分根法研究镧对水稻生长及其生理参数的影响

Effect of Lanthanum on Rice Growth and Physiological Parameters with Split-Root Nutrient Solution Method

用分根营养液培养法研究了镧对水稻生长及其促进作用的生理机制。结果表明:低浓度镧(0 05～1 5mg·L-1)提高水稻产量,增加实粒数;随着镧浓度从0 05增加到0 75mg·L-1,镧降低第一片完全展开叶和根中过氧化氢酶(CAT)活性;当镧浓度为0 75～9mg·L-1时,镧显著降低叶和根中超氧化歧化酶(SOD)活性;0 75mg·L-1镧增加叶中赤霉素(GA)和吲哚乙酸(IAA)含量,0 75和3mg·L-1镧增加根中细胞分裂素(iPAs)和IAA含量,但降低脱落酸(ABA)含量;秧苗移栽后46d,0 25～6mg·L-1镧显著增加叶片气孔导度;秧苗移栽后59和83d,当镧浓度分别为15和6mg·L-1时,镧显著降低叶片气孔导度;镧对叶片叶绿素(Chl)含量、叶和根中蛋白质,脂质过氧化产物丙二醛(MDA)含量没有发现显著作用。还讨论了镧促进水稻生长和消除超氧阴离子(·O2-)的可能机制。

Splitroot solution culture was used to study the effect of lanthanum on rice growth and its physiological response. The results show that low concentrations (005～15 mg·L-1) can increase rice yield and grain numbers With the increase of La concentration from 005 to 075 mg·L-1, catalase (CAT) activity decreases in the first fully expanded leaves and roots When La concentrations are less than 9 mg·L-1, La significantly decreases superoxide dismutase activity (SOD) in the leaves and root 075 mg·L-1 La increases gibberellic acid (GA) and indole3acetic acid (IAA) content in the leaves, and 075 and 3 mg·L-1 La increases iPAs and IAA content but decreases abscisic acid (ABA) content in the roots After 46 d transplantation La (025～6 mg·L-1) increases stomatal conductace When La concentrations are more than 15 and 6 mg·L-1 respectively, 59 and 83 d after transplantation, stomatal conductance decreases significantly No significant effects were found on chlorophyll, protein and malondialdehyde (MDA) content Possible mechanisms of La on rice growth and reduction of ·O2- were discussed