寄主植物对荔枝蒂蛀虫产卵的引诱作用

试验观察荔枝蒂蛀虫Conopomorpha sinensisBradley对寄主植物品种、器官及器官部位的产卵选择性规律。结果表明,与老梢相比,荔枝蒂蛀虫明显倾向于选择嫩梢产卵;4个荔枝品种果枝中以妃子笑上落卵数最多,在淮枝、糯米糍荔枝果实上较少,桂味荔枝上最少;不同的荔枝品种果实气味引诱雌虫产卵的能力不同,其中妃子笑引诱力最强,淮枝、糯米糍引诱力较低,桂味最低;在同一荔枝果实不同部位的落卵量,以果皮上、下两部分较大,全果明显低于果皮上部,而荔枝肉和荔枝核上没有落卵。     

荔枝蒂蛀虫绿色防控研究进展

中国是荔枝(Litchi chinensis)的原产地,种植面积和产量规模均居世界第一位,以“岭南果王”著称的中国荔枝在国际鲜果市场享有极高的声誉。荔枝蒂蛀虫(Conopomorpha sinensis)在我国广泛分布于热带南亚热带地区,是荔枝的主要害虫,其幼虫蛀食荔枝果核、果蒂,会影响果实生长发育及商品果率,造成严重的经济损失。荔枝蒂蛀虫的行为隐蔽,世代重叠,难以控制。目前生产上对该虫的控制主要依靠化学防治,但长期使用化学农药容易产生污染环境、药物残留、食品安全以及虫抗药性的问题。本文结合国内外研究进展,着重从荔枝蒂蛀虫生活习性及危害发生规律、预测预报、物理防治、生物防治及生物源农药应用等方面进行综述,并对荔枝蒂蛀虫绿色防控研究方向及以农业防治为基础的综合防治方法进行展望。     

荔枝蒂蛀虫室内饲养技术的研究

室内试验结果表明,利用荔枝种仁作为食物成功饲养荔枝蒂蛀虫至完成一世代.荔枝蒂蛀虫在荔枝、龙眼鲜果表皮产卵量较高,10 d产卵数分别为88.33和179.33粒/处理.蒂蛀虫卵散产在特制收卵卡的凹陷处且呈规则排列.选荔枝种仁作为其食物,并注入清水保持种仁的湿度,荔枝蒂蛀虫在角度90～150 °折纸内化蛹,化蛹率和羽化率分别为33.67%和94.06%.     

荔枝园荔枝蒂蛀虫常规爆发期的种群空间分布格局

荔枝蒂蛀虫Conopomorpha sinensis Bradley是我国最重要的荔枝、龙眼蛀果类害虫之一.为了准确把握荔枝园中荔枝蒂蛀虫的分布规律,以便对该虫的危害盛期进行预测预报和采取防治措施,本文采用生物学统计方法和地理统计学方法对荔枝园中荔枝蒂蛀虫卵、蛹和成虫的空间分布特征进行了研究.结果显示:2019年5月和6月,无挂果荔枝树的有虫株率分别为67.74％和68.57％,而挂果荔枝树的有虫株率达90.91％和91.67％.该时期荔枝园内荔枝蒂蛀虫蛹的半变异函数最佳拟合模型均为球型模型,成虫均为指数模型,而卵在5月和6月的拟合模型分别为球型模型和指数模型.不同时期荔枝蒂蛀虫各虫态的拟合变异函数模型虽存在一定差异,但所指明的空间分布格局均为聚集分布.引起荔枝蒂蛀虫卵和蛹聚集分布主要由生境和自身生物学特性共同所致,但当虫口密度降低时,成虫的聚集分布仅由生境引起.另外,用Kriging插值方法生成的空间分布图显示荔枝蒂蛀虫卵、蛹和成虫均明显趋向于以挂果荔枝树为中心的聚集分布,聚集斑块由聚集中心区域向四周逐渐减小.5月至6月,荔枝蒂蛀虫卵、蛹和成虫在荔枝园内趋向以挂果荔枝树为中心的聚集分布,不同时期荔枝园内荔枝蒂蛀虫的聚集分布成因随种群密度变化有所不同.     

