Differential Growth Inhibition of Diaporthe and Phomopsis Isolates by the Metabolic Activity of Five Actinomycetes

Fifty-five cultures derived from Diaporthe perithecia and Phomopsis pycnidia found on diverse host plant species collected at different times and sites in Vojvodina, Yugoslavia, showed distinguishing quantitative reactions to the fungistatic activity of five actinomycetes obtained as fortuitous laboratory contaminants coming from field material. Streptomyces albidoflavus , S. albus , S. diastaticus , Streptomyces sp., and Streptoverticillium sp. could be ranked by their growth-inhibitory potential, with S. albus showing the strongest, and Streptomyces sp. the lowest. The responses of the fungi varied depending on the tested actinomycetes, but two major groups could be distinguished: A, which encompased the isolates that were less affected by the proximity of the actinomycetes; and B, with those which exhibited high sensitivity in all the experiments. Group A was typically represented by Diaporthe arctii , Phomopsis longicolla, and the Phomopsis type-1 cultures from Xanthium italicum; group B was typically represented by Diaporthe/Phomopsis helianthi, Phomopsis type-2 cultures from X. italicum , and isolates from Lactuca serriola . The results obtained underscore the dissimilarities between D. arctii and D. helianthi , and corroborate the value of the physiological aspects of congeneric isolates in considering taxonomic problems in the coelomicete genus Phomopsis.     

Phomopsis (Diaporthe) Species as the Cause of Soybean Seed Decay in Korea

Soybeans are an important crop known to harbour a complex of Diaporthe and Phomopsis species. This complex has been reported to be involved in several soybean diseases, including Phomopsis seed decay. In this study, two species of Diaporthe/Phomopsis fungi from soybean plants were identified by morphological and molecular characterizations. Koch's postulates were confirmed by pathogenicity tests on hypocotyls of soybean seedlings. Phomopsis longicolla was found to be the most common and virulent pathogen to soybeans in Korea. Phomopsis sp., which was considered as a new soybean pathogen, might have been introduced from other plants given that similar strains of Phomopsis sp. have infected fruit trees in China, Japan and Portugal and vegetable plants in the United States.     

Cytoplasmic Incompatibility in Australian Populations of Drosophila Melanogaster

In Drosophila melanogaster, weak incompatibility in crosses between infected and uninfected strains is associated with a Wolbachia microorganism. Crosses between infected males and uninfected females show a reduction (15-30%) in egg hatch. Progeny tests indicated that the infection is widespread in Australian D. melanogaster populations and that populations are polymorphic for the presence of the infection. The infection status of 266 lines from 12 populations along the eastern coast of Australia was determined by 4',6-diamidino-2-phenylindole (DAPI) staining of embryos. All populations contained both infected and uninfected flies. Infection frequencies varied between populations but there was no discernible geographical pattern. Laboratory experiments indicated that the infection was not associated with a reduction in fecundity as in Drosophila simulans. Incompatibility levels could not be increased by laboratory selection on isofemale lines. Factors contributing to the persistence of the infection in D. melanogaster populations are discussed.     

Comparison of possible phytotoxic metabolites in culture filtrates of the Diaporthe/Phomopsis complex of soybeans

Filter-sterile culture filtrates of isolates of Diaporthe phaseolorum var. caulivora, Diaporthe phaseolorum var. sojae (anamorph Phomopsis sojae), and Phomopsis longicolla, causal agents of stem canker, pod and stem blight, and seed decay, respectively, on soybeans (Glycine max), grown on Czapek-Dox broth inhibited germination of soybean seeds (significant at P=0.05). Wilting and necrosis of excised soybean seedlings was significantly greater than the controls when treated with culture filtrates of P. longicolla and P. sojae. Soybean seedling radicle growth inhibited significantly when culture filtrates of P. longicolla were added.     

