پاسخ بویایی پسیل آسیایی مرکبات، Diaphorina citri به دو ترکیب شیمیایی گاما-بوتیرو لاکتون و متیل‌سالیسیلات در شرایط آزمایشگاهی

نوع مقاله: علمی پژوهشی-فارسی

نویسندگان

1 گروه گیا‌ه‌پزشکی، دانشکده کشاورزی، دانشگاه ولی‏‎عصر (عج) رفسنجان، رفسنجان

2 گروه گیا‌ه‌پزشکی، دانشکده کشاورزی، دانشگاه ولی‎عصر (عج) رفسنجان، رفسنجان

چکیده

توانایی درک و تشخیص ترکیبات فرار در حشرات گیاه‏خوار برای انتخاب گیاه میزبان، پیداکردن جفت و انتخاب میزبان مناسب برای تخم‏ریزی امری حیاتی می‎باشد. در این پژوهش پاسخ بویایی پسیل آسیایی مرکبات Diaphorina citri Kuwayama (Hem.: Psyllidae) به محرک‌های شیمیایی دو ترکیب گاما- بوتیرولاکتون (فرومون جنسی پسیل مرکبات) و متیل سالیسیلات (ترکیب هورمون گیاهی) در هفت غلظت 1000، 100، 10، 1، 1/0، 01/0 و 001/0 میکروگرم بر میلی‎لیتر با استفاده از دستگاه بویایی‎سنج Y- شکل در سال 1390 مورد ارزیابی قرار گرفت. نتایج مشخص کرد که ترکیب گاما-بوتیرولاکتون به‌طور معنی‌داری، در غلظت‎های 1000، 100، 10 و 1 میکروگرم بر میلی‎لیتر، حشرات نر پسیل آسیایی مرکبات را به خود جلب کرد. اما حشرات ماده پسیل آسیایی مرکبات به هیچ‎کدام از غلظت‎های این ترکیب جلب نشدند. هم‌چنین غلظت 01/0 میکروگرم بر میلی‎لیتر، ترکیب متیل سالیسیلات به‎طور معنی‎داری سبب جلب حشرات نر و ماده پسیل آسیایی مرکبات شد. غلظت 1000 میکروگرم بر میلی‎لیتر متیل سالیسیلات، برای حشرات نر و ماده پسیل آسیایی دور کننده بود. غلظت‎های 001/0، 1/0، 1، 10 و 100 میکروگرم بر میلی‎لیتر ترکیب متیل سالیسیلات اثری روی رفتار حشرات نر و ماده پسیل آسیایی مرکبات نداشت. ارزیابی ترکیبات شیمیایی موثر بر رفتار پسیل آسیایی مرکبات و دستیابی به ترکیب جلب‎کننده می‎تواند در مدیریت تلفیقی این آفت مهم و مخرب، نقش بسزایی داشته باشد.

کلیدواژه‌ها


عنوان مقاله [English]

Olfactory responses of Diaphorina citri Kuwayama (Hem.: Psyllidae) to chemical compounds Gamma-butyrolactone and Methyl salicylate in laboratory conditions

نویسندگان [English]

  • Amin Moghbeli Gharaei 1
  • Mahdi Ziaaddini 2
  • Mohammad Amin Jalali 1
1 Department of Crop Protection, Agriculture College, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
2 Department of Crop Protection, Agriculture College, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
چکیده [English]

Background and Objective
The Asian citrus psyllid, Diaphorina citri Kuwayama (Hem.: Psyllidae), is one of the most destructive pests of citrus because of its ability to vector the causal bacterial pathogen of citrus greening disease. This is one of the most devastating diseases of citrus worldwide. Feeding on citrus by Asian citrus psyllid also induces release of Methyl salicylate (MeSA), suggesting that it may be a cue revealing location of conspecifics on host plants. MeSA is a ubiquitous aromatic ester that is a well-known plant stress signal and enhances defense against herbivores with repellent properties. Gamma-butyrolactone (GBL) is a primary component of the volatile ingredients in the female sex pheromone of the D. citri. The ability to decrypt plant volatiles is essential for herbivorous insects for their choice of host plants and mating partners and oviposition hosts. D. citri is an oligophagous insect with a host range restricted to plants in the Rutaceae family. That is why olfaction plays an important role in its host finding and selection process. The use of olfactory cues by adult psyllids in host plant selection has been reported in many olfactometer studies. In order to achieve the attractive and repellent compounds for pest management strategies against this pest, we investigated the effect of volatiles emitted from Synthetic GBL and MeSA on olfactory response of D.citri in laboratory bioassays.
Materials and Methods
This study evaluated the olfactory responses of D. citri to chemical stimuli from seven concentrations of GBL and MeSA including 0.001, 0.01, 0.1, 1.0, 10, 100 and 1000 µg/ ml with individual release of 30 females and 30 males. The GBL and MeSA (>98% purity) were purchased from Sigma Aldrich (USA) and diluted in dichloromethane. A glass Y-tube olfactometer was used in laboratory conditions (27±2°C, 60–80% RH, under a fluorescent 1600 lux light source, 14:10 (L:D) photocycle period and constant airflow of 300 ml/min).
Results
The results revealed that a significant proportion of male D. citri were attracted to GBL at the 1.0, 10, 100 and 1000 µg/ ml concentrations. But female D. citri showed no response to odors emanating from this compound. The results also indicated that a significant proportion of male and female D. citri were attracted to MeSA at the 0.01 µg concentration. However MeSA at the concentration 1000 µg/ ml was repellent for psyllids. Other concentrations (0.001, 0.1, 1.0, 10 and 100 µg/ ml) did not attract or repel the male and female D. citri.
Discussion
In this study, results showed that GBL at high concentrations is attractive only for male insects. These results indicate the role of GBL as a sex pheromone in attracting male insects. Feeding by herbivores induces the production of MeSA, so that this compound is often found among the volatile compounds of plants damaged by herbivores. MeSA plays a role in plant defense against herbivores by either repelling herbivores or by attracting biological control agents. The results of this study show that, probably, release of MeSA by host plants at low concentrations (0.01 μg), can be a cue of the presence of conspecific for D. citri in the early stages of host finding. With increasing infestation of host plants and increasing MeSA concentration, this compound repels the insects and that this method is considered a defensive tool for the plant. It is also possible that increasing the concentration of MeSA for the insect has this cue that if attracted, it will encounter a high population of conspecifics and the insect would not be attracted to high concentrations in order to avoid potential competition for food sources. Evaluation of chemical compounds that are attractive or repellent to D. citri, can contribute to the improvement in integrated management projects against this pest.

کلیدواژه‌ها [English]

  • Asian citrus psyllid
  • Citrus Greening
  • Methyl salicylate
  • Olfactometer
  • Pheromone