Puccinia psidii is considered a biosecurity threat in Australia because of its broad host range that includes many species of Myrtaceae which dominate Australian ecosystems.Since it was first reported in this country, in April 2010, there has been little information about the population structure of the pathogen. In this study, six microsatellite loci were analysed to determine the genetic relationship among rust specimens from different hosts and locations in Australia, New Caledonia, Hawaii and China. The Chinese and New Caledonian specimens share a multi-locus genotype with the majority of the Australian specimens. The results also indicated a close relationship between Australian and Hawaiian samples. At present, the P. psidii population in Australia is genetically uniform with no evidence of sexual recombination. Five of the 104 collections varied by one allele at single loci, indicating that mutations are common but persistence of the mutants in the population may be less common.

Purpose The potential of the Cerrado fruit could be explored by development of new products, such as jellies that can be used to add value to the fruit, as well as to preserve this biome. This paper aims to evaluate the effect of processing, the glass packaging type and storage time on the quality of jelly, prepared from reconstituted murici pulp, over 12 months of storage. Design/methodology/approach The authors used a completely randomized design (CRD) in factorial 2 × 5, with two types of glass packaging (transparent and amber) and five storage periods (0, 3, 6, 9 and 12 months), with four replications and the experimental parcel consisting of 80 g of jelly (two bottles of 40 g). The quality of jelly was monitored through 12 months using physicochemical (proximal composition, color, soluble solids, titratable acidity and pH), microbiological (coliforms at 35 °C and 45 °C, filamentous fungi and Salmonella sp) and sensory analyses (sensory acceptance and purchase intent). Findings The pulp processing effectively affected the physicochemical and nutritional composition (proximal composition, soluble solids and color). It was found that only the storage time significantly influenced (p < 0.05) jelly quality, considering the variables analyzed, except the soluble solids, ash, dietary fiber and sensory texture attributes. However, the glass packaging factor (transparent and amber) did not result in significant changes in those variables. Moreover, the pulp processing allows a seasonal fruit with a short harvest period and short post-harvest life to be available to consumers as a new product throughout the year. Originality/value Based on the present study, the native Cerrado fruit such as murici [Byrsonima crassifolia (L.) Rich] is appreciated for its pleasant peculiarities such as color, aroma and taste; however, it is underutilized as food for lack of information and studies. Although the fruit does not have widespread use as food, it is necessary to make the population aware about its importance, not only as a source of nutrients, but also for its functional and sensory potential. Therefore, the production of murici jelly can increase consumption of the fruit, besides being a way to add value and extend the shelf life and sensory acceptance of the product prepared.

The antimicrobial activity of linalool, citral, eugenol and thymol was determined in growth studies of both planktonic (PC) and biofilm cells (BC) Shigella flexneri. These components were evaluated either in isolation or in combinations using a sequential experimental strategy with Plackett & Burman and central composite rotational designs totaling 47 treatments. The minimum inhibitory concentration for PC was 0.125% (v v−1) for linalool and 0.5% (v v−1) for citral, eugenol and thymol. The biofilm minimum bactericidal concentration was 3 and 1% (v v−1) for linalool and citral, respectively, and 2% (v v−1) for eugenol and thymol. In the mixtures, the minimum concentrations in the efficient assays for PC growth inhibition were 0.0003, 0.0443 and 0.0443% (v v−1), for linalool, citral and thymol, respectively. In the BC, only two assays with concentrations of 0.0558, 0.0558 and 0.319% (v v−1) and 0.035, 0.035 and 0.3999% (v v−1) for linalool, citral and thymol, respectively, inhibited Shigella growth. Synergism was observed among the components, where PC and BC growth inhibition occurred at lower concentrations than those noted individually. The bactericidal effect of the components in microplate was different from the observed in stain steel coupons. Therefore, the obtained model can describe and predict the PC count of S. flexneri in medium with the tested compounds and they could be an alternative for the use in microbiological control in food industry.

No abstract

Interest in rational use and reuse of water has increased in recent years, especially in forest nurseries. However, before water can be reused in nurseries, it must be properly treated to eradicate plant pathogens to reduce risks of pathogen dispersal and losses to disease. In the present study, the efficacy of irrigation water treatment by ultrafiltration and conventional physical-chemical treatment was studied to eliminate Botrytis cinerea, Cylindrocladium candelabrum, Ralstonia solanacearum, and Xanthomonas axonopodis, the pathogens most commonly found in Brazilian forest nurseries. Ultrafiltration eradicated over 99% of R. solanacearum, X. axonopodis, and B. cinerea and 100% of C. candelabrum. The few remaining cells or conidia of R. solanacearum and B. cinerea did not induce disease in irrigated rooted cuttings. Flocculation and fast sand filtration used in physical-chemical treatment completely eliminated C. candelabrum but the other pathogens were only removed after chlorination of the filtered water. Both forms of treatment are viable, practical, and safe methods for plant pathogen removal from irrigation water.