Papers by Katherine Steele
Food Chemistry, Function and Analysis, 2019
Basmati rice is a high-value, aromatic rice with unique eating properties grown in Northern India... more Basmati rice is a high-value, aromatic rice with unique eating properties grown in Northern India and Pakistan. Because of its high value, it is susceptible to adulteration with non-Basmati rice. When research commenced, 15 varieties of rice were approved as Basmati by the Indian and Pakistani authorities. DNA microsatellites were chosen as DNA markers for Basmati authenticity, and a 10-microsatellite protocol developed to identify both Basmati and non-Basmati varieties. Also, a quantitative test was developed using one of the microsatellites. This protocol was used for a UK-wide survey of the Basmati market, which showed serious levels of adulteration with non-Basmati. The DNA method was further developed, and an eight-microsatellite protocol was tested in an international ring trial. As part of the Government's programme to transfer DNA methodology to UK official control laboratories, new insertion and deletion (InDel) markers were chosen to adapt the test to a lab-on-a-chip p...
Forestry: An International Journal of Forest Research, 2021
Climate change is predicted to increase temperature and seasonal temperature variance in Great Br... more Climate change is predicted to increase temperature and seasonal temperature variance in Great Britain (GB). Sitka spruce (Picea sitchensis (Bong.) Carr) is the most important tree species used in commercial plantations throughout Europe and GB. Frosts that occur outside the winter dormancy period can negatively affect trees, since they happen after dehardening. Damage can be especially severe at bud burst, before emerging needles mature and form protective barriers. Here, we modelled the impact of climate change on frost sensitivity in Sitka spruce with temperature data from five climate projections. The UKCP09 climate model HadRm3 uses emission scenario SRESA1B for the years 2020–2099. The global and downscaled versions of the UKCP18 HadGem3 model use the emissions scenario RCP 8.5. The global model CMCC-CM uses the RCP 4.5 and RCP 8.5 emissions scenarios. The predictions based on these models were compared with results from gridded historical data for the period 1960–2015. Three ...
Food Analytical Methods, 2020
Authentication of Basmati rice has relied on microsatellite markers since 2004, but microsatellit... more Authentication of Basmati rice has relied on microsatellite markers since 2004, but microsatellites cannot distinguish between all of the forty-one Basmati varieties approved in 2017. This study investigated whether single nucleotide polymorphisms (SNP) and insertion/deletion (InDel) variations developed into KASP™ (Kompetitive Allele Specific PCR; LGC Biosearch Technologies) could be used to distinguish between commercial Basmati varieties. Suitable loci were identified by comparing whole genome sequences of 120 diverse rice accessions. Sequences flanking these loci were standardized across a wide range of rice genomes to produce optimal KASP designs. We selected 364 KASP designs to use for genotyping; they were either near to informative microsatellite markers, within the Badh2 and Waxy genes, or distributed throughout the rice genome. Genotypes for 327 KASP were obtained with 255 loci revealing polymorphism in up to 41 samples of approved Basmati varieties and 20 non-Basmati vari...
A study was carried out with the aim of establishing whether Phytophthora infestans exhibits host... more A study was carried out with the aim of establishing whether Phytophthora infestans exhibits host specificity on tomato in Great Britain. Samples of P. infestans were collected from tomato crops throughout Great Britain, and genotyped using an 11 SSR marker set adapted from that published by Li et al. (2013). Significant differences were observed between the samples collected from tomato and published data for P. infestans genotypes collected from British potato crops, with fewer 6_A1 and more 23_A1 and Miscellaneous genotypes on tomato. Further work is needed to establish the reasons for this.
