鋁對鳳梨根生長及養分吸收的影響

Effect of Aluminum on Root Growth and Nutrient Uptake of Pineapple

林永鴻(Yong-Hong Lin) ； 陳仁炫(Jen-Hshuan Chen)

《高雄區農業改良場研究彙報》 17卷2期 (2006/12) Pp. 19-33

https://doi.org/10.6958/RBKDAIS.200612.0019

摘要

鋁具有生物毒性且常於強酸性土壤中因活性高而抑制作物根系生長。本研究目的乃模擬強酸性土壤中不同鋁濃度對開英種、台農6號、台農13號及台農17號鳳梨根生長及養分吸收的影響。分別將鳳梨栽植於pH 4.5含0、100、200及300 μM AlCl3的水耕液中四週，測定四個品系的鳳梨於不同鋁濃度下之根的伸長度及根尖鋁聚積情形，並測定養分吸收及根尖分泌的有機酸種類與含量。結果顯示四個品系鳳梨在水耕液含100 μM AlCl3的溶液中，根生長都有促進作用，但在水耕液含200 μM AlCl3情況下，台農6號及台農13號鳳梨根生長受到抑制，而以台農13號較為顯著；在水耕液含300 μM AlCl3情況下則台農6號及台農13號根部均顯著受到抑制。在水耕液中不含鋁時四個品系的根養分吸收程度差，除了開英種鳳梨養分吸收程度隨著水耕液中鋁濃度的提昇而增加之外，台農6號、台農13號及台農17號鳳梨在水耕液含200 μM AlCl3時養分吸收即受到抑制，其中又以台農13號鳳梨較為顯著。當水耕液中AlCl3濃度高達300 μM時，台農6號鳳梨明顯受到抑制，而台農13號鳳梨受到抑制更為嚴重。當水耕液中鋁的濃度增高時，開英種鳳梨根分泌的酒石酸及蘋果酸濃度會增高，而台農13號及台農17號鳳梨根分泌的蘋果酸濃度會降低，因此，是否此兩種有機酸的分泌與鋁形成螯合物而降低了鋁的毒害值得進一步探討。

關鍵字

酸性土壤 ； 鋁毒害 ； 根的伸長 ； 根分泌物

並列摘要

Aluminum usually has phytotoxicity and inhibits the root growth in the strongly acidic soils. The purposes of this study were to simulate the influence of aluminum content in hydroponic culture on root growth and nutrient uptake of four cultivars of pineapple (Cayenne, Tainung No. 6, Tainung No. 13 and Tainung No. 17). The pineapples had been planted in the pH 4.5 hydroponic solution containing 0, 100, 200 and 300 μM AlCl3, respectively, for four weeks. The root elongation, the content of aluminum accumulation on the root tip, nutrient uptake and the kinds and amount of organic acids in root secretion were determined. The results showed that the root elongation of the four cultivars was improved when they were grown in the solution of 100 μM AlCl3 , however, the inhibition of root elongation was found for Tainung No. 6 and Tainung No. 13 as they were planted in the solution containing 200 and 300 μM AlCl3 , especially for Tainung No. 13 cultivar. The nutrition uptake was less inhibited when they were planted in the Al free solution, and uptake increased with the increase of Al concentration for Cayenne cultivar, but inhibited when the Al concentration was 200 μM for other three cultivars, especially for Tainung No. 13. In addition, the nutrient uptake of Tainung No. 6 and Tainung No. 13 cultivars were significantly inhibited when they grew in the solution containing 300 μM AlCl3, and more seriously inhibited was found for Tainung No. 13 cultivar. Results also showed that the contents of tartaric and malic acid in the root secretion increased with increasing Al concentration, however, the content of malic acid was decreased in the root secretion as Al addition increased, therefore, it need to be investigated if the reduction of Al toxicity is related to the chelation of Al with these two organic acids secreted from pipeapple root.

並列關鍵字

Acid soils ； Al toxicity ； root elongation ； root exudates