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Mycotoxins that contaminate grain can cause the devaluation of agricultural products and create health risks for the consumer. Fumonisins are one such mycotoxin. Produced primarily by Fusarium verticillioides (Hypocreales: Nectriaceae) (Nirenberg, 1976) on corn, fumonisins' economic impact can be significant by causing various diseases in livestock if contaminated corn is not monitored and removed from animal feed. Finding safe alternatives to the destruction and waste of contaminated grain and restoring its economic value is needed for a sustainable future. Safe reintroduction into the farm food web may be possible through a consumable intermediary such as insects. This study demonstrates the suitability of the house cricket, Acheta domesticus L. as an alternative protein source in domestic animal feed by quantifying fumonisin B1 (FB1) levels in their subsequent insect meal and frass. Small colonies of 2nd instar A. domesticus were reared to 5th instar adults on nutrient-optimized corn-based diets treated with 4 levels of FB1 from 0 to 20 ppm. Increasing levels of FB1 had no adverse effects on the survivorship or growth of A. domesticus. Insect meals prepared from A. domesticus had significantly lower levels of FB1, at 3%–5% of their respective diets, while frass did not differ significantly from their diet. The successful rearing to adulthood of A. domesticus on fumonisin-contaminated diet paired with lower levels of FB1 in their processed insect meal supports the idea that more sustainable agricultural practices can be developed through remediation of low-value mycotoxin-contaminated grain with safer, higher-value insects as livestock feed components. [ABSTRACT FROM AUTHOR]

Aflatoxin is a carcinogenic and toxic compound produced by the fungus Aspergillus flavus (Link:fr) that can be found at detrimentally high concentrations in maize (Zea mays L.) grain. Screening has led to the discovery of sources of resistance to aflatoxin accummulation in maize, but associated poor agronomic characteristics and complex inheritance have limited transfer of resistance to elite inbreds. A set of 210 [F.sub.2:3] families derived from a cross between inbred lines Mp313E (resistant) and B73 (susceptible) was evaluated in replicated trials in four environments for resistance to aflatoxin accumulation. Families were also genotyped using simple sequence repeal (SSR) markers to develop a genetic map for quantitative trait loci (QTL) analysis. Composite interval mapping (CIM) was used to identify 2, 3, 5, and 3 QTL within the tests at Stoneville (2000) and Mississippi Stale (2000, 2001, 2002), respectively. The QTL were primarily additive in nature, with Mp313E contributing to reduced aflatoxin concentration in all but one case. Two QTL regions were significant in at least three environments. The afl3 locus, represented by marker bnlg371, was located on chromosome two and accounted for 7 to 18% of variation in aflatoxin levels depending on environment. The afl5 locus, represented by marker bnlg2291, was located on chromosome four, with explained variance ranging from 8 to 18%. This QTL has been noted in earlier studies whereas afl3 is new. Identified QTL confirm important regions influencing aflatoxin accumulation previously identified and present new ones of equal effect., AFLATOXINS ARE TOXIC secondary metabolites produced by the fungal pathogen Aspergillus flavus. These toxins have carcinogenic, immunosuppressive, and hepatotoxic properties in animals (Castegnaro and McGregor, 1998). Aflatoxin B1 is the [...]

Film-coating is a widely used technology to apply plant protection agents, beneficial microorganisms, and other substances to seeds. During handling and planting operations, fragments of the seed coat can become detached by mechanical abrasion and are released into the environment. Modest reductions in abrasion losses have been achieved by selecting polymers and formulations with improved adherence to seed surfaces. The objective of this study was to investigate a novel approach for reducing abrasion risk with film-coated corn (Zea mays L.) seeds and to evaluate an improved image-based protocol for rapid and effective evaluation of seed abrasion. This study demonstrated that the risk of abrasion losses from film-coated corn seeds was minimized by removing the outer wax layer of the seed pericarp prior to applying coat formulations. Removal of the outer wax layer did not affect seed germination or seedling growth, but it did improve the adhesion strength of the coat to the seed surface and effectively reduced abrasion losses. Coating surface of dewaxed seeds with three different treatment formulations, viz., a commercial seed-coating polymer, a starch-based bioplastic and a soy protein isolate-based preparation, reduced fragment release by 97.6%, 94.8%, and 98.9%, respectively, with respect to non-surface dewaxed seeds. Seed coatings placed in soil for six days deteriorated 2.5% and 72.1% for commercial and bioplastic formulations, respectively, whereas the soy protein isolate coating formulation deteriorated almost completely under the same conditions. Thus, removing the outer wax layer before film-coating seeds and using novel seed coat formulations improved environmental profile of coated seeds. [ABSTRACT FROM AUTHOR]

Phytotoxin production by Myrothecium roridum Tode: Fries (IMI 394934) and in vitro bioactivity on water hyacinth leaves (WHL) were evaluated. Phytotoxin produced caused necrosis of WHL three days postapplication. Potato carrot broth and WHL broth formulations gave the highest phytotoxin production in culture. Phytotoxin production was light-dependent and peaked at pH 4.5. Xylose and glutamine were the best carbon and nitrogen sources, respectively. The phytotoxin was thermostable, and phytotoxicity was pH-dependent, but photoperiod-independent. Bioassay-guided fractionation indicated the active phytotoxin was roridin A. Phytotoxicity of roridin A and roridin E was similar (p > 0.05) to paraquat used for water hyacinth control. [ABSTRACT FROM AUTHOR]