为了明确外源茉莉酸对枸杞的诱导抗性及其对害虫的影响,在室内25℃条件下用3种浓度的茉莉酸喷施枸杞苗木,以喷施丙酮+蒸馏水(配比1:599)作为对照,测定了枸杞蚜在处理后苗木上的生长发育和繁殖情况。结果表明:外源茉莉酸诱导枸杞苗木后,枸杞蚜若虫发育历期延长,成虫寿命缩短、产仔量下降,枸杞蚜体重减轻,其影响程度与茉莉酸浓度有关。0.01mmol/L茉莉酸诱导枸杞蚜若虫期最长,为4.93d,比对照延长1.9d。茉莉酸诱导成虫产仔量显著减少,且浓度越高产仔量越少,0.1mmol/L浓度下产仔量为25头,比对照少19头。3种浓度的茉莉酸诱导均使枸杞蚜成虫寿命较对照缩短3d左右。茉莉酸诱导对枸杞蚜体重的影响从3日龄后逐渐显现,5日龄时最显著,处理组与对照组蚜虫体重相差0.128~0.184mg,对照组蚜虫平均重0.395mg,0.01mmol/L处理组蚜虫重量仅0.211mg。
In order to explore the induced resistance of wolfberry by exogenous jasmonic acid and the influence on insects,in the laboratory at 25℃ three concentrations of jasmonic acid (JA) and the control (acetone and distilled water at the ratio of 1:599) were used to spray seedlings of wolfberry Lycium barbarum Linn.,which were used to rear the wolfberry aphid Aphis sp.,and then the developmental duration,body weight and fecundity of these aphids were tested.The results showed that the developmental duration,adult longevity,fecundity and body weight were significantly influenced on JA-induced wolfberry seedlings and the influence was related to the JA concentration.The longest nymphal period was observed on 0.01 mmol/L JA-induced seedlings,which was 4.93 d,1.9 d longer than that of control.The adult fecundity was reduced significantly,and the higher the concentration of JA solution,the lower the fecundity of the adult.Nineteen less nymphs produced per adult on the 0.1 mmol/L JA-induced seedlings than on the control seedlings.The adult longevity on the induced seedlings was about 3 d shorter than that on control.The daily body weight began to be influenced significantly on the 3rd day post JA treatment.On the 5th day post JA treatment,the average body weight was 0.395 mg for aphids on the control,and only 0.211 mg for aphids on 0.01 mmol/L JA-induced seedlings,and the range of body weight difference between aphids on JA-induced and control seedlings was 0.128-0.184 mg.