Risk Estimation of HNA-3 Incompatibility and Alloimmunization in Thai Populations

Severe transfusion-related acute lung injury (TRALI) is often due to antibodies in blood components directed against human neutrophil antigen (HNA)-3a. This study aimed to report the genotype frequencies of the HNA-3 system and to estimate the potential risk of HNA-3 incompatibility and alloimmunization in two Thai populations. Eight hundred DNA samples obtained from 500 unrelated healthy blood donors at the National Blood Centre, Thai Red Cross Society, Bangkok and 300 samples from the Blood Bank, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand were included. HNA-3 genotyping was performed using an in-house polymerase chain reaction with sequence-specific primer (PCR-SSP) technique. The observed frequencies of the HNA-3a/3a, HNA-3a/3b, and HNA-3b/3b genotypes were 0.528, 0.380, and 0.092 in central Thais and 0.600, 0.350, and 0.050 in northern Thais, respectively. The frequencies were used to estimate HNA-3 incompatibility and risk of HNA-3a alloimmunization. The HNA-3 incompatibility in central Thais (33.28%) was higher than northern Thais (28.75%), corresponding to a significantly higher probability of HNA-3a alloimmunization (P<0.05) similar to Japanese and Chinese populations. This study showed the high risk of HNA-3 incompatibility and alloimmunization, especially in central Thai blood donors. A molecular-based identification of the HNA-3 genotype of female donors is suggested to reduce the risk of TRALI following plasma and whole blood allogeneic transfusion.     

Primers for mating-type diagnosis in Diaporthe and Phomopsis: their use in teleomorph induction in vitro and biological species definition

Sexual reproduction in ascomycete fungi is governed by the mating-type (MAT) locus. The MAT loci of Diaporthe and its Phomopsis anamorphs differ in only one gene: MAT1-1-1 in mating-type MAT1-1 and MAT1-2-1 in mating-type MAT1-2. In order to diagnose mating-types in Diaporthe and Phomopsis and evaluate their usefulness in teleomorph induction in vitro and biological species delimitation, we designed primers that amplify part of the MAT1-1-1 and MAT1-2-1 genes. MAT phylogenies were generated and compared with ITS and EF1-α phylograms. Species recognised in the EF1-α phylogeny corresponded directly with those determined in the MAT phylogenies. ITS was shown to be highly variable resulting in a large number of phylogenetic species that were discordant with MAT and EF1-α species. Mating experiments were conducted to evaluate the existence of reproductive barriers between some isolates, and their anamorphic morphologies were compared. The primers proved to be useful in the mating-type diagnosis of isolates, selection of compatible mating pairs, and in the assessment of biological species boundaries.     

Dynamics of Cytoplasmic Incompatibility and Mtdna Variation in Natural Drosophila Simulans Populations

In Drosophila simulans a cytoplasmically transmitted microorganism causes reduced egg hatch when infected males mate with uninfected females. The infection is rapidly spreading northward in California. Data on a specific mtDNA restriction site length polymorphism show that changes in the frequency of mtDNA variants are associated with this spread. All infected flies possess the same mtDNA allele, whereas the uninfected flies are polymorphic. Given that both paternal inheritance of the infection and imperfect maternal transmission have been demonstrated, one might expect instead that both infected and uninfected flies would possess both mtDNA variants. Our data suggest that imperfect female transmission of the infection (and/or the loss of the infection among progeny) is more common in nature than paternal transmission. A simple model of intrapopulation dynamics, with empirically supported parameter values, adequately describes the joint frequencies of the mtDNA variants and incompatibility types.     

Heteromorphism for Heterokaryon Incompatibility Genes in Natural Populations of NEUROSPORA CRASSA

Five Neurospora crassa isolates from each of three sites in Louisiana were compared for genotype at five heterokaryon incompatibility (het) loci. The comparisons were made using duplications (partial diploids), based on the fact that duplications heterozygous for het loci have strikingly abnormal phenotypes which greatly facilitate the study of such genes. Duplications were synthesized in crosses between the wild strains (normal chromosome sequence) and testers of defined het genotype and having duplication-producing chromosome rearrangements. Crosses segregating for phenotypes characteristic of duplications heterozygous for het loci indicated allelic differences between testers and wild strains for specific het genes. Whenever a wild strain differed from a tester for a specific het locus, but another wild strain did not, the two wild strains could be inferred to differ from each other.—No two isolates from any site were heterokaryon compatible (of identical het genotype), despite the fact that all isolates from each of two sites occurred within several meters of each other. Heteromorphism was found for all five genes studied at one site, four genes at another site, and three at another. Intra- and interpopulation differences between strains were approximately the same.—Confirmation is also provided that two het genes originally detected in duplications are in fact heterokaryon incompatibility loci.     

