Pollen morphology and structure of Tropical and Subtropical American genera of the Piptadenia -group (Leguminosae: Mimosoideae)

A survey of the pollen morphology of the American taxa of the Piptadenia -group (Mimoseae) was done including all together 384 species of the following genera: Piptadenia , Parapiptadenia , Pseudopiptadenia , Piptadeniopsis , Microlobius (= Goldmania ), Stryphnodendron , Adenopodia , Anadenanthera and Mimosa . Because of a high morphological and structural variation the definition and characterization of pollen types turned out to be very difficult. Nevertheless the presence and durability of some pollen characters allow a provisional grouping: (1) always tetrads or polyads, (2) small size 6 (20) 40 mum, (3) unstable shape but currently ovoidal and, if biconvex, ellipsoidal in the outline, (4) number of pollen grains of the polyads very variable and unstable; the most frequent numbers are 8-12-16, (5) pollen grains irregularly united in polyads, with homomorphous exine and, (6) pores always located in the angles of the pollen grains in distal-subdistal position, rarely subdistal, (7) without or with pseudocolpi or subpseudocolpi (never colpi) in the distal face, (8) endexine forming an annulus around the endoaperture with ends of free lamellae with a central white line, (9) the tectal stratum above the pores forming a small vestibular space (except in Anadenanthera ). These palynological characters or most of them confirm the affinity among genera in the Piptadenia -group and its distinction from other taxa of the subfamily Misosoideae with tetrads or polyads.     

Pollen morphology of the tribes Naucleeae and Hymenodictyeae (Rubiaceae – Cinchonoideae) and its phylogenetic significance

The tribe Naucleeae has recently been recircumscribed on the basis of both morphological and molecular [ rbcL , trnT-F , internal transcribed spacer (ITS)] evidence, and has been found to be the sister group of the tribe Hymenodictyeae Razafim. & B. Bremer. In order to find pollen morphological support for this new classification, the pollen and orbicules of 65 species, representing 23 Naucleeae and the two Hymenodictyeae genera, were investigated by scanning electron and light microscopy. Naucleeae pollen is very small (< 20 µm) to small (20–30 µm) and its shape in equatorial view is suboblate to spheroidal or, more rarely, subprolate. Three compound apertures are present, each comprising a long and narrow ectocolpus, a circular to slightly lolongate mesoporus, and an often H-shaped endoaperture. The sexine ornamentation is perforate, rugulate, or (micro)reticulate, and supratectal elements are always absent. Apart from the variation in sexine ornamentation, the tribe is rather stenopalynous. The pollen of Hymenodictyeae is very similar to that of Naucleeae. The H-shaped endoapertures often observed probably form a synapomorphy for the clade comprising Naucleeae and Hymenodictyeae. Our pollen morphological observations are not in conflict with the widened delimitation of Naucleeae. Unambiguous pollen support for the recent subtribal or generic concepts of Naucleeae could not be found because of a lack of variation of pollen characters within the tribe. Orbicules are invariably present in the ten Naucleeae taxa investigated. They are spheroidal and smooth or irregularly folded.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 329–341.     

The unique pollen morphology of Duparquetia (Leguminosae: Caesalpinioideae): developmental evidence of aperture orientation using confocal microscopy

BACKGROUND AND AIMS: The phylogenetic affinities of the aberrant monotypic genus Duparquetia (subfamily Caesalpinioideae) are at present unresolved. Preliminary results from molecular analyses suggest a basal, isolated position among legumes. A study of Duparquetia pollen was carried out to provide further morphological characters to contribute to multi-data set analyses. Understanding the development of Duparquetia pollen was necessary to clarify the orientation of the apertures. METHODS: Pollen grains and developing microspores were examined using light microscopy, confocal microscopy and scanning electron microscopy. Evidence for the orientation of the apertures was provided by the examination of microspores within developing tetrads, using (a) confocal microscopy to locate the position of the ectoapertures, and (b) light microscopy and Alcian blue stain to locate the position of the endoapertures. KEY RESULTS: Confocal microscopy has been used for the first time to examine developing microspores in order to obtain information on ectoapertures that was unavailable using other techniques. Pollen in Duparquetia develops in tetrahedral tetrads as in other eudicots, with the apertures arranged in a modified pattern following Fischer's rule. Pollen grains are asymmetrical and have one equatorial-encircling ectoaperture with two equatorial endoapertures, a unique feature in Leguminosae, and in eudicots. CONCLUSIONS: The pollen morphology of Duparquetia is so unusual that it provides little information to help determine its closest relatives. However, it does fit with a pattern of greater pollen morphological diversity in the first-branching caesalpinioid legume groups than in the more derived clades. The latitudinal ectoaperture of Duparquetia is unique within the Fabales and eudicot clades, resembling more closely the monosulcate pollen found in monocots and basal angiosperms; however, developmental patterns are recognizably similar to those of all other legume pollen types.     

