烤烟硒积累及其与土壤和气候关系

在我国南北主产烟区的7省11县采用统一栽培模式,研究了烤烟Se含量及其与环境的关系。结果表明,在烤烟各器官中,含Se量为根系>叶片≈烟杈(烟花)>茎;烟叶Se含量为下部叶<中部叶<上部叶。在烟株生长发育过程中,叶片含硒量差异不大,累积量成“S”形曲线增加,积累速率呈单峰曲线变化;就地域而言,南方烟叶的Se含量与北方基本一致。此外,烟叶Se含量的变异系数较大,说明环境条件影响烟叶中的Se含量。在气象因素中,烟叶Se含量与日均气温、日均10.cm地温呈显著正相关,与降雨量(或相对湿度)呈显著负相关。在土壤因素中,烟叶Se含量与pH、土壤含Se量呈正相关,与土壤速效磷、有机质呈负相关。

Se accumulation in flue-cured tobacco related to soil and climate

11 counties in 7 provinces were selected from south and north tobacco growing areas in China to investigate the contents of Se in tobacco in relation to environments under a same cultivation model.The results showed that Se in tobacco plants were changed in the sequence: roots > leaves≈shoots(flowers) > stems.Highest Se was detected in upper leaves,while lowest showed in lower ones.During the growing period,the contents of Se in leaves changed little if any, but the amount of Se accumulation went up with a "S" curve and the accumulation rate of Se appeared as a single peak curve.Even though mean concentrations of Se were similar in tobacco leaves produced in north and south China,the variation coefficients of Se concentrations in tobacco leaves were quite large,indicating the significant influences of environments on them.In regarding Se metrological factors,there was a negative correlation between Se contents in tobacco leaves and rainfall(or relative humidity),but a positive correlation with mean air temperatures(or soil temperatures at 10 cm).Furthermore,a positive correlation was found between the contents of Se in tobacco leaves with soil pH and total Se,whilst a negative correlation with available phosphorus and organic matter in soil.