Characterization and Pathogenicity of Phomopsis theicola Anamorph of Diaporthe foeniculina Causing Stem and Shoot Cankers on Sweet Chestnut in Italy

In March 2014, an outbreak of shoot cankers was observed on grafted Castanea sativa plants in a glasshouse in central Italy. Morphological characteristics led to the identification of isolates of Phomopsis recovered from cankered stems and shoots. Based on the morphological characteristics of colony appearance, shape of conidia and conidiomata as well as sequences of internal transcribed spacer regions (ITS), actin (ACT) and translation elongation factor (TEF‐1α), the fungus was identified as Phomopsis theicola/Diaporthe foeniculina. Pathogenicity test showed that P. theicola isolates were pathogenic to C. sativa when artificially inoculated, reproducing the symptoms originally observed. Koch's postulates were fulfilled by re‐isolating the pathogen. This is the first report of P. theicola/D. foeniculina causing stem and shoot cankers and dieback on C. sativa in Italy or elsewhere.     

Cytoplasmic Incompatibility in Drosophila Simulans: Dynamics and Parameter Estimates from Natural Populations

In Drosophila simulans, cytoplasmically transmitted Wolbachia microbes cause reduced egg hatch when infected males mate with uninfected females. A Wolbachia infection and an associated mtDNA variant have spread northward through California since 1986. PCR assays show that Wolbachia infection is prevalent throughout the continental US and Central and South America, but some lines from Florida and Ecuador that are PCR-positive for Wolbachia do not cause incompatibility. We estimate from natural populations infection frequencies and the transmission and incompatibility parameter values that affect the spread of the infection. On average, infected females from nature produce 3-4% uninfected ova. Infected females with relatively low fidelity of maternal transmission show partial incompatibility with very young infected laboratory males. Nevertheless, crosses between infected flies in nature produce egg-hatch rates indistinguishable from those produced by crosses between uninfected individuals. Incompatible crosses in nature produce hatch rates 30-70% as high as those from compatible crosses. Wild-caught infected and uninfected females are equally fecund in the laboratory. Incompatibility decreases with male age, and age-specific incompatibility levels suggest that males mating in nature may often be 2 or 3 weeks old. Our parameter estimates accurately predict the frequency of Wolbachia infection in California populations.     

Patterns and Processes in Cultural Evolution

Darwinian models of cultural change have been motivated, in part, by the desire to provide a framework for the unification of the biological and the human sciences. In this paper, drawing upon a distinction between the evolution of enabling mechanisms for the acquisition and dissemination of knowledge (EEM) and the evolution of epistemic theses as cultural products (EET), we propose a model of how culture emerges as a product of biological evolution on the basis of the concept of reaction norms. The goal of this model is to provide a means for conceptualizing how the biological and the cultural realms are connected, when they start to disconnect, and what the key transitions are. We then assess the viability of a Darwinian approach to cultural change. We conclude that the prospects of producing a Darwinian model of cultural change that unifies the human sciences in a way that mirrors the unification of the biological sciences in the light of Darwin’s theory are rather dim.     

