A metagenetic approach to determine the diversity and distribution of cyst nematodes at the level of the country, the field and the individual.

Distinct populations of the potato cyst nematode (PCN) Globodera pallida exist in the UK that differ in their ability to overcome various sources of resistance. An efficient method for distinguishing between populations would enable pathogen-informed cultivar choice in the field. Science and Advice for Scottish Agriculture (SASA) annually undertake national DNA diagnostic tests to determine the presence of PCN in potato seed and ware land by extracting DNA from soil floats. These DNA samples provide a unique resource for monitoring the distribution of PCN and further interrogation of the diversity within species. We identify a region of mitochondrial DNA descriptive of three main groups of G. pallida present in the UK and adopt a metagenetic approach to the sequencing and analysis of all SASA samples simultaneously. Using this approach, we describe the distribution of G. pallida mitotypes across Scotland with field-scale resolution. Most fields contain a single mitotype, one-fifth contain a mix of mitotypes, and less than 3% contain all three mitotypes. Within mixed fields, we were able to quantify the relative abundance of each mitotype across an order of magnitude. Local areas within mixed fields are dominated by certain mitotypes and indicate towards a complex underlying 'pathoscape'. Finally, we assess mitotype distribution at the level of the individual cyst and provide evidence of 'hybrids'. This study provides a method for accurate, quantitative and high-throughput typing of up to one thousand fields simultaneously, while revealing novel insights into the national genetic variability of an economically important plant parasite.

High-throughput diagnosis of potato cyst nematodes in soil samples.

Potato cyst nematode (PCN) is a damaging soilborne pest of potatoes which can cause major crop losses. In 2010, a new European Union directive (2007/33/EC) on the control of PCN came into force. Under the new directive, seed potatoes can only be planted on land which has been found to be free from PCN infestation following an official soil test. A major consequence of the new directive was the introduction of a new harmonized soil sampling rate resulting in a threefold increase in the number of samples requiring testing. To manage this increase with the same staffing resources, we have replaced the traditional diagnostic methods. A system has been developed for the processing of soil samples, extraction of DNA from float material, and detection of PCN by high-throughput real-time PCR. Approximately 17,000 samples are analyzed each year using this method. This chapter describes the high-throughput processes for the production of float material from soil samples, DNA extraction from the entire float, and subsequent detection and identification of PCN within these samples.

Ageing, cognitive disorders and professional practice.

BACKGROUND: the workforce is ageing. The contribution of older workers is considerable. Their occupational health profiles differ from those of younger workers. OBJECTIVE: we wished to establish whether consideration has been given by regulatory and professional bodies of the impact of ageing-related conditions such as dementia on professional practice. METHODS: We e-mailed a questionnaire to 22 regulatory and professional bodies in the UK and the Republic of Ireland. We asked whether there are supports for their practitioners should they develop age-related diseases, (particularly cognitive disorders),whether the body considered that the practitioner was responsible for their own health, and whether the body has resources to arrange for medical review for their professionals if concerns arose regarding competence. Where bodies did not respond, information relating to the questions was extracted from their on-line resources. RESULTS: thirteen bodies responded. None of these had specific supports to assist older workers. Some knew of other supports (occupational health, employee assistance supports, benevolent funds or counselling services). All of the bodies who responded either have or are developing structures to deal with concerns regarding their practitioners. CONCLUSION: The absence of specific policies for age-related diseases, (particularly dementia), among professional and regulatory bodies is a challenge for an ageing workforce in the liberal professions. Closer working between geriatric medicine, old age psychiatry, occupational health and professional bodies is recommended to develop age-attuned policies and systems which protect the public while supporting the professionals in both work and timely transition from work.

Potato cultivar genome analysis.

Due to the yearly increase in the numbers of new potato varieties obtaining Plant Breeders' Rights the reliable maintenance of large culture collections of reference varieties for DUS testing is becoming more and more difficult, as accidental mix ups might occur. Efficient identification methods and databases can act as an aid to overcome this problem. Identification of cultivars by morphological characteristics is a highly skilled and time-consuming task, and for these reasons a rapid and robust method for variety differentiation has become extremely desirable. By use of a set of nine microsatellite (SSR) markers we can differentiate over 1,000 cultivars, including the majority of varieties on the European Union Common Catalogue, but excluding somaclonal variants (e.g. Red King Edward and King Edward) and mutants. The whole identification process from DNA extraction to accurate identification can be carried out in a single day.

PCR detection of potato cyst nematode.

Potato cyst nematode (PCN) is responsible for losses in potato production totalling millions of euros every year in the EC. It is important for growers to know which species is present in their land as this determines its subsequent use. The two species Globodera pallida and Globodera rostochiensis can be differentiated using an allele-specific PCR.