恶臭假单胞菌P861(Gus)在油菜根部定殖的生态研究

本研究采用Gus 基因标记技术和常规方法跟踪考察了恶臭假单胞菌P861(Gus) 在缩影系统油菜根圈的定殖情况,以及缩影系统内土壤类型、土壤含水量对根部定殖的影响。土壤含水量分别为60% FC和75% FC时,P861(Gus) 在砂姜黑土中的定殖水平高于50% FC的,不但能散布至种子下8cm 以内的根段部位,且定殖水平分别为7.5×10²和2.8×10³cfu·g^-1。在灰潮土缩影中,P861(Gus) 在油菜根圈的定殖动态表现为在油菜播种后3 ～6 天,定殖密度可达最高水平(5.5×10⁶cfu·g^-1) ,然后急速下降,最后保持在一个相对稳定的较低水平(7.6×10²cfu·g^-1) 。P861(Gus) 在不同根段部位的定殖密度并无从上到下逐渐递减的规律。

ECOLOGY STUDIES BY Pesudomonas putido P861(Gus) ON ROOT COLONIZATION OF RAPESEED

This paper reported that root colonization of rapeseed was measured by Pesudomonas putida P861(Gus) in rhizosphere soil microcosms, and the effects of soil type and soil water content on root colonization of repeseed and movement of P861(Gus) along roots were investigated with technique of gene morking and convention method. In the lime concretion black soil microcosm, the numbers of P861(Gus) in rapeseed rhizosphere under the soil water content of 60% FC and 75% FC were greater than that under 50% FC, P861(Gus) could move to the place of 8cm of root from coated seed, the root colonization density reached 7.5×10² and 2.8×10³cfu·g^-1. The root colonization density of rapeseed reached the maxium (5.5×10⁶cfu·g^-1) by P861(Gus), after 3～6days of bacteria coated seeds broadcast, then declined rapidly relative stable lower colonization level (7.6×10²cfu·g^-1) in grey fluro aquic soil microcosm. The colonization density of P861(Gus) was not gradually decreased from the upper part to the lower part of root.