中国农业生态系统昆虫授粉功能量与服务价值评估

所有开花植物中大约有80%的物种需要动物作为授粉媒介。系统介绍了中国重要栽培作物花的结构和类型,授粉过程、媒介和方式,作物对昆虫授粉的依赖程度,昆虫授粉功能与服务的概念,以及昆虫授粉功能量与服务价值量的评估方法;同时评估了我国各省农业生态系统中昆虫对重要作物的授粉功能量与服务价值量。结果表明:粮食作物、水果作物、蔬菜作物和经济作物不同程度的依赖昆虫授粉。根据2015年主要农作物产量、作物产品价格、昆虫授粉依赖程度等数据,计算得出昆虫对我国22类主要农作物的授粉功能量为1.8亿吨农产品产量和授粉服务价值为8860.5亿元(占当年GDP的1.3%),具有巨大的经济价值。2015年昆虫对主要栽培作物的授粉功能量和服务价值排在前五名的都是山东、河南、河北、陕西和新疆,年授粉服务价值均大于500亿元,反映出这5个省的主要农作物对昆虫授粉依赖程度较高。昆虫对作物的授粉功能量评价有助于了解昆虫对作物生物量或产量的生物学和生态学效应以及作物对昆虫授粉的需求。昆虫对作物的授粉服务价值评估有助于掌握昆虫授粉为人类所带来的经济效应或经济价值,并帮助决策维持或增强授粉昆虫多样性和种群数量的人力、物力和财力投入。     

中国蜜蜂新病原的分离

蜜蜂是自然界最主要的授粉昆虫,它们除了为农作物授粉外,还为人类提供营养丰富的蜂产品,具有重要的经济价值和社会效益。然而春季蜜蜂的"爬蜂病"几乎是年复一年的发生,轻则削弱蜂群,重则使蜜蜂全部死亡。引起蜜蜂"爬蜂病"的病原包括细菌、孢子虫、花粉、病毒、螺原体等多种,因此,准确鉴定出蜜蜂发病的病因对于蜜蜂疾病的正确防治非常必要。     

第二届全国资源昆虫学术讨论会

<正> 由中国昆虫学会与湖南省昆虫学会主办于1989年11月在湖南召开。会议对近年来我国资源昆虫的研究和开发利用取得的新进展进行了总结归纳: ①利用蜜蜂为作物授粉的研究,在解决了蜜蜂采食油茶花蜜中毒的难题以来,调入油茶林为油茶授粉的蜂群由1985年不足10万群,发展到1988年的100万群,使油茶结实率提高1.7～2.4     

授粉昆虫与粮食产量关系新结论

最近,科学家得出结论,蜜蜂和许多其它昆虫的数量一直在下降,但令人惊奇地是,从全球的范围来看,依赖这些授粉昆虫的农业未曾受到影响。刊登在近期《自然》杂志网站上的该结论颠覆了以前关于授粉昆虫减少,粮食产量下降的相关研究,科学家对背后原因进行了分析并开始重新审视授粉昆虫和粮食产量的关系。     

不同授粉方式对设施西瓜授粉效果研究

为了探究不同方式组建授粉蜂群的授粉效率,利用意大利蜜蜂Apis mellifera蜂王上颚腺信息素(Queen mandibular pheromone, QMP)替代蜂群内的真正蜂王组建授粉蜂群给“日本新秀”西瓜授粉,比较有王群(Queenright)、无王群(Queenless)、假王群(QMP+queenless)和人工授粉(Hand pollinated)4种不同授粉方式对设施西瓜授粉后的产量、品质和蜂群采集活动及蜂群损失情况差异,以此验证利用蜂王上颚腺信息素替代蜂王组建蜂群为设施西瓜授粉的可行性。结果表明：假王群采集活动趋势可与有王群保持一致,两者蜂群损耗、出巢、回巢和带粉回巢的采集蜂数显著高于无王群;有王群和假王群授粉西瓜平均产量均显著高于无王群和人工授粉。有王群、假王群和无王群处理的西瓜果实种子饱子数均显著高于人工授粉。且有王群和假王群西瓜的可溶性固形物含量显著高于无王群和人工授粉处理。综上所述,使用蜂王上颚腺信息素替代蜂王组建小型授粉蜂群为设施西瓜授粉切实可行,该研究为设施作物授粉提供了新的思路和方法,也拓展了昆虫信息素在农业系统中的重要利用价值。     

