Xie G L, Mew T W
Plant Protection Department, Zhejiang Agricultural University, 310029 Hangzhou, People's Republic of. China.
Entomology and Plant Pathology Division, International Rice Research Institute, P.O. Box 933, Manila 1099, Philippines.
Plant Dis. 1998 Sep;82(9):1007-1011. doi: 10.1094/PDIS.1998.82.9.1007.
A leaf-inoculation method for detecting Xanthomonas oryzae pv. oryzicola in rice seed was developed and tested. The method is based on inoculating leaf segments on agar with seed washings in a moist chamber. Freshness of inoculated leaf segments is maintained by addition of 75 to 100 ppm benzimidazole to the 1% water agar after sterilization. Using cells from pure cultures, the minimum inoculum concentration to initiate leaf streak lesions on the segments was found to be 10 CFU/ml. Inoculum prepared from seeds harvested from severely infected mother plants induced lesions typical of leaf streak, followed by bacterial ooze. With 4 g of seed, the incubation period was 3.5 days and bacterial ooze appeared within 5 days. The minimum amount of seed needed to detect the bacterium based on seed washings varied according to disease severity of the mother plants. The bacteria isolated from lesions on the leaf segments were confirmed as X. oryzae pv. oryzicola after bacteriological, serological, and Biolog tests were conducted. The results confirm that the detached-leaf method is as simple and reliable as the immuno-radiometric assay and inoculation on intact pot-grown rice plants in the greenhouse.
开发并测试了一种用于检测水稻种子中水稻条斑病菌的叶接种方法。该方法基于在潮湿环境中用种子洗涤液接种琼脂上的叶片切段。灭菌后，通过向1%水琼脂中添加75至100 ppm苯并咪唑来保持接种叶片切段的新鲜度。使用纯培养物中的细胞，发现引发切段上叶条斑病斑的最低接种浓度为10 CFU/ml。从严重感染的母株收获的种子制备的接种物诱发了典型的叶条斑病斑，随后出现菌脓。用4克种子时，潜伏期为3.5天，5天内出现菌脓。根据种子洗涤液检测该细菌所需的最低种子量因母株的病害严重程度而异。在进行细菌学、血清学和Biolog测试后，从叶片切段病斑分离出的细菌被确认为水稻条斑病菌。结果证实，离体叶法与免疫放射分析以及在温室中盆栽完整水稻植株上接种一样简单可靠。
