烟台甜樱桃柱头的可授性、形态特征与坐果率

采用数码照相、电镜扫描、联苯胺-过氧化氢测试及去雄套袋等技术手段,对烟台甜樱桃（Cerasus avium）花期不同发育阶段柱头的可授性、形态特征和坐果状况进行了观察。结果表明,烟台甜樱桃在套袋状态下,柱头可授期从开花前1天开始可持续5–7天。从杯状花期到花瓣平展期,柱头逐渐有乳突细胞破裂并呈现分泌液,出现渐强的可授性;从花瓣平展期到花瓣脱落期,柱头由暗黄渐变至暗黑,逐渐萎缩并丧失可授性。去雄套袋及人工授粉实验结果显示,在大蕾期、杯状花期、花瓣展放期、花瓣平展期和花瓣脱落期进行人工授粉,烟台甜樱桃的坐果率分别为60.50%、58.33%、62.08%、57.14%和39.13%。在自然条件下烟台甜樱桃的坐果率一般为30%–42%,传粉成功的最佳期主要发生在杯状花期至花瓣平展期。     

龙眼的化学成分与药理活性研究

龙眼是一种应用价值很高的传统中药,含有很多重要成分,比如多糖、脂类、多元酚、黄酮类等,传统中医认为龙眼有补益心脾、止痛消肿之功,近年来的研究发现它还有抗癌、抗衰老、抗氧化和免疫调节的作用。本文从龙眼肉、龙眼核两个角度,针对鉴别、化学成分、药理活性等方面,将近年来国内外的研究成果综合分析,并提出对龙眼远大开发前景的展望。     

Oviposition dynamics and larval development of Helicoverpa armigera on a highly preferred unsuitable host plant,Solanum viarum

Oogenesis and oviposition dynamics of female moths of tomato fruitworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), were compared in a monoculture of tomato (Solanum lycopersicum L.) and in mixtures with a highly preferred but unsuitable host plant, Solanum viarum Dunal. Female H. armigera provided with S. viarum laid many more eggs than those provided with tomato, both in choice and no‐choice experiments. Gravid female moths did not display any preference for oviposition neither between young or old plants of S. viarum or tomato, nor between young and old leaves of S. viarum. Larval mortality and larval developmental period significantly increased, with subsequent reduction in pupal weight, when H. armigera larvae fed on S. viarum leaves compared to a meridic diet. Oviposition of female moths significantly increased in tomato in the presence of S. viarum volatiles. However, in screen cages with an increasing percentage of S. viarum as a trap crop, the number of eggs laid on tomato as the main crop was the same. The results of this study are discussed in light of the possibility of using S. viarum as a ‘dead‐end’ trap crop.     

Mapping of two suppressors of OVATE (sov) loci in tomato

Tomato fruit shape varies significantly in the cultivated germplasm. To a large extent, this variation can be explained by four genes including OVATE. While most varieties with the OVATE mutation bear elongated fruits, some accessions carry round fruit, suggesting the existence of suppressors of OVATE in the germplasm. We developed three intraspecific F₂ populations with parents that carried the OVATE mutation but differed in fruit shape. We used a bulk segregant analysis approach and genotyped the extreme classes using a high-throughput genotyping platform, the SolCAP Infinium Assay. The analyses revealed segregation at two quantitative trait loci (QTLs), sov1 and sov2. These loci were confirmed by genotyping and QTL analyses of the entire population. More precise location of those loci using progeny testing confirmed that sov1 on chromosome 10 controlled obovoid and elongated shape, whereas sov2 on chromosome 11 controlled mainly elongated fruit shape. Both loci were located in intervals of <2.4 Mb on their respective chromosomes.     

Pollen limitation and fruiting failure related to canopy closure in Calypso bulbosa (Orchidaceae), a northern food‐deceptive orchid with a single flower

Natural fruit set is constrained by pollen limitation and fruiting failure, and pollen limitation is expected to be especially severe in deceptive orchids. We performed hand cross‐pollinations in ten populations of a food‐deceptive orchid, Calypso bulbosa, under sparse and dense canopies in three non‐consecutive years. We explored the relationships between natural fruit set, pollen limitation and fruiting failure. Mean natural fruit set over the years was 60%, which is exceptionally high for a deceptive orchid. On average, hand cross‐pollination increased fruit set by 23%. Among open‐pollinated plants that did not set a fruit, 55.5% were estimated to be pollen limited and 44.5% to be limited by fruiting failure, i.e. inability to set a fruit after pollination. In species with high natural fruit set, hand cross‐pollination experiments may not always detect statistically significant pollen limitation. In our case, pollen limitation tended to become significant when the natural fruit set dropped below 60%. Canopy cover had a significant effect on fruiting failure, which was more severe under a dense canopy. Although our results demonstrate pollen limitation in many cases, they also highlight the fact that food deception can be a very effective pollination strategy. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013 , 171 , 744–750.     

Spatial and seasonal variation in niche partitioning between blue manakin (Chiroxiphia caudata) and greenish schiffornis (Schiffornis virescens) in southeastern Brazil

The diet of Chiroxiphia caudata and Schiffornis virescens were studied over three years in four forest sites in the southeastern Atlantic Forest of Brazil. Theory suggests that coexistence of similar species is possible by resource-use differences. To test this, patterns of niche overlap and niche breadth in diet were measured in different seasons and forest sites, based on fruit morphological traits and plant life forms. The results suggest seasonal and spatial variation in resource partitioning. During periods of high fruit availability, there was no evidence of fruit trait selection. In contrast, during periods of fruit scarcity in primary forests, there was evidence of niche partitioning, where C. caudata foraged for larger fruits in canopy and S. virescens searched for understory plants. The niche overlap was higher in secondary forest during periods of scarcity, when both species used small understory fruits.

