水稻稻曲病室内人工接种技术

为提高稻曲病人工接种的发病效果和稳定性,在温棚条件下采用水稻孕穗期注射接种法分别研究了稻曲病菌不同接种体、培养时间、接种浓度和接种时期的接种效果。采用病菌马铃薯蔗糖液体培养基（potato sucrose broth,PSB）作为接种体,其穗发病率为100%,明显好于病菌米糠培养液（23.33%）。病菌在PSB中培养5～7天接种效果较好,随病菌培养天数的延长,接种效果明显下降。接种的分生孢子浓度越低水稻病穗率和病粒数也越低。在水稻品种两优培九孕穗中后期,采用含分生孢子浓度为4×106个/mL的病菌PSB培养液注射接种,穗发病率达100%,平均病粒数35.1粒,最高达87粒。研究表明,温棚条件下建立的稻曲病人工接种技术能获得稳定的发病效果,并可区别水稻品种间的抗性差异。

Artificial inoculation techniques of rice false smut in greenhouse

To increase disease effect and stability of artificial inoculation of Ustilaginoidea virens, the inoculation effects caused by different inocula, culture time, concentrations of pathogen and inoculation periods of rice were studied by using methods of injection during booting stage of rice in greenhouse. The inoculation effects of pathogen in PSB culture liquid was obviously better than that in rice bran culture liquid with 100% and 23.33% of diseased panicles, respectively. The pathogen in PSB culture liquid cultured for 5-7 d had a better inoculation effect, and the effects were obviously decreased when prolong of culture days. The lower concentration of conidia resulted in lower percentage of diseased panicles and numbers of diseased grains with spore ball in a diseased panicle. When rice variety "Liangyoupeijiu" inoculated with pathogen at a concentration of 4×10⁶ conidia/mL in PSB culture liquid in the middle and later stages of booting, the percentage of diseased panicles were 100%, and the average and the highest numbers of diseased grains were 35.1 and 87 respectively. The result indicated that the techniques of artificial inoculation established could receive stable disease effect and could be also used to distinguish differences of resistance to rice false smut among rice varieties in greenhouse.