几种染色剂对桔小实蝇产卵孔的染色效果

为寻找水果上桔小实蝇产卵情况的快速检测方法,本文测定了甲基蓝、龙胆紫、品红、曙红、藏红和刚果红等6种染色剂对水果上桔小实蝇Bactrocera dorsalis（Hendel）产卵孔的染色效果。结果表明染色剂对可疑水果进行染色,若有产卵孔,产卵孔可迅速被染色,染色率最高可达100％。筛选出甲基蓝、藏红和刚果红作为芒果、番石榴和夏橙的最适染色剂,各种染色剂在浓度为0．5％时染色效果较佳,同时对持续冷藏保存后的水果上的产卵孔仍然具有较高的染色率。     

Intraspecific variation in the pollen exine sculpture of Jaborosa runcinata Lam. (Solanaceae)

The variability of ectexine sculpture in the pollen of Jaborosa runcinata (Solanaceae) was studied with light and scanning electron microscopy. Three main ectexine variants are recognized: incomplete reticulate, a combination of incomplete reticulate and gemmate‐granular, and gemmate‐granular. A range of transient conditions were also noted between the two extremes. Apertures vary from a basically triporate‐aspidate arrangement to pollen grains which appear to have a rudimentary colpus. The sculptural variability of the ectexine, and a tendency towards a colpus, in J. runcinata are interesting as intraspecific variation does not appear to be common within Solanaceae.     

Optimization for imaging through scattering media for confocal microscopes with divided elliptical apertures

We develop a confocal system equipped with optimal elliptical apertures to improve axial point spread function and signal‐to‐background ratio (SBR) for different detector sizes. By adjusting the parameters of the elliptical apertures, the axial half width at half‐maximum can be reduced to 4.986 (described in optical coordinates) and SBR can be improved to 0.176. We evaluate this system with the 1951 USAF resolution test chart and the primary cultured neuron from SD rat stained by Map‐2, and observe better imaging performance, which indicates the potential applications in biological science.      

Evolution of endoapertures in early-divergent eudicots, with particular reference to pollen morphology in Sabiaceae

Endoapertures, the inner openings of compound apertures in pollen grains, are common in eudicots, but occur infrequently in early-divergent eudicot lineages, in which they are restricted to three families: Menispermaceae, Sabiaceae and Buxaceae. Pollen of Sabiaceae was examined using light, scanning and transmission electron microscopy. The endoapertures are large and lalongate, and intine onci are associated with their development. Optimisation of endoapertures onto an existing angiosperm phylogeny indicates that endoapertures have evolved at least three times independently: in Menispermaceae, in Sabiaceae plus Buxaceae (or possibly separately in these two families), and in the core eudicot clade. Sabiaceae are unusual among early-divergent eudicots in that they possess some characters that are more common in core eudicots, including pollen with endoapertures and pentamerous flowers. This indicates either that they are more closely related to core eudicots than is indicated by current molecular evidence, or that these characters are homoplastic. The latter would suggest a high degree of experimentation prior to evolutionary canalisation of some key morphological features in eudicots. The evolution of endoapertures in early-divergent eudicots is probably associated with possession of endexine sculpture (endosculpture) such as endocracks; endoapertures may have been retained in eudicots as a harmomegathic mechanism.     

Septal apertures in the humerus of normal and experimental rats

Septal apertures of the humerus are rare in wild and domesticated rats but their occurrence is more frequent in females than in males and on the left than on the right side. Septal apertures can be produced experimentally by hypophysectomy due to an extreme reduction of the thickness of the septal wall. Other endocrine ablations, starvation and unilateral front leg paralysis do not produce a sufficient reduction of septal wall thickness to cause septal apertures. Their occurrence is also not correlated with total humeral robusticity. Thus, the manifestations of septal apertures in a non-specialized mammal such as the rat do not differ from those in higher primates.     

The start of the birch pollen season in Finnish Lapland: separating non‐local from local birch pollen and the implication for allergy sufferers

Determining the start of the birch pollen season requires the reliable separation of non‐local from locally produced birch pollen. The research was undertaken close to the latitudinal birch tree line at the Kevo Subarctic Research Institute (69°45′N 27°01′E) in northern Finland. By comparing phenological and aerobiological observations, the proportion of birch pollen present in the air before local anthesis commences can be delimited. We coupled this with data of pollen deposition monitored by means of a modified Tauber trap. The dominant birch species at Kevo is the mountain birch Betula pubescens ssp. czerepanovii, whereas B. pubescens ssp. pubescens is very rare, hence we consider the proportion of the southerly B. pubescens‐type pollen deposited in the pollen trap to be non‐local in origin.

We did not observe any trend towards an earlier start of the phenologically observed mountain birch anthesis at Kevo as predicted from work elsewhere. Moreover, the fixed 2.5% threshold method for determining the birch pollen season proved not to be applicable since in many years this threshold was reached before the end of continuous snow cover. The results indicate that in some years non‐local birch pollen contributes considerably to the allergen load in Lapland with up to 57% of the total birch pollen sum being recorded before the day on which local anthesis commenced, and up to 70% of the annual birch pollen deposited being of the southerly birch type.