干旱及复水对芭蕉芋干物质及氮磷钾积累与分配特征的影响

以抗旱性弱的‘兴芋-1’和抗旱性强的‘兴芋-2’芭蕉芋品种为材料,通过盆栽试验,研究了干旱及复水对芭蕉芋干物质以及N、P、K积累与分配的影响,以明确干旱条件下芭蕉芋干物质的构成特点及N、P、K吸收分配特性,为芭蕉芋节水高效栽培提供理论依据。结果表明:(1)干旱胁迫显著抑制了芭蕉芋的生长,降低了根茎、茎和叶中干物质积累及其在根茎中的分配,而促进了根中干物质积累与分配。(2)干旱胁迫显著降低了芭蕉芋对N、P、K的吸收和积累,且N、K的降幅大于P,同时也改变了N、P、K在各器官中的分配比例。(3)干旱胁迫条件下,N优先向芭蕉芋叶中分配,而P和K优先向根和叶中分配,同时这些变化存在品种差异,抗旱性强的‘兴芋-2’受影响程度小于抗旱性弱的‘兴芋-1’,但‘兴芋-2’根茎中K的分配率降幅大于‘兴芋-1’。(4)复水后芭蕉芋茎、叶恢复效果优于根茎,P吸收积累的恢复效果优于N和K,但短期复水的补偿效应仍不足以弥补干旱胁迫的伤害。研究发现,干旱胁迫增加了芭蕉芋根、叶中矿质元素的分配比例,增强其渗透调节能力,提高其耐旱性;干旱条件下抗旱性强的芭蕉芋品种‘兴芋-2’的K利用率低于抗旱性弱的品种‘兴芋-1’。

Characteristics of Accumulation and Translocation of Dry Matter and Mineral Elements in Canna edulis under Drought Stress and Rewatering

In this study,we conducted pot experiments to study the accumulation and translocation characteristics of dry matter and mineral elements(N,P and K)of‘Xingyu-1’,a drought-sensitive cultivar,and‘Xingyu-2’,a drought-resistant cultivar,under drought stress in order to provide theoretical reference for efficient water-saving cultivation of Canna edulis.The results showed that:(1)drought stress significantly suppressed C.edulis growth,decreased both dry matter accumulation of rhizomes,stems and leaves,and its distribution ratio in rhizomes,while those in root increased.(2)At the same time,the uptake and accumulation of N,P and K also declined significantly and the reduction of P was less than that of N and K.The distribution ratios of N,P and K among organs changed obviously as well.Under drought conditions,the leaf was the priority organ of N distribution,the P and K distributed to leaf and root firstly.(3)Simultaneously,the effect of drought on the accumulation and distribution of dry matter and N,P,K had obvious difference between two cultivars.The drought-resistant cultivar‘Xingyu-2’was affected less than the drought-sensitive cultivar‘Xingyu-1’,but the reduction of K distribution ratio in rhizome of‘Xingyu-2’was higher than that in‘Xingyu-1’.(4)The rehydration effect on the leaf and root was more obvious than on the rhizome,the effect of rehydration on P was better than on N and K,but short time rehydration could not compensate the damaging effects of drought.These results indicated that drought increased the distribution ratio of mineral elements in leaf and root and enhanced osmotic regulation capacity to improve its drought-tolerance under the drought conditions.The K use efficiency of‘Xingyu-2’was lower than that of‘Xingyu-1’under the drought conditions.