Biological Characterization Of Pathogens Causing Rice Spikelet Rot Disease And The Technology Of Disease Control In Anhui Province Of China

Rice Spikelet Rot disease was caused by a number of different parasitical and saprophytic pathogens and it was becoming the most important disease that influences the rice production and market price in recent years.The disease was widly happened in Anhui province,and had become to be the major limiting factor of rice high-yielding.This paper makes effort to identify the pathogen and to elucidate the distribution of the disease and the pathogenicity of pathogens.Fungicides to control the disease were preliminarily selected in lab,control efficiency test and resistant varieties screening test were conducted in field.The main results were summarized as follows:1.Based on morphological observation,biological testing and molecular characterization,the causal pathogens were identified as Fusarium proliferatum,Curvularia lunata,Nigrospora oryzae and Alternaria tenuis.Investigation indicated that pathogens were distributing differently in rice-growing area along the Yangzi River from the area along Huaihe River.2.The lethal temperature of Fusarium proliferatum,Curvularia lunata,Nigrospora oryzae and Alternaria tenuis.was 60,59,59 and 60? 10 minutes,respectively.The optimum temperature and pH value for four isolates growth and conidial germination were25-30? and 7.The C-source was glucose and starch,the N-source was KNO3,urea and proline.3.Four isolates can infected rice panicles at booting or flowering stage through spraying or injection inoculation,Fusarium proliferatum and Curvularia lunata were the main pathogens which can infected rice at low spore concentration,103(spore·ml-1).4.Indoor bioassays with propiconazole,prochloraz and flusilazole,respectively into agar were performed to have good effect on the pathogens.Carbendazim and Prochloraz mixture with the content proportion of 1:5 or 2:4,and Carbendazim and Propiconazole mixture with the content proportion of 1:5 respectively into agar were performed to have good effect on the pathogens.5.The field investigation results indicate that spraying carbendazim and propiconazole mixture with the content proportion of 1:5 or carbendazim and prochloraz mixture with the content proportion of 2:4 at filling stage can reached as 73.67% and65.81% control efficiency to the disease.6.The disease-resistant varieties were “Huaan501”,“Y-Liangyou9918”,“Liangyou6326”,and “Fengliangyou4”,“Huaan501” was the best.