Growth of Individuals in Plant Populations

Relationships between individual plant weight and net photosynthesisper day (G(t, x) function of plant weight) in plant populationsof various stand structures were simulated based on a canopyphotosynthesis model. The G(t, x) functions of plant weightare determined mainly by LAI (leaf area index), the relationshipbetween individual plant weight and leaf area, canopy structureand extinction coefficient. The concave relationship betweenindividual plant weight and leaf area at small LAI (<2),at small extinction coefficient (< 0.5), or at the canopystructure having the maximum leaf area density at the bottomproduces a concave G(t, x) function, which generates negativeskewness of plant weight. The linear relationship between individualplant weight and leaf area at large LAI (> 2) produces aconvex G(t, x) function, which generates positive skewness ofplant weight. These simulation results coincide with G(t, x)functions obtained experimentally and with the well-known phenomenonof stand dynamics in which skewness of plant weight becomesnegative in the early growth stage and then increases to a positivevalue as a stand grows and becomes crowded. Helianthus annuus L., individual plant size, mean growth rate, canopy photosynthesis model, skewness, stand structure     

Evolutionary Implications of Changing Nutritional Patterns in Human Populations

Malnutrition is a widespread problem in the tropical regions of the world, the same areas which are believed to be man's ancestral home. Much of the adaptive complex characterizing contemporary Homo sapiens was assembled during the period of at least partial reliance on dietary intake of animal protein. Adjustments to low protein intake are most difficult during the period of growth and development. Selection against individuals unable to make suitable adjustments exerts pressure on the human population to retain adaptability while maintaining appropriate body proportions and sexual dimorphisms for body size .     

Intervention or Inversion: Australian Indigenous Justice and the Politics of Cultural Incompatibility

Australian Indigenous affairs are underscored by a central tension between the rights of Indigenous peoples to self-determination, and assimilation policy premised on cultural homogeneity. This tension is most evident between the Northern Territory Government-commissioned Anderson and Wild (2007 Anderson, P. and Wild, R. Ampe akelyernemane meke mekarle: Little children are sacred. Report to the Northern Territory board of inquiry into the protection of Aboriginal children from sexual abuse. Darwin: Northern Territory Government.  [Google Scholar]) report, entitled Ampe akelyernemane meke mekarle: Little children are sacred, which recommends the continuation of community-led programs in response to childhood sexual abuse in Indigenous communities, and the Commonwealth's Northern Territory National Emergency Response Act 2007 (NTNER), commonly known as ‘the intervention’, which Altman and Hinkson (2007 Altman, J. and Hinkson, M. 2007. Coercive reconciliation: Stabilise, normalise, exit Aboriginal Australia, Melbourne: Arena Publications.  [Google Scholar]) claim represents a ‘coercive’ attempt to dismantle Indigenous rights to manage their affairs. In her critique of cultural incompatibility (culturalism), McConaghy (2000 McConaghy, C. 2000. Rethinking Indigenous education: Culturalism, colonialism and the politics of knowing, Flaxton: Post Pressed.  [Google Scholar]) observes that radicalism, or cultural difference policy in oppositional histories of power and control, seeks to invert colonial power relations. Instead, argues McConaghy, radicalism (much like assimilation) reinstitutes colonial relations of dominance. I draw on culturalism to explore the tension between Indigenous self-determination (a form of inversion), represented within the Little children are sacred report, and intervention, as a model not for coercive assimilation but for cultural integration (Sutton 2001a Sutton, P. 2001a. The politics of suffering: Indigenous policy in Australia since the 1970s. Anthropological Forum, 11: 125–173. [Taylor & Francis Online] [Google Scholar]; Pearson 2007 Pearson, N. 2007. The urgent quest for a radical political centre. The Age, 1 September Insight 11 [Google Scholar]). I propose that cultural inversion, as a justificatory model for addressing dysfunction within Indigenous communities, displaces the needs and rights of individuals for mainstream intervention.     

Growth and skeletal maturation in British Columbia Indian Populations

Stature and skeletal maturation in childhood, mature stature, and calorie and protein intakes were studied in two populations of British Columbia Indians. Although mature stature was similar in both groups, one population (Anaham) showed delayed stature achieved for age and delayed skeletal maturity in childhood, compared with the other population (Ahousat). Analysis of growth data suggests that environmental factors are probably the predominant cause of the differences, which coincide with differences in nutritional status. Mean calorie intakes at Ahousat approximate or exceed the Canadian Dietary Standards, but those at Anaham are consistently below the standards for all age groups. Although mean protein intakes are well above the standards for all age groups, except teen-age girls at both reserves, they are consistently lower at Anaham than at Ahousat.     