American Journal of Experimental Agriculture, 2015
Aims: To determine the genetic diversity existing within the Kenyan dry bean using SSR markers. P... more Aims: To determine the genetic diversity existing within the Kenyan dry bean using SSR markers. Place and Duration of Study: This study was conducted in Western Kenya and Bangor University, North Wales, between September 2010 and December 2012. Methodology: Thirty five (35) marketable dry bean samples collected from farmers, market centers as well as seed stockists were subjected to SSR analysis. Data generated was subjected to analysis with the GenAlEx 6.4 software assuming Hardy-Weinberg equilibrium to determine gene diversity index, number of polymorphic loci and alleles, genetic distances, analysis of molecular Original Research Article
Plant Pathology, 2001
Since its initial detection in Australia in 1979, wheat yellow (stripe) rust (Puccinia striiformi... more Since its initial detection in Australia in 1979, wheat yellow (stripe) rust (Puccinia striiformis f.sp. tritici) has evolved in Australia and New Zealand into more than 20 pathotypes with assorted virulence characteristics. This evolution is believed to have occurred in a stepwise fashion from an original single pathotype, with no subsequent new introductions. A combination of random amplified polymorphic DNA (RAPDs) and amplified fragment length polymorphisms (AFLPs) was used to examine the level of molecular variation in Australian and New Zealand isolates, and to compare this with variation amongst other isolates of P. striiformis. Using 60 RAPD primers on seven Australian isolates representing seven different pathotypes collected between 1979 and 1991, more than 300 potentially polymorphic loci were analysed and no polymorphisms were detected. Using the same primers on two UK isolates, 3% of loci showed a polymorphism. A similar level of polymorphism was found between UK isolates using AFLP primers, and between 5 and 15% of fragments were polymorphic between an isolate from the UK, an isolate from Denmark, and one from Colombia. However, no AFLP polymorphisms were found amongst 14 Australian and New Zealand isolates tested, at over 100 potentially polymorphic loci. The lack of molecular variation in the Australian and New Zealand collection is consistent with the stepwise mutation theory of pathotype evolution from a single introduction.
Genetic Resources and Crop Evolution, 2011
... Lam. Biodivers Conserv 14:1047–1057 Chalmers K, Waugh R, Sprent J, Simons A, Powell W (1992) ... more ... Lam. Biodivers Conserv 14:1047–1057 Chalmers K, Waugh R, Sprent J, Simons A, Powell W (1992) Detection of genetic variation between and within prove-nances of Gliricidia sepium and G. maculata using RAPD markers. ...
Field Crops Research, 2002
Root morphological characteristics are known to be important in the drought resistance of some ri... more Root morphological characteristics are known to be important in the drought resistance of some rice (Oryza sativa L.) varieties. As part of a research programme aimed at using molecular marker technology for the improvement of drought resistance in rice, it is necessary to identify quantitative trait loci (QTLs) associated with root morphology and other drought resistance-related traits. Stability across environments is critically important for the identi®cation of root growth QTLs that are valuable in breeding. Here, a mapping population of 140 recombinant inbred lines and the parental varieties Bala and Azucena were screened for root growth in thin glass-sided soil-®lled chambers. In each of 2 years, two treatments were used: an early water de®cit (WD0) in which seeds were sown into wet soil but received no more water, and a late water de®cit (WD49) in which the plants were watered for 49 days and water was withheld for a ®nal 7 days. Plant height, visible root growth, soil moisture at four depths and water use were monitored weekly. After 56 days, shoot mass, relative water content, root mass in four depth sections and adventitious root thickness at two depths were measured. In the WD0 treatment, shoot growth slowed markedly, while maximum root length was increased, indicating major changes in partitioning. This change in partitioning was also revealed as major differences in root mass (total and at depth) and root to shoot ratio between treatments. There were also large differences in partitioning between similar treatments in different years, which may in part re¯ect plant responses to soil water and nutrient status. In both treatments, water was extracted ®rst from the upper sections of the rooting zone and then from progressively deeper layers. Effective water extraction required a root length density of at least 0.4 cm cm À3 in both treatments, and in the WD49 treatment water extraction at 100 cm depth was also related to shoot size and stomatal conductance. Azucena had thicker roots and more roots at depth compared to Bala, which slowed shoot growth sooner and became less water-stressed than Azucena. Azucena has root traits that potentially contribute to drought resistance, while Bala has a number of shoot-related mechanisms that make it adapted to drought-prone environments. The data presented here have been used to identify QTLs for root growth traits in a companion paper.
Euphytica, 2011
Naked (hulless) barley was neglected by plant breeders in Europe during the period of intensive c... more Naked (hulless) barley was neglected by plant breeders in Europe during the period of intensive crop improvement in the 20th Century, but it is now receiving renewed interest due to the potential health benefits it can convey. Very few naked barley cultivars have been developed for modern UK or European agricultural systems, in contrast to the wide diversity of naked barley in Asia. Prior to initiating any breeding programme, phenotyping in UK field conditions is needed to assess the value of existing exotic landraces. This article reports such a programme where naked barley landrace lines were grown alongside modern cultivars and unimproved UK hulled landrace lines over 4 years at a research station in North Wales and assessed for yield and agronomic traits. Multivariate analysis of the traits suggested that accessions clustered by region of origin. Himalayan landrace lines formed Eastern and Western clusters while Japanese and Korean landrace lines were distinct from these. European naked barleys were found to be closest to European hulled barleys, suggesting that the distinctiveness of the Asian naked barley landrace lines was due to origin rather than the naked grain trait per se. The only agronomic trait that could be attributed to naked grain was poorer crop establishment, but some Himalayan landrace lines showed vigorous seedling growth. Modern lines of naked barley from Syria gave superior yields to old UK hulled barleys, indicating that there is potential for breeding modern UK cultivars of naked barley.
