Deadwood Structural Properties May Influence Aye-Aye (<Emphasis Type="Italic">Daubentonia madagascariensis</Emphasis>) Extractive Foraging Behavior

The identification of critical, limited natural resources for different primate species is important for advancing our understanding of behavioral ecology and toward future conservation efforts. The aye-aye (Daubentonia madagascariensis) is an Endangered nocturnal lemur with adaptations for accessing structurally defended foods: continuously growing incisors; an elongated, flexible middle finger; and a specialized auditory system. In some seasons, ca. 90% of the aye-aye’s diet consists of two structurally defended resources: 1) the larvae of wood boring insects, extracted after the aye-aye gnaws through decomposing bark (deadwood), and 2) the seeds of Canarium trees. Aye-ayes have very large individual home ranges relative to most other lemurs, possibly owing to limited resource availability. Identification of limiting dietary factor(s) is critical for our understanding of aye-aye behavioral ecology and future conservation efforts. To investigate whether aye-ayes equally access all deadwood resources within their range, we surveyed two 100 × 100 m forest plots within the territories of two aye-ayes at Sangasanga, Kianjavato, Madagascar. Only 2 of 150 deadwood specimens within the plots (1.3%) appeared to have been accessed by the aye-ayes. To test whether any external or internal deadwood properties explain aye-aye foraging preferences we recorded species, height and diameter, and quantified the internal tree density using a 3D acoustic tomograph for each foraged and nonforaged deadwood resource within the plots, plus 13 specimens (5 foraged and 8 nonforaged) outside the plots. We did not detect any statistically significant preferences for species, diameter, or height. However, results from the acoustic analysis tentatively indicated that aye-ayes are more likely to forage in trees with greater internal (≥6 cm from the bark) densities. This interior region may function as a sounding board in the tap-foraging process to help aye-ayes accurately identify potential grub-containing cavities in the outer 1–4 cm of deadwood.     

Two-tier vessel for photoautotrophic high-density cultures

Two-tier vessels, developed for culturing of microalgae and cyanobacteria at high cell density on a shaken platform, were assembled from a flat lower chamber to be filled with a CO₂ buffer and an upper flat sterile chamber for the culture that was separated from the lower chamber by a porous polypropylene membrane. Diffusive gas exchange with the atmosphere was controlled by the O₂ outlet channel. Referred to surface area, rates of CO₂ transfer to a shaken weakly alkaline buffer solution across the membrane were higher than those reached on the conventional pathway through the free upper liquid surface. Membrane-mediated CO₂ supply enabled rapid growth of Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7002 up to ultrahigh cell density. The biomass (dry weight) concentration of Synechococcus cultures reached more than 30 g L^?1 on a buffered medium with adequate concentrations of mineral nutrients. An increase of 15 to 20 g L^?1 was observed during repeated two-day cycles. Separate pathways for CO₂ supply and oxygen outlet prevented significant loss of CO₂. Convective gas flow through the oxygen outlet channel enabled the estimation of the O₂ generation rate. The permeability of the channel for diffusive O₂/N₂ exchange limited the O₂ concentration to a moderate value. It is concluded that shaken flat cultures using CO₂ supply through a porous hydrophobic membrane and diffusive release of O₂ through a separate pathway are promising for research on microalgae and cyanobacteria.     

Improving of lipid productivity of the biodiesel promising green microalga <Emphasis Type="Italic">Chlorella pyrenoidosa</Emphasis> via low-energy ion implantation

High lipid content in microalgae is an essential parameter for adopting of microalgal biomass as a feedstock for biodiesel. Mutation is one approach to obtain desired algal strain with high lipid production. In this study, a mutant strain of Chlorella pyrenoidosa was isolated using 1.5?×?10¹⁵ ions cm^?2 s^?1 of N⁺ ion beam implantation technique, which has been widely used in mutagenesis of agricultural crops. N⁺ implantation slightly improved the growth of the mutant over the corresponding wild strain with significant increase in lipid content (32.4 % higher than the wild strain), which resulted in significant increase in lipid productivity by 35 %. In addition, ion implantation mutagenesis of C. pyrenoidosa resulted in 21.4 % decrease in total saturated fatty acids (SFAs) compared to the wild type, with a noticeable increase in polyunsaturated fatty acids (PUFAs). The increase in PUFAs was due mainly to stimulation of hexadecadienoic acid (C16:2) and octadecadienoic acid (C18:2) production. However, the SFA content of wild and mutant strains was 31.7 and 24.9 % of total fatty acids, respectively, highlighting the oxidative stability of biodiesel produced by both strains according to the European standards. Cultivation of C. pyrenoidosa mutant in selenite enrichment medium for five successive cultivation experiments showed insignificant changes in biomass productivity, lipid content, and lipid productivity alongside the study period, which confirms the genetic stability of the produced mutant. The present study confirmed the feasibility of generation of microalgae mutants with significant high lipid production using ion beam implantation.     