拟除虫菊酯类杀虫剂对蜜蜂的毒性和影响

蜜蜂是最重要的农业授粉昆虫之一,蜜蜂在授粉过程中极有可能接触到广泛使用的广谱杀虫剂-拟除虫菊酯,大多数拟除虫菊酯对蜜蜂等农业授粉昆虫有较高的毒性.本文对拟除虫菊酯类杀虫剂的作用机理进行了综述;总结了蜂群及蜂产品中拟除虫菊酯类杀虫剂的残留现状、拟除虫菊酯对蜜蜂的急性毒性以及亚致死效应,讨论了拟除虫菊酯类杀虫剂复配农药对蜜...     

河南芝麻授粉昆虫初步调查

为了清楚了解芝麻花授粉昆虫种类、昆虫的授粉规律和授粉时间,2009年对河南省平舆县高杨店乡的13个样点芝麻花授粉昆虫进行调查,采集到授粉昆虫标本65份.经过整理鉴定,芝麻花授粉昆虫共计5目14科25种.其中,蜜蜂占授粉昆虫的92%,是大田芝麻主要的授粉昆虫.蜜蜂授粉出勤高峰出现在8:00～8:50和18:00～18:50.     

授粉昆虫与粮食产量关系新结论

最近，科学家得出结论，蜜蜂和许多其它昆虫的数量一直在下降，但令人惊奇地是，从全球的范围来看，依赖这些授粉昆虫的农业未曾受到影响。刊登在近期《自然》杂志网站上的该结论颠覆了以前关于授粉昆虫减少，粮食产量下降的相关研究，科学家对背后原因进行了分析并开始重新审视授粉昆虫和粮食产量的关系。相关论文发表在10月28日的《当代生物学》（Current Biology）杂志上。     

油茶传粉昆虫研究现状与方向的探讨

油茶是典型的异花授粉植物,其中虫媒是主要形式,所以利用野生传粉性昆虫来提高油茶授粉效率,解除花粉限制,是解决我国油茶产业"瓶颈"的有效方法之一。目前,关于油茶传粉昆虫的研究比较匮乏,仅限于传粉昆虫的种类调查和部分野生蜜蜂传粉生物学和营巢生物学特性研究,不能满足油茶产业发展的需要。在现有研究基础上,结合传粉昆虫研究发展趋势,本文将提出以下几个重要研究内容:油茶访花昆虫种类的调查和鉴定;主要传粉昆虫传粉生物学研究;优势传粉昆虫的筛选;野生传粉蜜蜂与油茶授粉间的关系;利用传粉昆虫与油茶的协同进化进行油茶品种选育。以期为油茶传粉昆虫的后续研究提供参考。     

意大利蜜蜂和小峰熊蜂在温室桃园的传粉行为及其影响因素

意大利蜜蜂Apis mellifera ligustica和小峰熊蜂Bombus hypocrita是我国设施农业中的两种主要授粉昆虫, 二者的传粉方式和传粉效率因不同作物而各有不同。为了选用最理想的蜂种为温室作物授粉, 提高作物的授粉效率, 我们于2008-2010年连续3年在北京的温室桃园进行了意大利蜜蜂和小峰熊蜂的传粉行为及其影响因素的研究。结果表明, 两种蜂的日活动规律不同, 和意大利蜜蜂相比, 小峰熊蜂的活动起点温度低、 日工作时间长、 单花访问时间长, 采集蜂在温室内距离蜂巢不同距离之间扩散比较均匀。而意大利蜜蜂采集蜂的数量随授粉半径的增大而明显减少。温室内环境因子对两种蜂传粉活动的影响基本一致, 温度对两种蜂的传粉活动影响最大, 其次是湿度、 单花花蜜浓度和光照强度, 而单花花蜜体积对蜂活动无明显影响。本研究认为对于温室桃授粉应优先选用授粉性能稳定的小峰熊蜂, 并且适当调节温室内环境条件, 以提高其授粉效率。     

