以耐铝品种安国栝楼和铝敏感品种浦江栝楼为试验材料,采用溶液培养法研究800μmol/L铝胁迫下,不同浓度水杨酸对2个栝楼品种的生长特性、光合特性及抗氧化酶活性、MDA和紫外吸收物含量的影响。结果表明,经过800μmol/L铝处理15d后,安国栝楼和浦江栝楼的相对根长、株高及地上部鲜重、叶绿素含量、最大光能转化效率(Fv/Fm)、最大荧光产量(Fm)及电子传递速率(ETR)明显下降,SOD、CAT活性却出现2种相反的变化趋势,显示出2个栝楼品种的耐铝性差异,POD活性和紫外吸收物含量降低,MDA含量及初始荧光(F0)升高。10,30,50μmol/L外源SA可不同程度地降低铝在根尖细胞壁中的积累、MDA含量及初始荧光(F0),提高栝楼的相对根长、株高、地上部鲜重、叶绿素含量及叶绿素荧光的相关指标和抗氧化酶活性。由此可知,外源SA通过提高栝楼抗氧化酶活性及光合作用能力增强栝楼抗铝毒能力。由隶属函数分析得出,SA具有缓解铝胁迫的效果,但并不能消除铝胁迫对栝楼生长的抑制作用。
A solution culture experiment was conducted to study the effects of different SA concentration on growth characteristics,photosynthesis,oxidation resistance,UV-B absorbing compounds and MDA content of two Trichosanthes kirilowii cultivars,Anguo(Al-tolerant genotype) and Pujiang(Al-sensitive genotype),under 800 μmol/L aluminum stress.The results showed that 800 μmol/L Al treated for 15 days,the relative root length,plant height and fresh shoot weight,chlorophyll content,the maximum energy conversion efficiency(Fv/Fm),maximum fluorescence yield(Fm) and electron transport rate(ETR) were significantly lower of the two T.kirilowii cultivars.SOD,CAT activity changed in the opposite trend,indicating the differences of the two T.kirilowii cultivars in aluminum tolerance,POD activity and UV-B absorbing compounds decreased,MDA content and initial fluorescence(F0) increased.Adding 10,30,50 μmol/L exogenous SA could reduce aluminum accumulation in the apical cell wall,MDA content and initial fluorescence(F0),also increased the relative root length,plant height,fresh shoot weight,chlorophyll content,chlorophyll fluorescence of the relevant indicators and antioxidant enzyme activity to a certain extent.By increasing antioxidant enzyme activities and photosynthesis-related indicators,SA enhanced the ability of T.kirilowii to resistance to aluminum toxicity.Comprehensive analyzing evaluation by the method of subjection function,the results showed that the external source of SA could alleviate aluminum toxicity to some extent,but it did not eliminate the inhibition of T.kirilowii growth caused by aluminum.