Influence of Nematode Parasitism,Body Size,Temperature, and Diel Period on the Flight Capacity of <Emphasis Type="Italic">Sirex noctilio</Emphasis> F. (Hymenoptera: Siricidae)

Sirex noctilio F. (Hymenoptera: Siricidae) is a woodwasp of pine trees that has recently invaded and established in North American forests. Although S. noctilio has had a limited impact in North America to date, there is some concern that it could have a significant impact on pine plantations, especially in the southeastern U.S.A. Moreover, there are few data on the flight capacity of male S. noctilio. We found no association between parasitism by D. siricidicola and whether or not S. noctilio initiated flight on the flight mill. Male wasps that were parasitized by nematodes were heavier than non-parasitized males, but there was no significant difference in mass between parasitized and non-parasitized females. We also examined the flight capacity of male and female S. noctilio in relation to nematode parasitism, body mass, temperature (for only males), and diel period. Body mass, temperature, and diel period affected flight in S. noctilio such that wasps were generally observed to fly faster, farther, and more frequently if they were heavier, flying at warmer temperatures, and flying during the photoperiod. The fact that nematode-parasitized male wasps were found to fly farther than the non-parasitized males is consistent with the hypothesis that nematode parasitism does not negatively affect the flight capacity of S. noctilio.     

Identifying <Emphasis Type="Italic">FATB1a</Emphasis> deletion that causes reduced palmitic acid content in soybean N87-2122-4 to develop a functional marker for marker-assisted selection

Palmitic acid is a major saturated fatty acid in soybean oil, and consumption of saturated fat is linked to a risk of coronary diseases. Development of soybean (Glycine max) cultivars with reduced palmitic acid content is an important goal of soybean breeding. The FATB1a gene was previously found to be responsible for reduced palmitic acid in the soybean line N87-2122-4. The objective of this research was to characterize the FATB1a gene identified in N87-2122-4 and develop a breeder-friendly, functional marker to facilitate marker-assisted selection and improve breeding efficiency for reduced palmitic soybeans. With the availability of soybean genetic maps, reference genome, and gene annotations, an approximate 254 kb deleted genomic region, including the FATB1a gene, was identified. Based on the gene deletion information, we developed a TaqMan marker and tested it with a segregating F ₂ population that consisted of 140 individual plants derived from ‘Cook’ × N87-2122-4. The marker performed well and accounted for 57 % of the phenotypic variation. The marker was also validated using a panel of 121 diverse soybean lines with known fatty acid profiles. The result indicated that the marker can be used effectively in marker-assisted breeding for reduced palmitic acid in soybean.     

Overexpression of <Emphasis Type="Italic">MuHSP70</Emphasis> gene from <Emphasis Type="Italic">Macrotyloma uniflorum</Emphasis> confers multiple abiotic stress tolerance in transgenic <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

A 70-KD heat shock protein (HSP70) is one of the most conserved chaperones. It is involved in de novo protein folding and prevents the aggregation of unfolded proteins under lethal environmental factors. The purpose of this study is to characterise a MuHSP70 from horsegram (Macrotyloma uniflorum) and elucidating its role in stress tolerance of plants. A MuHSP70 was cloned and characterised from a natural drought stress tolerant HPK4 variety of horsegram (M. uniflorum). For functional characterization, MuHSP70 was overexpressed in transgenic Arabidopsis. Overexpression of MuHSP70 was found to provide tolerance to the transgenic Arabidopsis against various stresses such as heat, cold, drought, salinity and oxidative stress. MuHSP70 transgenics were observed to maintain the shoot biomass, root length, relative water content, and chlorophyll content during exposure to multi-stresses relative to non-transgenic control. Transgenic lines have further shown the reduced levels of MDA, H₂O₂, and proteolytic activity. Together, these findings suggest that overexpression of MuHSP70 plays an important role in improving abiotic stress tolerance and could be a crucial candidate gene for exploration in crop improvement program.     

Genetics of frost hardiness in <Emphasis Type="Italic">Juglans regia</Emphasis> L. and relationship with growth and phenology

The growing interest in broadleaf timber plantations in the Mediterranean area has promoted several studies focusing on the identification and characterization of variability sources in main timber-producing species. J. regia is one of these species, well-adapted to this area, but with freezing, damages registrations. Breeding focused on productive traits should include knowledge of adaptation, required to obtain a good selection capable of producing a suitable turnover in timber plantations. In this study, the features evaluated were autumn and winter frost hardiness and some vegetative traits on 22 half-sib J. regia progenies. Budsticks were exposed to sub-zero temperatures in a controlled chamber and using measurements of relative electrolyte content, the LT50 values (°C) were calculated by each individual. The study was carried out on seven-year-old progenies. The familiar heritability of autumn frost hardiness was 0.68, and on winter, it was 0.77. The autumn frost behaviour correlated genetically with the length of the growing season (0.574 ± 0.351), and both autumn and winter frost hardiness correlated inversely with secondary annual growth measured at breast height (?0.654 ± 0.259 and ?0.740 ± 0.227, respectively). These results pointed that growth could therefore be improved without increasing the frost vulnerability. This should be important for growers, particularly under climate change conditions.