【作者】 张艳侠；

【导师】 王玮；

【作者基本信息】 山东农业大学 ， 植物学， 2006， 硕士

【摘要】 以抗旱性强的花生品系鲁花14和干旱敏感型品系红白保-5为材料,采用盆栽和大田栽培两种方式,于苗期(四叶期)根施和花针期、荚果形成期叶面喷施甜菜碱(苗期10mM,花针期、荚果形成期50mM)的方法,研究了外源甜菜碱对干旱胁迫下花生水分关系、渗透调节能力、抗氧化酶活性、光合能力及最终产量的影响,初步探讨了外源甜菜碱对干旱胁迫下光系统Ⅱ(PSⅡ)的保护机制。主要结果如下:1.外源甜菜碱对苗期花生抗旱性的影响(1)根施甜菜碱,改善了干旱胁迫下两花生品系的水分状况,提高了叶片水势(ψw)和相对含水量(RWC),并发现甜菜碱的这种作用与甜菜碱促进花生脯氨酸和可溶性糖的积累进而提高花生叶片的渗透调节能力(0A)有关。(2)外源甜菜碱可保护干旱胁迫下花生幼苗叶片的抗氧化酶活性。与未经甜菜碱处理的叶片相比,甜菜碱处理叶片在干旱胁迫下具有相对较小的电解质外渗值和相对较低的丙二醛(MDA)含量,表明甜菜碱能够稳定苗期干旱胁迫下花生叶片的生物膜,缓解活性氧(ROS)引起的膜脂过氧化。(3)外源甜菜碱可缓解干旱胁迫下花生叶片叶绿素的分解,提高干旱胁迫下花生叶片的气孔导度(Gs),缓解干旱引起的气孔和非气孔限制,从而增强了光合能力。(4)外源甜菜碱可缓解干旱胁迫和强光引起的光抑制,提高光抑制条件下的最大光化学效率(Fv/Fm)。2.外源甜菜碱对花针期和荚果形成期花生抗旱性的影响花针期和荚果形成期叶面喷施甜菜碱可提高干旱胁迫下两花生品系的产量,荚果形成期提高更明显。主要是因为叶面喷施甜菜碱提高干旱胁迫下花生的单株结果数、饱果数和百果重所致。叶面喷施甜菜碱还能在一定程度上提高正常浇水花生的百果重,使其产量有一定提高。更多还原

【Abstract】 Two peanut cultivars with different drought tolerance (drought-tolerant cultivar Luhua14 and drought-sensitive cultivar Hongbaibao-5) were used to study the effects of exogenous glycine betaine (GB) on the leaf water status, the osmotic adjustment, the antioxidant enzyme activities, the photosynthetic rate in leaves as well as the production. Peanut plants were grown either in pots or in the field.10 mM GB was irrigated to peanut seedlings with 4 leaves. 50 mM GB was sprinkled to the leaves at the anthesis stage and podding stage. We studied the protective mechanism of GB on the photosystem II (PSII) under drought stress. The main results are as follows:1. Effects of exogenous GB on water status of peanut seedlings under drought stress(1)In both cultivars of peanut, irrigation of 10mM GB could ameliorate water status in drought-stressed peanut leaves, increase leaf water potential (Ψw) and relative water content (RWC), this was related with h accelerating the accumulation of proline and soluble sugars and thus improving the osmotic adjustment (OA).(2)Exogenous GB protected activities of anti-oxidant enzyme (SOD、CAT). The GB-treated leaves exhibited a lower electrolyte leakage and MDA content, indicating that GB could stabilize the structure of membrane and alleviate the membrane lipid peroxidation resulting from active oxygen (ROS) under drought stress. (3)Exogenous GB alleviated the degradation of chlorophyll of peanut seedlings, improved the net photosynthetic rate (Pn), alleviated stomatal and non-stomatal limitation caused by drought stress and enhanced the stomatal conductance of drought stressed peanut leaves , thus strengthened the photosynthesis ability(4)Exogenous GB relieved the photoinhibition and photooxidation caused by drought stress and strong light, increased the max photochemical efficiency(Fv/Fm)under photoinhibition.2. Effects of exogenous GB at anthesis and poding stage on yield of peanut under drought stressSpraying peanut leaves with GB at anthesis and poding stages increased the production of both cultivars, especially at poding stage. Application of exogenous GB could improve the number of grains per individual plant, the number of plump grains and weight of per hundred grains. As well as, GB application improved the yield of peanuts under well-watered condition.更多还原