玉米抗旱基因资源的鉴定与评价研究

发布时间：2018-04-04 10:00

本文选题：玉米　切入点：抗旱性　出处：《中国农业大学》2016年博士论文

【摘要】：干旱是制约我国玉米发展的主要因素。玉米抗旱育种是提高品种的抗旱性、减少干旱带来损失的有效途径。抗旱性的常规改良比较困难,利用转基因技术可有效提高玉米抗旱育种效率。玉米抗旱基因资源的发掘、鉴定与评价,对筛选创新抗旱的玉米基因和种质、培育抗旱节水的玉米品种意义重大。本研究以玉米骨干自交系及转基因材料为基础,通过4年的田间试验,研究结果如-F：1、以10个玉米自交系为亲本,采用完全双列杂交方法,研究不同玉米双亲杂交组合对其F1代抗旱性的贡献。结果表明：玉米杂交后代的抗旱性取决于父母本双亲的抗旱性,母本的抗旱性贡献略大于父本；正反交F1代抗旱性之和基本等于双亲抗旱性之和。2、对61份转基因玉米材料进行大田抗旱性鉴定评价,结果表明：正常灌水条件下株体适当、产量较高,而在受旱后株高下降少、雌雄穗开花间隔时间(ASI)小的转基因玉米材料通常有较强的抗旱性；无论受旱与否,玉米的穗粗和轴粗、穗重和粒重、百粒体积和百粒重之间存在显著的正比关系。3、在150、225、300、375、450和600mm(CK)梯度灌水胁迫处理条件下,通过对8个转LOS5玉米株系及其受体郑58的大田抗旱性鉴定,结果表明：8个转基因玉米株系的产量在225-450mm灌水范围内均显著高于受体郑58,LOS5转入受体郑58后,对维持受旱玉米的穗长、行粒数和灌浆后期叶色等方面发挥了积极作用,提高了玉米的抗旱性,但抗旱性提高程度在不同转化株系间有显著差异,正常灌水量一半的胁迫强度能最大化玉米抗旱性差异,有利于鉴定筛选出有利用价值的转基因材料。4、在作物产量和水分的数量关系基础上推导出一个简单模型。该模型可拟合产量和累计灌水量间的S曲线或饱和曲线关系。模型中三个参数均有特定的生物学含义：产量生产能力(Ym)、半产需水量(Wh)和水分敏感系数K。利用5个模型和2个梯度灌水试验数据对模型进行了验证与对比,计算值与试验结果高度拟合。本模型可用于分析玉米的阶段水分利用率和抗旱性。5、对24个转基因玉米材料及受体连续4年在不同生育时期进行干旱处理。利用产量和累计灌水量关系模型对计算值和试验实测值之间进行拟合,效果良好。通过拟合和解析,24个转基因玉米材料的半产需水量均少于相应的受体,较受体表现出更好的抗旱性；模型深度解析了不同的基因转入受体后发挥作用的大小和时期,可有效应用于玉米阶段抗旱性的精准鉴定评价中。
[Abstract]:Drought is the main factor restricting the development of maize in China.Maize breeding for drought resistance is an effective way to improve drought resistance and reduce losses caused by drought.The conventional improvement of drought resistance is difficult, and the efficiency of drought resistance breeding can be effectively improved by using transgenic technology.It is of great significance to explore, identify and evaluate the drought-resistant genes and germplasm of maize, and to cultivate drought-resistant and water-saving maize varieties.Based on maize backbone inbred lines and transgenic materials, four years of field trials were carried out. The results were as follows: -F: 1, 10 maize inbred lines as parents, and complete diallel crossing method.The contribution of different hybrid combinations of maize parents to drought resistance of F1 generation was studied.The results showed that the drought resistance of maize hybrid progenies depended on the drought resistance of parents, and the contribution of female parents to drought resistance was slightly greater than that of male parents.The sum of drought resistance of F1 generation was equal to that of both parents. The drought resistance of 61 transgenic maize materials was evaluated in the field. The results showed that under the normal irrigation condition, the plant body was appropriate, the yield was higher, but the plant height decreased less after drought.Transgenic maize materials with small flowering interval between male and female ears usually have strong drought resistance; ear diameter and axis diameter, ear weight and grain weight of maize, no matter whether they are exposed to drought or not,There was a significant proportional relationship between 100-grain volume and 100-seed weight. Under the condition of 150225300375450 and 600mm CK gradient irrigation stress, the drought resistance of 8 transgenic LOS5 maize lines and their receptor Zheng 58 were identified in the field.The results showed that the yield of 8 transgenic maize lines was significantly higher than that of recipient Zheng 58 in 225-450mm irrigation range, and played an active role in maintaining ear length, grain number and leaf color in late grain filling stage.The drought resistance of maize was improved, but the degree of drought resistance was significantly different among different transformed lines. The stress intensity of half of the normal irrigation amount could maximize the difference of drought resistance of maize.It is helpful to identify and screen the useful transgenic material. 4. A simple model is derived on the basis of the relationship between crop yield and water content.The model can fit the S curve or saturation curve between yield and cumulative irrigation amount.The three parameters in the model all have specific biological meanings: yield production capacity (Ym), semi-yield water demand (WSD) and water sensitivity coefficient (K).Five models and two gradient irrigation test data were used to verify and compare the models, and the calculated values were highly fitted to the experimental results.The model can be used to analyze the water use efficiency and drought resistance of maize in different stages. 24 transgenic maize materials and their receptors were subjected to drought treatment at different growth stages for 4 consecutive years.The model of relation between yield and accumulative irrigation quantity is used to fit the calculated value and the experimental measured value, and the effect is good.By fitting and analyzing, the semi-yield water demand of 24 transgenic maize materials was less than that of the corresponding receptor, which showed better drought resistance than that of the receptor, and the model deeply analyzed the magnitude and time of the different genes being transferred to the receptor.It can be effectively applied to the accurate evaluation of drought resistance in maize stage.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S513

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