Importance of Leptosphaeria biglobosa as a cause of phoma stem canker on winter oilseed rape in the UK

Phoma stem canker is a major disease of oilseed rape in the UK, leading to annual yield losses worth more than £100M. The disease is caused by two closely related species, Leptosphaeria maculans and L. biglobosa. L. maculans is generally considered more damaging, causing stem base canker; L. biglobosa is generally less damaging, causing upper stem lesions. Therefore, previous work has mainly focused on L. maculans and there has been little work on L. biglobosa. This work investigated the contribution of L. biglobosa to stem canker epidemics by assessing the amounts of DNA of L. maculans and L. biglobosa in upper stem lesions or stem base cankers on winter oilseed rape cultivars with different types of resistance against L. mac ulans. Diseased upper stem and stem base samples were collected from nine oilseed rape cultivars in a 2011/2012 field experiment at Rothamsted. The presence of L. maculans or L. biglobosa in each stem sample was detected by speciesspecific PCR. The abundance of L. maculans or L. biglobosa in each stem sample was measured by quantification of L. maculans DNA and L. biglobosa DNA using quantitative PCR (qPCR). The amounts of L. biglobosa DNA were greater than those of L. maculans DNA in both upper stem and stem base samples. These results suggest that the severe upper stem lesions and stem base cankers in the 2011/2012 cropping season were mainly caused by L. biglobosa, suggesting that L. biglobosa can sometimes cause considerable yield loss in the UK. There were differences between cultivars in the amounts of L. maculans DNA and L. biglobosa DNA, with the susceptible cultivar Drakkar having more L. maculans DNA than L. biglobosa DNA while resistant cultivars had less L. maculans DNA than L. biglobosa DNA. These results suggest that L. biglobosa can be an important cause of phoma stem canker on oilseed rape in the UK.Peer reviewedFinal Published versio

Effectiveness of Rlm7 resistance against Leptosphaeria maculans (phoma stem canker) in UK winter oilseed rape cultivars

© 2018 The Authors. Plant Pathology published by John Wiley & Sons Ltd on behalf of British Society for Plant Pathology. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.The Rlm7 gene in Brassica napus is an important source of resistance for control of phoma stem canker on oilseed rape caused by the fungus Leptosphaeria maculans. This study shows the first report of L. maculans isolates virulent against Rlm7 in the UK. Leptosphaeria maculans isolates virulent against Rlm7 represented 3% of the pathogen population when cultivars with the Rlm7 gene represented 5% of the UK oilseed rape area in 2012/13. However, the Rlm7 gene has been widely used since then, representing >15% of the UK oilseed rape area in 2015/16. Winter oilseed rape field experiments included cultivars with the Rlm7 gene, with the Rlm4 gene or without Rlm genes and took place at five sites in the UK over four cropping seasons. An increase in phoma leaf spotting severity on Rlm7 cultivars in successive seasons was observed. Major resistance genes played a role in preventing severe phoma leaf spotting at the beginning of the cropping season and, in addition, quantitative resistance (QR) in the cultivars examined made an important contribution to control of phoma stem canker development at the end of the cropping season. Deployment of the Rlm7 resistance gene against L. maculans in cultivars with QR in combination with sustainable disease management practices will prolong the use of this gene for effective control of phoma stem canker epidemics.Peer reviewe

Evaluation of oilseed rape seed yield losses caused by Leptosphaeria biglobosa in central China

This document is the Accepted Manuscript version of the following article: Xiang Cai, Yongju Huang, Daohong Jiang, Bruce D. L. Fitt, Guoqing Li, and Long Yang, "Evaluation of oilseed rape seed yield losses caused by Leptosphaeria biglobosa in central China", European Journal of Plant Pathology, first published 9 June 2017. Under embargo. Embargo end date: 9 June 2018. The final publication is available at Springer via: http://dx.doi.org/10.1007/s10658-017-1266-x.Phoma stem canker of oilseed rape (Brassica napus), caused by Leptosphaeria maculans/L. biglobosa is a globally important disease. Severe phoma stem canker symptoms have been observed on winter oilseed rape in China but the seed yield loss caused by this disease remains unknown. In May 2012 and May 2013, 17 and 13 crops were surveyed, respectively, in seven counties of Hubei Province, central China. Stems with phoma stem canker disease symptoms were sampled for pathogen isolation and identification. Only L. biglobosa was identified by culture morphology and species-specific PCR; no L. maculans was found. To evaluate the yield losses, yield components (number of branches per plant, number of pods per plant, 1000-seed weight, number of seeds per pod) were assessed on healthy and diseased plants sampled from crops in four counties and on plants from inoculated pot experiments (plants of three cultivars were inoculated at the green bud stage by injecting L. biglobosa conidia into the stem between the first and second leaf scars). Results of the field surveys showed that diseased plants had 14–61% less branches and 32–83% less pods than healthy plants, respectively. The estimated seed yield loss varied from 10% to 21% and from 13% to 37% in 2012 and 2013, respectively. In the pot experiments, there were no differences in numbers of branches or pods but there were differences in number of seeds per pod between inoculated and control plants. For the three cultivars tested, the inoculated plants had yield losses of 29–56% compared with the control. This study indicates that L. biglobosa could cause substantial seed yield loss in China.Peer reviewedFinal Accepted Versio

