مقاومت پایه‌های امیدبخش سیب به شته مومی [(eriosoma lanigerum (hausmman] در شرایط تغذیه اجباری

شته مومی [(eriosoma lanigerum (hausmman] یکی از آفات خسارت زای باغات سیب است که می‌تواند تا 30 درصد محصول را کاهش دهد و به طور مستقیم به کیفیت میوه نیز آسیب برساند. این پژوهش باهدف ارزیابی مقاومت ده پایه امید بخش سیب شامل پایه‌های تجاری و بومی، نسبت به شته مومی سیب در شرایط تغذیه اجباری در شرایط گلخانه با دمای 5 ± 25 درجه سانتی‌گراد، رطوبت نسبی 10 ± 60 درصد و چرخه نوری 14 ساعت روشنایی و 10 ساعت تاریکی در سال های 1401 و 1402 انجام شد. در این پژوهش، شاخص‌های سرعت تغییرات جمعیت، سطح تعادل جمعیت و احتمال استقرار شته بر روی پایه‌های امید بخش سیب در طول فصل رشد به‌دقت بررسی شدند. نتایج نشان دادند که پایه‌m9op(387) ، به دلیل داشتن سازکارهای آنتی‌زنوز (جلوگیری از استقرار شته) و آنتی‌بیوز (کاهش بقا و باروری شته)، توانستند جمعیت شته را تا 60 درصد کاهش دهند. همچنین، احتمال استقرار شته در پایه‌های مقاوم حدود 20 تا 30 درصد کمتر از پایه‌های حساس‌تر مانند b9op(87) بود. ویژگی‌های فیزیکی نظیر تراکم کرک و ضخامت پوست شاخه نیز به‌عنوان عوامل موثر در مقاومت پایه‌ها شناسایی شد. نتایج این پژوهش نشان داد که استفاده از پایه‌های مقاوم می‌تواند به طور موثری در مدیریت تلفیقی این آفت سیب مورد استفاده قرار گیرد و راهکاری پایدار برای کنترل شته مومی فراهم کند. یافته‌های این پژوهش می تواند در برنامه‌های به نژادی و گزینش پایه‌های مقاوم سیب مناسب و سازگار با شرایط متنوع اقلیمی در ایران استفاده شوند.

resistance of promising apple rootstocks to the woolly aphid [eriosoma lanigerum (hausmman)] under forced feeding conditions

