Partial self-compatibility in ‘Tombul’ and ‘Montebello’ hazelnuts

Summary Self-pollination of hazelnut (Corylus avellana L.) cultivars in 1988 and 1990 revealed the existence of partial self-compatibility in Tombul and Montebello. Percent cluster set in these cultivars averaged 44 and 20%, respectively, but was less than 10% in 8 other cultivars investigated. Percent cluster set from pollination with Segorbe averaged 62 and 41% in 1988 and 1990, respectively. Self-pollination produced 40% fewer nuts per cluster and twice as many blanks as cross-pollination. All cultivars and selections have an active sporophytic incompatibility system.Evaluation of self-compatibility in seedlings from the cross Montebello × Compton revealed that the partial self-compatibility of the maternal parent was transmitted to some of the progeny. Self-pollination resulted in greater than 10% cluster set in two selections, OSU 41.134 and OSU 43.025, in both years, but only in 1988 in OSU 42.089 and Willamette. Three other selections had very low set in both years. Results of incompatible crosses with standard testers were generally in agreement with those of self-pollination, except that the S₂ tester induced greater set on 3 genotypes in 1988 and the S1 tester on 2 genotypes in 1990 than self-pollination. The partial self-compatibility of Montebello, OSU 41.134, and OSU 43.025 appears to be due to a failure of their stigmas to prohibit pollen tube growth in incompatible crosses. There is no evidence of a pollen-part mutation in Montebello, nor is there evidence that partial self-compatibility is due to the interaction of S-alleles, as Barcelona, which has the same alleles as these three genotypes, failed to set nuts in all incompatible crosses.     

Singular and interactive effects of blowdown, salvage logging, and wildfire in sub-boreal pine systems

The role of disturbance in structuring vegetation is widely recognized; however, we are only beginning to understand the effects of multiple interacting disturbances on ecosystem recovery and development. Of particular interest is the impact of post-disturbance management interventions, particularly in light of the global controversy surrounding the effects of salvage logging on forest ecosystem recovery. Studies of salvage logging impacts have focused on the effects of post-disturbance salvage logging within the context of a single natural disturbance event. There have been no formal evaluations of how these effects may differ when followed in short sequence by a second, high severity natural disturbance. To evaluate the impact of this management practice within the context of multiple disturbances, we examined the structural and woody plant community responses of sub-boreal Pinus banksiana systems to a rapid sequence of disturbances. Specifically, we compared responses to Blowdown (B), Fire (F), Blowdown-Fire, and Blowdown-Salvage-Fire (BSF) and compared these to undisturbed control (C) stands. Comparisons between BF and BSF indicated that the primary effect of salvage logging was a decrease in the abundance of structural legacies, such as downed woody debris and snags. Both of these compound disturbance sequences (BF and BSF), resulted in similar woody plant communities, largely dominated by Populus tremuloides; however, there was greater homogeneity in community composition in salvage logged areas. Areas experiencing solely fire (F stands) were dominated by P. banksiana regeneration, and blowdown areas (B stands) were largely characterized by regeneration from shade tolerant conifer species. Our results suggest that salvage logging impacts on woody plant communities are diminished when followed by a second high severity disturbance; however, impacts on structural legacies persist. Provisions for the retention of snags, downed logs, and surviving trees as part of salvage logging operations will minimize these structural impacts and may allow for greater ecosystem recovery following these disturbance combinations.     

The chemical genomic portrait of yeast: uncovering a phenotype for all genes

Genetics aims to understand the relation between genotype and phenotype. However, because complete deletion of most yeast genes ( approximately 80%) has no obvious phenotypic consequence in rich medium, it is difficult to study their functions. To uncover phenotypes for this nonessential fraction of the genome, we performed 1144 chemical genomic assays on the yeast whole-genome heterozygous and homozygous deletion collections and quantified the growth fitness of each deletion strain in the presence of chemical or environmental stress conditions. We found that 97% of gene deletions exhibited a measurable growth phenotype, suggesting that nearly all genes are essential for optimal growth in at least one condition.     

A selective activity-dependent requirement for dynamin 1 in synaptic vesicle endocytosis

Dynamin 1 is a neuron-specific guanosine triphosphatase thought to be critically required for the fission reaction of synaptic vesicle endocytosis. Unexpectedly, mice lacking dynamin 1 were able to form functional synapses, even though their postnatal viability was limited. However, during spontaneous network activity, branched, tubular plasma membrane invaginations accumulated, capped by clathrin-coated pits, in synapses of dynamin 1-knockout mice. Synaptic vesicle endocytosis was severely impaired during strong exogenous stimulation but resumed efficiently when the stimulus was terminated. Thus, dynamin 1-independent mechanisms can support limited synaptic vesicle endocytosis, but dynamin 1 is needed during high levels of neuronal activity.     

