修剪物与茶多酚对茶树矿质吸收及根系有机酸分泌的影响

探究茶树修剪物水溶性成分及茶多酚对茶树生长的影响与作用机制。水培茶苗,于15、35、55、75、95 d收集根系分泌物,通过阴、阳离子树脂纯化、减压浓缩后,利用高效液相色谱（HPLC）测定分泌物中有机酸主要组成与含量。同时测定茶苗干物质量、茶多酚及矿质元素含量等指标。研究表明,茶多酚会抑制茶树对Ca、Mg、Fe、Mn、Zn的吸收,抑制生长,同时诱导茶树根系分泌苹果酸、柠檬酸;适量修剪物水溶物能够补充矿质营养,提高茶树K、Ca、Fe、Mn、Zn、Al的吸收,促进生长,但同时也会诱导草酸、苹果酸、柠檬酸和琥珀酸的分泌,降低收集液pH值,而收集液pH值变化与有机酸分泌量变化显著相关,结果提示茶树修剪物水溶性成分可能是导致土壤酸化的机理之一。

Effects of Tea Pruning Materials and Tea Polyphenols on Organic Acids Secretion and Mineral Uptake in Tea Plant

The effects of aqueous solution of tea pruning materials and tea polyphenols on tea plant Camellia sinensis (L.)] growth and the mechanisms were investigated using hydroponic culture in this paper. The plants were harvested and root exudates were collected after growing periods of 15, 35, 55, 75 and 95 d. The contents of organic acids in the secretes from roots were determined using a HPLC equipped with C₁₈ column after passed through cation and anion exchange resin and concentrated. Besides, the dry weight, tea polyphenols and mineral uptake were analyzed. The results showed that tea polyphenols added in nutrient solution inhibited the uptake of Ca, Mg, Fe, Mn, Zn and growth rate and induced citric and succinic acids efflux from roots. However, the aqueous solution of tea pruning materials added in nutrient solution promoted the uptake of K, Ca, Mg, Fe, Mn, Zn, Al and growth rate and at the meantime induced oxalic, malic, citric and succinic acids efflux from roots. Besides, the aqueous solution of tea pruning materials also lowered pH of collection solution, which were closely linked with organic acids secretion changes, hinting tea pruning materials may result in soil acidification.