In this study, the effects of a silicon (Si) application on the biomass, chlorophyll level and silicon level of sugarcane moderate pest resistance (RB72454) and susceptible (SP801842) cultivars were tested. Investigat...In this study, the effects of a silicon (Si) application on the biomass, chlorophyll level and silicon level of sugarcane moderate pest resistance (RB72454) and susceptible (SP801842) cultivars were tested. Investigations were also carried out to assess the effect of silicon on Diatraea saccharalis infestation. The experiments were conducted in a greenhouse using the treatments consisting moderate pest resistant and susceptible culivar, with or without silicon application. The silicon was applied to the soil around the plants. The experiment was laid in complete randomized design with 4 treatments and 10 replicates. The data were subjected to an analysis of variance, and the averages were compared using the Tukey test (p ≤ 0.05). Significant changes were observed in the fresh and dry masses of the aerial portions and the root system, as well as in the plant chlorophyll and silicon levels. The silicon content increased in the susceptible variety which was significantly equal for moderate resistance variety. Chlorophyll content increased in silicon treated cultivars. Sixty days after the last application, 10 adult D. saccharalis moths were released onto each pot. However, due to the low infestation, the effects of silicon on the insect incidence could not be determined. One can conclude that silicon is beneficial for the growth of the aerial portions of sugarcane and causes a significant increase in chlorophyll levels.展开更多
The sugarcane borer, Diatraea saccharalis （E）, is a major maize borer pest and a target of transgenic maize expressing Bacillus thuringiensis （Bt） proteins in South America and the mid-southern region of the Unite...The sugarcane borer, Diatraea saccharalis （E）, is a major maize borer pest and a target of transgenic maize expressing Bacillus thuringiensis （Bt） proteins in South America and the mid-southern region of the United States. Evolution of resistance in target pest populations is a great threat to the long-term efficacy of Bt crops. In this study, we compared the genetic basis of resistance to CrylAb protein in 3 resistant colonies of sugarcane borer established from field populations in Louisiana, USA. Responses of larvae to the CrylAb protein for the parental and 10 other cross colonies were assayed in a diet-incorporated bioassay. All 3 resistant colonies were highly resistant to the CrylAb protein with a resistance ratio of 〉 5 5 5.6 fold. No maternal effect or sex linkage was evident for the resistance in the 3 colonies; and the resistance was functionally nonrecessive at the CrylAb concentrations of 〈 3.16 μg/g, but it became recessive at 〉10μg/g. In an interstrain complementation test for allelism, the Fl progeny from crosses between any 2 of the 3 resistant colonies exhibited the similar resistance levels as their parental colonies, indicating that the 3 colonies most likely shared a locus of CrylAb resistance. Results generated from this study should provide useful information in developing effective strategies for managing Bt resistance in the insect.展开更多
基金the National Council for Scientific and Technological Development(Conselho Nacional de Desenvolvimento Cientifico e Tecnologico—CNPq)for providing a fellowship and other financial supportthe Minas Gerais Research Foundation(Fundacao de Pesquisa de Minas Gerais—FAPEMIG)for their financial support.
文摘In this study, the effects of a silicon (Si) application on the biomass, chlorophyll level and silicon level of sugarcane moderate pest resistance (RB72454) and susceptible (SP801842) cultivars were tested. Investigations were also carried out to assess the effect of silicon on Diatraea saccharalis infestation. The experiments were conducted in a greenhouse using the treatments consisting moderate pest resistant and susceptible culivar, with or without silicon application. The silicon was applied to the soil around the plants. The experiment was laid in complete randomized design with 4 treatments and 10 replicates. The data were subjected to an analysis of variance, and the averages were compared using the Tukey test (p ≤ 0.05). Significant changes were observed in the fresh and dry masses of the aerial portions and the root system, as well as in the plant chlorophyll and silicon levels. The silicon content increased in the susceptible variety which was significantly equal for moderate resistance variety. Chlorophyll content increased in silicon treated cultivars. Sixty days after the last application, 10 adult D. saccharalis moths were released onto each pot. However, due to the low infestation, the effects of silicon on the insect incidence could not be determined. One can conclude that silicon is beneficial for the growth of the aerial portions of sugarcane and causes a significant increase in chlorophyll levels.
文摘The sugarcane borer, Diatraea saccharalis （E）, is a major maize borer pest and a target of transgenic maize expressing Bacillus thuringiensis （Bt） proteins in South America and the mid-southern region of the United States. Evolution of resistance in target pest populations is a great threat to the long-term efficacy of Bt crops. In this study, we compared the genetic basis of resistance to CrylAb protein in 3 resistant colonies of sugarcane borer established from field populations in Louisiana, USA. Responses of larvae to the CrylAb protein for the parental and 10 other cross colonies were assayed in a diet-incorporated bioassay. All 3 resistant colonies were highly resistant to the CrylAb protein with a resistance ratio of 〉 5 5 5.6 fold. No maternal effect or sex linkage was evident for the resistance in the 3 colonies; and the resistance was functionally nonrecessive at the CrylAb concentrations of 〈 3.16 μg/g, but it became recessive at 〉10μg/g. In an interstrain complementation test for allelism, the Fl progeny from crosses between any 2 of the 3 resistant colonies exhibited the similar resistance levels as their parental colonies, indicating that the 3 colonies most likely shared a locus of CrylAb resistance. Results generated from this study should provide useful information in developing effective strategies for managing Bt resistance in the insect.
