【摘要】 以3个烤烟基因型农大202、K326和NC89为材料,采用土培和砂培试验,研究了烤烟根系阳离子交换量(CEC)及根际和非根际土壤速效钾、缓效钾含量的变化,以及根系分泌物、根际微生物数量对土壤钾的活化效应。结果表明,各基因型烤烟根际和非根际土壤速效钾含量不同,依次为农大202>K326>NC89;3个基因型烤烟根系分泌物对土壤钾素均有活化作用,农大202活化能力最强,各基因型间差异达极显著水平;与烤烟非根际相比,各基因型烤烟根际真菌数量增加。农大202根际真菌数量较大,极显著的高于K326和NC89,K326和NC89两基因型间差异不显著。3个烤烟基因型根际细菌数量差异达到极显著,而放线菌数量差异不显著。农大202根系阳离子交换量(CEC)高于NC89和K326的,但K326和NC89两基因型间的差异不显著。选育富钾烟草品种,应注重根系生理特性。更多还原

【Abstract】 An experiment was carried by soil culture and sand culture on variation of cation exchange capacity(CEC) of roots,readily available K and slowly available K in rhizospheric and non-rhizospheric soils of flue-cured tobaccos (Nicotiana tabacum L.) different in genotype (i.e. Nongda 202,K326 and NC89),and activating effects of root exudates,and population of rhizospheric microbes on soil K. Results showed that in terms of soil readily available K in both rhizospheric and non-rhizospheric soils,the three treatments followed the order was Nongda202>K326 >NC89. Root exudates from tobaccos,regardless of genotype,activated potassium in the soils. However,among the three Nongda 202 showed the strongest effect,and the differences between Nongda 202,K326 and NC89 were extremely significant. The number of fungi in the rhizospheric soils of the three genotypes of flue-cured tobacco increased over those in the non-rhizospheric soils,especially in the rhizospheric soil of Nongda 202,much higher than of K326 and NC89. However,the difference between the latter two was not significant. The differences among the three genotypes of tobacco in population of rhizospheric bacteria were extremely significant,but not in number of actinomycete. Nongda 202 was the higher than NC89 and K326 in CEC of the root exudates,but the latter two were not so different. So it is important to pay attention to physiological properties of the roots in selecting K-enriching tobacco varieties.更多还原