【作者】 尹飞；

【导师】 李潮海；

【作者基本信息】 河南农业大学 ， 作物栽培学与耕作学， 2004， 硕士

【摘要】 本试验以3个耐旱性不同的玉米杂交种及其各自的亲本为材料，采用盆栽方式，在玉米全生育期内进行不同的水分处理，研究了中度水分胁迫对不同耐旱性玉米生长发育、光合特性、叶片内活性氧代谢和产量等方面的影响，以及杂交种与亲本自交系耐旱性状之间的相关关系。主要结果如下：1. 水分胁迫对玉米生长发育和器官建成造成显著的影响，且不同耐旱性玉米材料间存在明显的差异。水分胁迫缩短了玉米叶片功能期；减少了玉米单株叶面积；降低了玉米的株高和茎粗；延迟了散粉期和吐丝期，且吐丝期延迟的程度较散粉期的大，从而造成散粉吐丝间隔期（ASI）的增大，使花期不协调。供试的3个杂交种中，耐旱性弱的掖单13生长发育和器官建成受水分胁迫的影响最大，耐旱性中等的豫玉22受水分胁迫影响居中，耐旱性强的掖单2号受影响最小。掖单13的亲本丹340和478生长发育和器官建成对水分胁迫敏感性高于豫玉22和掖单2号的亲本，表明亲本耐旱性是决定杂交种耐旱性的主要因素。2. 水分胁迫阻碍了玉米的物质积累，使全生育期内玉米的根干重和地上部干重均降低。由于地上部干重对水分胁迫更敏感，所以，水分胁迫下根冠比升高。耐旱性弱的掖单13干物质积累受水分胁迫影响最大，耐旱性强的掖单2号受影响最小，耐旱性中等的豫玉22受影响程度居中。3. 水分胁迫降低了玉米叶片中叶绿素含量，特别是叶绿素a含量，降低了玉米叶片光合速率和蒸腾速率。使吐丝期玉米叶片光合速率日变化的峰值降低。同时水分胁迫也使吐丝期玉米各荧光参数发生变化，降低了光系统Ⅱ（PSⅡ）的最大光化学效率（Fv/Fm）、<WP=8>实际光化学效率（ΦPSⅡ）和光化学猝灭系数（qP），增加了非光化学猝灭（NPQ），且这种影响在一天当中10时至14时表现尤为明显。耐旱性弱的杂交种掖单13在水分胁迫下出现了光合午休，光合、荧光参数受水分胁迫影响最大，耐旱性较强的豫玉22受影响程度居中，耐旱性强的掖单2号受影响最小。水分胁迫处理下，掖单13的亲本丹340耐旱性也弱，也出现了光合午休现象；掖107和黄早4，综3和87-1两对亲本自交系的光合速率、qP、Fv/Fm、NPQ和ΦPSⅡ等指标表现出较强耐旱性。4. 水分胁迫使玉米叶片中超氧阴离子自由基的产生速率变大、过氧化氢含量增加。水分胁迫下玉米叶片内超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（ASP）的活性及抗坏血酸（ASA）的含量在玉米生育前期有不同程度的增加，但在生育后期都明显低于正常供水处理下的水平。同时，水分胁迫处理下玉米叶片MDA含量增多。说明水分胁迫下，特别是在生育后期，玉米活性氧的清除能力下降，玉米叶片活性氧的积累增加，细胞膜系统脂质过氧化程度升高，受损程度加重。在水分胁迫处理下，自交系丹340和478的超氧阴离子产生速率、叶片过氧化氢含量增幅较其它4个自交系大，生育中后期叶片SOD活性、CAT活性、ASP活性和ASA含量降低程度较重，表现出较弱的耐旱性，其杂交种掖单13在这些方面也表现出比豫玉22和掖单2号弱的耐旱性。5. 从水分胁迫下活性氧及其清除系统的变化关系发现，玉米叶片SOD活性、CAT活性、ASP活性和ASA含量在水分胁迫处理下与正常供水处理下数据的比值（WS/CK值）对维持玉米体内活性氧代谢平衡是至关重要的。且对于SOD来说，保持生育后期较高的WS/CK值对清除叶片中超氧阴离子自由基是至关重要的。而对于清<WP=9>除过氧化氢的CAT、ASP和ASA来说，水分胁迫逆境下，在保持生育中后期较高的WS/CK值的基础上，提高生育前期WS/CK值也是很重要的。6. 水分胁迫降低了玉米的籽粒产量，但不同材料受水分胁迫减产的程度不同，各材料的耐旱系数之间存在较大差异。丹340和478的经济系数极显著地低于其它4个自交系的经济系数，杂交种掖单13的经济系数也极显著地低于豫玉22和掖单2号。7. 亲本自交系耐旱性与杂交种后代耐旱性之间存在着正相关关系，且在籽粒产量、生物产量、ASI、qP、CAT活性、ASP活性和ASA含量等7个指标方面，亲本与杂交种耐旱性之间相关系数达到显著水平。更多还原