All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
Theoretical and Applied Genetics, 2000
A combined RFLP and AFLP linkage map of an F 6 recombinant inbred population, which was derived f... more A combined RFLP and AFLP linkage map of an F 6 recombinant inbred population, which was derived from a previously mapped F 2 of a cross between the two drought resistant upland rice varieties Bala and Azucena, is presented. The map contains 101 RFLP and 34 AFLP markers on 17 linkage groups covering 1680 cM. Also presented is the approximate mapping position of a further four RFLP and 75 AFLP markers, which either could not be given a unique place on the map or for which the available data is not sufficient to allow confident positioning, and the result of quantitative trait locus (QTL) mapping of traits related to root-penetration ability. Root penetration was assessed by counting the number of root axes that penetrated a 3 mm-thick layer consisting of 80% wax and 20% white soft paraffin. Good root penetration would be expected to increase drought resistance where soil strength is high. Single-marker analysis revealed seven QTLs for the number of roots which penetrate the wax layer. In identical locations were seven QTLs for the ratio of penetrated to the total number of roots. Transgressive inheritance of positive alleles from Bala explained four of these QTLs. Comparison of the QTLs identified here with previous reports of QTLs for root morphology suggest that alleles which improve root penetration ability may also either make the roots longer or thicker.
Field Crops Research, 2013
Abstract Low glycemic index (GI) grains with high levels of β glucan soluble fibre are beneficial... more Abstract Low glycemic index (GI) grains with high levels of β glucan soluble fibre are beneficial for health. Naked barley (Hordeum vulgare L.) cultivars generally have higher grain β glucan contents than hulled barley, but lower yields. Naked grain requires no pearling or processing for use in wholegrain health foods and it is widely recognised that consumption of wholegrain barley is beneficial for health. Nearly all commercially available UK barley cultivars are hulled and have been bred for low (
Journal of Cereal Science, 2011
(1,3:1,4)-β-d-Glucan is an important bioactive that contributes to the ability of barley foods to... more (1,3:1,4)-β-d-Glucan is an important bioactive that contributes to the ability of barley foods to help prevent type-2 diabetes. Realisation of these benefits requires understanding of genotype and environment effects on β-glucan concentration and how this variation affects biological activity of barley foods. Field experiments showed genetic variation in β-glucan concentration (3.0–7.0 g/100 g DM), but also considerable variation between environments. β-Glucan concentrations
Journal of Cereal Science, Jan 1, 2011
(1,3:1,4)-β-d-Glucan is an important bioactive that contributes to the ability of barley foods to... more (1,3:1,4)-β-d-Glucan is an important bioactive that contributes to the ability of barley foods to help prevent type-2 diabetes. Realisation of these benefits requires understanding of genotype and environment effects on β-glucan concentration and how this variation affects biological activity of barley foods. Field experiments showed genetic variation in β-glucan concentration (3.0–7.0 g/100 g DM), but also considerable variation between environments. β-Glucan concentrations were lower in the wet summer of 2007 than 2006 or 2009; and slightly less in the dry summer of 2006 than 2009. β-Glucan was not diluted by higher grain yields. The role of β-glucan as an assimilate buffer adds complexity to interpreting the effects of environment during grain filling. Autumn sowing and fungicide increased the duration of grain filling, decreased β-glucan concentration but increased environmental stability; possibly due to lower demand for assimilate buffering. Lodging and foliar disease decreased β-glucan concentration, by decreasing assimilate supply leading to remobilisation of carbohydrate from β-glucan, so that fungicide increased β-glucan in some disease-susceptible accessions. Sequential harvesting starting at GS 91 suggested an optimum harvest window for maximum β-glucan concentration. The variability in β-glucan reported here between genotypes and environments was sufficient to affect control of post-prandial blood glucose in healthy volunteers.
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Papers by Katherine Steele