Pollen‐feeding in hover‐flies (Diptera: Syrphidae)

Analyses of the pollen contents of the crop and intestine of 11 species of New Zealand Syrphidae . showed that small, sparsely haired hover‐flies with unbranched hairs, short, simple bristles, and a short proboscis had ingested at least 99% anemophilous pollens, and that larger, more hairy hover‐flies with pollen‐collecting hairs, long, spirally grooved bristles, and elongate mouthparts had ingested pollens almost exclusively from nectar‐bearing flowers. Pollen‐feeding behaviour was studied in one hairy species, the drone‐fly Eristalis tenax, and in one sparsely‐haired species, Melanostoma fasciatum. Using granulated charcoal as a substitute for pollen, it was found that in E. tenax particles trapped among the body hairs are combed off by the front and hind tibiae and transferred to pollen‐retaining bristles on the front and hind tarsi respectively. Particles retained among the front tarsal bristles are ingested directly from the bristles. Those retained by the hind tarsi are transferred in flight by leg‐scraping movements to the front tarsi, from which they are subsequently eaten. E. tenax also eats pollen directly from anthers. In M. fasciatum apparently all the pollen ingested is taken directly from anther lobes or stigmas. The few pollen grains that adhere to the body of this species are combed off by the front and hind tibiae and transferred to the front and hind tarsi, but are not retained there because the bristles are short and simple. The mouthparts, hairs, and bristles of E. tenax and M. fasciatum are illustrated. Drawings of leg movements associated with pollen collection and ingestion, and photographs showing leg scraping in E. tenax are included. Morphological similarities between drone‐flies and honey‐bees, previously regarded as the result of mimicry, can be explained by convergent evolution in response to similar food‐gathering behaviour. Probably the majority of Syrphidae, and also the related Acroceridae, collect pollen by means of branched or curly‐tipped hairs.     

Comparison between the diameter of hair cross-sections and the thickness of the enclosed hairs in Japanese monkeys (Macaca fuscata fuscata)

The thickness of hairs from Japanese monkeys was measured by enclosing the hairs on slide glasses with balsam. Nine monkeys were used for the study. Forty to 69 hairs from the back were examined per head. High correlations between the thickness of the enclosed hairs and the diameter of cross-sections were obtained in all monkeys. In the Japanese monkey, therefore, it is considered possible to utilize enclosed hairs for measuring the thickness without preparing cross-sections. Moreover, the medullae of which the air layers are strongly related to thermoregulation, were readily observed in the enclosed hairs.     

Effect of environmental pollution on the proteins, allergenic bands, ontogeny and structure of Avicennia marina (Forsk.) Vierh (Avicenniaceae) pollen grains

In Bushehr province of Iran, Avicennia marina trees have grown in Bordekhoon (Mond Protected Area) and Assaluyeh (Marine National Park of Nayband). Contrary to Bordekhoon, Assaluyeh is a petrochemical region with environmental pollution. This study was aimed to studying protein profiles, allergenic bands, ontogeny, structure and elemental composition of tectum of A. marina pollens in Assaluyeh and Bordekhoon. Pollens were collected from two regions and extracted in PBS, and protein profiles of pollens were determined by sulfate–polyacrylamide gel electrophoresis (SDS-PAGE). As an experimental model, 20 female 6–8-week-old Balb/C mice were divided into two groups. The mice of first and second groups were sensitized by Bordekhoon and Assaluyeh pollen extracts, respectively, and mice serum samples were used for immunoblotting. Pollen characteristics were studied using light and scanning electron microscopes. SDS-PAGE showed some differences between pollen protein profiles of two regions. Immunoblotting assay detected that pollens have two allergenic bands and the protein band at 100 KD is the common allergenic protein in two regions. Light microscopy revealed that the development of anther wall was basic type and some abnormalities were observed in microspores and pollens of Assaluyeh. Scanning electron microscopy studies showed that the apertures in considerable numbers of Assaluyeh pollens were closed. The comparison of elemental composition of pollen tectum between two regions showed that pollens of Assaluyeh have accumulated Cu on their tectum. Results obtained indicated that environmental pollution can affect protein profile, allergenic bands, structure and elemental composition of tectum of A. marina pollens.     

