Grape berry skin features related to ontogenic resistance to <Emphasis Type="Italic">Botrytis cinerea</Emphasis>

This work investigated the structural and biochemical changes during grape berry development which account potentially for the onset and increase in susceptibility to Botrytis cinerea. Using the cv. Sauvignon blanc, we quantified at seven developmental growth stages from herbaceous to over-mature berries: (1) fruit ontogenic resistance using three strains (II-transposa), (2) the morphological and maturity fruit characteristics and (3) preformed biochemical compounds located in the berry skin. From the mid-colour change stage onwards, susceptibility of unwounded fruit increased sigmoidally in both rot and sporulation severities at the berry surface. A principal component analysis identified a very close connection between fruit susceptibility and the level of fruit maturity. Berry susceptibility was significantly and positively correlated with the phenolic compounds in the skin cell walls and negatively correlated with the total tannin content in the skin and with water activity (Aw) at the fruit surface. On the berry, Aw decreased from 0.94 at bunch closure to 0.89 at berry maturity, with a relatively low value (0.90) at the stage of mid-colour change. Using artificial media, different Aw levels led to significant differences in mycelial growth (Aw ≤0.95 resulted in the lowest growth rate ≤0.34 mm day⁻¹). Thus, besides the level of fruit maturity, both water activity on the fruit and the total tannin content in the skin may affect fungal growth and berry colonisation. The potential of these variables for use as indicators of grape berry susceptibility as well as associated mechanisms for the development of disease are discussed.     

密闭畜舍的蓄粪池涌风技术

1 简介 在一个环境受控的、地面为漏缝地板的畜舍中,通风系统应为舍内蓄粪池及动物生活区域提供通风.蓄粪池通风有利于防止蓄粪池污气漂向动物生活区域、减少舍内臭味程度,使舍内新鲜空气分布更加均匀,同时有助于舍内的保温和干燥.因此,所有以漏缝地板为地面的畜舍将很可能从蓄粪池的通风中获益,即使经常采用冲或刮方式清除污物的畜舍也能从中受益(图1).     

High-pruning of European beech (Fagus sylvatica L.) and pedunculate oak (Quercus robur L.): work efficiency for target pruning as a function of tree species,pruning height,branch characteristics,pole saw type and operator

The objective of this study was to establish an operational model of productive work time per tree (work efficiency) for high-pruning of young European beech and pedunculate oak depending on tree species, pruning height, branch characteristics, pole saw type and operator. The final model included all of these independent variables with branch characteristics specified in terms of number of live branches and cross-sectional area of the thickest branch at the cut. Work time increased with increasing values of each of the three numeric variables. For a given pruning height the size of the largest branch was for all practical purposes more influential than the number of live branches. Beech took 28% longer to prune than oak. The German Ergo-Schnitt saw was 21% slower than the Japanese Silky Hayauchi saw. The variation in worker performance within our study was larger than that attributed to tree species and pruning equipment.     

Improving Genetic Engineering Secondary Education Through a Classroom-Ready Online Resource

Genetic engineering has long been used in food production in the United States. However, consumers' science literacy in genetic engineering is poor. Teacher knowledge, time, and resources are lacking in science curriculums on genetic engineering. Through interviews conducted with six high school agriculture teachers we show how a new online resource, The Journey of a Gene, addresses these barriers to help improve their knowledge and increase time spent on genetic engineering. The positive outcomes support funding for genetic engineering education. Education is key to help consumers make informed purchasing decisions and societal decisions about advancing genetic engineering research.     

The Allometric Quarter-Power Scaling Model and Its Applicability to Grand Fir and <Emphasis Type="Italic">Eucalyptus</Emphasis> Trees

The use of the allometric model \(y = \beta x ^{\alpha }\) to describe the relative growth of morphological traits of trees is a source of contention in ecology. This is particularly so in a specific form, the West, Brown and Enquist model, which predicts values of \(\alpha \) that are multiples of 1/4 for various allometric relationships—the quarter-power scaling law. We use statistical techniques to test the appropriateness of the quarter-power scaling allometric model in a number of different relative growth relationships of trees. Two separate datasets are used, one of repeated measures of Abies grandis (Grand fir) trees, another of independent measures of Eucalyptus trees. Nonlinear mixed-effects modelling is used to fit allometric models to the datasets. Generalised additive models, equivalence testing and traditional significance testing are used to assess the adequacy of the allometric models fitted and the values of the estimated exponents relative to those predicted by the WBE model. In only one of the five models fitted was there empirical evidence for the WBE-predicted quarter-power exponent. However, the adequacy of the allometric models was generally supported, though a need for further analysis over a larger range of tree ages/sizes is indicated.Supplementary materials accompanying this paper appear online.     

A new phoretic association: Bursaphelenchus minutus (Nematoda: Parasitaphelenchidae) and Orthotomicus erosus (Coleoptera: Scolitydae) recorded on Pinus pinea (L.)

A new phoretic association between Bursaphelenchus minutus and the bark beetle Orthotomicus erosus collected on Pinus pinea is described for the first time. Nematode identification was based on morphological observation and biometric measurements of males and females. Moreover, B. minutus was characterized by ITS sequences and RFLP profile.     

Development of a core set of SSR markers for the characterization of <Emphasis Type="Italic">Gossypium</Emphasis> germplasm

Molecular markers such as simple sequence repeats (SSR) are a useful tool for characterizing genetic diversity of Gossypium germplasm. Genetic profiles by DNA fingerprinting of cotton accessions can only be compared among different collections if a common set of molecular markers are used by different laboratories and/or research projects. Herein, we propose and report a core set of 105 SSR markers with wide genome coverage of at least four evenly distributed markers per chromosome for the 26 tetraploid cotton chromosomes. The core marker set represents the efforts of ten research groups involved in marker development, and have been systematically evaluated for DNA polymorphism on the 12 genotypes belonging to six Gossypium species [known collectively as the cotton marker database (CMD) panel]. A total of 35 marker bins in triplex sets were arranged from the 105 markers that were each labeled with one of the three fluorescent dyes (FAM, HEX, and NED). Results from this study indicated that the core marker set was robust in revealing DNA polymorphism either between and within species. Average value of polymorphism information content (PIC) among the CMD panel was 0.65, and that within the cultivated cotton species Gossypium hirsutum was 0.29. Based on the similarity matrix and phylogenetic analysis of the CMD panel, the core marker set appeared to be sufficient in characterizing the diversity within G. hirsutum and other Gossypium species. The portability of this core marker set would facilitate the systematic characterization and the simultaneous comparison among various research efforts involved in genetic diversity analysis and germplasm resource preservation.