利用微卫星标记初步分析橘小实蝇4个地理种群的遗传多态性

橘小实蝇Bactrocera dorsalis(Bactrocera)(Hendel)是我国重要的检疫性害虫,对果蔬生产及其国际贸易造成很大影响。作者运用微卫星分子标记技术,用6对微卫星引物对采自我国福建、广东、云南3个地区及邻近国越南橘小实蝇种群间的遗传关系进行了初步分析,结果显示上述4个橘小实蝇地理种群间存在一定的遗传差异,地理隔离是造成这一差异的主要原因。     

Effects of native pollinator communities on the physiological and chemical parameters of loquat tree (Eriobotrya japonica) under open field condition

Wild and managed pollinators are the key component of biodiversity, contributing to important ecosystem services such as pollination and supporting human food security. Pollination by insects is a crucial component of the food chain that ensures the production of fruits and strongly affects the fruit quality, but the effect of insect pollination on fruit physiological and chemical parameters is largely unknown. The current study was conducted to determine the insect pollinators diversity and their relative abundance in the loquat (Eriobotrya japonica) orchard during 2017–2019. Further, the effect of insect pollinators pollination on the physiological and chemical parameters of fruit quality as compared to control pollinated flowers was investigated. The results revealed that a total of 22 species from 3 families (Apidae, Halictidae, and Syrphidae) were identified during the flowering season. The Apidae and Syrphidae were the most frequently observed families with major groups honey bees (67.89%) and hoverflies (21.57%), respectively. Moreover, results indicated that the fruit yield by the open-pollinated flowers (22.31 ± 0.34 kg/tree) was significantly higher than the control pollinated flowers (14.80 ± 0.25 kg/tree). Physiological and chemical parameters of loquat fruit differed significantly when fruits obtained from open-pollinated flowers as compared to control pollinated flowers. These results suggested that native insect pollinators play important role in the fruit quality of loquat. Hence, maintenance of appropriate habitat of native pollinators near loquat orchards is necessary to ensure good productivity and fruit quality.     

The role of termites in the decomposition of wood and leaf litter in the Southern Guinea savanna of Nigeria

Summary The number of flowers produced by inflorescences of Yucca whipplei (Agavaceae) consistently exceeds the number of fruits produced by about one order of magnitude. To determine the factors responsible for low fruit set, the relation between pollinator availability, the amount of resources spent on reproduction (as indicated by inflorescence size), and the number of fruits matured was studied during 1978 and 1979 at 18 locations in chaparral, coastal sage scrub, and desert scrub communities of southern California.The following results support the conclusion that pollinators do not usually limit fruit production in Yucca whipplei. Rather, fruit production is limited by the amount of resources available to support developing fruits. (1) Fruit production is positively correlated with inflorescence size both within and between populations. The average size of inflorescence for a population is an excellent predictor of mean fruit production. Furthermore, 54% of the total variance in fruit production of individual plants can be explained by inflorescence size. (2) In contrast, although fruit production within most populations is positively correlated with an index of the number of pollinator visits to an inflorescence, the relative abundance of pollinators for a population is a poor predictor of mean fruit production, and only 9% of the total variance in fruit production can be explained by the visitation index. Furthermore, at four sites studied for two years, there was little change in average inflorescence size or fruit production from 1978 to 1979, despite large differences in relative abundance of pollinators at each of the sites. (3) Based on geographic proximity, and physiographic and vegetational similarities, study sites were grouped into regional clusters. Both inflorescence size and fruit production varied considerably between regions. Of the total variation in fruit production, 27% can be attributed to differences between regions. Most of this variation is the result of regional differences in inflorescence size, which in turn influence fruit production.Why does Yucca whipplei produce such large inflorescences if so few fruits can be supported? Two relevant hypotheses are discussed: (1) the floral display is the result of selection for pollen dissemination at the expense of fruit set; and (2) the floral display is the result of selection for a bet-hedging strategy either to increase the probability of adequate pollination when pollinators are unusually rare, or to allow individuals to support more fruits when resources are unusually abundant.     

