【作者】 付凤玲；

【导师】 潘光堂；

【作者基本信息】 四川农业大学 ， 生物化学与分子生物学， 2006， 博士

【摘要】 干旱是影响粮食生产的主要非生物因素。据统计，从1950年至今，全国平均每年受旱面积达3.26亿亩，成灾1.34亿亩，直接减收粮食200亿斤以上，约占各种自然灾害造成粮食损失的60％。玉米在我国的栽培面积为2000多万公顷，占作物总面积的1／3，其中2／3是旱作，干旱造成的产量损失平均为15％，仅次于病虫害的危害。而玉米一生需水量大，对水分胁迫又非常敏感。因此，研究玉米耐旱性的遗传特性，对了解玉米耐旱机理，寻找耐旱基因，进而改良玉米自身的耐旱性，以及耐旱品种选育具有重要指导意义。 本试验采用控制灌水措施，在土壤含水量略高于萎蔫系数的干旱条件下，鉴定了生产上常用的以及新近选育的57个玉米自交系的耐旱性。筛选强耐系和不耐系，以及与籽粒产量耐旱系数相关显著的耐旱性状指标。在此基础上，对耐旱性的基因效应和遗传模型进行了研究，并对强耐旱自交系在mRNA水平和蛋白质水平的表达差异进行了分析鉴定。为了对优良自交系的耐旱性进行改良，也为了获得研究耐旱性遗传的突变材料，我们结合物理化学诱变，对优良自交系愈伤组织进行了诱变筛选。主要结果如下： 1．利用塑料大棚，在土壤含水量略高于萎蔫系数的干旱强度下（土壤绝对含水量为10％-12％），以籽粒产量耐旱系数为指标，鉴定了57个常用玉米自交系的耐旱性。耐旱系数变异幅度在0.810-0.048之间，以81565的耐旱性最强，R09和N87-1次之，200B、丹340、9526最弱。对其中耐旱性强、中等、弱的12个代表自交系的15个与耐旱性有关的生长发育和生理生化指标进行了调查和测定，根据其与正常灌水对照的差异计算耐旱系数，并与籽粒产量耐旱系数进行多元回归分析。结果表明，播种出苗期可用出苗率与生物学产量耐旱系数的乘积作为自交系耐旱性鉴定指标，成株期可用株高、雌雄花期间隔、出叶速度、根重等的耐旱系数预测自交系的耐旱性。对苗期与成株期耐旱性的相关分析表明，苗期出苗率与生物学产量耐旱系数的乘积与成株期单株籽粒产量耐旱系数的简单相关系数r=0.840^**，达极显著水平，说明苗期耐旱性的强弱与成株期的耐旱性有显著相关性，可以通过苗期耐旱性鉴定来预测成株期的耐旱性。 2．在耐旱性鉴定结果的基础上，选择耐旱性差异较大的亲本配成两对组合（81565×9526；R09×丹340），并组配成P1、P2、F1、F2、B1、B2六个世代群体。又选耐旱性不同的11个自交系，按Griffing完全双列杂交方法4，组配55个杂交组合。随机区组设计，三次重复，干旱处理同前。分别调查与耐旱性相关显著的耐旱指标株高、ASI、出叶速度、根重和单株籽粒产量，并分析和估计了这5个指标的基因效应、配合力和遗传力大小。结果表明：耐旱性的基因效应在不同指标和不同组合间变化较大。对于出叶速度，加性效应和显性效应表现相当，另外4个指标显性效应明显大于加性效应。更多还原

【Abstract】 Drought is one of significant factors that restrict the production of foodstuff. According to the statistics of the State Information Center, there are more than 27 million ha plowland that have been bearing drought every year in china from 1950 year to today, and cutting harvest production was more than 100 hundred million kilogram, accounting for 60% of sum of many natural disasters. There are 20000 thousand ha areas that plant maize in our country, accounting for one third of sum of crops planting areas, and among that there are two third maize planted in dryland. Losing yield average were about 15% due to drought, only inferior to harm of plant diseases and insect pests. Maize needs much of water to complete its life, and it is very sensitive to short of moisture than other kinds of crops. Therefore, studying about inheritance of drought tolerance in maize is very important to understand drought tolerant mechanisms, find drought tolerant genes, and improve maize-self drought tolerance, breed drought tolerant varieties that can tolerate drought and get stable yield in stress of water deficiency.This trial identified and valued drought tolerance of 57 maize inbred lines that have been popularizing in China or breeding newly in recent years, with taking of control water irrigation according to soil moisture condition that was little higher than maize wilting coefficient in sandy loam soil. Then, the strong and sensitive drought tolerant germplasm, and drought tolerant indexes were selected. Based on these results, the gene effects and hereditary models of drought tolerance in maize were studied. The expressional differences of mRNA and proteins were displayed and analyzed with strong drought tolerance inbred line. In order to improving drought tolerance of excellent inbred line and gaining mutant material used to study on inheritance of drought tolerance, the embryonic calluses of excellent inbred line were mutated and screened with physical and chemical mutating method. The main results showed as follows.1. The 57 maize inbred lines were sown in a plastic roof to prevent rainfall. Under soil moisture was controlled at little higher than wilting coefficient (soil absolute moisture is 10%-12%),the drought tolerance of these materials was identified with drought tolerant coefficients of grain yield as indexes. Variational range of drought tolerant coefficients is from 0.810 to 0.048, and drought tolerance of inbred line "81565" belonged to the strongest更多还原