苹果绵蚜对不同苹果品种春梢生长期生理指标的影响

为了筛选培育对苹果绵蚜(Eriosoma lanigerum Hausmann)的抗性品种,实现持续有效治理苹果绵蚜的目的,通过测定红富士、金帅、昭锦108、秦冠、红将军等5种不同苹果品种春梢生长期被苹果绵蚜危害前后枝条内可溶性糖、蛋白质、游离氨基酸、总酚含量以及防御性酶的活性变化,探讨苹果生理指标与抗蚜性的关系。结果表明,被害后可溶性糖含量除红将军外均有所上升,其中红富士上升达13.7%;蛋白质含量除红富士外均有所降低;氨基酸含量均有所上升,其中红将军变化明显,变化率达68.8%。酚类物质是一种重要的抗蚜物质,红富士、昭锦108、秦冠被害后总酚含量均升高,其中昭锦108、秦冠中总酚含量上升率约为红富士的2倍。红富士品种正常枝条内超氧化物歧化酶(Superoxide Dismutase,SOD)、多酚氧化酶(Polyphenol Oxidase,PPO)、过氧化物酶(Peroxidase,POD)以及过氧化氢酶(Catalase,CAT)活性均显著低于昭锦108,被害后各苹果枝条SOD活性均出现上升趋势,除红将军的PPO、POD活性降低外,其他品种均升高;金帅、红富士的CAT活性上升明显,分别为110.8%、45.5%。植物的防御性酶与其抗虫性有密切关系,苹果春梢生长期对苹果绵蚜的抗性与苹果体内的可溶性糖、游离氨基酸、SOD、PPO、POD以及CAT活性均有关,而且不同苹果品种被害后生理指标的变化也与其抗蚜性有一定关系。     

不同灰霉病抗性苹果果实中酚类物质代谢特征

以‘秦冠’、‘富士’、‘金冠’苹果果实为材料,通过对损伤接种灰葡萄孢菌(Botrytis cinerea Pers)后果肉组织酚类代谢主要产物和相关酶活性变化的分析测定,揭示苹果采后酚类物质代谢与灰霉病抗性的关系,为苹果灰霉病抗性鉴定和筛选抗灰霉病苹果资源提供理论指导。结果表明:(1)接种灰葡萄孢菌后,3个苹果品种的果实灰霉病发病率和病斑直径大小均为‘秦冠’‘富士’‘金冠’,而且3个品种间的发病率和病斑直径均差异显著,各品种对灰霉病的抗性由强到弱依次为‘秦冠’‘富士’‘金冠’。(2)抗病品种‘秦冠’果肉组织中类黄酮、木质素含量及苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)活性均显著高于感病品种‘富士’和‘金冠’,但总酚含量为‘秦冠’‘金冠’‘富士’,且3品种间总酚含量差异显著。研究表明,抗病苹果品种通过调节果肉内酚类物质代谢,增强次生代谢能力,其中类黄酮和木质素含量的增加强化了果实的抗性反应,进而提高对灰霉病的抗性,但总酚含量与植物抗病性关系不大。     

苹果绵蚜在不同寄主果园中的种群数量动态比较

【背景】在我国,苹果绵蚜对苹果等寄主的危害日益严重,发生面积不断扩大,而品种抗性是害虫治理的一种重要手段。【方法12007—2009年于山东莱阳地区系统调查了苹果绵蚜在不同寄主果园的发生动态规律,比较了不同寄主对苹果绵蚜的抗性差异。【结果】苹果绵蚜在红富士、乔纳金、新红星苹果园和西府海棠果园中1a有2个发生高峰,5月底到7月下旬是第1个高峰,也是全年发生的最高峰,9月初到10月底是全年发生的第2个高峰,而7月底到8月底是苹果绵蚜发生的低谷期。苹果绵蚜在红富士苹果上的发生数量显著高于在乔纳金、新红星苹果和西府海棠上的发生数量。在3a的调查时间内,苹果绵蚜在红富士、乔纳金、新红星苹果上每次平均发生量分别为153．2、31．6、30．3头·株^-1。越冬前调查表明,苹果绵蚜对红富士的为害率显著高于青香蕉、乔纳金、新红星和小国光,小国光的被害率以及虫落数量最低。【结论与意义】红富士是苹果绵蚜的感虫品种,而小国光、乔纳金和新红星相对抗虫。文中讨论了苹果绵蚜抗性品种的筛选方法,为掌握不同寄主对苹果绵蚜的抗性差异以及制定苹果绵蚜的抗性治理策略提供了依据。     