Mathematical Modeling of Quadcopter Dynamics

Recently, Google, Amazon and others are attempting to develop delivery drones for commercial use, in particular Amazon Prime Air promising 30 minute delivery. One type of commonly used drone proposed for such purposes is a quadcopter. Quadcopters have been around for some time with original development in the 1920’s. They are popular now because they are mechanically simple and provide a good vehicle for unmanned flight. By controlling the speed of the four propellers, a quadcopter can roll, change pitch, change yaw, and accelerate. This research will focus on the study of classical mechanics theories on rigid body motion using the modern mathematical formulation which is based on Lie Group Theory and Differential Topology (abstract manifolds). The goal of this research is to develop a mathematical model for kinematics and dynamics of a quadcopter, and the algorithms for trajectory control

Mathematical Modeling of Quadcopter Dynamics

Recently, Google, Amazon and others are attempting to develop delivery drones for commercial use, in particular Amazon Prime Air promising 30 minute delivery. One type of commonly used drone proposed for such purposes is a quadcopter. Quadcopters have been around for some time with original development in the 1920’s. They are popular now because they are mechanically simple and provide a good vehicle for unmanned flight. By controlling the speed of the four propellers, a quadcopter can roll, change pitch, change yaw, and accelerate. This research will focus on the study of classical mechanics theories on rigid body motion using the modern mathematical formulation which is based on Lie Group Theory and Differential Topology (abstract manifolds). The goal of this research is to develop a mathematical model for kinematics and dynamics of a quadcopter, and the algorithms for trajectory control

THE IMPACT OF SWINE PRODUCTION ON LAND VALUES IN ILLINOIS

Based on a spatiotemporal hedonic farmland price model and county-level data in Illinois from 1979 to 1999, we examined the impact of swine production on farmland values. Our results show that, in addition to the conventional determinants of farmland values, an increase in swine production intensity has a negative relationship with farmland values while an increase in swine operation scale had a positive association with farmland values at the county level in Illinois. We also estimate the impact of changes in the Illinois swine industry over the period 1980-1999 on farmland values at the state level and find that changes in swine inventory and scale of swine operations have led to changes in farmland prices from $-10.56 to$62.96 per acre. In general, the changes in Illinois swine industry increase farmland values in Illinois.Land Economics/Use,

Morse Quasiflats II

This is the second in a two part series of papers concerning Morse quasiflats - higher dimensional analogs of Morse quasigeodesics. Our focus here is on their asymptotic structure. In metric spaces with convex geodesic bicombings, we prove asymptotic conicality, uniqueness of tangent cones at infinity and Euclidean volume growth rigidity for Morse quasiflats. Moreover, we provide some immediate consequences.Comment: This paper and "Morse quasiflat I" were originally posted as a single paper arXiv:1911.04656v1. We have added several new results and rewritten the proof of the main theorem to improve readability. v2: minor corrections. v3: many modifications in the introduction, add a more detailed discussion of proofs with pictures in Section 4, add a short appendix on quasi-isometric classification. 3 Figure

Glycomic analysis of high density lipoprotein shows a highly sialylated particle.

Many of the functional proteins and lipids in high density lipoprotein (HDL) particles are potentially glycosylated, yet very little is known about the glycoconjugates of HDL. In this study, HDL was isolated from plasma by sequential micro-ultracentrifugation, followed by glycoprotein and glycolipid analysis. N-Glycans, glycopeptides, and gangliosides were extracted and purified followed by analysis with nano-HPLC Chip quadrupole time of flight mass spectrometry and MS/MS. HDL particles were found to be highly sialylated. Most of the N-glycans (∼90%) from HDL glycoproteins were sialylated with one or two neuraminic acids (Neu5Ac). The most abundant N-glycan was a biantennary complex type glycan with two sialic acids (Hexose5HexNAc4Neu5Ac2) and was found in multiple glycoproteins using site-specific glycosylation analysis. The observed O-glycans were all sialylated, and most contained a core 1 structure with two Neu5Acs, including those that were associated with apolipoprotein CIII (ApoC-III) and fetuin A. GM3 (monosialoganglioside, NeuAc2-3Gal1-4Glc-Cer) and GD3 (disialoganglioside, NeuAc2-8NeuAc2-3Gal1-4Glc-Cer) were the major gangliosides in HDL. A 60% GM3 and 40% GD3 distribution was observed. Both GM3 and GD3 were composed of heterogeneous ceramide lipid tails, including d18:1/16:0 and d18:1/23:0. This report describes for the first time a glycomic approach for analyzing HDL, highlighting that HDL are highly sialylated particles