【作者】 王州飞；

【导师】 胡晋； 王世恒；

【作者基本信息】 浙江大学 ， 作物遗传育种， 2004， 硕士

【摘要】 本文以sh₂甜玉米超甜2018和蔬选1号2个品种的F₁种子为材料，研究了sh₂甜玉米F₁种子活力的形成过程；以sh₂甜玉米超甜2018和对照苏玉1号种子为材料，探讨了sh₂甜玉米种子贮藏劣变的原因；以sh₂甜玉米自交系及其组配得到的F₂籽粒为材料，分析sh₂甜玉米F₂籽粒乳熟期品质性状的遗传特点；以sh₂甜玉米超甜2018为材料，分析了F₂籽粒乳熟期品质的动态变化及其与气候因素的关系。主要结果如下： 在种子发育过程中，2个sh₂甜玉米品种种子大小变化趋势一致，种子长、宽、厚、体积、鲜重和干重先上升后下降，在授粉后38天趋向稳定。种子长度、宽度、厚度和体积分别在授粉后30天、26天、18天和26天达到最大，表明厚度最先长足，而种子鲜重和干重分别在授粉后26天和38天达到最大值。α-淀粉酶活性呈双峰曲线变化，在授粉后38天其活性消失，β-淀粉酶活性先上升后下降，在授粉后42天趋向最低。种子过氧化物酶（POD）和过氧化氢酶（CAT）活性在种子成熟期间呈上升趋势，在授粉后34～42天活性增加迅速，在授粉后42天达到最大值。在种子成熟期间，丙二醛（MDA）和电导率逐渐下降，在授粉后42天趋向最低，种子可溶性总糖、还原糖含量逐渐下降，淀粉、可溶性蛋白含量逐渐上升。随着种子发育进程，其发芽率、发芽势、发芽指数和活力指数呈逐渐上升的趋势，在授粉后38天趋向最大。时间序列回归分析表明，sh₂甜玉米种子发育过程中，种子干重、电导率和还原糖含量对种子活力有显著影响，种子发芽率、发芽势、发芽指数和活力指数与种子干重呈正相关，与电导率和还原糖含量呈负相关。分别建立了种子干重与活力、种子电导率大小与活力、种子还原糖含量与活力的时间序列回归方程，能有效预测不同发育阶段的种子活力高低。 sh₂甜玉米种子贮藏劣变研究表明，随着贮藏时间的延长，种子发芽率和活力指数逐渐下降，超甜2018较对照苏玉1号种子易发生劣变，室温贮藏较低温（4-5℃）贮藏易发生劣变，高含水量（12.5％）较低含水量（10.9％）种子易发生劣变。随着贮藏时间的延长，种子渗透液电导率、渗透液可溶性糖和核苷酸含量逐渐增加，超甜2018较苏玉1号增加量大，室温贮藏较低温贮藏增加量大，高含水量较低含水量种子增加量大。室温贮藏的萌发种子胚POD活性逐渐下降，而低温贮藏其活性逐渐上升。贮藏期间，超甜2018萌发种子胚CAT活性逐渐下降，而苏玉1号其活性保持在较低水平且基本保持不变。贮藏180天后，MDA积累量，超甜2018种子高于苏玉1号种子，室温贮藏高于低温贮藏种子。相关分析表明，种子发芽率和活力指数分别与种子渗透液电导率大小、渗透液可溶性糖和核苷酸含量、萌发种子胚CAT活性及种子内MDA含量呈显著负相关。试验认为，贮藏种子细胞膜完整性变化和种子有毒物质MDA积累是sh₂甜玉米种子发生贮藏劣变的主要原因。 25个sh₂甜玉米自交系及其组配的15个sh₂型F₂籽粒的5个品质性状的遗传特点、杂种优势和亲子回归关系研究表明，亲本间，除籽粒还原糖含量外，可溶性总糖、蔗糖、淀粉、可溶性蛋白含量是否存在显著差异，对F₂籽粒品质有明显影响。F₂籽粒可溶性总糖、还原糖、淀粉、可溶性蛋白含量近浙江大学硕士学位论文:摘要（Abstract）低亲遗传，而蔗糖含量近高亲遗传。杂种F:籽粒可溶性总糖、淀粉、可溶性蛋白含量普遍介于双亲之间，杂种优势不强;还原糖含量普遍表现为低亲，没有超亲优势;蔗糖含量以超亲为主，有明显杂种优势。亲本对F:杂交籽粒可溶性总糖、还原糖、蔗糖、淀粉、可溶性蛋白含量均表现为正效应;除还原糖品质外，其他品质性状受父本的影响较大。研究表明，了解、h:甜玉米亲本营养品质性状，能很好的预测其F:籽粒营养品质性状，使育种更有目的性。 对夏季两个不同播期的、h:甜玉米乳熟期籽粒大小、糖分积累、酶活性的动态变化及其相关性研究表明，由于籽粒乳熟后期脱水，籽粒长度、宽度、厚度、体积和可溶性总糖、果糖含量呈中间高，两头低的抛物线型;籽粒淀粉酶、POD、超氧化物岐化酶（SOD）活性变化也均呈抛物线型;曲线符合方程y二。十bx+cxZ伽为籽粒大小、糖含量、酶活性，x为授粉后天数，。，b，。为参数)。相关分析表明，在播期一，a一淀粉酶、p一淀粉酶、POD、SOD活性与籽粒长度、宽度、厚度、体积和可溶性总糖、果糖含量均未显著相关;在播期二，a一淀粉酶活性与籽粒长度、宽度、体积和可溶性总糖、果糖含量，SOD活性与籽粒长度、体积存在显著负相关。 采用夏季不同播期，研究了:h:超甜玉米乳熟期籽粒重量和碳水化合物的变化，用多重回归分析方法对气温、降雨量与籽粒重量、碳水化合物含量的关系进行了分析。结果表明，两个播期的可溶性总糖、果糖、蔗糖含量变化趋势有明显差异。夏季早播，提高了乳熟期籽粒鲜重和干重，灌浆速率，可溶性总糖和淀粉含量。说明夏季早播有利于提高甜玉米的独特甜风味和产量构成。移栽一收获期的乙T（温差）、K（有效积温）和天尸（降雨量）是影响乳熟期籽粒鲜重和干重，可溶性总糖、果糖、蔗糖、淀粉含量的主要因子，K、尺尸表现正相关效应;在授粉一收获期，K是影响的主要因子，K与籽粒?更多还原