苹果果实中几种生化物质的含量与抗采后炭疽病的关系

接种炭疽菌前与苹果果实品种的病情指数呈正相关的生化物质是果实中的可溶性总糖含量(r=0.9978),负相关的生化物质是果实中的木质素(r=-0.9811)和绿原酸含量(r=-0.9939),接种前果实的总酸含量与品种的病情指数无关;接种后48和96 h的寄主体内可溶性总糖和有机酸含量有增有减,病情指数不同的品种变幅不同,接种96 h后果实中总酸含量与品种的病情指数呈现负相关(r=-0.9412),木质素和绿原酸含量都呈上升趋势,抗病品种的增幅高于感病品种。     

苹果绵蚜与苹果绵蚜日光蜂种间关系的模拟研究——Ⅱ.自然系统的模拟及灵敏度分析

本文在生物学特性研究的基础上,组建了苹果绵蚜(Eriosoma lanigerum)及其日光蜂(Aphelinus mali)寄主——天敌作用系统的Boxcar train模型,对苹果绵蚜猖獗期的二种群数量进行了模拟,其结果与果园调查基本吻合。用此模型做系统的灵敏度分析,结果表明系统的内部因子(如蚜蜂的基数比例)和外部因子(温湿度)对系统均有影响。温度升高,二种群数量增加,反之则下降。湿度增加,苹果绵蚜日光蜂种群数量上升,反之则下降。湿度变化对苹果绵蚜无不良影响。比较而言,温度对系统的影响比湿度大得多。减少苹果绵蚜基数比增加日光蜂基数对系统的影响大,据此可从理论上估计生物防治的局限性。     

不同地区苹果绵蚜对三种杀虫剂的抗性监测

【目的】了解苹果绵蚜Eriosomalanigerum对不同类别杀虫剂的抗药水平,为田间苹果绵蚜化学防控过程中的药剂选择提供理论基础。【方法】2018年6-7月间,采用玻璃管药膜法测定了3省14个地区苹果绵蚜对阿维菌素、高效氯氰菊酯和吡虫啉的抗药性。【结果】研究表明,西安杨凌地区苹果绵蚜种群对阿维菌素的抗性水平最低,LC50值仅为6.813 mg/L;烟台招远地区苹果绵蚜种群对阿维菌素的抗性水平最高,LC50值为79.496 mg/L。多数地区苹果绵蚜种群对高效氯氰菊酯的抗药水平较低,其中烟台龙口地区抗药水平最低,LC50值为4.341 mg/L,烟台栖霞地区抗药性最高,LC50值为37.689 mg/L。青岛即墨地区苹果绵蚜种群对吡虫啉的抗性水平最低,LC50值仅为5.261 mg/L;烟台招远地区苹果绵蚜种群对吡虫啉已经产生了中等水平的抗性(RR=10.859),LC50值为57.128 mg/L。不同虫态抗药性检测表明,除了烟台蓬莱地区的若蚜对阿维菌素和吡虫啉出现了抗药性提高的现象外,其它大部分苹果绵蚜3龄若蚜对药剂的抗性与成蚜相近。【结论】苹果绵蚜在北方大部分地区对常用杀虫剂的抗药性保持在低水平或敏感状态。在今后防治中应继续坚持交替轮换的用药原则,防止苹果绵蚜抗药性的产生。     

