RESUMO
Mycotoxins pose a large threat to human and livestock besides reducing the quality of food/feed.It is believed that these toxins are biosynthesized as a mechanism of defense (stress-response) of fungi. The most important mycotoxin for winter-cereal crops is known by deoxynivalenol (DON), a trichothecene biosynthesized mainly by Fusarium graminearum. This manuscript brings data of three years (2018, 2019 and 2020) of field research (24 fieldexperiments) in Western Santa Catarina and North-Western Rio Grande do Sul, Brazil using a sulphated polysaccharide exclusive from red seaweed, carrageenan, associated with fungicides to help suppressing deoxynivalenol (DON) biosynthesis and accumulation in wheat kernels. A reduction of 36.4% in DON contamination was observed. Weather conditions have influenced the accumulation of DON in wheat kernels. Carrageenan has shown to be a biological compound capable of helping on the suppression of DON biosynthesis and accumulation in wheat kernels regardless of weather conditions.(AU)
As micotoxinas representam uma grande ameaça para humanos e animais, além de reduzirem a qualidade de alimentos/rações. Acredita-se que essas toxinas sejam biossintetizadas como mecanismo de defesa (resposta ao estresse) de fungos. A micotoxina de maior interesse para cereais de inverno é conhecida por desoxinivalenol (DON), um tricoteceno biossintetizado principalmente por Fusariumgraminearum. Esse estudo traz dados de três anos (2018, 2019 e 2020) de pesquisa de campo (24 experimentos) conduzidos no Oeste de Santa Catarina e no Nordeste do Rio Grande do Sul, Brasil,utilizando um polissacarídeo sulfatado exclusivo de algas vermelhas, carragena, associado a fungicidas para ajudar na supressão da biossíntese e acúmulo de desoxinivalenol (DON) em grãos de trigo. Foi observada uma redução de 36,4% na contaminação por DON. As condições climáticas influenciaram no acúmulo de DON nos grãos de trigo. A carragena se demostrou como um composto biológico capaz de atenuar a biossíntese e acúmulo de DON em grãos de trigo independente das condições climáticas.(AU)
Assuntos
Triticum/química , Imunossupressores/síntese química , Micotoxinas , Biossíntese de Proteínas , FusariumRESUMO
Mycotoxins pose a large threat to human and livestock besides reducing the quality of food/feed. It is believed that these toxins are biosynthesized as a mechanism of defense (stress-response) of fungi. The most important mycotoxin for winter-cereal crops is known by deoxynivalenol (DON), a trichothecene biosynthesized mainly by Fusarium graminearum. This manuscript brings data of three years (2018, 2019 and 2020) of field research (24 field experiments) in Western Santa Catarina and North-Western Rio Grande do Sul, Brazil using a sulphated polysaccharide exclusive from red seaweed, carrageenan, associated with fungicides to help suppressing deoxynivalenol (DON) biosynthesis and accumulation in wheat kernels. A reduction of 36.4% in DON contamination was observed. Weather conditions have influenced the accumulation of DON in wheat kernels. Carrageenan has shown to be a biological compound capable of helping on the suppression of DON biosynthesis and accumulation in wheat kernels regardless of weather conditions.
As micotoxinas representam uma grande ameaça para humanos e animais, além de reduzirem a qualidade de alimentos/rações. Acredita-se que essas toxinas sejam biossintetizadas como mecanismo de defesa (resposta ao estresse) de fungos. A micotoxina de maior interesse para cereais de inverno é conhecida por desoxinivalenol (DON), um tricoteceno biossintetizado principalmente por Fusarium graminearum. Esse estudo traz dados de três anos (2018, 2019 e 2020) de pesquisa de campo (24 experimentos) conduzidos no Oeste de Santa Catarina e no Nordeste do Rio Grande do Sul, Brasil, utilizando um polissacarídeo sulfatado exclusivo de algas vermelhas, carragena, associado a fungicidas para ajudar na supressão da biossíntese e acúmulo de desoxinivalenol (DON) em grãos de trigo. Foi observada uma redução de 36,4% na contaminação por DON. As condições climáticas influenciaram no acúmulo de DON nos grãos de trigo. A carragena se demostrou como um composto biológico capaz de atenuar a biossíntese e acúmulo de DON em grãos de trigo independente das condições climáticas.
RESUMO
The decline of the North American native lady beetle, Coccinella novemnotata Herbst, is strongly correlated with the introduction of Coccinella septempunctata L., and C. novemnotata are locally extirpated across much of the United States. Since C. novemnotata's decline, the invasive Harmonia axyridis Pallas has become dominant in North America. This study investigated whether H. axyridis has the potential to impede the recovery of C. novemnotata populations. To determine how H. axyridis interacts with C. novemnotata via intraguild predation and competition for prey, we paired first-instar C. novemnotata with first-instar H. axyridis at low and high densities of pea aphid. Coccinella novemnotata survival when paired interspecifically was significantly lower than H. axyridis survival at both aphid densities. Both species had similar weights at eclosion across aphid densities; however, H. axyridis developed faster than C. novemnotata. To examine the effect of larval size on intraguild interactions, we conducted a second experiment where we varied the C. novemnotata and H. axyridis instar in our pairings. Coccinella novemnotata survival and final weight increased when paired with younger H. axyridis larvae. The percentage survival of C. novemnotata in interspecific treatments, at the low aphid density, was lower than for same-aged C. novemnotata reared conspecifically, except for pairs initiated with C. novemnotata larvae that were two instars more advanced than H. axyridis larvae. These results suggest that intraguild predation and competition for prey by H. axyridis have the potential to affect the recovery of C. novemnotata populations negatively.