【作者】 刘开昌；

【导师】 董树亭； 胡昌浩；

【作者基本信息】 山东农业大学 ， 作物学， 2003， 博士

【摘要】 1、玉米抽丝后相对绿叶面积的衰减符合方程：y=ae^b-cx/(1+e^b-cx)，不同基因型玉米保绿度、叶片衰减速率、植株衰老启动时间等存在着显著的差异，根据叶片保绿度和衰减速率，按照Hierarchical聚类分析方法，将不同玉米基因型划分为保绿型和非保绿型。保绿型玉米叶片保绿度在60％以上，叶片衰减速率低，在0.516～0.868％·d^-1范围内；非保绿型保绿度平均为20.56％；平均叶片衰减速率高，变幅是0.798～2.371％·d^-1，叶片保绿度与叶面积持续期、单株产量呈正相关。 保绿型玉米在抽丝后积累较多的干物质，植株干物质转移率和经济系数相对低；植株可溶性糖含量显著高于非保绿型；根量增加，根活力增强；叶片开始衰老时间略晚，衰减速率较慢，后期能维持较高的绿叶面积和叶面积持续期，有利于提高光合面积，延长光合时间；库容量与源供应能力的比值小，果穗的秃顶和败育粒数减少，库充实度较高。籽粒灌浆期延长，灌浆速率差异不大，灌浆后期ADPGPPase、UDPGPPase、SSS、GBSS的活性明显高于其它类型，有利于粒重增加。 2、保绿型玉米叶片光合色素含量降低缓慢，后期含量较高，叶绿素与蛋白质结合牢固；光合速率、气孔导度、量子效率和羧化效率在抽丝期的差异并不明显，在灌浆期以后，保绿型玉米表现出明显的优势。功能叶片PEPase、RuBPase、SPS和SS活性在灌浆后期显著高于非保绿型。 荧光参数的变化变化表明，在一定时期内Fm、Fv变化幅度较小，基本维持稳定，蜡熟期以后Fm、FV、Fv/Fm和Fv/Fo有降低的趋势，表明在叶片衰老的后期，PSⅡ电子传递、PSⅡ的最大光化学效率和潜在活性都有所降低。玉米叶片电子传递速率光量子产量Φ_PSⅡ、光化学猝灭系数qP和ETR随着生育时期的推进均呈降低趋势，非光化学淬灭刘开昌:不同基因型玉米叶片保绿性生理机理及其遗传研究系数N户Q则呈增加的趋势，在生育后期更为明显。保绿型玉米有较高的PSn的潜在活性和最大光化学效率，光能的捕获效率、光化学电子传递份额和电子传递效率的降低幅度小，后期光合机构保持完整，有较高的光合活性。 3、保绿型玉米叶片、茎鞘氮含量高，植株氮素抽丝前积累量、抽丝后积累量、总同化量高，其转移量、转移率和氮素收获指数则显著低于非保绿型，抽丝后积累量的比例增加;氮素代谢的关键酶如硝酸还原酶、GS活性、GOGAT活性在各时期均高于NSG，其活力大小则与保绿性呈显著正相关。 4、保绿型玉米叶片SOD、POD和CAT活性显著高于非保绿型，膜脂过氧化的产物MDA含量很低，避免由于膜脂过氧化造成的叶片衰老。相关分析显示，叶片的保绿度与内源保护酶SOD、POD和CAI，活性的大小呈显著正相关。保绿型玉米有较高的ZR含量和较低的ABA含量，二者的比值ZR/ABA显著高于非保绿型。较高的玉米素含量和相对低的脱落酸含量是玉米叶片保绿的生理原因之一。 5、叶片保绿度、叶片衰减速率、叶片衰老启动的时间均受加性和非加性基因的共同作用。保绿度的广义遗传力为99.87%，狭义遗传力为%.26%。叶片衰减速率的广义遗传力为99.71%，狭义遗传力为8629%。叶片衰老启动时间的广义遗传力为98.91%，狭义遗传力为5.70%，它主要是由基因型决定，加性遗传方差在表型遗传中比例非常小。 玉米杂交Fl代的优势是许多生理优势的综合体现。玉米的根系中根活力、根千重、根活性表面等指标，玉米光合性能中，叶面积持续期、梭化效率、光合速率、C02固定的关键酶pE户梭化酶和RuB户梭化酶等生理指标，氮素代谢中，氮积累量、转移率、氮收获指数和硝酸还原酶活性等指标，叶片保护酶CAT、500、户00活性和内源激素ZR等指标，均有较强杂种优势;而MDA、ABA含量等指标则表现为负优势。更多还原