The genomic sequence of the accidental pathogen Legionella pneumophila

We present the genomic sequence of Legionella pneumophila, the bacterial agent of Legionnaires' disease, a potentially fatal pneumonia acquired from aerosolized contaminated fresh water. The genome includes a 45-kilobase pair element that can exist in chromosomal and episomal forms, selective expansions of important gene families, genes for unexpected metabolic pathways, and previously unknown candidate virulence determinants. We highlight the genes that may account for Legionella's ability to survive in protozoa, mammalian macrophages, and inhospitable environmental niches and that may define new therapeutic targets.     

Shade coffee in Hawai‘i – Exploring some aspects of quality,growth, yield,and nutrition

In a harsh (Kunia) and an ideal (Kona) growing region of Hawai‘i, sun grown Coffea arabica L. was compared to coffee shaded with varying degrees of black and aluminized shade cloth, macadamia trees, and a novel, spray-on shade composed mostly of kaolin. Shading did not appreciably affect organoleptic quality. Shading resulted in statistically different yields in the macadamia (16% of sun) and kaolin (199% of sun) treatments in the second year compared to full sun treatments in their respective locations, although a negative, linear trend was observed with increased shading. The lack of significant differences in yields between the shade cloth and sun treatments was likely a result of large yield variation among replicates. Bean sizes differed little between shade treatments and the percentage of defects and broken beans were generally not significantly different among the treatments in Kunia. Kona bean sizes and characteristics were not different. Shading reduced surface leaf temperatures and increased specific leaf area but generally did not affect lateral nodal growth. Leaf nutrient concentration differed between treatments.     

Significant increases in pulping efficiency in C4H-F5H-transformed poplars: improved chemical savings and reduced environmental toxins

The gene encoding ferulate 5-hydroxylase (F5H) was overexpressed in poplar (Populus tremula x Populus alba) using the cinnamate-4-hydroxylase (C4H) promoter to drive expression specifically in cells involved in the lignin biosynthetic pathway and was shown to significantly alter the mole percentage of syringyl subunits in the lignin, as determined by thioacidolysis. Analysis of poplar transformed with a C4H-F5H construct demonstrated significant increases in chemical (kraft) pulping efficiency from greenhouse-grown trees. Compared to wild-type wood, decreases of 23 kappa units and increases of >20 ISO brightness units were observed in trees exhibiting high syringyl monomer concentrations. These changes were associated with no significant modification in total lignin content and no observed phenotypic differences. C4H-F5H-transformed trees could increase pulp throughputs at mills by >60% while concurrently decreasing chemicals employed during processing (chemical pulping and bleaching) and, consequently, the amount of deleterious byproducts released into the environment.     

Comparative Efficacy of Anesthetics for the Freshwater Prawn Macrobrachiurn rosenbergii

Abstract— The freshwater prawn Macrobrachiurn rosenbergii is a commercially important culture species in the South Central United States. Two major constraints in the commercial culture of the freshwater prawn in the U.S. are poor survival during live transportation of seed‐stock to growout ponds, and live transportation of pond harvested prawn to distant live markets due to the territorial and cannibalistic nature of prawn. The use of anesthetics could possibly improve transport survival; however, to date anesthetic agents have not been evaluated for use with prawn. Two trials were conducted with juvenile freshwater prawn to compare the efficacy of anesthetics commonly used on fish. The first trial was designed to identify the most promising candidates. In Study 1, tricaine methanesulfonate (MS‐222), 2‐phenoxyethanol, quinaldine sulfate (quinaldine), clove oil, and Aqui‐S^TM were evaluated at 25 and 100 mg/L for 1 h in three replicate 10‐L glass containers, containing five juvenile prawn each. Relative sedation level was determined every 3 min for 1 h, then recovery time and survival were measured. In Study 1, MS‐222 and 2‐phenoxyethanol were determined to be ineffective on prawn at all rates tested. Based on their performance in Study 1, quinaldine, clove oil, and AquiS^TM were evaluated at 100, 200, and 300 mg/L in Study 2. Observations were determined as in Study 1. Clove oil and Aqui‐S^TM induced anesthesia faster and at lower concentrations than quinaldine. At the highest treatment rate (300 mg/L) prawn suffered 60% mortality in the Aqui‐S^TM treatment, 13% mortality in the quinaldine treatment, and 0% mortality in the clove oil treatment and control following a 1‐h exposure to these concentrations. Based on these data, Aqui‐S^TM and clove oil applied at 100 mg/L may be suitable anesthetic treatments for prawn. Additional research is needed to determine optimal time and dose relationships to minimize stress during holding, handling, and transportation of prawn.