逆境下玉米幼叶气孔分布与密度研究
时间:2017-04-23 16:26 来源:毕业论文 作者:毕业论文 点击:次
| 摘 要：以丹科7号、平玉8号和郑单958三种玉米为材料，采用实验室水培法，测得各种玉米的发芽率后，采用15%PEG-6000与hoagland’s营养液混合液模拟干旱。测定模拟干旱胁迫下试验组、对照组的形态指标与生理生化指标的变化规律，探求玉米抗旱生理机制。结果发现，郑单958发芽率最高，平玉8号次之，丹科7号第三；对照组的植株在株高、鲜重、侧根数目优于试验组，根长不及试验组；气孔呈条带状排列，同一叶片中气孔密度叶基大于叶中，叶中大于叶尖；玉米叶片气孔密度从叶中脉到叶边缘逐渐增加；脯氨酸（Pro）、还原性糖含量较对照组高，叶绿素含量则表现为下降趋势。关键词：玉米；气孔；干旱胁迫；生理生化指标；气孔密度7540 Effects of Stress on Stomata Distribution and Density of Maize Young Leaves Abstract: Laboratory hydroponics was used to measure the germinative rate of three different species of maize (Danke7, Pingyu 8, and Zhengdan 958). Furthermore, to explore the physiological mechanism of drought resistance in Maize, morphological, physiological, and biochemical changes were compared treatment group and control group under drought stress simulated by 15% PEG-6000 and Hoagland 's nutrition liquid mixture. The results showed that the highest germination was zhengdan958, followed by pingyu8 and danke7. The plant height, fresh weight, number of lateral root was decreased, while the root length was increased in treatment group relative to control group. We also found that the stomata had a strip and vein arrangement. The stomata density order in a leaf was leaf blade > the middle part of the blade, and the middle part of the blade > the blade tip. The stomata density of maize leaves increased gradually from middle to leaf blade margin. Compared with control group, proline (Pro), soluble sugar content was increased, while the content of chlorophyll was decreased in treatment group. Key Words: Maize; Stomata; Drought tress ;Physiological and biochemical indexes; Stomata density 目 录 摘 要 1 引言 2 1.材料和方法 3 1.1 供试材料 3 1.2供试试剂与仪器 3 2.实验方法 3 2.1 材料培养和处理 3 2.2相关指标的测定方法 3 2.2.1形态指标的测定 3 2.2.2生理生化指标测定 4 2.3 数据处理 4 3.结果与分析 4 3.1发芽率的统计 4 3.2 形态指标测定结果 5 3.3生理生化指标测定结果 8 3.3.1游离脯氨酸（Pro）的含量 8 3.3.2叶绿素的含量 9 3.3.3还原性糖的含量 9 4.讨论 10 5.展望 11 参考文献 12 致谢 14 逆境下玉米幼叶气孔分布与密度研究引言 水分胁迫是干旱、半干旱地区一种最普遍的环境胁迫，干旱的最直接危害的造成农作物减产，使农业歉收，严重时形成大饥荒。在干旱严重时，人们饮水发生困难，生命受到威胁。目前世界范围内干旱、半干旱地区耕地约占总耕地面积的43%[1]，由缺水造成的粮食减产超过其他因素所导致产量损失的总和[2]。幅员辽阔的中国，在三大阶梯板块的基础上形成了各自的地形地貌特点。我国的西北一些地区因经常发生干旱，干旱造成人畜饮水极端的困难，被迫进行人口大迁移。干旱造成沙漠化，使土地资源造成极大的破坏。常年农作物受旱面积约3亿至4亿亩，每年损失粮食近158亿公斤，占各种自然灾害损失总量的60%。玉米又称为蜀黍，全世界范围内广泛种植的粮食作物。也是我国北方地区的主要的粮食作物及饲料生产的重要原料。最新的调查表明自2012年以后，我国的玉米种植面积约5.24亿亩，粮食生产2.08亿吨占粮食总产量5.89亿吨的35%，所以不论是种植面积、总产量，玉米都是我国第一大作物。因此抓好玉米生产，就抓好了我国粮食持续稳定发展的关键。 (责任编辑：qin) |