苹果不同品种果实原花青素含量及其动态变化

用香草醛-盐酸法测定了苹果(Malus domestica Mill.)5个品种的幼果和成熟果原花青素含量,并对品种‘富士'和‘新红星'果实发育期间原花青素含量的变化动态进行了研究.结果表明,苹果幼果富含原花青素,5个品种含量在8.46～13.90 mg*g-1(FW)之间,以品种‘金冠'最高,‘乔纳金'次之.苹果成熟果实原花青素主要存在于果皮中,含量达4.232～7.307 mg*g-1(FW),果肉中含量为0.525～1.034 mg*g-1(FW),以品种‘新红星'和‘富士'最高.‘富士'和‘新红星'果实发育期间原花青素含量变化动态基本一致,发育早期果皮原花青素含量呈增加趋势,5月底达最高值,之后下降,7月中旬以后基本稳定;果肉原花青素含量一直呈下降趋势,8月中旬以后基本保持稳定.     

不同苹果品种对褐斑病抗性的鉴定及抗性生理研究

对42个苹果栽培品种叶片褐斑病进行了田间发病状况调查与抗性鉴定,分析了叶片气孔密度和大小与抗病性之间的关系,同时研究了不同抗性品种离体叶片接种病原菌后超氧化物歧化酶（SOD）、多酚氧化酶（vPo）、过氧化物酶（POD）、苯丙氨酸解氨酶（PAL）活性和木质素含量的差异变化。依照抗性分级标准,供试材料中抗病品种有14个（其中高抗品种2个）,感病品种有28个（其中高感品种7个）;叶片气孔密度与病情指数之间存在显著正相关,相关系数r=0．683;叶片接种后,诱导了4种酶活性和木质素含量的升高,抗病和感病品种的SOD和PP0活性无显著差异,而抗病品种的POD和PAL活性以及木质素含量显著高于感病品种。苹果叶片的气孔密度、POD和PAL的活性以及木质素含量与褐斑病抗性有关。     

自然贮存条件下苹果的营养成分分析

对自然贮存条件下分别贮存了 2个月、4个月及 6个月的秦冠、红富士、新红星、北斗及黄元帅苹果果实的硬度以及主要营养成分 (果胶质、总糖、粗蛋白 )进行了统计分析和对比研究 ,结果表明 :在自然贮存条件下 ,苹果果实的硬度、果胶质、总糖及粗蛋白的含量均随贮存时间的延长而下降 ,不同的品种间及同一品种或不同品种在不同贮存时期的差异均极显著( P<0 .0 1 ) ;3种不同营养成分彼此间密切相关 ( R>0 .80 ) ,因此可以任取其中之一作为测试这些营养成分的指标。对于不同的品种而言 ,红富士、秦冠果实的硬度较大 ,其果胶质、总糖及粗蛋白含量也较高 ,说明秦冠和红富士为较好的耐贮品种。     

八个苹果品种对苹果叶螨和金纹细蛾的抗性

采用我国苹果生产上较普遍的8个品种对苹果叶螨和金纹细蛾的自然抗性进行了观察,结果表明,这些品种对这两种害虫的抗性比较一致,而不同品种间的抗性差异却很明显。其中金冠、青香蕉等为高抗品种,可以减缓苹果叶螨的增长速度,也使金纹细蛾在整个苹果生长期一直被抑制于可以允许的经济受害水平以下;国光、富士、新红星乃系高度感虫,它们受这两种虫害都较严重;秦冠的抗虫性是属中间水平;只有红星和短枝型金冠对这两种害虫的抗感程度变化较大,它们对金纹细蛾表现高抗,而对苹果叶螨却为易感。     

Phenolic acid content – a criterion for selection of resistant apple cultivars against Podosphaera leucotricha (Ell. and Ev.) Salmon

