Population genetics of Galápagos land iguana (genus Conolophus) remnant populations

The Galápagos land iguanas (genus Conolophus) have faced significant anthropogenic disturbances since the 17th century, leading to severe reduction of some populations and the extinction of others. Conservation activities, including the repatriation of captive‐bred animals to depleted areas, have been ongoing since the late 1970s, but genetic information has not been extensively incorporated. Here we use nine species‐specific microsatellite loci of 703 land iguanas from the six islands where the species occur today to characterize the genetic diversity within, and the levels of genetic differentiation among, current populations as well as test previous hypotheses about accidental translocations associated with early conservation efforts. Our analyses indicate that (i) five populations of iguanas represent distinct conservation units (one of them being the recently discovered rosada form) and could warrant species status, (ii) some individuals from North Seymour previously assumed to be from the natural Baltra population appear related to both Isabela and Santa Cruz populations, and (iii) the five different management units exhibit considerably different levels of intrapopulation genetic diversity, with the Plaza Sur and Santa Fe populations particularly low. Although the initial captive breeding programmes, coupled with intensive efforts to eradicate introduced species, saved several land iguana populations from extinction, our molecular results provide objective data for improving continuing in situ species survival plans and population management for this spectacular and emblematic reptile.     

Isolation and characterization of microsatellite DNA loci from the golden cuttlefish,Sepia esculenta Hoyle (Cephalopoda)

The first microsatellite markers were isolated from the golden cuttlefish, Sepia esculenta Hoyle. Eleven primer sets were designed to amplify the marker sequences via polymerase chain reaction. The 45–50 individuals from one wild population in the coastal waters of Ehime Prefecture, Japan were used to screen polymorphism in the 11 microsatellite loci. All the microsatellite loci were polymorphic, with the range of alleles from seven to 27 per locus. The observed and expected heterozygosities ranged from 0.380 to 0.980 and from 0.654 to 0.940, respectively. These marker loci except for one locus showing significant deviation from Hardy–Weinberg equilibrium will be useful for the assessment of genetic variation and population structure of this species.     

The influence of time and temperature on molecular gut content analysis： Adalia bipunctata fed with Rhopalosiphum padi

Gut content analysis is a useful tool when studying arthropod predator-prey interactions. We used polymerase chain reaction （PCR） technique to examine how detection of prey DNA in the gut content of predators was influenced by digestion time and temperature. Such knowledge is critical before applying PCR-based gut content analysis to field collected predators. Larvae of the two-spotted ladybeetle （Adalia bipunctata L.） were fed with the bird cherry-oat aphid （Rhopalosiphum padi L.） at either 21℃ or 14℃. After consuming one aphid, the predators were allowed to digest the prey for a range of time periods up to 24 hours. The influence of temperature on A. bipunctata feeding behavior was also recorded. From the fed larvae, total DNA was extracted and PCR reactions with R. padi specific primers were run. The number ofA. bipunctata that tested positive for R. padi DNA was negatively related to the length of digestion time. Temperature influenced larval feeding behavior but did not have a significant effect on R. padi DNA detection. After pooling the data from both temperature treatments we estimated the time point when R. padi DNA could be amplified from 50% of the fed A. bipunctata by PCR to be 4.87 hours. With such a rapid decrease in prey DNA detection success, positive PCR reactions will most likely be the result of predation events occurring shortly before capture. If a defined digestion temperature range has proven not to influence prey detection, PCR data obtained from predators collected within that particular range can be interpreted in the same way.     

Photosynthetic activities of cadmium-treated tomato plants

Tomato plants (Lycopersicum esculentum Mill. cv. Moneymaker) grown on nutrient medium containing cadmium exhibit reduced net photosynthesis and reduced contents of chlorophyll and accessory pigments. In chloroplasts isolated from cadmiumtreated plants photosystem II activity, as measured by 2,6-dichlorophenolindophenol photoreduction, and photosystem II + I activity (H₂O → methyl viologen) were both inhibited to about 60%. When 1,5-diphenylcarbazide was used as artificial electron donor, no significant cadmium effect was observed. Photosystem I activity was not affected by cadmium. The fine structure of chloroplasts in cadmium-treated plants was degenerated, similarly to senescence response. The principal symptom of cadmium action was the occurrence of large plastoglobules and a disorganization of the lamellar structure, mainly grana stacks. Transfer of cadmium-treated plants into a medium with increased manganese level caused grana stacking and restoration of photosystem II activity.     

LACTOBACILLI AND SILAGE-MAKING

SUMMARY: An examination of green crops has indicated that the counts of lactobacilli may not always be sufficiently high to ensure preservation when the fodder is made into silage.     

Adverse Effects of Capture and Handling Little Bustard

Abstract Capturing wild animals for research or conservation purposes may cause some adverse effects, which is only acceptable if these are outweighed by conservation benefits. We used information from 3 on-going telemetry studies on the endangered little bustard (Tetrax tetrax) in Western Europe to evaluate the risk factors associated with capture and handling. Of 151 telemetered birds, 23 (15.2%) exhibited impaired mobility and coordination after release, probably related to the occurrence of capture myopathy. Among the 23 impaired birds, 10 (43.5%) died before recovering normal mobility (6.6% of all birds captured). Logistic regression analyses identified longer handling time, longer restraint time, use of cannon nets, and capture of juveniles as inducing factors for these disorders. We conclude that little bustard is fairly susceptible to suffering ataxia and paresia after release as a result of restraint associated with capture and manipulation. Researchers can reduce this risk by keeping handling and restraint time below 10–20 minutes, particularly when using cannon nets or when capturing juveniles.     

Pathogenicity of Fusarium oxysporum to Easter lily, narcissus and gladiolus

Isolates of Fusarium oxysporum from roots, bulbs and stems of Easter lilies (Lilium longiflorum) differed widely in pathogenicity and also, apparently, in tissue specificity. Virulent isolates caused a typical basal rot and root rot (but not a wilt) in which the mycelium advanced intercellularly through the scales and basal plates. Mildly pathogenic isolates became established in mature or senescent outer scales, at first producing only superficial effects, but further growth of mycelium occurred as the outer scales died and sometimes continued until the dead tissues were permeated and chlamydospores were formed. The underlying scales were then colonized. The modes of pathogenicity and survival in Easter lily were compared with those of the F. oxysporum formae causing bulb rots of gladiolus and narcissus. It is suggested that advance of hyphae by penetration between the cells of the vascular parenchyma, which is common in isolates causing rots in bulbs and corms, represents a stage in the evolution of the truly vascular habit among fusaria.