荔枝蒂蛀虫成虫对LED光的趋性及其繁殖响应特征

为明确荔枝蒂蛀虫Conopomorpha sinensis成虫对不同LED光的趋性行为反应,初步筛选出该虫趋光性不同的光色并进一步研究其对成虫繁殖生物学特性的影响,以期为今后研发特异性强且绿色高效的荔枝蒂蛀虫灯光防控技术提供理论依据.本文采用对比实验法,测试了荔枝蒂蛀虫雌蛾对9种供试光源的趋性行为反应,并进一步研究夜间LED光照射对荔枝蒂蛀虫成虫交配率、繁殖力及寿命的影响.结果显示,荔枝蒂蛀虫雌成虫对不同LED光的趋光反应率由高到低为:蓝(445～450 nm)>紫(400～405 nm)>红(655～665 nm)>蓝绿(475～480 nm)>橙(600～605 nm)>绿(515～520 nm)>黄(570～575 nm)>白(400～700 nm)>黑暗>紫外(365 nm),试虫对紫外光表现出明显的避光性,对7种单色光表现为不同程度的趋光性,其中对黄光和白光的趋光率在50％以下.在繁殖生物学方面,夜间50 lx的LED黄光和白光持续照射能使荔枝蒂蛀虫成虫的交配率由93.75％降低至50％以下,且产卵前期延长,雌蛾产卵量显著降低.此外,夜间不同LED光源照射能抑制已交配荔枝蒂蛀虫雌蛾产卵活动,白光照射组的单雌日均产卵量降低程度最大,为50.71％,黄光次之(48.96％),蓝光最小,为38.06％.综上所述,荔枝蒂蛀虫雌蛾对LED白光和黄光的趋光性较弱,夜间适当的LED白光(400～700 nm)和黄光(570～575 nm)持续照射可有效降低成虫交配率和繁殖力,该结果对促进LED白光干扰防控荔枝蒂蛀虫技术的优化升级具有一定指导意义.     

荔枝果实酸性转化酶LcSAI生物信息学和表达分析

酸性转化酶作为蔗糖代谢中的关键酶,在还原糖积累型荔枝中表达及酶活性显著高于蔗糖积累型荔枝。为了全面了解酸性转化酶的生物学特征,该文通过运用生物信息学方法对荔枝果实酸性转化酶LcSAI基因的基本理化性质、蛋白二级结构、亲水性/疏水性、跨膜结构域、信号肽、磷酸化位点、保守结构域、系统进化进行系统的分析;利用qRT-PCR技术对LcSAI在'妃子笑'不同组织和果实不同发育阶段进行表达分析。结果表明:(1)荔枝果实酸性转化酶为定位于液泡的亲水性不稳定蛋白,无信号肽,其蛋白的二级结构主要有无规则卷曲和延伸链构件,并散布于整个蛋白;(2)在N-端含有一个跨膜区,包含两个保守结构域,位于N-端的Pfam DUF3357结构域和Glyco_32结构域,属于糖基水解酶基因家族32超家族;(3)系统进化分析结果显示LcSAI与龙眼酸性转化酶基因同源,不同组织间LcSAI表达水平为雄花根嫩茎种子嫩叶雌花果皮老叶,果实不同发育阶段LcSAI表达具有特异性。该研究为深入研究LcSAI果实酸性转化酶基因调控蔗糖代谢途径机理提供数据依据。     

根系输液改善妃子笑荔枝钙营养的研究

在妃子笑果实膨大期,用CaCl2进行根系输液、果实蘸果及树冠喷施三种不同的补钙处理,研究不同补钙方式对改善妃子笑荔枝钙营养的作用。结果表明,用CaCl2根系输液,能够显著改善树体钙素营养,果皮和叶片的钙含量比对照分别提高了85.19%和50.28%,效果显著好于树冠喷施和果实浸蘸。与对照相比,果实浸蘸、树冠喷施也有显著改善钙营养的作用,果皮和叶片的钙含量比对照分别提高了33.48%、8.85%和28.43%、51.54%。综合比较三种补钙方式的效果,根系输液好于蘸果,蘸果处理好于树冠喷施。     

