氟环唑与氟唑菌酰羟胺及其复配对小麦赤霉病菌的室内毒力及田间防效

为了降低小麦赤霉病菌潜在抗药性的产生,筛选出高效防治药剂,本研究测定氟环唑和氟唑菌酰羟胺及其5种不同配比混剂的室内毒力,并进行了增效组合筛选及田间防效验证试验。结果表明,氟环唑、氟唑菌酰羟胺的EC_(50)分别为0.8702、0.2895 mg/L;氟环唑和氟唑菌酰羟胺按照1∶1质量比混配后的EC_(50)为0.2706 mg/L,协同增效系数为1.6056,具有增效作用。其按质量比1∶1复配后的组合物防效显著优于其单剂的防效及市场上其他单剂防效,最高可达90.16%。

Rapid and specific identification of Fusarium pseudograminearum by qPCR based on RPB sequence

Fusarium crown rot,mainly caused by Fusarium pseudograminearum,is a destructive disease in wheat production.To establish a rapid and reliable detection method for F.peasudeograminearum,the specific PCR primer pair(Fpg-F1;R2)was designed based on the RPB sequence,and real-time fluorescence quantitative PCR(qPCR)was used to validate the efficiency of the primer.The results showed that the primer pair had high specificity and sensitivity of 100 pg of DNA.Furthermore,the qPCR system for early and rapid detection of F.peasudeograminearum had an amplification efficiency of 87.5%and correlation coefficient of 0.99,and the pathologic threshold of F.pseudograminearum in soil was determined by using this detection system.It was found that F.pseudograminearum could cause Fusarium crown rot when the DNA concentration of F.pseudograminearum in field soil exceeded 213 pg·g^(-1).Hence,the qPCR-based method we developed for F.pseudograminearum detection has the advantages of high specificity and sensitivity,and can be used for rapid and early detection of F.pseudograminearum even in field soils.

氟吡菌酰胺对南方根结线虫的作用效果

为明确琥珀酸脱氢酶抑制剂类(SDHI)杀线剂氟吡菌酰胺对南方根结线虫Meloidogyne incognita的作用效果,在室内盆栽条件下研究不同剂量、不同施药时期该药剂对线虫侵入、根结和雌虫数量以及产卵量的影响。结果显示:在黄瓜幼苗移栽前进行土壤处理,氟吡菌酰胺施用剂量为31.25μg/株时,每株2龄幼虫侵染数量和根结数量分别为11.3条和6.4个,相比对照处理显著减少;在接种南方根结线虫后0~11 d,以施药量为125μg/株的氟吡菌酰胺进行灌根时,可大幅减少根结数量,每株根结数量减少至12.8~22.5个,同时,施药后根系内未见成熟雌虫产生;在接种后15 d,以施药量为250μg/株的氟吡菌酰胺进行灌根时,可大幅减少根内成熟雌虫数量,每株雌虫数量减少至16.9条;接种后20 d施药,施药量为500μg/株时可大幅减少根部产生的根结线虫卵块数量,每株卵块数量减少至18.9个。表明氟吡菌酰胺能抑制土壤内线虫对黄瓜根系的侵染并抑制根内线虫发育,但随着施药时间的推迟,防治已侵入根系的线虫需增加施药剂量,在生产上使用氟吡菌酰胺防治根结线虫病应在作物移栽前或线虫侵染早期施药效果更好。