MeSA诱导茶树抗叶蝉取食效应的DC-EPG分析

DC-EPG analysis on effect of tea plant induced by methyl salicylate against feeding of tea green leafhopper

用可视直流刺探电位技术(DC-EPG)记录试虫在3h内呈现的各种EPG波型。共明确7种波型,根据这些波型确定15个描述叶蝉取食行为的EPG参数,以评判茶树抗叶蝉取食特性。与未诱导茶苗(CK)上叶蝉刺吸行为相比,在0.2、0.4和0.8mmol/LMeSA诱导24h的茶苗上,总刺探次数增加,即n(ck)=8.30±1.13,n(0.2)=13.25±3.95,n(0.4)=15.01±2.68,n(0.8)=34.50±7.56;非取食刺探时间明显延长,即NP(ck)=110.97±5.2min,NP(0.2)=128.39±6.76min,NP(0.4)=148.35±6.14min,NP(0.8)=131.94±10.75min;韧皮部取食时间显著减少,即E(ck)=52.90±2.22min,E(0.2)=9.08±2.6min,E(0.4)=8.87±1.44min,E(0.8)=15.89±2.21min。3个MeSA处理剂量相比较,0.4mmol/L的诱导效应最明显。24h与48h诱导时间相比,24h的效应较显著。茶树被诱导之后,对叶蝉的取食适合度明显下降,表明产生了一定程度的抗性。

After tea seedlings were induced by methyl salicylate （MESA） which had been slowly emitted for 24 h or 48 h, tea green leafhoppers of the third instar were introduced on the tea seedlings. The videodirect current-electrical penetration graphy was used to record the various waveforms formed by the tested leafhoppers for 3 h. Seven distinct types of waveforms were recognized, based on which fifteen EPG parameters, describing the feeding behaviour of the leafhopper, were determined, and used to evaluate the resistance of tea seedlings against leafhoppers. Compared with pierce-sucking behaviour of the leafhopper on non-induced tea seedlings （ CK）, the probing number on 0.2, 0.4 and 0.8 mmol/L MeSA induced tea seedlings increased, which was respectively 8.30 ± 1.13, 13.25 ± 3.95, 15.01± 2.68 and 34.50 ±7.56 ; accordingly, the non-feeding probing time was 110.97± 5.2 min, 128.39 ± 6.76 min, 148.35± 6.14 min and 131.94 ± 10.75 min; and the accumulative duration of the phloem phase was evidently shortened, i. e. , 52.90 ± 2.22 min, 9.08 ± 2.6 min, 8.87 ± 1.44 min and 15.89± 2.21 min. The induction effect by 0.4 mmol/L was most obviously among the three treatment dosages. The effect induced for 24 h was stronger than that induced for 48 h. It should be considered that the dainty degree of the tea seedling to the leafhopper deteriorates after they are induced by MESA, to a certain extent, the resistance of tea plants against the leafhopper is induced.