Three fungicide formulations, namely M1, M2 and M3, were prepared from sodium bicarbonate, citronella essential oil and sunflower slurry. The stability of M1, M2 and M3 formulations was determined based on pH, tempera...Three fungicide formulations, namely M1, M2 and M3, were prepared from sodium bicarbonate, citronella essential oil and sunflower slurry. The stability of M1, M2 and M3 formulations was determined based on pH, temperature, order of incorporation of the inputs and storage time. The most stable formulations were used for antagonistic tests on Pythium myriotylum. The Minimum Inhibitory Concentration (MIC) was used for the greenhouse tests and the mode of action was determined in vitro. The study showed that the order of incorporation of the inputs “Essential Oil-Tween 80-Bicarbonate-Slurry” (EO-T80-B-S) promotes stability. M1 and M2 are stable at 4°C, 25°C, 37°C and 40°C temperatures and have a pH of 7 and 8 respectively. The Minimum Inhibitory Concentration of M1 and M2 is 1% on P. myriotylum. M1 and M2 act on Pythium by membrane lysis, inhibiting proton pumps and inhibiting protein synthesis. The formulations M1 and M2 reduce the incidence of root rot disease in cocoyam plants growth in the greenhouse. M1 and M2 are potential candidates for improvement of cocoyam seedlings production in Cameroon.展开更多
Rose root rot disease caused by Pythium helicoides Drechsler has brought heavy damage to cut rose production in Japan,and it has became apparent that Rosa multiflora showed resistance to this disease.Roses have been b...Rose root rot disease caused by Pythium helicoides Drechsler has brought heavy damage to cut rose production in Japan,and it has became apparent that Rosa multiflora showed resistance to this disease.Roses have been bred by interspecies crossing with Rosa species including of R.multiflora,and many progenies of R.multiflora have been bred as determined cluster-flowered roses.However,the genetic architecture of this resistance remains.So,in this study,four kinds of R.multiflora and 21 rose cultivars that have been clarified in the cross-fertilization genealogy with R.multiflora were used as plant materials,and the inheritability of resistance to root rot disease was investigated.Four kinds of R.multiflora had all high resistance,and the resistance to root rot disease in R.multiflora was inherent characteristic of species.Five varieties not less than 50% in relatedness with R.multiflora were shown as varied ‘resistant’ and ‘moderately resistant’.Therefore,the inherent resistant characteristic in R.multiflora was not controlled by single major gene,and the resistibility in R.multiflora was not cytoplasmic but nuclear heredity.Although there was significant negative relation between relative root rot severity and relatedness with R.multiflora,the variance of relative root rot severity had tendency to expand as relatedness with R.multiflora reduced.This result,therefore,indicated that the contingency of resistance expression increased as the relatedness with R.multiflora was reduced.The varieties having low degree of relatedness with R.multiflora had similar relative root rot severity with R.multiflora.These results indicated that we would be able to select resistant roses from progenies crossed with R.multiflora.展开更多
文摘Three fungicide formulations, namely M1, M2 and M3, were prepared from sodium bicarbonate, citronella essential oil and sunflower slurry. The stability of M1, M2 and M3 formulations was determined based on pH, temperature, order of incorporation of the inputs and storage time. The most stable formulations were used for antagonistic tests on Pythium myriotylum. The Minimum Inhibitory Concentration (MIC) was used for the greenhouse tests and the mode of action was determined in vitro. The study showed that the order of incorporation of the inputs “Essential Oil-Tween 80-Bicarbonate-Slurry” (EO-T80-B-S) promotes stability. M1 and M2 are stable at 4°C, 25°C, 37°C and 40°C temperatures and have a pH of 7 and 8 respectively. The Minimum Inhibitory Concentration of M1 and M2 is 1% on P. myriotylum. M1 and M2 act on Pythium by membrane lysis, inhibiting proton pumps and inhibiting protein synthesis. The formulations M1 and M2 reduce the incidence of root rot disease in cocoyam plants growth in the greenhouse. M1 and M2 are potential candidates for improvement of cocoyam seedlings production in Cameroon.
基金Supported by the Doctoral Scientific Research Foundation of Liaoning Province
文摘Rose root rot disease caused by Pythium helicoides Drechsler has brought heavy damage to cut rose production in Japan,and it has became apparent that Rosa multiflora showed resistance to this disease.Roses have been bred by interspecies crossing with Rosa species including of R.multiflora,and many progenies of R.multiflora have been bred as determined cluster-flowered roses.However,the genetic architecture of this resistance remains.So,in this study,four kinds of R.multiflora and 21 rose cultivars that have been clarified in the cross-fertilization genealogy with R.multiflora were used as plant materials,and the inheritability of resistance to root rot disease was investigated.Four kinds of R.multiflora had all high resistance,and the resistance to root rot disease in R.multiflora was inherent characteristic of species.Five varieties not less than 50% in relatedness with R.multiflora were shown as varied ‘resistant’ and ‘moderately resistant’.Therefore,the inherent resistant characteristic in R.multiflora was not controlled by single major gene,and the resistibility in R.multiflora was not cytoplasmic but nuclear heredity.Although there was significant negative relation between relative root rot severity and relatedness with R.multiflora,the variance of relative root rot severity had tendency to expand as relatedness with R.multiflora reduced.This result,therefore,indicated that the contingency of resistance expression increased as the relatedness with R.multiflora was reduced.The varieties having low degree of relatedness with R.multiflora had similar relative root rot severity with R.multiflora.These results indicated that we would be able to select resistant roses from progenies crossed with R.multiflora.