为害荔枝和龙眼的两种细蛾科昆虫

本文首次报道荔枝蒂蛀虫Conopomorpha sinensis和荔枝尖细蛾C. litchiclla在广东和福建省为害荔枝,并发现龙眼也是荔枝尖细蛾的寄主.订正了过去一直将这两个近缘种混淆起来误以为可可细蛾(国内称荔枝爻纹细蛾)Acrocercops cramerella的这一错误.事实上,国内迄今仍未发现可可细蛾的分布.本文详细地描述和比较了这两种细蛾各虫态的态,并简要地描述了它们的生物学特性.在食性方面首次发现荔枝蒂蛀虫既为害果又为害叶梢、花穗,而荔枝尖细蛾只为害叶梢.花穗而不取食果.     

基于转录组数据的荔枝蒂蛀虫SSR位点信息分析

荔枝蒂蛀虫Conopomorpha sinensis Bradley是专一性危害我国荔枝和龙眼的重要害虫。简单重复序列标记(Simple sequence repeat,SSR)为短串联重复序列或微卫星标记,其在荔枝蒂蛀虫偏嗜选择寄主的遗传进化机制研究和荔枝蒂蛀虫综合治理中具有重要意义。本研究基于高通量测序获得的荔枝蒂蛀虫转录组数据,利用MISA软件从68996条转录组unigenes结果中发掘出10521个SSR位点,出现频率为15.25%。荔枝蒂蛀虫转录组中SSR的主要重复类型为单碱基重复,占SSR总数的66.22%。其次是三碱基重复,占SSR总数的24.94%。在发现的33种重复基元中共筛选获得8种优势重复基元,其中A/T在单碱基重复基元中所占的比例达98.55%。基于筛选的SSR设计的9对引物中,有4对引物得到扩增预期大小的条带。荔枝蒂蛀虫SSR位点的信息分析将为探究荔枝蒂蛀虫种群遗传结构、遗传多样性和进化关系、害虫综合治理等研究提供重要科学依据。     

为害荔枝和龙眼的两种细蛾科昆虫

本文首次报道荔枝蒂蛀虫Conopomorpha sinensis和荔枝尖细蛾C.litchiclla在广东和福建省为害荔枝,并发现龙眼也是荔枝尖细蛾的寄主。订正了过去一直将这两个近缘种混淆起来误以为可可细蛾(国内称荔枝爻纹细蛾)Acrocercops cramerella的这一错误。事实上,国内迄今仍未发现可可细蛾的分布。本文详细地描述和比较了这两种细蛾各虫态的态,并简要地描述了它们的生物学特性。在食性方面首次发现荔枝蒂蛀虫既为害果又为害叶梢、花穗,而荔枝尖细蛾只为害叶梢。花穗而不取食果。     

套袋苹果果实质地及其显微结构与果面裂纹的关系北大核心CSCD

以套白色单层纸袋的着色富士系‘天红2号’和短枝富士后代优系4-1-103,以及不着色姊妹系‘冀苹4号’和‘冀苹5号’4个苹果品种(系)为试验材料,利用质构仪整果穿刺和质地多面分析法(texture profile analysis,TPA)测定果实质地,光学显微镜观察果实显微结构,探讨苹果果实质地及其显微结构与果面裂纹的关系,为抗裂纹品种的选育和潜在裂纹机制提供理论依据。结果表明:(1)盛花后132~185 d,‘天红2号’和‘冀苹4号’裂纹率和裂纹指数始终高于4-1-103和‘冀苹5号’,其裂纹主要部位为果肩部。(2)‘天红2号’和‘冀苹4号’的果肉脆裂性、果肉硬度分别显著小于4-1-103和‘冀苹5号’。(3)‘天红2号’和‘冀苹4号’的表皮细胞密度显著小于4-1-103和‘冀苹5号’,其果肉细胞间隙率显著大于4-1-103和‘冀苹5号’,且其角质膜有“V”型凹陷,并发生龟裂,而4-1-103和‘冀苹5号’角质膜完整均一。(4)主成分和灰色关联度分析表明,果肉硬度、果皮果肉硬度比和果肉细胞间隙率是解释裂纹的主要指标。研究发现,果实角质膜完整均一、果肉硬度大、果肉细胞间隙率小的苹果品种不易发生果面裂纹。     

