【摘要】 以盆栽4年生的苹果砧木湖北海棠(Malushupehensis)为试材,叶面喷施100mmol·L-1的甜菜碱,研究外源甜菜碱对干旱胁迫下湖北海棠叶片超微弱发光(UWL)、丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢(H2O2)、脯氨酸(Pro)及甜菜碱(GB)含量的影响.结果表明,轻度干旱胁迫下,叶片UWL强度提高,但随着干旱胁迫程度的加重而下降,至严重干旱胁迫时UWL明显低于正常供水处理;H2O2、MDA含量随干旱胁迫加重而升高;SOD和POD活性随胁迫加重而升高,但至重度干旱时下降.与单独干旱处理相比,叶片喷施甜菜碱显著提高了轻度和中度干旱胁迫叶片的UWL(分别提高35·27%和43·95%)、SOD和POD活性,降低了H2O2和MDA含量;促进了Pro和GB的积累.表明甜菜碱及通过甜菜碱诱导的脯氨酸积累,能够提高干旱胁迫下叶片的抗氧化能力,减轻过氧化损伤,对叶片细胞起到保护作用.更多还原

【Abstract】 In a pot experiment with 4-year-old apple root stock （Malus hupehensis）, this paper studied the effects of foliar-spraying exogenous glycinebetaine （GB） on the leaf ultraweak luminescence （UWL）, contents of malondialdehyde （MDA）, hydrogen peroxide （H₂O₂）, endogenous GB and proline （Pro）, and activities of superoxide dismutase （SOD） and peroxidase （POD） under drought stress. The results showed that UWL intensity increased under slight- and mid drought stress, but decreased with increasing drought stress till lower than the control. Under slight- and mid drought stress, foliar-spraying GB improved the UWL intensity by 35.27% and 43.95%, respectively, decreased H₂O₂ and MDA contents, increased SOD and POD activities, and promoted the accumulation of GB and Pro. The exogenous GB and its induced Pro accumulation could increase the anti-oxidative capability of M. hupehensis leaves, and protect the leaf cells from oxidative damage under drought stress.更多还原