Best Linear Unbiased Prediction (BLUP) for regional yield trials: a comparison to additive main effects and multiplicative interaction (AMMI) analysis

Multilocation trials are often used to analyse the adaptability of genotypes in different environments and to find for each environment the genotype that is best adapted; i.e. that is highest yielding in that environment. For this purpose, it is of interest to obtain a reliable estimate of the mean yield of a cultivar in a given environment. This article compares two different statistical estimation procedures for this task: the Additive Main Effects and Multiplicative Interaction (AMMI) analysis and Best Linear Unbiased Prediction (BLUP). A modification of a cross validation procedure commonly used with AMMI is suggested for trials that are laid out as a randomized complete block design. The use of these procedure is exemplified using five faba bean datasets from German registration trails. BLUP was found to outperform AMMI in four of five faba bean datasets.     

Association of the catalytic subunit of aspartate transcarbamoylase with a zinc-containing polypeptide fragment of the regulatory chain leads to increases in thermal stability.

The regulatory enzyme aspartate transcarbamoylase (ATCase), comprising 2 catalytic (C) trimers and 3 regulatory (R) dimers, owes its stability to the manifold interchain interactions among the 12 polypeptide chains. With the availability of a recombinant 70-amino acid zinc-containing polypeptide fragment of the regulatory chain of ATCase, it has become possible to analyze directly the interaction between catalytic and regulatory chains in a complex of simpler structure independent of other interactions such as those between the 2 C trimers, which also contribute to the stability of the holoenzyme. Also, the effect of the interaction between the polypeptide, termed the zinc domain, and the C trimer on the thermal stability and other properties can be measured directly. Differential scanning microcalorimetry experiments demonstrated that the binding of the zinc domain to the C trimer leads to a complex of markedly increased thermal stability. This was shown with a series of mutant forms of the C trimer, which themselves varied greatly in their temperature of denaturation due to single amino acid replacements. With some C trimers, for which tm varied over a range of 30 degrees C due to diverse amino acid substitutions, the elevation of tm resulting from the interaction with the zinc domain was as large as 18 degrees C. The values of tm for a variety of complexes of mutant C trimers and the wild-type zinc domain were similar to those observed when the holoenzymes containing the mutant C trimers were subjected to heat denaturation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Behavioral responses of the whitebacked planthopperSogatella furcifera (Homoptera: Delphacidae) on rice plants whose odors have been masked

In a two-choice test, moreS. furcifera females settled more often on exposed plants than on parafilm-masked ones, regardless of the susceptibility of rice varieties. This indicates that rice volatiles play an important role in the insect's short-range orientation to its host. The fact that more insects settled on exposed resistant Rathu Heenati (RHT) than to masked susceptible Taichung Native 1 (TN1) suggests that there must be certain common volatiles released by both varieties. Few females landed on masked plants of either RHT or TN1. This implies that the insect could not recognize at a distance that a plant was resistant or susceptible without olfactory stimuli.S. furcifera excreted less honeydew on masked plants than on exposed ones for both varieties and more on masked TN1 than on exposed RHT. The electronic monitoring of feeding behavior demonstrates that the insect made more frequent probes and had shorter phloem ingestion durations on exposed RHT than on exposed TN1 and on masked RHT than on masked TN1. Moreover, the insect had longer phloem ingestion durations on masked TN1 than on exposed RHT. These results suggest that volatile chemicals given off by resistant RHT plants have a negative effect on feeding.     

In vivo definition of the functional origin of replication (ori(+ )) of the promiscuous plasmid pLS1

The nocR gene of Agrobacterium tumefaciens Ti plasmid pTiT37 is the regulatory gene of the nopaline catabolism (noc) operon of pTiT37. We have cloned and sequenced nocR, which encodes a DNA-binding protein. The deduced amino acid sequence is similar to those of members of the LysR family of prokaryotic activator proteins. Gel retardation experiments demonstrated that the NocR protein binds to the nocR promoter in both the presence and absence of nopaline. The increased mobility of the complex and alterations in the DNase I footprints revealed a nopaline-induced conformational change in the NocR-DNA complex. Sequence analysis of the NocR binding site indicated the presence immediately downstream of the –10 sequence of the nocR promoter of a 12 by putative operator overlapping a consensus gyrase recognition sequence and an 18 by long alternating purine-pyrimidine sequence. These results suggest that nopaline-induced alterations in the NocR protein-nocR promoter complex might control gene expression in the noc operon.     