【Abstract】 Pot-cultivation experiment was conducted to explore effects of middling water stress on growth, photosynthesis characteristics, active oxygen metabolism, and yield of different drought-tolerance-type maize. The correlation between the drought-tolerance of hybrids and that of their own parents was also researched. This experiment included two factors: variety and content of water in soil. Three maize hybrids and their own parents were selected in this experiment and water stress was performed in the whole life of maize. The main results were as follows:1. The growth and organ forming were significantly affected by water stress, and the effects were obviously different between different hybrids and their own parents. The function period of leaves was shortened, the plant height and stem diameter were reduced, and the anthesis and silking date, especially the silking date, were postponed under water stress. Therefore the anthesis-to-silking interval (ASI) was prolonged, which caused asynchrony between pollen shed and silking. The influence of water stress was larger on Yedan 13 than on the other two hybrids, and it was the least on Yedan 2 in term of growth and organ forming, while the drought-tolerance of Yedan 2 was bigger than that of Yuyu 22, whose drought-tolerance was larger than Yedan 13. The sensitivity of D340 and 478 who were the parents of Yedan 13 was higher than that of the parents of Yuyu 22 and Yedan 2. It showed that their parents determined the difference of drought -tolerance between hybrids.2. Water stress cumbered dry matter accumulation of maize. The dry weight of both root and shoot was decreased by waster stress, especially the dry weight of shoot, and therefore the root/shoot rate was increased in the whole life of maize. The order of the influence of water stress on dry matter accumulation was: Yedan 13> Yuyu 22> Yedan 2, while the drought-tolerance order is: Yedan 2> Yuyu 22> Yedan 13.3. The content of chlorophyll, especially that of chlorophyll a, was decreased by water stress in maize leaves. Water stress decreased the net photosynthesis rate (Pn) and transpiration rate (Tr), and also lowered the peak of the diurnal variations of photosynthesis rate and transpiration rate in silking stage. At the same time, water stress changed the diurnal variations of fluorescence parameters. Under water stress, the chlorophyll fluorescence parameters Fv/Fm, ΦPSⅡ and qP decreased, while NPQ increased, and this trend is more obvious from 10:00 to 14:00. weak <WP=71>drought-tolerance-type maize, Yedan 13 and Dan 340, manifested photosynthetic midday depression under water stress. Yedan 2, Yuyu 22 and their own parents were affected slightly by the water stress in terms of the photosynthesis parameters and fluorescence parameters when compared with Yedan 13 and its parents.4. Under water stress the superoxide production rate and the content of H2O2 in maize leaves were increased in the whole growth stage, and the activities of SOD, CAT and ASP and the content of ASA were increased in the early period, while all of them were decreased in the late period. The content of MDA in leaves was increased by water stress in the whole growth stage. These results suggested that the ability of maize to scavenge Active Oxygen Species (AOS) was decreased rapidly in the late period of growth, the accumulation of AOS was increased, and the damage of cell membrane system was aggravated by water stress. The superoxide production rate and the content of H2O2 in leaves of D340 and 478 were increased more significantly than others. The activity of SOD、CAT、ASP and the content of ASA were decreased more obviously in the later growth stage of D340 and 478. This showed D340 and 478 were weak drought-tolerance. So did theirs hybrids, Yedan 13. 5. The relation between AOS and AOS scavengers indicated that the rate of the activities or content of AOS scavengers under water stress against normal water irrigation (WS/CK) was very important to remain the balance of active oxygen metabolism. To SOD, the high ratio of WS/CK in t更多还原