甘蓝型油菜CMS微粉活力研究及其对杂交制种纯度的影响

通过对微粉和正常花粉在不同和同一雌蕊上的结实力比较和结实竞争研究,表明微粉虽能够授粉结实,但活力低、萌发慢、持续时间短、受精结实能力差,与正常花粉的竞争力弱,授微粉后间隔３－７２ｈ,再授恢复系花粉,其结实表现仍可达到或超过单独授恢复系花粉的结实率,最高的还超过了只授恢复系花粉结实率的９．５７％;授微粉后间隔０－４８ｈ再授恢复系花粉仍可获得７０．３５％－９１．００％的异交率,说明微粉对油菜杂交制种过     

Morphological characteristics of the hair of Japanese monkeys (Macaca fuscata fuscata): Length,diameter and shape in cross-section,and arrangement of the medulla

A morphological study was carried out on hairs of the Japanese monkey. The shapes in cross-section were circles or ellipses. The diameters of the hairs ranged from 13.5 to 92 μ, and the mean value in each monkey was between about 30 and 40 μ. The average value of the fibre index was approximately 90 in each monkey. The arrangement of the medulla was considered to be of the narrow medulla lattice type. Medullae were developed poorly or disappeared in hairs with a diameter of less than 30 μ. A correlation was noted between the hair thickness and presence of medulla: medullated hairs were thicker than non-medullated hairs. A tendency was found for thicker hairs to be of greater length. The hairs of the Japanese monkey could be divided broadly into two types: medullated hair and non-medullated hair. The medullated hairs could be regarded as guard hair-like hairs since they were thick and long, and the non-medullated hairs as underhair-like hairs since they were thin and short.     

土圞儿属和旋花豆属(豆科)的孢粉学研究

在扫描电子显微镜下,对豆科土儿属(Ap ios)和旋花豆属(Coch lianthus)7个种植物的花粉进行了观察.结果表明,2个属的花粉均为三孔沟,形状为三角球形或球形.土儿属的花粉可划分为2种类型:肉色土儿(A.carnea)的花粉外壁为典型的网状纹饰,其它种的花粉外壁较光滑,具颗粒状或短条纹状纹饰,研究结果不支持土儿属下亚属的划分;肉色土儿花粉外壁的网状纹饰式样可能反映了其在土儿属中处在较进化的位置.土儿属东亚分布种的花粉类型较为多样,原始和进化2种类型并存,表明东亚可能是土儿属的起源地和演化中心.旋花豆属的花粉特征和肉色土儿相似,说明两者之间的亲缘关系可能较近.     

A note on the hairy achenes of four African species of Scleria Bergius (Cyperaceae)

Surface features of hirsute achenes of four African species of Scleria have been examined by SEM. All bear unicellular, terete hairs with swollen bases. As the achenes mature and dry, the hairs collapse, except for their partly silicified bases, which appear as pit-like depressions from which the now-flattened hairs emerge. If the achene surface is not smooth the hairs are localized on the interlacunar ridges. In addition to the hairs, three of the four species examined show minute papillate protuberances from the silicified outer tangential walls of the epidermal cells. These papillae form a further ornamentation to the achenes visible only at high magnification. The fourth species entirely lacks these papillae.     

Glandular hairs in the genusDrosera (Droseraceae)

On the leaves and sepals of 52 species, representing all sections of the genusDrosera except one, 14 different types of glandular hairs were found: two-celled papillae, peltate scales, several types with unbranched, bi- or multiseriate stalk with a two- or multicellular gland, and one type with a multiseriate stalk and a two-armed gland. The combination of these hairs and the presence of non-glandular hairs confirm the actual classification of the genus. In combination with simple morphological characters (e.g., the type of insertion of the petiole) glandular hairs facilitate the identification of species even in the pharmaceutically important cut crude drug.     

Intracellular motility,the actin cytoskeleton and germinability in the pollen of wheat (Triticum aestivum L.)

Summary The tricellular pollen of wheat germinates rapidly on a receptive stigma without the often protracted activation period characteristic of bicellular pollens. This is associated with a high level of hydration in the mature pollen and the absence of a dormancy period. Intracellular movement of organelles continues throughout development; in the mature pollen along pathways related both to the aperture site and the distribution of the amyloplasts in the vegetative cell. The movement pathways reflect the organisation of the actin cytoskeleton, elements of which are already focused upon the germination site at the time of dispersal, a disposition only achieved during rehydration and activation in bicellular pollens. Dehydration after dispersal rapidly arrests movement, disrupts the actin cytoskeleton and leads to loss of germinability. These effects are irreversible, again in contrast to the situation found in bicellular pollens such as those of the Liliaceae, species of which have been shown to be capable of withstanding several cycles of hydration and dehydration while still retaining some capacity for germination.     

LEAF HAIRS IN ENCELIA (ASTERACEAE)

Four different kinds of leaf hairs occur in Encelia species. These are unicellular-based and multicellular-based uniseriate hairs, moniliform hairs, and biseriate glandular hairs. The unicellular-based uniseriate hairs appear responsible for increased leaf spectral reflectance by species within the genus. In particular, it appears that elongation of the distal cell of the uniseriate hair is necessary for increased leaf reflectance.     

