Effects of elevated CO2 and plant genotype on interactions among cotton,aphids and parasitoids

Abstract Effects of CO₂ level (ambient vs. elevated) on the interactions among three cotton (Gossypium hirsutum) genotypes, the cotton aphid (Aphis gossypii Glover), and its hymenoptera parasitoid (Lysiphlebia japonica Ashrnead) were quantified. It was hypothesized that aphid‐parasitoid interactions in crop systems may be altered by elevated CO₂, and that the degree of change is influenced by plant genotype. The cotton genotypes had high (M9101), medium (HZ401) and low (ZMS13) gossypol contents, and the response to elevated CO₂ was genotype‐specific. Elevated CO₂ increased the ratio of total non‐structural carbohydrates to nitrogen (TNC: N) in the high‐gossypol genotype and the medium‐gossypol genotype. For all three genotypes, elevated CO₂ had no effect on concentrations of gossypol and condensed tannins. A. gossypii fitness declined when aphids were reared on the high‐gossypol genotype versus the low‐gossypol genotype under elevated CO₂. Furthermore, elevated CO₂ decreased the developmental time of L. japonica associated with the high‐gossypol genotype and the low‐gossypol genotype, but did not affect parasitism or emergence rates. Our study suggests that the abundance of A. gossypii on cotton will not be directly affected by increases in atmospheric CO₂. We speculate that A. gossypii may diminish in pest status in elevated CO₂ and high‐gossypol genotype environments because of reduced fitness to the high‐gossypol genotype and shorter developmental time of L. japonica.     

Evaluation of production efficiencies at pasture of lactating suckler cows of diverse genetic merit and replacement strategy

Feed costs account for the largest proportion of direct cost within suckler beef production systems. By identifying the cow type with enhanced capability of converting grazed herbage to beef output across lactations, suckler cow systems would become more efficient and sustainable. The objective of this study was to estimate grass DM intake (GDMI) and production efficiency among lactating suckler cows of diverse genetic merit for the national Irish maternal index (Replacement Index) which includes cow efficiency components such as milk yield and feed intake. Data from 131 cows of diverse genetic merit within the Replacement Index, across two different replacement strategies (suckler or dairy sourced), were available over two grazing seasons. Milk yield, GDMI, cow live weight (BW) and body condition score (BCS) were recorded during early, mid and late-lactation, with subsequent measures of production efficiency extrapolated. Genetic merit had no significant effect on any variables investigated, with the exception of low genetic merit (LOW) cows being 22 kg heavier in BW than high genetic merit (HIGH) cows (P < 0.05). Beef cows were 55 kg heavier in BW (P < 0.001), had a 0.31 greater BCS (P < 0.05) and 0.30 Unité Fourragère Lait (UFL) greater energy requirement for maintenance compared to dairy sourced beef × dairy crossbred (BDX) cows (P < 0.001). The BDX had 0.8 kg greater GDMI, produced 1.8 kg more milk (P < 0.001), had a 0.8 UFL greater energy requirement for lactation and produced weanlings that were 17 kg heavier in BW than beef cows (P < 0.05). Subsequent efficiency variables of milk per 100 kg BW (P < 0.001), milk per kg GDMI (P < 0.001) and GDMI per 100 kg BW (P < 0.001) were more favourable for BDX. The correlations examined showed GDMI had moderate positive correlations (P < 0.001) with intake per 100 kg BW, net energy intake per kg milk yield, RFI and intake per 100 kg calf weaning weight but was weakly negatively correlated to milk yield per kg GDMI (P < 0.001). No difference was observed across genetic merit for beef cows for any of the traits investigated. Results from the current study showed that, while contrasting replacement strategies had an effect on GDMI and production efficiency, no main effect was observed on cows diverse in genetic merit for Replacement Index. Nonetheless, utilising genetic indexes in the suckler herd is an important resource for selecting breeding females for the national herd and phenotypic performance generated from this study can be included in future genetic evaluations to improve reliability of genetic values.     

Does operational sex ratio influence relative strength of purging selection in males versus females?

According to theory, sexual selection in males may efficiently purge mutation load of sexual populations, reducing or fully compensating ‘the cost of males’. For this to occur, mutations not only need to be deleterious to both sexes, they also must affect males more than females. A frequently overlooked problem is that relative strength of selection on males versus females may vary between environments, with social conditions being particularly likely to affect selection in males and females differently. Here, we induced mutations in red flour beetles (Tribolium castaneum) and tested their effect in both sexes under three different operational sex ratios (1:2, 1:1 and 2:1). Induced mutations decreased fitness of both males and females, but their effect was not stronger in males. Surprisingly, operational sex ratio did not affect selection against deleterious mutations nor its relative strength in the sexes. Thus, our results show no support for the role of sexual selection in the evolutionary maintenance of sex.     