Presence of predatory wasps and stinkbugs alters foraging behavior of cryptic and non-cryptic caterpillars on plantain (Plantago lanceolata)

We examined the foraging patterns of two species of caterpillar (Junonia coenia: Nymphalidae and Spilosoma congrua: Arctiidae) that contrast in feeding specialization and crypticity on plantain (Plantago lanceolata) in the absence and presence of two different insect predators [stinkbugs, Podisus maculiventris (Pentatomidae) and wasps, Polistes fuscatus (Vespidae)]. Junonia larvae were quite apparent to human observers, feeding on upper leaf surfaces during daylight, whereas Spilosoma larvae were relatively cryptic, often hiding under leaves and in soil crevices during daylight. In the presence of either predator species, the non-cryptic Junonia caterpillars more quickly left the plant on which they were initially placed and were less apparent than Junonia larvae not exposed to predators. The presence of predators had no detectable influence on where the caterpillars occurred on the plants (new, intermediate-aged or mature leaves, or reproductive stalks). Surprisingly, the predators influenced the behavior of the inherently cryptic Spilosoma: the apparency of these larvae at night increased when wasps had access to the plots during the day. Survivorship of the non-cryptic Junonia was less than 12% when stinkbugs were present compared to 60% in their absence. Although the presence of wasps resulted in a lower relative growth rate for the non-cryptic Junonia larvae, the indirect effect of predators on reduction in survivorship due to alterations in prey growth rate through behavioral changes was less than 3%. After taking into account the decline in caterpillars per plot through predation, we found that both the amount of leaves eaten and the proportion of plants eaten were altered on plots with predators present, which suggests that the caterpillars' increased consumption countered increased maintenance costs due to the presence of predators. Overall, our results indicate that hostplant size, level of predation and type of predator can influence the degree to which these caterpillars react to the presence of insect predators. In contrast, degree of inherent feeding specialization and cryptic behavior seemed to have little effect on the expression of reactive behaviors of these caterpillars to predators.     

Tansley Review No. 59 Leaf boundary layers

Studies of heat and mass exchange between leaves and their local environment are central to our understanding of plant-atmosphere interactions. The transfer across aerodynamic leaf boundary layers is generally described by non-dimensional expressions which reflect largely empirical adaptations of engineering models derived for flat plates. This paper reviews studies on leaves, and leaf models with varying degrees of abstraction, in free and forced convection. It discusses implecations of finding for leaf morphology as it affects – and is affected by – the local microclimate. Predictions of transfer from many leaves in plant communities are complicated by physical and physiological feedback mechanisms between leaves and their environment. Some common approaches, and the current challenge of integrating leaf-atmosphere interactions into models of global relevance, are also briefly addressed.     

Nonlinear effect of dynamic self-organization in macromolecular systems caused by photocontrolled electron flux

We use the electron-conformational interaction approach to develop a physical model which self-consistently describes the photomobilized electron transfer kinetics and structure conformational transitions in reaction centers (RCs) of purple bacteria. We consider the kinetics of electron transition from pigment onto primary acceptor and the subsequent charge recombination accounting for the change of distance between the above-mentioned cofactors. It is shown that, given natural values of RC parameters, the kinetic constant's dependence on the acting light intensity is monotone. As opposed to the previous case, similar dependencies for the chain of electron transfer between primary and secondary quinone acceptors revealed anS-like relationship. This can lead to bistability of the RC optical transmission coefficient and a fundamental dependence of charge recombination kinetics upon the prehistory of the RC's interaction with exciting radiation.     

Divalent cation and lipid-protein interactions of biomembranes

Divalent cations play an important role in the functions of biomembranes. This review deals with three topics: (1) Mg²⁺-mediated change in physical state of phospholipid induces conformation and activity change of reconstituted mitochondrial H⁺-ATPase, (2) a proper transmembrane Ca²⁺ gradient is essential for the higher enzymatic activity of adenylate cyclase, and (3) role of transmembrane Ca²⁺ gradient in the modulation of reconstituted sarcoplasmic reticulm Ca²⁺-ATPase activity.     

Behavior of bonobos (Pan paniscus) following their capture of monkeys in Zaire

For the first time, three cases of capture and forced interaction were observed between bonobos (Pan paniscus)and two other species of primates (Colobus angolensisand Cercopithecus ascanius)in the Lilungu (Ikela) region, Republic of Zaire. The bonobos interacted with the captured primates as if they were dealing with individuals of their own species. They sought cooperation in their interactions with the captured young primates without scccess. There is no evidence that they ate the captives.     

Genetic dominance and worker interactions affect honeybee colony defense

Colonies of honeybees (Apis mellifera L.) were established thatvaried in the proportions of their workers that were of Europeanand hybrid (Africanized x European) descent. Colony defensiveresponses increased with higher proportions of hybrid workers.Colonies consisting exclusively of hybrid workers did not differin their response from "pure" Africanized colonies, suggestingthat the strong defensive behavior of Africanized workers isgenetically dominant. European workers became more defensivein colonies that also contained hybrid workers, whereas hybridworkers became less defensive in the same mixed colonies. Inmixed colonies hybrid workers were individually more likelythan Europeans to sting a leather target but not more likelyto guard the entrance.