Patterns of Allelic Diversity in Spring Wheat Populations by SSR-Markers

Precise assessment of diversity in available breeding germplasm helps to preempt epidemics and abrupt environmental changes. Spring wheat germplasm consisting of 84 accessions including cultivars, breeding lines and landraces from various origins was scanned with 44 SSRs. For allele frequencies, allelic patterns, heterozygosity and polymorphism the selected population was divided in three subpopulations: (i) pre-green revolution (pre-1965), (ii) post-green revolution (post-1965), (iii) post-veery (post-2000). Alleles produced in pre-1965, post-1965 and post-2000 subpopulations were 115, 144 and 131, respectively. Mean PIC values for pre-1965, post-1965 and post-2000 subpopulations were 0.48, 0.52 and 051, respectively. Allelic patterns showed no locally common alleles in any of the subpopulation. The pre-1965 subpopulation had also no private allele, however, average number of private alleles decreased from post-1965 to post-2000 subpopulation. In case of effective alleles and Shannon’s information index trend was increasing from pre-1965 to post-1965 and then decreasing from post-1965 to post-2000. The decreasing trend alarms the reduced genetic diversity in wheat varieties developed after 2000. PCA and cluster analysis didn’t clearly differentiated subpopulations, though pre-1965 genotypes showed higher genetic distance from post-1965 and post-2000 subpopulations. The decreasing measures of genetic diversity in post-2000 wheat genotypes should be a concern for wheat breeders, therefore, all sources of broadening genetic diversity should be exploited.     

Patterns of Forest Decline and Regeneration Across Scots Pine Populations

To predict future changes in forest ecosystems, it is crucial to understand the complex processes involved in decline of tree species populations and to evaluate the implications for potential vegetation shifts. Here, we study patterns of decline (canopy defoliation and mortality of adults) of four Scots pine populations at the southern edge of its distribution and characterized by different combinations of climate dryness and intensity of past management. General linear and structural equation modeling were used to assess how biotic, abiotic, and management components interacted to explain the spatial variability of Scots pine decline across and within populations. Regeneration patterns of Scots pine and co-occurring oak species were analyzed to assess potential vegetation shifts. Decline trends were related to climatic dryness at the regional scale, but, ultimately, within-population forest structure, local site conditions, and past human legacies could be the main underlying drivers of Scots pine decline. Overall, Scots pine regeneration was negatively related to decline both within and between populations, whereas oak species responded to decline idiosyncratically across populations. Taken together, our results suggest that (1) patterns of decline are the result of processes acting at the plot level that modulate forest responses to local environmental stress and (2) decline of adult Scots pine trees seems not to be compensated by self-recruitment so that the future dynamics of these forest ecosystems are uncertain.     

Patterns of Gene Variation in Central and Marginal Populations of DROSOPHILA ROBUSTA

