Soil apparent electrical conductivity and must carbon isotope ratio provide indication of plant water status in wine grape vineyards

Precision Agriculture - Proximal sensing is being integrated into vineyard management as it provides rapid assessments of spatial variability of soils’ and plants’ features. The...     

Impact of insecticide‐manipulated defoliation by Japanese beetle (Popillia japonica) on grapevines from vineyard establishment through production

BACKGROUND: Japanese beetle (JB), Popillia japonica Newman, is a severe pest of grapes in the southeastern USA where viticulture is a growing industry. This study evaluated the impact of foliar injury from JB field populations on growth, fruit ripening, berry composition and yield of young vines of six cultivars from vineyard establishment through the first year of production. Three spray regimes, carbaryl applied every 7 or 14 days, or no insecticide, were used to manipulate levels of defoliation by JB. RESULTS: Cultivars varied in susceptibility and response to defoliation by JB. Some (e.g. Norton) showed reduced vine growth and delayed post‐veraison increase in total soluble sugars and pH, as well as reduced cluster number and weight, berries per cluster and yield. Others (e.g. Concord) showed little or no measurable impact from JB. Notably, the biweekly spray regime was as effective as weekly sprays in mitigating the impacts of defoliation. CONCLUSION: Foliar loss from JB feeding can set back establishment and productivity of young grapevines. Nevertheless, many growers can reduce spray frequency without compromising the benefits of JB management. Even susceptible cultivars can tolerate low to moderate (<20%) levels of defoliation, and some are resistant enough to be grown without treating for JB. Copyright © 2010 Society of Chemical Industry     

Evaluation of Parameters Accounting for Phomopsis Resistance Using Natural Infection and Artificial Inoculation on Recombinant Inbred Lines From a Cross Between Susceptible and Resistant Sunflower

HA89, a sunflower line susceptible to Phomopsis, was crossed with a resistant line, LR4-17. Two hundred and forty-one F2/F3 progenies and 232 recombinant inbred (RI) lines were derived from this cross. F2/F3 progenies were tested in semi-natural infections in 1994. F7, F8 and F9 were tested with semi-natural infections in 1997, 1998 and 1999, respectively. F7 RI lines were artificially infected with Phomopsis mycelium on leaves in 1997. Family effects were significant in F2/F3 progenies for attack rates on stems and encircling spots rates on stems after semi-natural infections. Line effects were significant for attack rates on stems and encircling spot rates in F7 and F8. F7 RI lines showed a high heritability for speed of necrosis on leaf blades after artificial infection. Continuous and unimodal distributions were observed for attack rates on stems in all experiments done in semi-natural conditions. In contrast, speed of necrosis on leaf blades showed a bimodal distribution. Significant rank correlations were observed between the speed of necrosis on leaf blades and the attack rates on stems. It is suggested that resistance to Phomopsis is the consequence of several mechanisms, independently inherited. It was concluded that speed of necrosis on leaf blades in artificial infections and attack rates on stems in natural infections should be retained as parameters for quantitative trait locus mapping of Phomopsis resistance.     

Identification of reference genes for real-time quantitative polymerase chain reaction based gene expression studies on various Olive (Olea europaea L.) tissues

Reference genes are essential for the normalisation of the expression data of quantitative real-time PCR for the purposes of validation. Although several reference genes have been validated for the olive, comprehensive analyses including an excessive number of candidate reference genes still require study in various olive tissue samples. In this work, a total of 40 candidate reference genes were tested for their stability in 8 different olive tissues (root, apical bud, lateral bud, pedicel, young leaf, mature leaf, fruit mesocarp, and seed) with the utilisation of the most popular software programs including GeNorm, NormFinder, BestKeeper, and ΔC_t. The analyses of expression stability of candidate reference genes using quantitative real-time PCR demonstrated ubiquitin-conjugating enzyme (UBC1) as the most stable reference gene for the studied tissues of the olive. The GeNorm software also calculated the optimum reference gene combinations as two which consist of UBC1 and the Clathrin adaptor complex medium subunit (CLATHRIN) genes. This study provides the most stable reference gene combination for normalisation of target genes for quantitative real-time PCR gene expression studies on the olive.     

Public private partnerships in global food governance: business engagement and legitimacy in the global fight against hunger and malnutrition

This article compares two transnational public–private partnerships against hunger and malnutrition, the Global Alliance for Improved Nutrition and the International Alliance Against Hunger with regard to their degree of business involvement and their input and output legimacy. We examine the participation of stakeholders, the accountability and transparency of the decision-making process, and the perceived provision of a public good. We identify a link between business involvement and output legitimacy, and we discuss the implications for public and private food governance.     

The structure of the kinesin-1 motor-tail complex reveals the mechanism of autoinhibition

When not transporting cargo, kinesin-1 is autoinhibited by binding of a tail region to the motor domains, but the mechanism of inhibition is unclear. We report the crystal structure of a motor domain dimer in complex with its tail domain at 2.2 angstroms and compare it with a structure of the motor domain alone at 2.7 angstroms. These structures indicate that neither an induced conformational change nor steric blocking is the cause of inhibition. Instead, the tail cross-links the motor domains at a second position, in addition to the coiled coil. This "double lockdown," by cross-linking at two positions, prevents the movement of the motor domains that is needed to undock the neck linker and release adenosine diphosphate. This autoinhibition mechanism could extend to some other kinesins.