甘蔗钾素吸收、累积和分配的动态变化特征

以国内当前甘蔗主栽品种ROC22为材料,通过田间实验分析了甘蔗主要器官钾素含量、累积、分配和吸收的动态变化特征。结果表明:在相同生育期,上部茎和青叶鞘始终是钾素含量较高的器官,青叶和中、下部茎次之,根系、枯叶和枯叶鞘则始终相对较低。钾素主要累积于青叶(鞘)和蔗茎中。拔节前青叶(鞘)中的钾素占植株总累积量的95%以上,拔节后其钾素分配比例持续下降,而蔗茎中则持续上升,在工艺成熟期分配至蔗茎的钾素占整个植株的83.3%。甘蔗钾素阶段吸收量和吸收速率则呈现了先上升后下降的趋势,分蘖期至茎伸长4期为甘蔗主要钾素吸收积累阶段,占生育期总吸收的86.8%,其中分蘖期至拔节期的钾素阶段吸收量(4 791.3 mg/plant)和吸收速率(159.7 mg/plant·d)最高,为甘蔗钾素吸收的最大效率期。

Dynamic Characteristics of Potassium Absorption, Accumulation and Distribution in Sugarcane

The aim of this study is to investigate the dynamic characteristics of potassium(K)content, accumulation, distribution and absorption in sugarcane variety ROC22 during the whole growth period under K fertilization. The results showed that K content was always higher in the green leaf sheaths and upper canes, followed in the green leaves, middle and lower canes, and in bone-dry leaves, bone-dry leaf sheaths and roots which was lower in the same growth stages. K nutrient mainly accumulated in green leaves (sheaths) and canes. Before jointing stage, more than 95% of K was distributed into the green leaves (sheaths). K distribution ratio of green leaves(sheaths)continually decreased, and that of canes kept elevating. In technical maturity stage, most of K was gathered in canes, reached 83.3% of the whole plant. K absorption in the whole plant exhibited an obvious trend of first increase and then fall, and K absorption amount from tiller stage to cane elongation 4 stage accounted for 86.8% of total absorption amount during the entire growing period. The most efficient period for K utilization was tiller to jointing stage in sugarcane, K absorption amount and ratio during this period reached the peak value, 4 791.3 mg/plant and 159.7 mg/plant·d respectively.