Biocontrol Mechanism Of Silthiopham Against Wheat Take-All Disease

Wheat take-all is one of the devastating disease on wheat, has expanded to Winter wheatregional in north, northwest spring wheat and wheat of the middle and lower Yangtze total of19provinces (areas)in our country, the case of area and harm degree have increased, theserious influence wheat production. In theory, breeding and the promotion of the variety ofimmune or high resistant is the most economic and effective measures, but so far none ofresistance cultivars promotion to wheat take-all; In different regions and climate conditions,even the bad environment born bacteria resistant agent effect is not quite stable, to use inlarge area and many restrictions applied. Wheat is the main food crops, planting area is large,long-term rotation is impractical. At present the main production is bayleton to control wheattake-all. Because the chemical can reduce the emergence rate, the control effect is low, easyto cause the phytotoxicity.So development and screening safety, efficient control of thedisease chemicals also become a top priority. Silthiopham have been registered, is one of thebest chemicals to control wheat take-all. Although this chemical has started to popularizeapplication, but its suppression of disease mechanism is not yet clear. The study was carriedout the antifungal mechanism of silthiopham to the Pathogen of Wheat Take-all by potexperiment and micro technology,to provide the basis for the future development of newchemicals prevention and control the pathogen, and have the following main results:1. Silthiopham to wheat take-all have nice prevention and treatment effect. In wheatphysiological growth, The chemical can promote the growth of wheat root system, Includingincreased capillary root number, root length and root fresh weight.Through silthiopham affect the wheat seedling stage growth, and to wheat Compensationeffect, find that silthiopham can promote the growth of wheat root system, including theincreased number of fine roots, promote hair root length, increase root fresh weight, and haveno effect of wheat emergence rate and the ground of the department. In incidence after wheatroot system, the chemical can stimulate wheat to grow new capillary root quickly, so tocompensate for the root damaged on wheat growth and yield influence.2. Silthiopham can effectively relieve amine of the pathogen growth and infection, toreduce the number of the pathogen invading wheat, wheat root breeding and delay the timepathogen infect it. Through silthiopham inhibit the Gaeumannomyces graminis var.tritici in PDA,silthiopham to the wheat growth impact ultrastructural structure analysis, to find dress seedsin the soil of forms around the elixir group, to protect the root system will not be infected orless infected, can improve wheat root against wheat take-all, enhance the wheat root defensereactions. Silthiopham can eliminate hypha cell walls and cause hyphae distortion and evendeath, effectively relieve the expansion of the pathogen, inhibit the hypha growth andreproduction, interference of the pathogen synthesis, Thus influence and prevent germs spore,the formation of the germination and infection, effectively suppress disease germs sporegermination to wheat seeds and wheat root system implementation of the comprehensiveeffective protection, and reducing the disease caused damage.3. Silthiopham can eliminate amine hypha cell walls and cause hyphae distortion andeven death, effectively enhance defense reactions of the host cell, including inductionproduce large amounts of lignituber,the host cell wall thickening, and eliminate wheat rootendodermis into the hyphae.Through the electronic microscope observe silthiopham antibacterial action againstdiseases; find that the chemical agent can strengthen defense reactions of the host celleffectively. Hyphae infect speed slow to silthiopham dress seeds wheat, then nothing usewheat can be found in large hyphae. Dress seeds with silthiopham, the wheat root hyphaeuncovered after cortical cells, the cell wall can form the lignituber to prevent germs invasion,and inside the cell wall formed sedimentary electron dense material. Silthiopham can protectthe wheat root endodermis effectively, Restrain in the cortical cells into the hypha. So thechemical can improve wheat root and resist the eclipse of the pathogen invading wheat,restrain the invasion of the pathogen effectively, can straight damage hyphal in wheat rootendodermis, Strengthen defense reactions of the host cell, diversified prevent wheat take-all.