this study aimed to evaluate the resistance of 10 apple rootstocks to the woolly apple aphid [eriosoma lanigerum (hausmman)] during 2022 and 2023 growing seasons. this research examined the population growth rate, population equilibrium level, and the likelihood of aphid establishment on 10 apple rootstocks during the growing season. the results showed that m9op(387) rootstock, due to its antixenosis (prevention of aphid establishment) and antibiosis (reduced survival and fertility of aphids) mechanisms, was able to reduce the aphid population by up to 60%. additionally, the probability of aphid establishment on resistant rootstocks was about 20 to 30% lower than on more susceptible rootstocks like b9op(87). morphological characteristics, such as lint density and bark thickness, were identified as factors influencing the rootstock’s resistance. the findings of this research have great potential for being used in breeding programs for development and selection of resistant apple rootstocks to the wooly apple aphid adapted to different climatic conditions. keywords: apple rootstock, susceptible, population indices, morphological characteristics, biological stability, control. introduction the woolly apple aphid [eriosoma lanigerum (hausmman)], a globally important pest, imposese significant challenges to apple fruit production. published researches has indicated that infestations can reduce apple yields by 10 to 30 percent, depending on environmental and varietal susceptibility (adhikari, 2022; kamusiime et al., 2023).chemical controls are widely applied but are costly, cause pesticide resistance, and impose environmental concerns and challenges. biological control, although effective, are rather slow and have limitations in it immediate effectiveness. choosing rootstocks resistant to the woolly apple aphid is one of the effective and sustainable approach to control this pest. resistant rootstocks can prevent the growth and reproduction of aphids and help to reduce the attendant costs of chemical and biological controls.rootstocks resistant to the wooly apple aphid can reduce up to 50 to 70 percent of infestation by this pest. using resistant rootstocks can reduce chemical control costs by 60% (nicholas et al., 2005). an alternative, choosing sustainable approaches for managing the woolly apple aphids is using resistant rootstocks, as a component of integrated pest mangemnet (ipm) to control the pest. certain rootstocks exhibit inherent resistance, minimizing aphid establishment and reproduction rates.this study evaluated the resistance of promising apple rootstocks to the woolly apple aphids under controlled forced-feeding conditions to identify traits associated with resistance mechanisms, and providing insights for improvement of pest management and control through apple breeding programs. materials and methods this experiment was carried out in 2022 and 2023 growing seasons. ten apple rootstocks including; azop(385), azop(386), az × m9(285), az × m27(85), azop(285), azop(286), m9op(387), b9op(87), az × m9(185) and azop(486) were studied . each one-year-old hybrid rootstock was transplanted into containers filled with a sterilized soil mixture and grown under greenhouse conditions. the glasshouse environmental conditions were maintained at 25°c ± 5°c, 60% ± 10% relative humidity and 14:10 light-dark cycle. the rootstocks were infested, through three wounds created on the stem of each, with 15 adult woolly apple aphids collected from a local orchard.wooly apple aphid population metrics including; colony number, colony size, and gall formation were recorded weekly during growing season. additionally, aphid colony growth rate, population equilibrium and establishment probability levels were calculated. vegetative traits of apple rootstock were studied using the national guidelines for apple d.u.s tests.data analysis was performed using ibm spss statistics 27.0, with resistance comparisons based on rates of aphid establishment, population stability and seasonal changes. for grouping of the rootstocks, based on the levle of resistance to the wooly apple aphid, cluster analysis method and the rootstocks that were similar in level of resistance were grouped in the same group. results and discussion the results indicated significant variability in resistance levels to the wooly apple aphid among the apple rootstocks. rootstocks m9op(387) demonstrated the highest resistance level, by reducing population growth rates and lower aphid establishment probability in comparison with susceptible rootstocks such as b9op(87) and azop(486). specifically, the seasonal population growth rate for m9op(387) averaged 161.81 aphids, whereas b9op(87) had the rate of 255.29 aphids.the population equilibrium of the woolly aphid colonies was lower in m9op(387) (26.5 colonies) in comparion with more susceptible azop(486) (28.88 colonies). morphological charateristics including; lint density and increased bark thickness in m9op(387) and azop(385) contributed to their antixenotic resistance by deterring aphid colonization. antibiosis mechanism, such as reduced aphid survival and reproduction, were also observed in the resistant rootstocks. these findings are in accordance with studies by sandanayaka et al. (2020) and nicholas et al. (2005) who reported reduced aphid colonization in resistant apple varieties with high lint density.antixenosis mechanism reduces the attraction of the rootstocks for aphids, and the mechanism of antibiosis, which is associated with the reduction of survival and reproduction rates of aphids, plays an important role in the resistance of resistant rootstocks. for example, the rootstocks m9op(387)  and azop(385) reduceed the population of aphids by 60 to 70 percent in comparison with more susceptible rootstocks. the findings of the present study support using resistant rootstocks in apple breeding programs, and encouraging the adoption and application of environmentally sustainable pest control strategies for different climatic conditions. referencesadhikari, u. 2022. distribution, biology, nature of damage and management of woolly apple aphid, eriosoma lanigerum (hausmann) (hemiptera: aphididae) in apple orchard: a review. reviews in food and agriculture, 3(2), pp.92-99. doi: 10.26480/rfna.02.2022.92.99kamusiime, e., nantongo, j. s. and wacal, c. 2023. insect pests in apple (malus domestic borkh) gardens. gsc advanced research and reviews, 15(1), pp.030-053. doi: 10.30574/gscarr.2023.15.1.0109nicholas, a. h., spooner-hart, r. n. and vickers, r. a. 2005. abundance and natural control of the woolly aphid eriosoma lanigerum in an australian apple orchard ipm program. biocontrol, 50, pp.271-291. doi: 10.1007/s10526-004-0334-2sandanayaka, w. r. m., bus, v. g. m. and connolly, p. 2005. mechanisms of woolly aphid [eriosoma lanigerum (hausm.)] resistance in apple. journal of applied entomology, 129(9‐10), pp.534-541. doi: 10.1111/j.1439-0418.2005.01004.x