The Pool Size of Protochlorophyllide during Different Stages of Greening of Dark Grown Wheat Leaves

The pool size of protochlorophyllide in wheat leaves irradiated for 5 minutes to 6 hours was studied. Protochlorophyllide then accumulated in the dark, but the pool size of regenerated protochlorophyllide was considerably smaller in leaves irradiated for six hours than in leaves irradiated for 5 minutes. The decrease in pool size of regenerated protochlorophyllide was found to take place at the time when the chlorophyll formation had accelerated and reached the linear phase. The protochlorophyllide accumulated is the form with absorption maximum at 650 nm, which is phototransformed to chlorophyllide with maximum absorption at 684 nm. This species goes through the Shibata shift when formed even after 6 hours of irradiation. If leaves, irradiated for 1 or 6 hours, were fed with δ-amino-levulinic acid the protochlorophyllide synthesis was only 1.2 times faster in the leaves irradiated for 6 hours than in those irradiated for 1 hour. In the case of leaves fed with δ-amino-levulinic acid the absorption maximum of protochlorophyllide is at 636 nm and the absorption maximum of the chlorophyllide formed is at 672 nm.     

Spectral properties of a long-wavelength absorbing form of protochlorophyll in seeds of Cyclanthera explodens

The in vivo absorbance spectrum of the inner seed coat of Cyclanthera explodens Naud. showed a main peak in the red region at 671 nm and a weak shoulder at about 640 nm. The pigments were extracted with acetone. separated by paper chromatography and analysed spectrophotometrically. The only detectable pigment was protochlorophyll. The in vivo fluorsecence emission spectra had two main peaks, one at 632 and one at 691 nm. The relation between the two peaks was changed when the exvcitation wavelength was altered from 440 to 460 nm. Excitation at 420 nm gave an additional fluorescence emission peak at 595 nm. These data indicate the presence of at least three forms of protochlorophyll in the Cyclantera seed coat. The spectrum of circular dichroism had a very intence and characteristic signal in the red region with a negative asymmetrical Cotton effect (664 (+), 669 (0) and 687 (?) nm). This indicates that at least one of the protochlorophyll forms is present in a more or less crystalline form.     

Very long diapause and extreme resistance to population disturbance in a galling insect

1. Some insects have a prolonged diapause – a dormancy that extends over more than 1 year. In most species prolonged diapause involves one or a few extra years, but in extreme cases diapause may surpass 10 years. Few cases of very long diapause have been described, and very little is known about the population consequences of the temporal refuge formed by the diapausing individuals. 2. The gall midge Contarinia vincetoxici Kieffer galls the flowers of a long‐lived herb Vincetoxicum hirundinaria Med. After completing development, larvae leave the galls for the ground where they enter diapause. Extending an earlier published inoculation experiment, we show that the diapause may last up to at least 13 years, with a median duration of at least 6 years. 3. The gall midge is attacked by two parasitoid species. Dissections of gall midge larvae for presence of parasitoids revealed that Omphale salicis Haliday had a maximum 2 year diapause and Synopeas acuminatus Kieffer a maximum 4 years. The very long diapause of the gall midge may thus provide a temporal refuge from these enemies. 4. In a 15‐year field experiment all galls were removed every year from six isolated habitat patches. Density changes in experimental populations were not statistically different from control populations for over a decade. After 14–15 years a modest decline could be observed. This slow response illustrates that prolonged diapause in C. vincetoxici provides a very strong population buffer against mortality during the galling stage.     