光敏雄性不育谷子683小孢子败育途径观察

对光敏雄性不育谷子（Setaria italica）683在长日（＞15h）和短日（＝10h）下小孢子的发育途径、花药中药粉总数及游离花粉总数作了观察和统计,发现长日条件下,小孢了败育主要发生在造孢细胞和花偻母细胞时期,此时,有60％－80％的药室的造胞细胞和花偻母细胞严重收缩,细胞结构破坏,演变成着色极深的“异常黑块”（埃氏苏木精染色）。每花药中花粉平均数,长日条件下为66.84,短日照下为111.86,差异显著,每视野中的游离花粉平均数,长日条件下为13.73,而在短日条件下为20.1.研究对“异常黑块”的出现与花粉总数大幅度降低的关系作了分析,并讨论了“异常黑块”发生的可能原因及其与小孢子败育的关系。     

Innervation of the cercal sensilla on the ovipositor of the Australian sheep blowfly (Lucilia cuprina)

ABSTRACT. The ovipositor of the female sheep blowfly, Lucilia cuprina (Wied.) (Diptera: Calliphoridae), has a complement of cercal sensilla that includes long, medium and short tactile hairs, two campaniform domes, four olfactory pegs, and ten double-channelled gustatory hairs. This sensory array is suited to assess oviposition site resources, prior to and during the laying of an egg batch.
The tactile hairs and campaniform sensilla are each innervated by a single, tubular body containing dendrite. The olfactory pegs are each innervated by a single, moderately branched dendrite, which gains access to the external environment via pores at the bottom of deep grooves in the peg wall. The gustatory hairs fall into two categories. Four hairs have a single, tubular body containing dendrite at their base, and four unbranched dendrites running up to the hair tip which has a terminal pore. Six of the taste hairs have no tubular body containing dendrite at the base, and three unbranched dendrites running up to a terminal pore.     

Genotypic differences in the presence of hairs on roots and gynophores of peanuts (Arachis hypogaea L.) and their significance for phosphorus uptake

Root hairs substantially increase the surface area of plant roots with positive effects for phosphorus (P) uptake, but the ability of peanuts to form root hairs has been questioned. The aim was to examine hair development on roots and gynophores of a variety of peanut genotypes and to relate genotypic differences in hair formation to differences in P uptake. Five out of eighteen genotypes completely lacked hairs on both organs whereas others consistently developed hairs on roots and gynophores, although with considerable variation in hair density. The ability to form root hairs as well as root hair density concurred with the presence and density of hairs on gynophores, suggesting a possible connection between both developmental processes. The contribution of root hairs to P uptake was studied in three genotypes differing in hair density. The final amount of P taken up by roots did not differ between genotypes but two distinct P uptake strategies could be identified. The genotype lacking root hairs maintained P uptake due to the development of a large root system whereas densely covered roots of genotype 'Wasedairyu' were three times as efficient in extracting P from a P-deficient soil. Furthermore P uptake through gynophores contributed about 20% to the total P uptake of Wasedairyu but only insignificant amounts to other genotypes. The ability to form hairs on roots and gynophores can therefore be seen as an adaptation to low P availability and if combined with a large root system, could substantially increase the tolerance of peanuts to P deficiency.     

Oviposition behaviour and the sensilla of the ovipositor of Chilo partellus and Spodoptera littoralis (Lepidoptera: Noctuidae).

Observations of oviposition behaviour by Chilo partellus revealed that antennae, ovipositor tip and possibly tarsi were all involved in the choice of oviposition site. Among a very large number of typical mechanoreceptor hairs on the tip of the ovipositor valves, two pairs of stouter, blunt-tipped hairs were discovered. These hairs alone took up silver nitrate stain and transmission electron microscope sections revealed that the hair shaft had a hollow lumen within which ran a group of four or five dendrites. It is concluded that these sensilla are contact chemoreceptors and they are positioned in such a way that, with the placing of each egg, they would contact the oviposition substrate. Similar hairs were found on the ovipositor of Spodoptera littoralis . It is suggested that the hairs may prevent oviposition on surfaces directly chemically harmful to the eggs.     

Epidermis Is the Site of Action of Tabby (TA) in the Mouse

The site of action of the sex-linked tabby (Ta) locus was analyzed by the technique of dermal-epidermal recombination grafting. Skin components from normal and tabby 14-day embryos were separated, recombined and grown 21 days in testes of histocompatible mice. Grafts of the combinations normal epidermis-normal dermis and normal epidermis-tabby dermis produced predominantly zig-zag hairs. Grafts of the combination tabby epidermis-normal dermis and tabby epidermis-tabby dermis produced hairs with a morphology similar to hairs found in tabby mice. We conclude from these results that the tabby locus acts within the epidermis, and has no effect on the dermis.     