Foi estudada a dieta de Chiroxiphia caudata e Schiffornis virescens durante três anos, em quatro tipos de fisionomias florestais no sudeste da Mata Atlântica, Brasil. A teoria sugere que a coexistência de espécies semelhantes é possível pelas diferenças no uso dos recursos. Assim, nós mensuramos a amplitude e sobreposição de nicho considerando a morfologia dos frutos consumidos e a forma de vida das espécies de plantas utilizadas em quatro tipos florestais e em diferentes estações. Os resultados sugerem mudanças sazonais e espaciais na partilha de recursos. Durante períodos de alta disponibilidade de frutos, não há evidências de partilha de recursos. Já em períodos de escassez de frutos nas florestas primárias, C. caudata consumiu frutos grandes presentes no dossel enquanto S. virescens utilizou os frutos pequenos do sub-bosque. Na floresta secundária, o período de escassez foi marcado por sobreposição intensa de nicho onde ambas as espécies consumiram frutos pequenos de sub-bosque.     

Studies on host preference and its biological effects on the Red Palm weevil,Rhynchophorus ferrugineus Olivier in Egypt B. vegetable crops

The investigation on some Egyptian vegetables preference by the Red Palm weevil (RPW), Rhynchophorus ferrugineus has been carried out under laboratory conditions to explore a suitability of alternative host plants. The choice test of insect larvae showed that Taro, Squash, Eggplant, common potato, yellow carrot, tomato and sweet pepper were accepted food, while the Table beet (Vegetable) was rejected. Non-choice feeding of R. ferrugineus larvae on vegetables affected larval body weight and increased larval mortality. Highest rate of pupation was recorded from larvae fed on C. pepo (92%) and B. vulgaris (97%). Adult emergence reached 80% and 92% on C. pepo and Sugar beet (field crop) (field crop). The external skin of sugar cane was not acceptable food for insect larvae, while injured sites and internal soft fibres were preferred as food. Therefore, vegetable fruits, stem of sugarcane are believed to be the most vulnerable hosts for red weevil attack. The alternative host plant examined can be used to monitor the dynamics of the population of RPW in order to take effective preventive measures and most powerful tool available for use in pest management.     

Factors affecting the efficacy of trapping system to the peach fruit fly (PFF) males,Bactrocera zonata (Saunders) (Diptera: Tephritidae)

This study was conducted in Arab-Elmadabegh region located at the Northern West part of Assiut city at the border with the Western Desert. Four types of traps; Bottle trap, Glass McPhail trap, Plastic McPhail trap, and Abdel-Kawi trap baited with different doses of methyl eugenol (ME) were used. Obtained results indicated that Abdel-Kawi trap charged with 0.5?ml ME, it was the most effective trapping system. ME seemed to be with highly attracting effect, but most of the attracted males were found on the outside surface of the trap and on the branches surround the trap. Under these conditions, the females/males ration became 1:171. Thus, the believing tactic that fruit flies populations will decline due to the lack of males in the population available to females for mating seemed to be an erroneous believing. Results proved that PFF males had the highest activity at the dawn period between 5 and 7am. We strongly recommend using the trapping system consists of Abdel-Kawi trap charged with 0.5?ml ME only at dawn period (The first appearance of light in the morning followed by sunrise).     

Inter‐specific competition and competition‐free space in the tephritid parasitoids Utetes anastrephae and Doryctobracon areolatus (Hymenoptera: Braconidae: Opiinae)

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Studies on host preference and its biological effects on the red palm weevil,Rhynchophorus ferrugineus Olivier in Egypt The fruit trees

A comparative bioassay (choice or non-choice) was developed to evaluate the efficacy of different species of fruit trees as alternative host plants on the morphological and biological aspects of the red palm weevil, Rhynchophorus ferrugineus and also the latent effect of feeding the larvae on pupal and adult stages. Highly significant differences exist between averages of larval body weight of R. ferrugineus larvae fed on fruit trees. The lowest average of larval weight occurred in the larvae fed on the pieces of sour orange, mandarin followed by olive and lime trees. A small increase in body weight appeared in larvae fed on mango, fig and guava in comparison with those fed on date palm trees (control). The larval mortality reached the highest percentages (100%) by obligatory feeding of R. ferrugineus insects on olive, lime, sour orange and mandarin followed by mango (97%) and guava (96%) compared with control (0%), respectively. The latent effect of obligatory feeding on the larvae of R. ferrugineus was highly decreased during pupation (4%, 4% and 8%) when the insect fed on mango, guava and fig, compared with 100% pupation in the case of larvae fed on ornamental palm or date palm, respectively. Most pupae resulting from the treated larvae by R. ferrugineus failed in adult emergence especially those insects fed on olive, lime, sour orange and mandarin trees compared to untreated insects (95.6–96.2%), respectively. Data also proved that if an insect is forced to feed on a non-preferred host plant, this results in death of the insect often during the larval stage, a decrease of pupation or failure of adult emergence. These results led to the conclusion that mango, fig, and guava trees are believed to be vulnerable hosts for red weevil attack. The lowest percentage of food consumption appeared in those larvae fed on mandarin, sour orange, lime and olive trees compared with those fed on palm. The present results emphasise the need to test the efficiency of the compounds extracted from these host plants if it is considered as an insecticide or an alternative host protectant for management of the red palm weevil R. ferrugineus.