【Abstract】 In order to elucidate the physiological mechanism and inheritance of leaf stay-green traits, a full diallel was designed by crossing three stay-green inbred lines and three non stay-green inbred lines. The studies were conducted combining the field experiment and analysis in the lab by using physiological analysis, biochemical methods, and their integrations. Leaf photosynthesis and photochemical mechanism, enzymology characten’stic related to carbon assimilation, physiological characteristic of nitrogen metabolic activity, some cell protective enzymes to eliminate active oxygen, and regulation of endogenous hormone were researched, the genetic effect of leaf green trait and physiological heterosis were estimated. The main results were as follows:1. The changes of relative green leaf area after silking were fit the equation: y=aeb-cx/(1+eb-cx) There were significant differences in stay green degree, leaf reducing velocity, and the time of beginning to senescence between maize genotypes. According to Hierarchical’s classify method, based on the stay green degree in maturity and leaf reducing velocity, all the maize genotypes were classified into two analogs: one was stay green type(SG), its stay green degree was higher than 60 percent, its reducing velocity was in the range of 0.516 to 0.868%-d-1; another was non stay green type(NSG), its average stay green degree was 20.56 percent, the range of reducing velocity was 0.798 to 2.371%-d-1. Correlation analysis proved that there was positive correlation between stay green degree and yield per plant and leaf area duration.Maize hybrid with stay green trait accumulated more dry matter after silking, had lower translocation rate and economic index; Its soluble sugar content in plant was higher than that of non stay green types; and its root number added, root vigor increased; the time of its leafs beginning to senescence was delayed, and leaf reducing velocity was very low, which resulted in higher green leaf area and longer leaf area duration; the ratio of sink capacity to source supplying ability was smaller, and bald length and abortive kernel number decreased, which resulted in higher sink capacity realize;!; its kernel filling duration was longer, ADPGPPase activity, UDPGPPase activity, SSS activity and GBSS activity in kernels were higher than that of non stay-green type after filling stage, and this was very helpful to increase kernel weight.2. Maize hybrid with stay green trait had higher photosynthetic pigment and chlorophyll-protein binding degree. Its photosynthetic rate, stomatal conductance, quantum efficiency and carbonxylation efficiency had not significant difference between the stay greemand non stay green in silking stage, but after filling stage, stay .green type was superior to non stay green in all the photosynthetic traits. PEPase activity, RuBPase activity, SPS activity and SS activity in ear leaf of stay green were higher than that of non stay green.Changes of fluorescence parameters indicated that there were steady Fm and Fv within silking stage and waxy maturity stage, but after waxy maturity stage, Fm, Fv, Fv/Fm, and Fv/Fo began to decrease, and PS ,qP, ETR decreased too, but NPQ increased. The stay green type had higher PS potential activity and Maximum photochemical efficiency.3. There was higher nitrogen content in leaf, stem and sheath of stay green type, and its nitrogen accumulation before silking, nitrogen accumulation after silking, total nitrogen accumulation were also higher, but its nitrogen translocation, translocation rate and nitrogen harvest index were significantly lower than that of non stay green type. Some key enzymes to physiological characten’stic of nitrogen metabolic activity such as nitrate reductase. activity(NR), glutamate synthetase(GOGAT), glutamine synthetase(GS) in leaf of stay green type were significantly higher than that of non stay green type, and their activity were positive related to stay green degree.4. SOD activity, POD activity, and CAT activity in leaf of s更多还原