all over the world. The disease costs millions of dollars to vine growers, due to intensive use of fungicides and yield losses. Recently in population of E. necator two genetic groups have been described, the two groups seem to occupy different temporal niches, with a temporal alternation that is clear-cut in vineyards intensively treated with chemical fungicides. QoI-STAR (Quinol Outside Inhibitors-Strobilurin Type of Action and Resistance) fungicides are widely used to control the disease, and generally carry a high risk of pathogen resistance development. To clarify the behaviors of the biotrophic fungus when treated with azoxystrobin as a representative of QoI-STAR, baseline sensitivity of laboratory isolates were determined. A leaf bioassay and the primers RSCBF1 and RSCBR2 designed on the highly conserved regions of cytb gene in fungi were used. Partial sequence of E. necator cytb gene were obtained. Attempts to obtain a laboratory mutant were not totally successful. The sensitivity to azoxystrobin (EC50) in isolates of genetic group B was significantly higher than in isolates of group A, to which all the isolates collected later in the season belonged. The higher sensitivity to azoxystrobin fungicides observed in group B isolates can be at the basis of their precocious disappearance in vineyards, and can have important implications for powdery mildew control strategies.
文摘[目的]吡唑醚菌酯是巴斯夫公司开发的一种高活性的具有保健作用的QoI类杀菌剂。主要研究了吡唑醚菌酯对大豆炭疽病的田间防效及其对大豆的保健增产作用。[结果]田间防效试验结果表明:25%吡唑醚菌酯EC 67.5、100、135 g a.i./hm2对大豆炭疽病的防效分别为58.5%7、5.8%和85.7%1;8.3%Opera SC 90、110 g a.i./hm2的防效分别为69.6%和82.5%;对照药剂25%丙环唑EC 169 g a.i./hm2的防效为61.2%。在使用吡唑醚菌酯处理后的田块,大豆的产量、株高、底荚高度和百粒质量显著提高,但对大豆植株的有效分枝数、主茎节数、每株结荚数并未产生影响。[结论]用吡唑醚菌酯处理后,大豆豆荚的颜色更为鲜亮美观,颗粒饱满,提高了大豆的品质。
