Survival of Strains of Soft Rot Coliform Bacteria on Microthreads Exposed in the Laboratory and in the Open Air

Survival of 5 strains of the plant pathogen, Erwinia carotovora var. atroseptica and 3 strains of the plant pathogen E. carotovora var. carotovora , grown in a liquid tryptone medium and held as 'captive'aerosols on gossamer microthreads, was determined under different atmospheric conditions in a controlled environment room and in the open air. Although these bacteria lost viability more quickly than a robust reference strain of Escherichia coli , sufficient numbers survived for 15 min or more to indicate that airborne spread of viable propagules could take place, especially under cool humid atmospheric conditions. Cells of one strain of each organism extracted from rotted potato tuber tissue were shown to behave rather like those cultured in the tryptone medium.     

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.     

Development and optimization of microsatellite DNA primers for boreal owls (Aegolius funereus)

We developed 22 microsatellite loci for boreal owls (Aegolius funereus). We genotyped 275 unrelated boreal owls (Aegolius f. richardsoni) and 36 unrelated Tengmalm's owls (Aegolius f. funereus) using seven loci that were polymorphic and did not have detectable null alleles. Among North American and Scandinavian boreal owls, respectively, allelic diversity ranged from three to 11 alleles and from one to 11 alleles, observed heterozygosity ranged from 0.31 to 0.80 and from 0.00 to 0.81, and expected heterozygosity ranged from 0.28 to 0.81 and from 0.00 to 0.81. These markers appeared to amplify DNA in six other Strigidae species.     

Fourteen polymorphic microsatellite loci characterized in the house sparrow Passer domesticus (Passeridae,Aves)

We characterized 14 polymorphic microsatellite loci in the house sparrow Passer domesticus. Four loci were isolated from house sparrow genomic libraries and 10 loci were identified by testing 100 loci that had been originally isolated in other passerine species. Loci were characterized in 37–54 unrelated sparrows from British and Norwegian populations. Each locus displayed between two and 31 alleles, with the observed heterozygosity ranging between 0.30 and 0.91.     

Nitrogen Deficiency Slows Leaf Development and Delays Flowering in Narrow-leafed Lupin

Effects of nitrogen (N) supply on leaf and flower developmentinLupinus angustifolius L. cv Merrit were examined in a temperature-controlledglasshouse. Low N supply (0.05 or 0.4 mM N) had little effecton leaf initiation but slowed leaf emergence on the main stemcompared with plants receiving high N supply (6.0 or 6.4 mMN), or with symbiotic N₂-fixation. Plants experiencing transientN deficiency had slower leaf emergence than plants with a continuoussupply of 6.4 mM N. Nitrogen supply did not affect the timeof floral initiation, which occurred within 4 weeks of sowing,by which time nine to ten leaves had emerged. However, the floweringof low-N plants was delayed by 68 to 220 °C d (i.e. 4–14d) even though they had fewer leaves. The effect of N deficiencyon flowering time was largely a result of slower leaf emergence. Lupinus angustifolius L.; nitrogen; leaf; flower initiation; thermal time; plastochron; phyllochron     

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.     

Stress Proteins in Mammalian Hibernation

Many organisms whose body temperatures (T_b) vary when they areexposed to a wide range of environmental temperatures exhibitdifferential expression of stress (heat shock) proteins, presumablyto minimize protein damage during thermal stress. In contrast,we know relatively little about natural variation in stressproteins in homeotherms (i.e., birds and mammals), perhaps dueto the relatively constant T_b that is the hallmark of this vertebrategroup. The significant changes in T_b and metabolism characteristicof mammalian hibernators suggest they could provide insightinto the ecological relevance of stress proteins in mammals.Here we examined differential expression of stress proteinsin several tissues of active and torpid 13-lined ground squirrels.There were few significant differences in expression of inducibleHsp70 protein in liver, kidney, heart, intestine, and skeletalmuscle between active and torpid squirrels, and neither fastingin active squirrels nor torpor bout length in hibernators significantlyaltered Hsp70 abundance in these tissues. However, Hsp70 proteinwas lower in brown adipose tissue (BAT) of torpid compared withactive squirrels. In contrast, abundance of GRP75, the mitochondria]form of Hsp70, was greater in liver, skeletal muscle and intestineof torpid compared with active squirrels, with the greatestchange in intestine. Because GRP75 has been shown to be inducedby non-thermal stressors including glucose deprivation and oxidativestress, these results suggest that the ecological significanceof stress proteins for hibernators may be more closely associatedwith the metabolic demands of heterothermy rather than thermalstress per se.     

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.