The reproductive biology and effective pollinators of the endangered beardtonguePenstemon penlandii (Scrophulariaceae)

Penland's beardtongue, a rare endemic plant of the Colorado Plateau, displays a mixed breeding system. Plants are partially self-compatible but set more fruits when cross-pollinated than when self-pollinated. Fruit production is significantly increased by pollinators. However, in two years of study there was no indication that fruit set was being limited by inadequate pollinator visitation. Pollinator effectiveness was judged by correlating bee behavior at the flowers with analysis of the pollen carried on bee bodies. The most important pollinators were native megachilid bees, particularly in the genusOsmia. The bees that pollinate Penland's beardtongue are essential to its reproduction and must be preserved along with this rare plant.     

Sex‐specific reproductive components and pollination ecology in the subdioecious shrub Fuchsia microphylla

In subdioecious populations, functional female, male and hermaphrodite individuals coexist. Subdioecy may be a transitional state towards dioecy or a breakdown of dioecy, although lability in sex expression may maintain subdioecy as a stable condition. To better understand the ecological aspects involved in sex ratio dynamics and breeding system evolution, we studied the pollination and female fitness components of female and hermaphrodite individuals of the subdioecious shrub Fuchsia microphylla. In two natural populations at the Trans‐Mexican Volcanic Belt we estimated female frequency and several reproductive components of female and hermaphrodite plants under natural pollination and experimental pollination treatments. Average female frequency was 42%, and on average, 42.5% of hermaphrodites produced fruits. Female plants showed a 17‐fold female fertility advantage over hermaphrodites through increased fruit production, as the number of seeds and germination rates did not differ between morphs. Hermaphrodite flowers were larger, with similar nectar production and concentration to female flowers, and pollinators did not show consistent morph preferences. Some hermaphrodites produced fruits autonomously, and female flowers excluded from pollinators produced fruits putatively by apomixis. Fruit production in hermaphrodites, but not in females, was related to height, suggesting increased investment of hermaphrodites in the female function at higher resource status. For sex ratios to be at equilibrium, the female fertility advantage should be reduced about eightfold. However, it may be that hermaphrodites are maintained by producing fruits at no cost to the male function at higher resource status, as the gender plasticity hypothesis proposes.     

Modification of flavonoid biosynthesis in crop plants

Flavonoids comprise the most common group of polyphenolic plant secondary metabolites. In plants, flavonoids play an important role in biological processes. Beside their function as pigments in flowers and fruits, to attract pollinators and seed dispersers, flavonoids are involved in UV-scavenging, fertility and disease resistance. Since they are present in a wide range of fruits and vegetables, flavonoids form an integral part of the human diet. Currently there is broad interest in the effects of dietary polyphenols on human health. In addition to the potent antioxidant activity of many of these compounds in vitro, an inverse correlation between the intake of certain polyphenols and the risk of cardiovascular disease, cancer and other age related diseases has been observed in epidemiological studies. The potential nutritional effects of these molecules make them an attractive target for genetic engineering strategies aimed at producing plants with increased nutritional value. This review describes the current knowledge of the molecular regulation of the flavonoid pathway and the state of the art with respect to metabolic engineering of this pathway in crop plants.     

Climate‐driven spatial mismatches between British orchards and their pollinators: increased risks of pollination deficits

Understanding how climate change can affect crop‐pollinator systems helps predict potential geographical mismatches between a crop and its pollinators, and therefore identify areas vulnerable to loss of pollination services. We examined the distribution of orchard species (apples, pears, plums and other top fruits) and their pollinators in Great Britain, for present and future climatic conditions projected for 2050 under the SRES A1B Emissions Scenario. We used a relative index of pollinator availability as a proxy for pollination service. At present, there is a large spatial overlap between orchards and their pollinators, but predictions for 2050 revealed that the most suitable areas for orchards corresponded to low pollinator availability. However, we found that pollinator availability may persist in areas currently used for fruit production, which are predicted to provide suboptimal environmental suitability for orchard species in the future. Our results may be used to identify mitigation options to safeguard orchard production against the risk of pollination failure in Great Britain over the next 50 years; for instance, choosing fruit tree varieties that are adapted to future climatic conditions, or boosting wild pollinators through improving landscape resources. Our approach can be readily applied to other regions and crop systems, and expanded to include different climatic scenarios.     