植物激素对果树单性结实调控的研究进展

尽管种子与果实的发育过程密切相关,但由于无籽果实提高了果实的品质并延长了货架期,因此无籽果实受到生产者和消费者的广泛青睐。果实的生长受激素调控,而相关研究也初步揭示了激素在单性结实果实形成过程中的作用。本文对单性结实的概念、诱导单性结实的激素种类及功能、诱导机理,以及转基因技术在单性结实果实生产中的应用概况进行了综述,以期为果树单性结实的研究提供参考。     

Quinic acid esters of hydroxycinnamic acids in stone and pome fruit

In 21 varieties of stone and pome fruit the quinic acid esters of caffeic, p-coumaric and ferulic acids have been determined by capillary GC and HPLC. The total content of hydroxycinnamoylquinic acids was found to be between 80 and almost 900 ppm fr. wt. The results confirm that the main hydroxycinnamic acid compound in pome fruit is 5′-caffeoylquinic acid, whereas in stone fruit it is 3′-caffeoylquinic acid. Our investigations also show the regular occurrence of 3′-p-coumaroylquinic acid in stone fruit species. In sweet and sour cherries it can be the main component in concentrations of 100–200 ppm. Significant amounts of feruloylquinic acid are only found in plums and apricots. The 4′-isomers of all acids occur only in very small concentrations with the exception of 4′-p-coumaroylquinic acid in apples, the content of which exceeds that of 5′-p-coumaroylquinic acid.     

Evaluation of lures and traps for male and female monitoring of Mediterranean fruit fly in pome and stone fruit

Commercial traps and lures have recently become available for monitoring male and female Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in Australia, with possible applications in monitoring and mass trapping. This study investigated the attractiveness of commercially available male [Capilure^® (CPL), Trimedlure (TML) cone, plugs, and wafers] and female‐targeted synthetic lures (three‐component BioLure^®, BioLure^® Unipak, Ceratitis^® Unipak, TMA Plus^® Unipak and Biotrap^® gel), and five female‐targeted traps [Maxi^® trap, Sorygar Tephri‐trap, Probodelt^® cone trap, and BioTrap Globe^® traps (two versions)]. Results showed that TML and CPL lures were equivalent up to 8 weeks, but TML‐baited traps captured 1.2–4.6 times more male medflies than CPL‐baited traps with lures aged 9–16 weeks. For female‐targeted trapping, all tested lures were female selective. Ceratitis^® Unipak was equivalent to three‐component (3‐C) BioLure^®, whilst BioLure^® Unipak captured 1.1–1.5 times more medflies than 3‐C BioLure^®. The least efficient lures were TMA Plus^® Unipak and Biotrap Fruit Fly Attractant Gel. Tephri‐traps were the least efficient trap, with Maxi traps catching 1.9–6.7 times more medflies than the Tephri‐trap. The appropriate selection of lures and traps for applications in monitoring and mass trapping are discussed.     

Effects of defoliation and girdling on fruit production in Ilex aquifolium

1. The effects of defoliation and girdling on fruit production in European holly Ilex aquifolium were studied in a northern Spanish population. Three defoliation treatments (control, 50% and 100% leaf removal) were applied at branch level in 10 trees. Six branches were used per treatment in each tree and half of these branches were girdled (a ring of bark and cambium was removed from the branch base).
2. Leaf removal from ungirdled branches had little effect on fruit set, fruit production and reproductive allocation at branch level. However, these variables decreased as the extent of defoliation increased on girdled branches.
3. Fruit production in undefoliated branches did not differ between girdled and ungirdled branches, showing that girdled branches were autonomous for fruit production when undamaged. Mean fruit mass of girdled-100% defoliated branches averaged 8% of fruit mass produced by control branches.
4. Fruit production of ungirdled-100% defoliated branches did not differ from control branches, showing the importance of resource importation from other branches. Hence the branches may be regarded as only partially autonomous for fruit production.
5. Fruit production of girdled-50% defoliated branches was 42% of fruit production of control branches, while ungirdled-50% defoliated branches amounted to 70% of controls. These results also demonstrated resource importation but did not support the existence of photosynthetic compensatory mechanisms.
6. The ability of resource importation developed by fruiting branches might be a mechanism to reduce the effect of reproductive costs in this species.     