Seasonal development and variation in abundance among four annual flight periods in a butterfly: a 20‐year study of the speckled wood (Pararge aegeria)

Insects typically spend the winter in a species‐specific diapause stage. The speckled wood butterfly, Pararge aegeria, is unique in having two alternative diapause stages, hibernating as larvae or pupae. In southern Sweden this creates a seasonal flight pattern with four annual adult flight periods: the first in May (pupal diapause), the second in June (larval diapause), and the third and fourth directly developing offspring generations in July and August, respectively. We address the raison d'être of the two diapause pathways by (1) outdoor rearing of cohorts, and (2) performing transect censuses throughout the season for 20 years. We contend that an early start of next season provides a benefit accruing to pupal diapause; conversely, a large proportion of the offspring from adults of the fourth flight peak are unable to reach the pupal stage before winter, providing a benefit accruing to larval winter diapause. The results obtained show that the two hibernation pathways are unlikely to be genetically distinct because of a strong overlap between the two offspring generations, and because sibling offspring from the third and fourth flight periods are likely to choose either of the two hibernation pathways, thereby resulting in a genetic mixing of the pathways. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 635–649.     

Taxonomic Revision of the Marine Genus Heterodrilus Pierantoni (Oligochaeta,Tubificidae)1

Marine tubificids possessing trifid anterior setae are morphologically and taxonomically reviewed, on the basis of material from the Atlantic and Pacific Oceans. Heterodrilus Pierantoni, 1902 is revised to include thirteen species, H. arenicolus Pierantoni, 1902, H. minisetosus sp.n.H. ascensionensis sp.n. H. queenslandicus (Jamieson, 1977), H. lacertosus sp.n. H. scitus sp.n. H. keenani sp.n. H. claviatriatus sp.n. H. subtilis (Pierantoni, 1917), H. jamiesoni sp.n. H. occidentalis sp.n. H. pentcheffi sp.n. and H. bulbiporus sp.n. The genus is briefly defined: marine tubificids with trifid setae in preclitellar segments (with H. subtilis as the only exception); paired spermathecae located in segment X; vasa deferentia entering apical, ental ends of slender, ciliated atria, which bear broadly attached masses of prostate glands; paired male pores, and generally with penial setae arranged in bisetal bundles. Heterodriloides gen.n. is established for H. quadrithecatus sp.n. distinguished from Heterodrilus by two main features: its spermathecae are located in XII, with a supplementary pair generally located in XI; and its vasa enter the ectal part of the atria. Giereidrilus gen.n. a third genus with trifid setae, is established to include Phallodrilus ersei Giere, 1979 and G. inermis sp.n. Both species have unpaired spermathecal and male pores, and their atria are not ciliated. Heterodrilus, Heterodriloides and Giereidrilus are placed in the subfamily Rhyacodrilinae Hrabě, 1963.     

New and Little-Known Species of Deep-sea Tubificidae (Oligochaeta) from the North-West Atlantic

Eight species of Tubificidae are reported from deep-sea samples taken south of Massachusetts. Phallodrilus grasslei sp. n., with heavily muscular vasa deferentia, and penial setae, two per bundle, oriented with ectal ends obliquely pointing towards the anterior, and P. rostratus sp. n., with a long and narrow, snout-like prostomium, heavily muscular, tripartite atria, and small, hooked penial setae, about five per bundle, are described. Phallodrilus biparis Erséus, previously known only from off France in the north-east Atlantic, is reported and depicted. Taxonomic notes are provided for Adelodrilus voraginus (Cook), A. fimbriatus Erséus, Bathydrilus asymmetricus Cook, and B. atlanticus Erséus. The depth distribution of all eleven deep-sea tubificid species known to occur south of Massachusetts are briefly discussed.     

The genus Rhanterium (Asteraceae: Inuleae)

WIKLUND, A., 1986. The genus Rhanterium (Aateraceae: Inuleae) . This revision of the genus Rhanterium Desf. of the /nu/a-group in the Asteraceae: Inuleae, subtribe Inulinae, is based on studies of herbarium material. The genus is distributed over western North Africa, the Arabian peninsula, Iraq and Iran. Three species are recognized: R. adpressum Coss. & Durieu, R. epapposum Oliver and R. suaveolens Desf. A fourth previously accepted species, R. intermedium Coss. & Durieu ex Pomel, is here considered to be composed of hybrids between R. adpressum and R. suaveolens. A laxonomical recognition of these hybrids is not found to be justified. The morphology, phylogeny and phytogeography of the species are discussed and a cladogram of the genus is proposed.