Development of powdery mildew (Podosphaera leucotricha) on five popular cultivars of apple, viz., Scarlet Gala, Golden spur, Mollies Delicious, Red Fuzi and Red Chief was studied to determine incidence–severity relationship. The disease was confined primarily to the vegetative terminal shoots early in the season which also traversed later onto other leaves. Several biochemical changes occur in the trees due to fungal/microbial infection. We studied the qualitative/quantitative changes in phenolic acids in apple-powdery mildew pathosystems. Scarlet Gala and Red Chief are very rich in phenolic acids, and had shown resistances to the pathogen but those with low amount of phenolic acids, viz., Golden spur, Mollies Delicious, and Red Fuzi, were highly susceptible. Thus, the quantity of phenolic acids (secondary metabolites) has been taken as a biochemical parameter in screening apple cultivars for resistance/susceptibility against powdery mildew of apple.     

Susceptibility of selected apple cultivars to the Mediterranean fruit fly

Ceratitis capitata (Wiedemann), the Mediterranean fruit fly, is one of the key pest species affecting deciduous fruit orchards along the Mediterranean coasts. Because of global warming, C. capitata is gradually spreading north and is becoming a major pest of apples. Determining the susceptibility of the main apple varieties grown in the region will serve as a cornerstone to the management of this pest. In this study, we show the results of a field and laboratory no‐choice test conducted to determine the Medfly preferences on different apple cultivars. The seven main varieties of apples (Gala, Red Delicious, Golden Delicious, Granny Smith, Kanzi, Morgen Dallago and Fuji) were tested. The results demonstrate that C. capitata lays eggs on all apple cultivars in both field and laboratory conditions. The Granny Smith, Red Delicious and Morgen Dallago varieties showed the lowest susceptibility in laboratory conditions, (0.75, 1.55, 2 oviposition punctures/fruit, respectively), with significant differences in oviposition compared to the Golden Delicious, Kanzi and Fuji (3.27, 3.31, 3.1 oviposition punctures/fruit, respectively) varieties, which were shown to be the most susceptible to Medfly attack in laboratory conditions. On the other hand, only slight and not statistically significant differences emerged from the field trials. In relation to the physico‐chemical characteristics, the apple cultivars showing the lowest susceptibility (Granny Smith, Red Delicious and Morgen Dallago) had harder peels and pulps and lower sugar contents than the most susceptible cultivars (Golden Delicious, Fuji and Kanzi). These results were also confirmed through evaluation of larval development on different varieties. In fact, Granny Smith, Red Delicious and Morgen Dallago were the three varieties that did not allow adequate larval and adult development and reduced the possibility of the emergence of a new generation.     

The phenylpropanoid pathway affects apple fruit resistance to Botrytis cinerea

Apple fruits are rich in phenolic compounds that may enhance resistance to grey mould disease caused by Botrytis cinerea. Using Malus domestica Borkh. cultivars Fuji and Qinguan, we analysed the contents of total phenols, total flavonoids, eight individual phenolic compounds, H₂O₂ and O₂^.? as well as the activities of key enzymes in the phenylpropanoid pathway in the flesh of control and B. cinerea‐inoculated fruits. Chlorogenic acid contents increased for a short period in the less susceptible cultivar Qinguan fruits, but decreased in the disease‐susceptible Fuji fruits. Additionally, ferulic acid production was induced in both cultivars in response to B. cinerea. Furthermore, the activities of phenylalanine ammonia lyase, cinnamate 4‐hydroxylase, 4‐coumarate:coenzyme A ligase and cinnamyl alcohol dehydrogenase were differentially induced between the two apple cultivars. Remarkably, the contents of H₂O₂ and O₂^.? as well as the activities of enzymes in phenolic metabolism tested in this study were always higher in Qinguan fruits than in Fuji fruits. Our data imply that phenylpropanoid metabolism is closely associated with apple fruit resistance to grey mould disease. These findings may be useful for characterizing the mechanism(s) underlying plant resistance to B. cinerea, with potential implications for the screening of grey mould disease‐resistant apple varieties in breeding programmes.     

