铝胁迫对葡萄苗铝吸收分配及抗氧化系统的影响

为了探明葡萄苗在不同浓度铝胁迫下树体的铝积累特征和生理响应,研究以‘水晶’葡萄为试材,在无土栽培条件下,用1.0~8.0 mmol·L~(-1) KAl(SO4)2处理60 d后测定树体铝含量及相关生理指标。结果表明,过量的铝在葡萄苗中的分配为细根粗根老叶树皮嫩叶木质部新枝,2.0 mmol·L~(-1)铝处理后植株生长旺盛,生物量最大,单株铝积累总量最高,5.0 mmol·L~(-1)铝处理后植株生长较弱,生物量较小,单株铝含量最低;铝浓度超过3.0 mmol·L~(-1)时显著降低葡萄苗叶绿素a、叶绿素b、叶绿素a+b的含量,铝浓度超过4.0 mmol·L~(-1)显著降低葡萄苗类胡萝卜素含量;随着铝浓度的增大,葡萄叶片和根系的脯氨酸含量逐渐升高且显著高于CK;铝浓度达到3.0mmol·L~(-1)时,各处理叶片和根系的丙二醛含量均显著高于CK;铝处理提高了葡萄叶片和根系中的氧自由基产生速率和过氧化氢含量;铝胁迫下,葡萄苗叶片和根系的POD活性高于CK;铝浓度低于4.0 mmol·L~(-1)时,SOD活性高于CK,而浓度达到4.0 mmol·L~(-1)时则显著低于CK。可见,低于3.0 mmol·L~(-1)铝对葡萄苗的伤害较小,甚至还能促进其生长,但超过3.0 mmol·L~(-1)铝将对葡萄苗造成不同程度的伤害。

The effect of aluminum stress on aluminum uptake, distribution and antioxidant system in grape seedlings

In order to investigate the aluminum accumulation characteristics and physiological responses of grape seedlings under different concentrations of aluminum stress, ''Shuijing'' grape was grown in a soilless culture system. The contents of aluminum in the plant and related physiological indexes were measured after 1.0-8.0 mmol·L^-1 KAl(SO₄)₂ treatment for 60 days. The results showed that the distribution of the excess aluminum in grape seedlings in the fine root > thick root>old leaf >bark >new leaf> xylem>new branch. After 2 mmol·L^-1 aluminum treatment, the biomass was the largest, the plant growth was vigorous, and the total accumulation of aluminum in the individual plants was the highest. After treated with 5 mmol·L^-1 aluminum, the plant growth was weak, the biomass was smaller, and the aluminum content in the individual plants was the lowest. When the aluminum concentration was more than 3 mmol·L^-1, the content of chlorophyll a, chlorophyll b, chlorophyll a+b were decreased and when the aluminum concentration was more than 4 mmol·L^-1, the carotenoid content in grape seedlings was significantly reduced. With an increase of aluminum concentration, the proline content in the leaf and root increased gradually and was significantly higher than that of CK. When the aluminum concentration reached 3.0 mmol·L^-1, the content of MDA in the leaf and root in all treatments was significantly higher than that of CK. The aluminum treatment increased the production rate of oxygen free radicals and H₂O₂ content in the leaf and root. Under aluminum stress, the POD activity in the leaf and root was higher than that of CK. When the concentration of aluminum was lower than 4.0 mmol·L^-1, the SOD activity was higher than that of CK and when the concentration reached 4.0 mmol·L^-1, it was lower than that of CK. It is obvious that the aluminum concentration of < 3.0 mmol·L^-1 was less harmful to the grape seedlings and even possibly promoted its growth, but > 3.0 mmol·L^-1 aluminum would cause various degrees of