Genotypes and their interaction effects on reproduction and mating‐induced immune activation in Drosophila melanogaster

Mating causes considerable alterations in female physiology and behaviour, and immune gene expression, partly due to proteins transferred from males to females during copulation. The magnitude of these phenotypic changes could be driven by the genotypes of males and females, as well as their interaction. To test this, we carried out a series of genotype‐by‐genotype (G × G) experiments using Drosophila melanogaster populations from two distant geographical locations. We expected lines to have diverged in male reproductive traits and females to differ in their responses to these traits. We examined female physiological and behavioural post‐mating responses to male mating traits, that is behaviour and ejaculate composition, in the short to mid‐term (48 hr) following mating. We then explored whether a sexually transferred molecule, sex peptide (SP), is the mechanism behind our observed female post‐mating responses. Our results show that the genotypes of both sexes as well as the interaction between male and female genotypes affect mating and post‐mating reproductive traits. Immune gene expression of three candidate genes increased in response to mating and was genotype‐dependent but did not show a G × G signature. Males showed genotype‐dependent SP expression in the 7 days following eclosion, but female genotypes showed no differential sensitivity to the receipt of SP. The two genotypes demonstrated clear divergence in physiological traits in short‐ to mid‐term responses to mating, but the longer‐term consequences of these initial dynamics remain to be uncovered.     

Future energy potential of Miscanthus in Europe

European field experiments have demonstrated Miscanthus can produce some of the highest energy yields per hectare of all potential energy crops. Previous modelling studies using MISCANMOD have calculated the potential energy yield for the EU27 from mean historical climate data (1960–1990). In this paper, we have built on the previous studies by further developing a new Miscanthus crop growth model MISCANFOR in order to analyse (i) interannual variation in yields for past and future climates, (ii) genotype-specific parameters on yield in Europe. Under recent climatic conditions (1960–1990) we show that 10% of arable land could produce 1709 PJ and mitigate 30 Tg of carbon dioxide-carbon (CO₂-C) equivalent greenhouse gasses (GHGs) compared with EU27 primary energy consumption of 65 598 PJ, emitting 1048 Tg of CO₂-C equivalent GHGs in 2005. If we continue to use the clone Miscanthus × giganteus , MISCANFOR shows that, as climate change reduces in-season water availability, energy production and carbon mitigation could fall 80% by 2080 for the Intergovernmental Panel on Climate Change A2 scenario. However, because Miscanthus is found in a huge range of climates in Asia, we propose that new hybrids will incorporate genes conferring superior drought and frost tolerance. Using parameters from characterized germplasm, we calculate energy production could increase from present levels by 88% (to 2360 PJ) and mitigate 42 Tg of CO₂-C equivalent using 10% arable land for the 2080 mid-range A2 scenario. This is equivalent to 3.6% of 2005 EU27 primary energy consumption and 4.0% of total CO₂ equivalent C GHG emissions.     

哈尔滨地区假丝酵母菌DNA异质性及药物敏感性分析

研究假丝酵母菌的DNA异质性及药物敏感性,为预防和监控院内假丝酵母菌感染奠定基础。将临床分离的假丝酵母菌菌株,用科玛嘉显色培养基鉴定菌种,经纸片扩散法进行药敏试验,应用随机扩增多态性DNA（RAPD）技术对这些菌株进行基因分型。结果显示：93株假丝酵母菌中白假丝酵母菌68株,非白假丝酵母菌25株,所有菌株对制霉菌素,两性霉素B两种药物的敏感率最高（100％）,酮康唑其次（70．9％）,氟康唑的敏感率最低（50．5％）,引物1和引物2将来源不同的68株白假丝酵母菌分别分成4型（A1、B1、C1、D1）和6型（A2、B2、C2、D2、E2、F2）。哈尔滨地区的假丝酵母菌感染以白假丝酵母菌为主,且主要为A1、B1型（引物1）或A2、B2型（引物2）;基因型与药敏谱无明显相关性。     

猪钙蛋白酶抑制蛋白基因的基因型与肉质性状的关联性分析

钙蛋白酶抑制蛋白基因是影响猪肉质性状的候选基因之一。本研究以125头地方猪和117头外来猪为材料,研究CAST基因的多态性。结果在CAST基因上检测到一个多态性位点(A876G),并引起了氨基酸残基的改变Lys250 Arg。在地方猪种中仅检测到G (Arg)等位基因,而在外来猪种中A (Lys) 和 G (Arg)两个等位基因均检测到。基因型与肉质性状的关联性分析结果表明,CAST基因型与肌肉的嫩度,屠宰45 min后的pH值及滴水损失存在强相关,又由于地方猪种与外来猪种的肉质性状间存在显著差异。因此,在CAST基因上检测到的多态型位点Lys250Arg的基因型效应有待于进一步研究,并将其有效应用于商品猪生产中。     