Demography and mass-rearing of Carposina sasakii Matsumura (Lepidoptera: Carposinidae) reared on Golden Delicious and Red Fuji apples in the laboratory

Carposina sasakii Matsumura (Lepidoptera: Carposinidae), is one of the most serious fruit-boring pests in over ten species of fruit trees, and is especially damaging apples in the northern of China. The application of new planting systems, i.e., high-density and dwarfing rootstock orchard systems with mixed apple varieties, makes it important to study the fitness of C. sasakii on these apple varieties to gain fundamental knowledge for use in pest management involving this insect. In this study, life table data of C. sasakii were collected using Golden Delicious and Red Fuji apples as hosts. The egg-larva duration of male C. sasakii reared on Golden Delicious apples (22.81 d) was significantly shorter than that reared on Red Fuji apples (24.27 d). The egg-larva mortality in Golden Delicious apples (59.00%) was lower than that in Red Fuji apples (72.49%). The mortality of the pupal stage, however, was higher in Golden Delicious (10.51%) than in Red Fuji (0%). The total oviposition period (TPOP) on Golden Delicious apples (32.94 d) was significantly shorter than in individuals reared on Red Fuji apples (34.19 d). The intrinsic rate of increase (r = 0.0581 d⁻¹), net reproductive rate (R₀ = 7.57 offspring), and finite rate of increase (λ = 1.0598 d⁻¹) were all higher on Golden Delicious than those on Red Fuji. When the net reproductive rate (R₀) was used, the harvest rate of pupae was higher (0.8678) when reared on Golden Delicious apples than when reared on Red Fuji apples (0.8398). When a large cohort size (n = 200) was used for effective bootstrap sample, the P_E values for C. sasakii reared on Golden Delicious apples and Red Fuji apples were both almost equal to 1. For C. sasakii culturing purposes, Golden Delicious apples would be more productive than Red Fuji.     

Interaction between natural and synthetic fruit odor influences response of apple maggot flies to visual traps

In order to improve perimeter trapping for apple maggot fly behavioral control, we designed a set of experiments which aimed to reach a better understanding of the nature of the interaction between the natural host odor released by susceptible and low‐susceptibility apple cultivars, and an artificial host odor currently employed as a lure along with visual traps for apple maggot fly, Rhagoletis pomonella (Walsh) (Diptera: Tephritidae), perimeter trapping programs. The response of apple maggot flies to lured and unlured visual traps deployed in different rectangular arrays of susceptible and low‐susceptibility apple cultivars (two central trees of a particular cultivar surrounded by four perimeter trees of the same or a different cultivar) was evaluated over 2 years under field conditions. In uniform blocks of susceptible (Tidemann Red, Jersey Mac) or low‐susceptibility (Marshall McIntosh) cultivars, lured traps recovered a significantly greater proportion of the total capture than unlured traps, irrespective of lure position (center or perimeter trees). Unlured traps on central susceptible apple cultivars (Red Astrachan, Gala, Fuji) recovered a significantly greater proportion of the total capture than unlured traps on surrounding low‐susceptibility cultivars (Marshall McIntosh, Paula Red, Red Delicious, and Golden Delicious). Placing the lures near traps on low‐susceptibility cultivar trees surrounding unlured traps on central susceptible cultivar trees reduced apple maggot fly visits to traps on central trees, but the latter still recovered a similar proportion of the total capture as lured traps on perimeter trees. By contrast, placing the lures near traps on central susceptible cultivar trees surrounded by unlured traps on low‐susceptibility cultivar trees allowed lured central traps to receive a significantly greater proportion of the total capture than unlured perimeter traps. We conclude that the synthetic and natural host odor of susceptible cultivars interact additively in attracting apple maggot flies to visual traps, and that, when given the choice, traps and lures should be deployed on preferred rather than on less preferred cultivar trees. Implications for trap deployment strategies for tephritid monitoring and control are discussed in the light of our findings.     

