2,4-D和乙烯利对玉米幼苗抗旱性效应的研究

STUDY ON EFFECTS OF 2,4 D AND ETHREL ON DROUGHT RESISTANCE IN MAIZE SEEDLINGS

水分胁迫下，２０ｍｇ／Ｌ２，４－Ｄ和４００ｍｇ／Ｌ乙烯利（ＣＥＰＡ）分别不同程度地降低和提高玉米幼叶生长部位的相对含水量（ＲＷＣ）、水势（ψｗ）和渗透调节能力（ＯＡ）。胁迫后期，玉米幼叶中脯氨酸含量（Ｐｒｏ）为：ＣＥＰＡ＞对照（ＣＫｓ）＞２，４－Ｄ。随胁迫的进行，２，４－Ｄ处理幼叶的膜相对透性（ＲＰ）始终处于较高水平且增长幅度较大，叶片延伸生长速率（ＬＥＲ）对ＲＰ的变化较为敏感；而ＣＥＰＡ处理则与此相反。胁迫７２ｈ，２，４－Ｄ和ＣＥＰＡ分别降低和提高玉米幼叶生长部位质膜Ｈ＋－ＡＴＰａｓｅ（ＰＭＨ＋－ＡＴＰａｓｅ）活性，质膜Ｈ＋－ＡＴＰａｓｅ活性与此时的ＬＥＲ呈一定正相关。

Under water stress,20 mg/L 2,4 D and 400 mg/L ethrel (CEPA) reduced or promoted respectively relative water content (RWC),water potential (ψ w),osmostic adjustment capacity (OA) in the elongation regions of maize leaves to some extent.At later period of stress,proline (Pro) content in maize young leaves was in the orders of CEPA>control (CKs)>2,4 D.With prolonging duration of drought,the relative membrane permeability (RP) treated with 2,4 D always held a higher level and increased quickly,leaf elongation rate (LER) was more sensitive to the change of RP;but CEPA was the opposite.At stress 72 h,2,4 D and CEPA reduced or improved respectively plasma membrane H + ATPase (PMH + ATPase) activity in the elongation region of maize leaves,PMH + ATPase activity was positively correlated with LER at this time.