van Bruggen A H C, Semenov A M, Zelenev V V
Organic Farming Systems Group, Department of Plant Sciences, Wageningen University, Marijkeweg 22, 6709 PG Wageningen, The Netherlands.
Microb Ecol. 2002 Jul;44(1):30-8. doi: 10.1007/BF03036871. Epub 2002 May 20.
Previously, we showed that copiotrophic and oligotrophic bacteria fluctuate as moving waves along roots. These waves probably originate as a result of growth and death cycles at any location where a moving nutrient source passed. In this study, we placed sclerotia of Rhizoctonia solani AG8 along growing roots of wheat and showed that the proportions of root sections from which R. solani was isolated fluctuated with distance from the root tip. Similarly, proportions of root sections from which naturally occurring Pythium spp. were isolated fluctuated with distance from the root tip. Fourier analysis showed that these fluctuations constituted significant waves. Cross-correlation analyses demonstrated that there were negative correlations between R. solani infections and colony forming units of copiotrophic bacteria at the time of inoculation at the same locations on the root (lag = 0 cm), indicating that infection by R. solani could have been inhibited by these bacteria. There was a positive correlation between Pythium infections and copiotrophic bacteria at a lag of 6 cm along the roots. It therefore appears that Pythium infection took place shortly after the initial peak in copiotrophic bacteria following the passage of the root tip.
此前，我们发现富养型和贫养型细菌会沿着根系以移动波的形式波动。这些波动可能源于移动养分源经过的任何位置处的生长和死亡周期。在本研究中，我们将立枯丝核菌AG8的菌核放置在小麦生长的根系上，结果表明，分离到立枯丝核菌的根段比例随距根尖的距离而波动。同样，分离到自然存在的腐霉菌的根段比例也随距根尖的距离而波动。傅里叶分析表明，这些波动构成了显著的波。互相关分析表明，在根系相同位置接种时（滞后 = 0厘米），立枯丝核菌感染与富养型细菌的菌落形成单位之间存在负相关，这表明立枯丝核菌的感染可能受到这些细菌的抑制。沿着根系在滞后6厘米处，腐霉菌感染与富养型细菌之间存在正相关。因此，腐霉菌感染似乎发生在根尖经过后富养型细菌的初始峰值出现后不久。