Characteristics associated with Woolly Apple Aphid Eriosoma lanigerum, resistance of three apple rootstocks

The resistance characteristics of the apple resistance genes (Er1, Er2, and Er3) to the woolly apple aphid, Eriosoma lanigerum (Hausmann) (Homoptera: Aphididae) were studied according to the performance measured on apple cultivars containing these resistance genes. The resistance characteristics of Northern Spy (Er1), Robusta 5 (Er2), and Aotea (Er3) were compared to the susceptible cultivar Royal Gala, by measuring the aphid settlement, development, and survival rates correlated with electronically monitored probing behaviour. Er1 and Er2 had a higher level of resistance with a significantly shorter period of phloem feeding, suggesting that the resistance factors were present in the phloem tissue. Phenological measurements indicated that the aphids showed poor settlement, development, and survival on Er2. Er1 also showed low settlement and survival, although not as low as Er2. Aphid performance and feeding on Aotea (Er3) were similar to Royal Gala, suggesting that some woolly apple aphids in New Zealand may have recently overcome Er3 resistance. The differences in resistance mechanisms of Er1, Er2, and Er3 are discussed in relation to the strategy of pyramiding these genes to give a durable resistance to woolly apple aphid.     

Cacopsylla costalis (Flor 1861), as a Vector of Apple Proliferation in Trentino

Recently, a epidemic of apple proliferation (AP) in an orchard area of Trentino (North Italy) occurred. The most affected cultivars were Golden Delicious, Florina and Renetta Canada grafted on different rootstocks. In this area the known or supposed vectors of the disease were not present. At the same time as the AP symptoms appeared, a notable increase of the presence of psyllids was observed on apple trees so a correlation between these insects and the AP was hypothesized. Four different psyllid species were found in the orchard: Cacopsylla melanoneura (Förster 1848), Cacopsylla costalis (Flor 1861), Cacopsylla mali (Schmidberber 1836) and Trioza urticae (Linnaeus 1758). The first two were more frequent in spring at the adult stage. In 1997 C. costalis was particularly numerous and was used to plan AP transmission trials. The transmission from infected AP apple trees to the insect in field and from the psyllids to non-infected Golden Delicious and Florina plants in the greenhouse were conducted. For the control of phytoplasma presence in the psyllids and in the apple plants polymerase chain reaction (PCR), nested PCR and restriction fragment length polymorphism analysis were used. In autumn 1997, some inoculated plants showed symptoms of AP. Molecular results were consistent with the presence of phytoplasma in C. costalis and in inoculated apple cultivars.     

Sex ratios in natural populations ofAphelinus mali (Hym.: Aphelinidae) in relation to host size and host density

In an apple orchard at Armidale, the Northern Tablelands of NSW, population sex ratios ofAphelinus mali (Haldeman), an endoparasitoid of the woolly apple aphid,Eriosoma lanigerum (Hausmann) varied from 0.51 (proportion of males) at low host densities to female-biased at high host densities (proportion of males ranged from 0.35–0.39). This shift in sex ratio seems to be caused by the differences in allocation of sons and daughters to hosts of different sizes. In the fieldA. mali parasitizes all life stages (four nymphal instars and adult) of the woolly aphid upon encountering. According to Hughes'(1979) optimal diet model, such general host acceptance seems to be the best strategy. However, it allows the host nymphs or adults to continue to develop or reproduce until about to mummify (pupate). No mortality was observed when first or second-instar hosts were parasitized in the laboratory. Field collected small mummified hosts yielded male-biased sex ratios whereas large mummified hosts produced mainly females. In the laboratory, progeny from smaller hosts (first to third-instars) produced sex ratios which were not significantly different from 0.5 whereas progeny from larger hosts (third and fourth-instars) produced female-biased sex ratio. During winter (June–August) and early spring (September–October) when the host populations in the orchard were predominantly nymphs, the parasitoid tended to allocate equal resources to male and female offspring. In contrast, at peak population densities in summer and autumn (December–May) when larger hosts were available, the sex ratios were female-biased. The host size ofE. lanigerum andA. mali is, therefore, an important component in the dynamics of host-parasitoid interactions.