Quantification of ethephon requirements for abscission in olive fruits

Ethepon is used commercially in Israel to facilitate mechanical harvesting or hand picking of olive fruits, but the results are often not satisfactory, due to insufficient reduction of the fruit removal force. Studies with ¹⁴C-ethephon were carried out to follow the fate of the applied ethephon from treatment until fruit harvest and to determine the actual uptake and efficiency of the sprayed compound.Only a small portion (less than 3%) of the applied ethephon actually penetrated the target tissue i.e. the pedicels, and released the ethylene responsible for promoting fruit loosening. There was almost no translocation of ethephon from other organs (leaves, fruits) to the fruit pedicels. Extended imbibition in the ethephon solution increased ethephon uptake, which was also enhanced by higher ambient temperatures. Penetration of ethephon varied among different tissues (leaves, fruits and pedicels). Field applications enabled some calculations of the relationship between the amount of ethephon applied and that actually required to achieve proper fruit loosening.     

光照强度对苹果果实表面温度变化的影响

光照强度对于果实温度的变化具有重要影响。一天中 ,日落后和日出前 ,果实表面温度都接近气温。树冠外围暴露果实表面温度主要来源于气温和由于吸收光能后转化成热能所增加的温度。当光照强度较低和持续时间较短时 ,光照对果实表面温度的影响较小。不同月份光致果实温度增加的幅度有所不同 ,6～ 10月日光致最大果实温度的变化幅度范围为 14 .4 6～ 18.98℃。光照强度与光致果实增温具有极显著相关 ,其回归方程为 Y=0 .0 0 88x 6 .0 97,r=0 .4 3382 * * 。遮荫由于减少了果实表面接受的光能 ,因而可以明显降低果实表面的温度     

Identification of mRNAs with enhanced expression in ripening strawberry fruit using polymerase chain reaction differential display

Fruit ripening is a complex developmental process that involves specific changes in gene expression and cellular metabolism. In climateric fruits these events are coordinated by the gaseous hormone ethylene, which is synthesized autocatalytically in the early stages of ripening. Nonclimacteric fruits do not synthesize or respond to ethylene in this manner, yet undergo many of the same physiological and biochemical changes associated with the production of a ripe fruit. To gain insight into the molecular determinants associated with nonclimacteric fruit ripening, we examined mRNA populations in ripening strawberry fruit using polymerase chain reaction (PCR) differential display. Five mRNAs with ripening-enhanced expression were identified using this approach. Three of the mRNAs appear to be fruit-specific, with little or no expression detected in vegetative tissues. Sequence analysis of cDNA clones revealed positive identities for three of the five mRNAs based on homology to known proteins. These results indicate that the differential display technique can be a useful tool to study fruit ripening and other developmental processes in plants at the RNA level.     

Nutritional and Morphological Traits of Invasive and Exotic Fleshy‐fruits in South Africa

While fleshy‐fruited invasive alien plants are recognized as some of the worst invaders on a global scale, until recently, little consideration has been given to the frugivores that feed on these fruits and, more specifically, the fruit traits, which may influence this. We investigated a series of morphological and nutritive fruit traits for ca 30 species of fleshy‐fruited invasive alien and exotic species in South Africa. Invasive alien fruit traits were compared with comparable traits of a similar sample size of indigenous fleshy fruits, which occur in the same area. Finally, the similarity of traits for the same invasive alien species was compared with those fruits in Australia. Invasive alien fleshy fruits were similar in morphology, but greater in some nutritive aspects when compared with indigenous fruits. Furthermore, they were very similar in all aspects to their counterparts in Australia. Most seeds of invasive fleshy fruits were small and light, which may explain some of their invasive success, as benefits associated with small seededness may promote invasive potential. Nutritionally, most invasive alien fleshy‐fruits were hexose‐dominant, containing low lipid and nitrogen content. While frugivore preference trends remain to be formally investigated, this study provides insights into fruit traits, which may tentatively outline why invasive fruits are universally fed on and thus successfully spread.