Ultrastructure of the antennal sensilla of the cockroach-egg parasitoid,Tetrastichus hagenowii (Hymenoptera: Eulophidae)

Eggs of a number of cockroach species are parasitized by Tetrastichus hagenowii. The ultrastructure of the sensilla on the antennae of females and males was examined by scanning and transmission electron microscopy. The females have two types of multiporous plate sensilla while the males have only one. Type 1 is found in females and males and has a relatively thin cuticular wall and many pores, while type 2 is found only in females and has a relatively thick cuticular wall and few pores. Both sexes have nonporous, thick-walled, socketed hairs; multiporous, nonsocketed hairs; multiporous, thick-walled pegs; and terminal hairs. In addition, males have multiporous, nonsocketed, long hairs. The sensilla are similar, in many respects, to the sensilla of other chalcid parasitoids. The antennal sensilla of female T. hagenowii are probably involved in ovipositional behavior. The multiporous, long hairs of the male possibly receive stimuli during mating behavior A chemoreceptive function is proposed for the multiporous plate sensilla.     

Direct evidence on participation of root hairs in phosphorus (32P) uptake from soil

Root hairs substantially extend root surface for ion uptake. Although many reports suggest a relationship between root hairs and phosphorus (P) uptake of plants, the role of root hairs in phosphorus uptake from soils is still debated. We measured uptake of phosphorus from soil directly via root hairs. Root hairs only were allowed to penetrate through a tightly stretched nylon screen (53 µm) glued to the bottom of a PVC tube. The penetrating root hairs grew for 2 and 4 days in soil labelled with radioisotope phosphorus (P) tracer ³²P (185 kBq g^-1 dry soil) filled in another PVC tube. Transparent plastic rings of thickness ranging from 0.25 mm to 2.0 mm were inserted between the two PVC tubes. This provided slit width for microscopic observations in situ, which confirmed that only root hairs were growing into the ³²P labelled soil. In some cases no rings were inserted (slit width = 0) where both root hairs and root surface were in contact with the labelled soil (total ³²P uptake). The uptake of³² P from soil via the root hairs only was quantified by measuring activity of ³²P in the plant shoot (³²P uptake only via root hairs).The results showed that when 70 percent of the root hairs grew into the labelled soil, they contributed to 63 percent of the total P uptake. With decreasing number of root hairs growing into the ³²P labelled soil, the quantity of ³²P in the plant shoot decreased. In this study, P uptake via root hairs was measured in a soil-based system, where root hairs were the only pathway of ³²P from soil to the plant shoot. Therefore, this study provides a strong evidence on the substantial participation of root hairs in uptake of phosphorus from soil.     

Studies on Atmosphere Spores and Pollen and Their Influences on the Sporopollen Assemblages in the Sediments of Huanghai Sea

Totally, 321 grains of spores and pollens which consist of 23 genera and species, were collected from the atmosphere over Huanghai Sea during the survey in 1978–1979. It has been found that the amount of spores and pollen in the atmosphere was high in spring, lower in autumn and the lowest in summer and winter. The content of arboreal pollens amount to 74%, with 23% of herbaceous pollens and SM of spores. By comparing the spores and pollens in the atmosphere with those in the marine sedments it was revealed that they were well correlated but the former influences distinctly to the distribution of the latter, thus making a high content of herbaceous pollens in the sporopollen distributions in the marine sediments nearshore area and high content of arboreal pollens in area far from the coast.     

Auxin modulates the enhanced development of root hairs in Arabidopsis thaliana (L.) Heynh. under elevated CO(2)

Root hairs may play a critical role in nutrient acquisition of plants grown under elevated CO(2) . This study investigated how elevated CO(2) enhanced the development of root hairs in Arabidopsis thaliana (L.) Heynh. The plants under elevated CO(2) (800 μL L(-1)) had denser and longer root hairs, and more H-positioned cells in root epidermis than those under ambient CO(2) (350 μL L(-1)). The elevated CO(2) increased auxin production in roots. Under elevated CO(2) , application of either 1-naphthoxyacetic acid (1-NOA) or N-1-naphthylphthalamic acid (NPA) blocked the enhanced development of root hairs. The opposite was true when the plants under ambient CO(2) were treated with 1-naphthylacetic acid (NAA), an auxin analogue. Furthermore, the elevated CO(2) did not enhance the development of root hairs in auxin-response mutants, axr1-3, and auxin-transporter mutants, axr4-1, aux1-7 and pin1-1. Both elevated CO(2) and NAA application increased expressions of caprice, triptychon and rho-related protein from plants 2, and decreased expressions of werewolf, GLABRA2, GLABRA3 and the transparent testa glabra 1, genes related to root-hair development, while 1-NOA and NPA application had an opposite effect. Our study suggests that elevated CO(2) enhanced the development of root hairs in Arabidopsis via the well-characterized auxin signalling and transport that modulate the initiation of root hairs and the expression of its specific genes.