HCV Antibody Response and Genotype Distribution in Different Areas and Races of China

Hepatitis C virus (HCV) heterogeneity accounts for the failure of effective vaccine development and the lack of successful anti-viral therapy in some patients. Little is known about the immune response to HCV peptides and the region or race specific genotypes in China. The objective of this study was to characterize HCV antibody immune response to HCV peptides and HCV genotypes in different regions and races of China. A total of 363 serum samples were collected from HCV carriers in 6 regions in China. The immune response to HCV peptides was evaluated by ELISA. HCV genotypes were examined using nested RT-PCR. We found that the anti-HCV antibody neutralization rates were significantly different among the serum samples from different areas or from different races in the same area. For samples from Tibet and Sinkiang, the rates of neutralization by HCV peptides were only 3.2% and 30.8%, respectively. The genotypes of samples from Tibet and Sinkiang were apparently heterogeneic and included type I, II, III and multiple types (I/II/III, I/II, I/III, II/III). One specific sample with multiple-genotype (I/II/III) HCV infection was found to consist of type I, II, III, II/III and an unclassified genotype. These studies indicate that the anti-HCV antibody immune response to HCV peptides varied across regions and among races. The distribution of HCV genotypes among Tibetans in Tibet and Uighurs in Sinkiang was different from that in the inner areas of China. In addition, a “master” genotype, type II, was found to exist in HCV infection with multiple HCV genotypes.     

Sources of Wilhelm Johannsen’s Genotype Theory

This paper describes the historical background and early formation of Wilhelm Johannsen’s distinction between genotype and phenotype. It is argued that contrary to a widely accepted interpretation (For instance, W. Provine, 1971. The Origins of Theoretical Population Genetics. Chicago: The University of Chicago Press; Mayr, 1973; F. B. Churchill, 1974. Journal of the History of Biology 7: 5–30; E. Mayr, 1982. The Growth of Biological Thought, Cambridge: Harvard University Press; J. Sapp, 2003. Genesis. The Evolution of Biology. New York: Oxford University Press) his concepts referred primarily to properties of individual organisms and not to statistical averages. Johannsen’s concept of genotype was derived from the idea of species in the tradition of biological systematics from Linnaeus to de Vries: An individual belonged to a group – species, subspecies, elementary species – by representing a certain underlying type (S. Müller-Wille and V. Orel, 2007. Annals of Science 64: 171–215). Johannsen sharpened this idea theoretically in the light of recent biological discoveries, not least those of cytology. He tested and confirmed it experimentally combining the methods of biometry, as developed by Francis Galton, with the individual selection method and pedigree analysis, as developed for instance by Louis Vilmorin. The term “genotype” was introduced in W. Johannsen’s 1909 (Elemente der Exakten Erblichkeitslehre. Jena: Gustav Fischer) treatise, but the idea of a stable underlying biological “type” distinct from observable properties was the core idea of his classical bean selection experiment published 6 years earlier (W. Johannsen, 1903. Ueber Erblichkeit in Populationen und reinen Linien. Eine Beitrag zur Beleuchtung schwebender Selektionsfragen, Jena: Gustav Fischer, pp. 58–59). The individual ontological foundation of population analysis was a self-evident presupposition in Johannsen’s studies of heredity in populations from their start in the early 1890s till his death in 1927. The claim that there was a “substantial but cautious modification of Johannsen’s phenotype–genotype distinction” (Churchill, 1974, p. 24) from a statistical to an individual ontological perspective derives from a misreading of the 1903 and 1909 texts. The immediate purpose of this paper is to correct this reading of the 1903 monograph by showing how its problems and results grow out of Johannsen’s earlier work in heredity and plant breeding. Johannsen presented his famous selection experiment as the culmination of a line of criticism of orthodox Darwinism by William Bateson, Hugo de Vries, and others (Johannsen, 1903). They had argued that evolution is based on stepwise rather than continuous change in heredity. Johannsen’s paradigmatic experiment showed how stepwise variation in heredity could be operationally distinguished from the observable, continuous morphological variation. To test Galton’s law of partial regression, Johannsen deliberately chose pure lines of self-fertilizing plants, a pure line being the descendants in successive generations of one single individual. Such a population could be assumed to be highly homogeneous with respect to hereditary type, and Johannsen found that selection produced no change in this type. Galton, he explained, had experimented with populations composed of a number of stable hereditary types. The partial regression which Galton found was simply an effect of selection between types, increasing the proportion of some types at the expense of others.