Examination of 330 samples of animal feed ingredients for the presence of a number of mycotoxins has been carried out. These samples were drawn from 186 animal feed mills in the United Kingdom. Aflatoxin B1 was the mycotoxin found most frequently, occurring in most samples of rice bran, maize products, palm kernels and cottonseed, but not in only 3 out of 20 samples of sunflower, in 1 out of 20 samples of soya and in no samples of peas, beans or manioc. Analytical difficulties were met with some combinations of commodity and mycotoxin and all results are uncorrected for recovery. The highest level was detected in a sample of maize gluten: 41 micrograms/kg of aflatoxin B1 (47 micrograms/kg total aflatoxins). Maize products also frequently contained fumonisins B1 and B2 at levels up to nearly 5,000 micrograms/kg in total and zearalenone up to a maximum level of 500 micrograms/kg. Ochratoxin A and citrinin were found in approximately 20% of wheat and barley samples. One sample of barley contained ochratoxin A at a level of 102 micrograms/kg and citrinin at a level of 8 micrograms/kg. Low levels of ochratoxin A also occurred in a few samples of other ingredients: rice bran, palm kernel and beans. Sterigmatocystin at 18 micrograms/kg was found in one sample of organically grown wheat and a trace amount of zearalenone in one sample of manioc. Multi-mycotoxin contamination also occurred, particularly in some samples of maize for which 19 out of 50 samples contained both aflatoxins and fumonisins.

Resistance to rose rosette disease (RRD), a fatal disease of roses (Rosa spp.), is a high priority for rose breeding. As RRD resistance is time-consuming to phenotype, the identification of genetic markers for resistance could expedite breeding efforts. However, little is known about the genetics of RRD resistance. Therefore, we performed a quantitative trait locus (QTL) analysis on a set of inter-related diploid rose populations phenotyped for RRD resistance and identified four QTLs. Two QTLs were found in multiple years. The most consistent QTL is qRRV_TX2WSE_ch5, which explains approximately 20% and 40% of the phenotypic variation in virus quantity and severity of RRD symptoms, respectively. The second, a QTL on chromosome 1, qRRD_TX2WSE_ch1, accounts for approximately 16% of the phenotypic variation for severity. Finally, a third QTL on chromosome 3 was identified only in the multiyear analysis, and a fourth on chromosome 6 was identified in data from one year only. In addition, haplotypes associated with significant changes in virus quantity and severity were identified for qRRV_TX2WSE_ch5 and qRRD_TX2WSE_ch1. This research represents the first report of genetic determinants of resistance to RRD. In addition, marker trait associations discovered here will enable better parental selection when breeding for RRD resistance and pave the way for marker-assisted selection for RRD resistance.

Rose rosette disease (RRD), caused by the Rose rosette emaravirus (RRV), is a major threat to the garden rose industry in the United States. There has been limited work on the genetics of host plant resistance to RRV. Two interconnected tetraploid garden rose F1 biparental mapping populations were created to develop high-quality tetraploid rose linkage maps that allowed the discovery of RRD resistance quantitative trait loci (QTLs) on linkage groups (LGs) 5, 6, and 7. These QTLs individually accounted for around 18–40% of the phenotypic variance. The locus with the greatest effect on partial resistance was found in LG 5. Most individuals with the LG 5 QTL were in the simplex configuration; however, two individuals were duplex (likely due to double reduction). Identification of resistant individuals and regions of interest can help the development of diagnostic markers for marker-assisted selection in a breeding program.