【Abstract】 The process of F1 seed vigor formation in sh2 sweet corn, cv. Chaotian 2018 and Shuxuan No. 1, was investigated. The causes of seed deterioration in sh2 sweet com cv. Chaotian 2018 and general corn cv. Suyu No. 1 during storage were studied. The genetic traits, dynamic changes of nutrition characteristics in F2 kernel of sh2 sweet corn, cv. Chaotian 2018, during milk maturation and the correlation analysis between nutrition characteristics and temperature, rainfall were investigated. Main results obtained were as follows:The length, width, thickness, volume, fresh weight and dry weight of seed increased firstly, and declined afterward during seed developmental stage. The change of seed size was similar between Chaotian 2018 and Shuxuan No.l in sh2 sweet corn during seed developmental stage. Seed length, width, thickness and volume had the highest values in 30, 26, 18 and 26 day after pollination (DAP), respectively. Seed thickness reached firstly the highest value. Seed fresh weight and dry weight reached the highest values in 26 and 38 DAP. There was a double-peak curve change in cc-amylase activity. The a-amylase activity disappeared in 38 DAP. The p-amylase activity increased firstly and then declined, it had the lowest activity in 42 DAP. The peroxidase (POD) and catalase (CAT) activities increased gradually during seed maturation, the activities rose rapidly during 34~42 DAP and reached the highest values in 42 DAP. The contents of malondialdehyde (MDA) and leachate conductivity decreased gradually and reached the lowest contents in 42 DAP. It also observed that the contents of total soluble sugars and reducing sugar declined gradually, the contents of starch and soluble protein increased gradually during seed developmental stage. The germination percentage, the energy of germination, germination index and vigor index increased gradually along with seed development and reached the highest values in 38 DAP. The time series regression analysis showed that the seed dry weight, leachate conductivity and reducing sugar content had significant effect on seed vigor. There were positive correlations between the seed dry weight and germination percentage, the energy of germination, germination index and vigor index. There were negative correlations between the seed leachate conductivity, reducing sugar content and germination percentage, the energy of germination, germination index and vigor index, respectively. Time series regression equations between seed dry weight and seed vigor, seed leachate conductivity and seed vigor, seed reducing sugar and seed vigor were developed, respectively. Seed vigor parameters in" different developmental stage of sh2 sweet com seeds could be predicted effectively.The results showed that the seed germination percentage and vigor index were declined gradually during seed storage. During storage, Chaotian 2018 seeds with sh2 gene was deterioration sensitive as compared with general com seeds of Suyu No. 1 (as control); seed deterioration at room temperature was faster than that at low temperature (4-5℃); deterioration in the seeds with low moisture content (10.9%) was slower than that with high moisture content (12.5%). The contents of leachate conductivity, total soluble sugars and nucleic acid in seed leachate during the seed storage were increased gradually, and the increased values of Chaotian 2018 seeds were larger than that of Suyu No.l seeds, the increased values of storage seeds at roomtemperature were larger than that at low temperature and of the seeds with high moisture content were larger than that with low moisture content. The POD activity of germinating embryos stored at room temperature was declined gradually, however, the activity was increased gradually during seed storage at low temperature. The CAT activity of germinating embryos in Chaotian 2018 was declined gradually, the CAT activity in Shuyu No. 1 was lower than that in Chaotian 2018 and kept stable low level during storage. After seed storage for 180 days, there was a higher MDA content in C更多还原