Distribution and multiplication of Ralstonia solanacearum (Synonym Pseudomonas solanacearum) in tomato plants of resistant rootstock cultivar LS-89 and susceptible Ponderosa
Distribution and multiplication of Ralstonia solanacearum (Synonym Pseudomonas solanacearum) in tomato plants of resistant rootstock cultivar LS-89 and susceptible Ponderosa
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DOI：
10.3186/jjphytopath.63.83
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发表时间：
1997-01-01
期刊：
影响因子：
--
通讯作者：
Nakaho, Kazuhiro
中科院分区：
文献类型：
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作者：
Nakaho, Kazuhiro
研究了青枯病病原菌在番茄抗病砧木品种LS-和感病品种Ponderosa的根和茎中的分布和繁殖情况。在30℃的生长室中，切去侧根并将根球浸泡在10-7cfu/ml的细菌悬浮液中后，用青枯菌8107S菌株接种30日龄的幼苗，在接种的黄粉菌植株中，所有被测的主根和茎样本中都有细菌回收。根和茎组织中的病原菌密度在10d内增加到10-8或10-9cfu/g鲜物。接种LS-89的植株潜伏感染该病原菌。在LS-89植株接种后14天，主根和上部下胚轴的病原菌回收率约为90%，第一节间的病原菌回收率约为80%，但茎中的病原菌回收率较高(第五节间的病原菌回收率为30%)。病原菌密度前4d在主根、上胚轴和第一节间增加到10~(-6)cfu/g鲜物，之后趋于稳定。在侵染植株上胚轴的横切面上，黄杨的初生和次生木质部组织中有细菌团，而LS-的只有部分初生木质部组织中有细菌团。这些结果表明，细菌定位于初生木质部组织中，在抗性的LS-89植株中，它们的运动受到限制。
We examined the distribution and multiplication of Ralstonia solanacearum (Synonym Pseudomonas solanacearum) in roots and stems of tomato plants of resistant rootstock cultivar LS-89 and susceptible cultivar Ponderosa. In a growth chamber at 30 degree C, 30-day-old seedlings were inoculated with R. solanacearum strain 8107S after trimming lateral roots and immersing the root ball in a bacterial suspension of 10-7 cfu/ml. In inoculated Ponderosa plants, bacteria were recovered from all taproot and stem samples tested. Pathogen density increased in root and stem tissues to 10-8 or 10-9 cfu/g fresh matter in 10 days. Inoculated LS-89 plants were latently infected with the pathogen. Recovery of the pathogen in these LS-89 plants at 14 days after inoculation was about 90% in taproots and the upper hypocotyls, and about 80% in the first internodes, but the percentage decreased higher in the stem (30% recovery at the fifth internode). Pathogen density increased to 10-6 cfu/g fresh matter in taproots, upper hypocotyls and the first internodes in the first 4 days, but it was steady afterwards. Transverse sections of the upper hypocotyls of infected plants showed bacterial masses in the primary and secondary xylem tissues in Ponderosa, but only in a portion of the primary xylem tissues in LS-89. These results indicate that the bacteria are localized in the primary xylem tissues and their movement is limited in resistant LS-89 plants.