Microsatellite loci from the Caribbean Fruit Fly,Anastrepha suspensa (Diptera: Tephritidae)

The lack of polymorphic genetic markers suitable for genotyping sperm, eggs, and all life stages of the important agricultural pest, Anastrepha suspensa, have prevented detailed genetic studies of its breeding system, reproductive dynamics, and population dynamics. We describe polymerase chain reaction (PCR) primers and reaction conditions for amplifying nine polymorphic microsatellite DNA loci isolated from this species. The PCR primers were tested on four to five individuals each collected from five geographically distant locations in Florida. Heterozygosity values and the number of alleles per locus varied from 0.11 to 0.89, and from two to 12, respectively.     

Analysis of Genetic Diversity at the arom Locus in Isolates of Pneumocystis carinii

ABSTRACT. The DNA sequences of a portion of the 5-enolpyruvyl shikimate phosphate synthase domain of the arom gene, encoding the pentafunctional AROM protein, were determined from isolates of Pneumocystis carinii from five mammalian host species (rat, human, ferret, rabbit and mouse). High levels of genetic divergence were found among P. carinii derived from different hosts species, 7–22% at the DNA sequence level, and 7–26% at the derived amino acid sequence level. Two separate and distinct sequences were isolated from infected ferret lungs. Low levels of divergence were seen in human-derived organisms.     

A behavioural syndrome in the field cricket Gryllus integer: intrasexual aggression is correlated with activity in a novel environment

Behavioural syndromes, or suites of correlated behaviours across different contexts and situations, have recently drawn attention from evolutionary biologists. In the field cricket Gryllus integer , males are aggressive with one another and fight vigorously over females and territories. We examined whether aggressiveness with other males was correlated with activity in a potentially dangerous context (a novel environment) in laboratory-raised virgin males. Aggressiveness was measured as fighting ability against a weight-matched opponent. First, we measured each cricket's latency to become active in a novel environment and latency to emerge from a refuge within a novel environment. Next, we determined which of two weight-matched males was more aggressive, by pitting the males together in an agonistic contest and counting the number of fights won by each male. More aggressive males, who won more fights, had shorter latencies to become active when placed in a novel environment and shorter latencies to emerge from a safe refuge. These results suggest that a behavioural syndrome exists in G. integer , in which more aggressive males are also more active in general, and possibly less cautious towards predation risk.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 475–482.     

The Relation of Migration of Oncopeltus fasciatus to Distribution of Phytomonas elmassiani in the Eastern United States*

SYNOPSIS. A total of 4,866 plants belonging to the family Asclepiadaceae was examined in the eastern part of the United States; 291 (6%) of 11 species naturally infected with Phytomonas elmassiani; 9 of these were new host records. Eight of the 9 infected species belonged to the genus Asclepias, one to Cynanchum. Infections were recorded between 25.5° and 41.0° N latitude, and from 74.0° to 90.5° west longitude. At the southernmost latitude Asclepias curassavica, an exotic annual, perennates, harbors phytomonads and is infested the year round with Oncopeltus. Usually but not always infection is correlated with the presence and abundance of insect vectors. The annual die-back of the usually infected perennial plant hosts, the uninfected emerging vernal growth, the reservoir nidus of infected plants in the southern latitudes, and the known proclivity of O. fasciatus to migrate suggest the spread of flagellosis of Asclepiadaceae thru migration of the vector hemipteron.     

Effects of some surfactant fungicides on Rhizobium trtfolii and its symbiotic relationship with white clover

Effects of the surfactant apple mildew eradicants Manoxol OT, Alk 3, Triton X45, PP 222, Ethylan CP, Hyamine 3500, Aromox DMMCDW and Aromox C12W on growth and respiration of R. trifolii in vitro and on its symbiotic nitrogen fixation in association with white clover were measured. Most treatments reduced growth up to 8 wk; after 12 wk plant weight and nitrogenase activity were significantly reduced (P = 0.01) by Triton X45, Manoxol OT and PP 222 at concentrations of 1000, 2500 and 5000 μg/gram of soil respectively. Electron microscopy showed that bacteroids in root nodules where nitrogen fixation was inhibited had contracted away from the host membrane leaving an intracellular space. Damage to the bacteroid membrane was apparent. Surfactants had no demonstrable effect on adhesion of the bacteria to root hairs. In apple orchards run-off of surfactant fungicides, applied to apple trees at the recommended rates is unlikely to have adverse effects on Rhizobium nodulated white clover.     

The Effects of Light Intensity and Sucrose on Root Formation, Photosynthetic Ability, and Senescence in Detached Cotyledons of Sinapis alba L. and Raphanus sativus L.

The ability of detached cotyledons cultured in the light toassimilate ¹⁴CO₂, was reduced by the presence of sucrose inthe culture medium. This was due, at least in part, to an increasedrate of chlorophyll loss and yellowing of the blade. When cotyledondiscs were used, the inhibition of ¹⁴Carbon fixation by sucrosewas even more marked than in entire cotyledons. This could bedue to a higher level of penetration of the sucrose into discsor to the absence of the petiole which normally accumulatesphotosynthetic products. Sucrose culture also inhibited root production in cotyledonscultured in the light but promoted root formation in dark-grownor DCMU-treated cotyledons. The DCMU-inhibition of ¹⁴Carbonfixation by the blades was alleviated to some extent by sucroseculture. The sucrose effect on rooting was not permanent inthat transfer into water from sucrose led to root formationalthough this was delayed and present in a lower proportionof cotyledons than the controls. Thus, although a carbohydrate source either from photosynthesisor as applied sucrose, is essential for root production to takeplace, the combination of culture in the light with the presenceof sucrose in the medium may lead to an accumulation of carbohydrateto a level which directly or indirectly increases blade yellowingand inhibits root production.