Rose rosette disease, caused by rose rosette virus (RRV), is an epidemic affecting nearly every rose cultivar in the United States. The only hosts for Phyllocoptes fructiphilus, the eriophyid mite that vectors RRV, are Rosa species. Eighteen Rosa species were evaluated for mite resistance by collecting foliage samples from July to November in 2016 and 2017, from which mites were extracted. Mites were isolated through a series of sieves and counted using a stereomicroscope. The response variable was expressed as the number of mites per gram of optimal rose tissue. Mite data were evaluated to determine the peak week for mite populations for each year. The mite populations varied by rose species (α = 0.05) in 2016 but not 2017. Due to high variability in mite counts, the species were not as clearly distinguishable as expected. This high variability is likely due to factors such as differential growth rates of the roses, weather, presence of RRV in the rose, and the quality of the tissue collected throughout the season. Experimental design revisions are proposed for future studies looking at Rosa species resistance to eriophyid mite populations. Index words: rose rosette virus, rose rosette disease, Phyllocoptes fructiphilus Keifer, virus, vector. Species used in this study: Phyllocoptes fructiphilus (Keifer), Prairie Rose [Rosa arkansana (Porter), Forest Farm]; Carolina Rose [Rosa carolina (L.), Forest Farm]; Rosa clinophylla (Thory), Rogue Valley Rose; White Prairie Rose [Rosa foliolosa (Nutt.), Rogue Valley Rose]; White Prairie Rose [Rosa foliolosa (Nutt.) Antique Rose Emporium]; Father Hugo Rose [Rosa hugonis, Rogue Valley Rose]; Musk Rose [Rosa moschata (J. Herrm.), Antique Rose Emporium]; Multiflora Rose [Rosa multiflora (Thunb.)]; Shining Rose [Rosa nitida (Willd.), Rogue Valley Rose]; Shining Rose [Rosa nitida (Willd.), Antique Rose Emporium]; Nootka Rose [Rosa nutkana (C. Presl.), Rogue Valley Rose]; Tea Rose [Rosa odorata (Andrews), Foundation Plant Services, Davis, CA]; Swamp Rose [Rosa palustris (Marshall), Antique Rose Emporium]; Swamp Rose [Rosa palustris (Marshall), Ever Blooming Antique Rose Emporium]; Chestnut Rose [Rosa roxburghii (Tratt.), Antique Rose Emporium]; ‘Plena' Chestnut Rose [Rosa roxburghii (Tratt.), Rogue Valley Rose]; Rugosa Rose [Rosa rugosa (Thunb.), Bailey's Nursery]; ‘Alba' Rugosa Rose [Rosa rugosa (Thunb.), Bailey's Nursery]; Climbing Prairie Rose [Rosa setigera (Michx.), Antique Rose Emporium]; Rosa soulieana (Crép.), Ralph Moore; Virginia Rose [Rosa virginiana (Mill.), Forest Farm]; Porterfolia Memorial Rose [Rosa wichuraiana (Crép.), Antique Rose Emporium]; Mountain Woods' Rose [Rosa woodsii (Lindl.), Rogue Valley Rose].

The eriophyid mite, Phyllocoptes fructiphilus, vectors the causal agent, Rose rosette virus (RRV), that results in rose rosette disease. Parts of the southeastern United States have remained free of the disease, except for infected plant material introductions that were eradicated. A survey of sampling points through Alabama, Georgia, and Mississippi (n = 204) revealed the southeastern border of RRV. The presence of RRV in symptomatic plant tissue samples (n = 39) was confirmed by TaqMan-quantitative reverse transcription polymerase chain reaction (RT-qPCR). Samples were also collected at every plot for detection of eriophyid mites, specifically for P. fructiphilus. Three different species of eriophyid mites were found to be generally distributed throughout Alabama, Georgia, and Mississippi. Most of these sites (n = 60) contained P. fructiphilus, found further south than previously thought, but in low populations (<10 mites/gram of tissue) south of the RRV line of incidence. Latitude was found to be significantly correlated with the probability of detecting RRV-positive plants, but plant hardiness zones were not. Plot factors such as plant size, wind barriers, and sun exposure were found to have no effect on P. fructiphilus or the presence of RRV. The reason for the absence of RRV and low populations of P. fructiphilus in this southeast region of the United States are unclear.