Conservation implications of the reproductive ecology of Agalinis acuta (Scrophulariaceae)

Reproductive ecology of Agalinis acuta was investigated by examining potential for self-fertilization before and at anthesis, reproductive output from outcrossed vs. selfed matings, and effects of browsing, plant size, and conspecific plant density on seed and fruit production. These features of a plant species can provide indirect information pertinent to conservation such as patterns and maintenance of genetic diversity, risk associated with inbreeding depression, and changes in pollinator abundance or effectiveness. The species is self-compatible, with 97% of selfed flowers setting fruit; pollinators were not required for reproduction. However, seed set in self-pollinated fruits averaged 17-20% less than that in open-pollinated fruits. Geitonogamous and facilitated selfing are possible throughout anthesis and autonomous selfing is possible late in anthesis as corollas abscise. Delaying self-pollination until after outcrossing opportunities likely limits selfing rates and thus reduces risks associated with inbreeding but allows reproduction in absence of pollinators. Supplementing pollen on open-pollinated flowers yielded no additional seed set over controls. Neither early-season browsing of primary stems nor conspecific plant density had significant effects on number of fruits per plant, on fruit size, or on number of seeds from open-pollinated flowers. Currently, reproduction appears to be high (about 2400 seeds/plant), and future risks due to lack of genetic diversity are likely low.     

Dietary Exposure Assessment of Potentially Toxic Trace Elements in Fruits and Vegetables Sold in Town of Kapan,Armenia

Fruits and vegetables grown under the impact of Armenia’s mining industry are widely sold in markets of adjacent towns. As the share of fruits and vegetables in Armenians’ diet is significant, the present study aims to assess the dietary exposure of potentially toxic trace elements through the intake of fruits and vegetables sold in Kapan town, located in the biggest mining region of Armenia. The concentrations of Cu, Mo, Ni, Cr, Pb, Zn, Hg, As, and Cd in 15 types of fruits and vegetables were determined. Non-carcinogenic and carcinogenic risks were assessed. Although the estimated daily intakes of trace elements for each studied food item did not exceed health-based guidelines values, in case of the combined consumption of fruits and vegetables estimated cumulative daily intakes exceeded reference doses for Cu and Mo. Moreover, carcinogenic risk for the majority of fruits and vegetables exceeded the EPA recommended risk level of 10⁻⁶, indicating adverse health effect to local population. The outcomes of this study can serve as a basis for further research that will consider many other exposure pathways (i.e., inhalation or dermal pathways) in order to ensure the safety of the residents living under the impact of mining industry.

     

Reproductive biology of Cyrtopodium polyphyllum (Orchidaceae): a Cyrtopodiinae pollinated by deceit

The genus Cyrtopodium comprises about 42 species distributed from southern Florida to northern Argentina. Cyrtopodium polyphyllum occurs on rocks or in sandy soils, in restinga vegetation along the Brazilian coast. It flowers during the wet season and its inflorescences produce a high number of resupinate yellow flowers. Cyrtopodium polyphyllum offers no rewards to its pollinators, but mimics the yellow, reward-producing flowers of nearby growing Stigmaphyllon arenicola (oil) and Crotalaria vitellina (nectar) individuals. Several species of bee visit flowers of C. polyphyllum , but only two species of Centris ( Centris tarsata and Centris labrosa ) act as pollinators. Visits to flowers of C. polyphyllum were scarce and, as a consequence, low-fruit set was recorded under natural conditions. Such low-fruit production contrasts with the number of fruits each plant bears after manual pollination, suggesting deficient pollen transfer among plants. C. polyphyllum is self-compatible and has a high-fruit set in both manual self- and cross-pollinated flowers. Furthermore, fruits (2%) are formed by self-pollination assisted by rain. This facultative self-pollination mechanism is an important strategy to provide reproductive assurance to C. polyphyllum as rainfall restricts the foraging activity of its pollinating bees. Fruits derived from treatments and under natural conditions had a similar high rate of potentially viable seed. Moreover, these seeds had a low polyembryony rate, which did not exceed 5%. C. polyphyllum acts by deceit involving optical signals and exploits other yellow-flowered species within its habitat by attracting their pollinators. The low capsule production under natural conditions was expected, but its reproductive success is assured through self-pollination by rain and high seed viability.