The central and marginal populations of D. robusta differ greatly in the level of inversion polymorphism; the marginal populations are monomorphic or nearly so and the central populations are highly polymorphic. This paper presents the frequencies of alleles at forty gene loci in various populations of D. robusta, studied by electrophoresis of proteins and enzymes. Population samples were obtained from eight widely separated populations of D. robusta which included the central, the extreme marginal and the intervening populations between the center and the margins. We find that the proportion of polymorphic loci and average heterozygosity per individual is slightly higher in the marginal populations than the central populations. In D. robusta on an average, 39% of the loci are polymorphic and the average proportion of loci heterozygous per individual is 11%. A breakdown of loci in three categories, viz, hydrolytic enzymes and some other enzymes, larval proteins and glycolytic and Kreb's cycle enzymes, shows that in all populations the level of polymorphism is highest in the hydrolytic enzymes, intermediate in larval proteins and least in the glycolytic and Kreb's cycle enzymes. On the average, the proportion of loci heterozygous per individual for three groups of loci is: hydrolytic enzymes and others (.164), larval proteins (.115) and glycolytic and Kreb's cycle enzymes (.037). We also observe that in all populations the level of polymorphism on the X chromosome is far less than the expected 38%; in salivary gland cells the euchromatic length of the X chromosome is 38% of the entire genome. Lower levels of polymorphism for the X chromosome loci are explained due to low probability of balanced polymorphisms for the X-linked loci since the conditions for establishment of balanced polymorphism for X-linked loci are more restrictive than for the autosomal loci.-The polymorphic loci can be grouped according to pattern of allele frequencies in different populations as follows: (1) The allele frequencies are similar in all populations at the XDH, Pep-1 and Hex-1 loci. (2) The alleles at the Est-1, Est-2, Amy loci and the AP-4(1.0) and the LAP-1(.90) alleles show north south clinal change in frequency. (3) There is north south and east west differentiation at the Pt-5, Pt-8 and Pt-9 loci and the allele AP-4(.81). (4) Polymorphism at loci such as Fum, B.Ox, Hex-8, Pep-2 and Pep-3 are restricted to only one or two of the populations. (5) Allele frequencies at the MDH and ODH loci fluctuate between populations. (6) Allele frequencies at many polymorphic loci such as Est-1, Est-2, LAP-1, AP-4, Pt-5, Pt-8, Pt-9, Pt-16, MDH, Fum change clinally within a gene arrangement. The pattern of gene variation in D. robusta is very complex and cannot be easily explained due to migration of neutral alleles between once-isolated populations or to semi-isolation of neutral alleles. The observations of the pattern of allele variation in different populations, high levels of polymorphism in the marginal populations which have small population size and low levels of polymorphism of the X chromosome loci all support the argument in favor of balancing selection as the main mechanism for the maintenance of these polymorphisms. Environmental factors must play a role in the maintenance of a great deal of these polymorphisms, since we observe clinal allele frequency changes even within a given inversion type.     

On the Structure-Bounded Growth Processes in Plant Populations

If growing cells in plants are considered to be composed of increments (ICs) an extended version of the law of mass action can be formulated. It evidences that growth of plants runs optimal if the reaction–entropy term (entropy times the absolute temperature) matches the contact energy of ICs. Since these energies are small, thermal molecular movements facilitate via relaxation the removal of structure disturbances. Stem diameter distributions exhibit extra fluctuations likely to be caused by permanent constraints. Since the signal–response system enables in principle perfect optimization only within finite-sized cell ensembles, plants comprising relatively large cell numbers form a network of size-limited subsystems. The maximal number of these constituents depends both on genetic and environmental factors. Accounting for logistical structure–dynamics interrelations, equations can be formulated to describe the bimodal growth curves of very different plants. The reproduction of the S-bended growth curves verifies that the relaxation modes with a broad structure-controlled distribution freeze successively until finally growth is fully blocked thus bringing about “continuous solidification”.     

Switching and Growth for Microbial Populations in Catastrophic Responsive Environments

Phase variation, or stochastic switching between alternative states of gene expression, is common among microbes, and may be important in coping with changing environments. We use a theoretical model to assess whether such switching is a good strategy for growth in environments with occasional catastrophic events. We find that switching can be advantageous, but only when the environment is responsive to the microbial population. In our model, microbes switch randomly between two phenotypic states, with different growth rates. The environment undergoes sudden catastrophes, the probability of which depends on the composition of the population. We derive a simple analytical result for the population growth rate. For a responsive environment, two alternative strategies emerge. In the no-switching strategy, the population maximizes its instantaneous growth rate, regardless of catastrophes. In the switching strategy, the microbial switching rate is tuned to minimize the environmental response. Which of these strategies is most favorable depends on the parameters of the model. Previous studies have shown that microbial switching can be favorable when the environment changes in an unresponsive fashion between several states. Here, we demonstrate an alternative role for phase variation in allowing microbes to maximize their growth in catastrophic responsive environments.