【作者】 孙刚；

【导师】 曹敏建；

【作者基本信息】 沈阳农业大学 ， 作物学， 2014， 博士

【摘要】 种子活力是反映种子在各种条件下具有的潜在萌发与出苗能力,是衡量种子质量高低的一项重要指标。提高种子活力对种子提高出苗率、抵御不良环境、提升竞争能力,增强抗寒力、增加作物产量等具有重要作用。玉米是喜温作物,对低温条件适应能力差。东北地区,春季低温干旱。玉米种子早播常会遇到低温,晚播容易出现干旱,研究抗寒剂提高玉米种子的抗寒性,对于适时早播、抢墒播种,提高玉米产量,具有重要的理论和实践意义。本文通过室内试验与田间试验相结合的方法,首先以创奇518陈种子为研究材料,通过玉米种子活力引发单一试剂、复合试剂筛选研究及田间验证试验,确定提高种子活力的最优药剂。进一步在此药剂基础上,采用创奇518新种子为材料,有针对性的添加具有抗寒作用药剂,研究筛选出提高种子抗寒能力的组合,并采用正交试验设计方法确定该组合的最优浓度配比。同时,测定相关形态与生理指标,进一步研究其提高玉米种子抗寒能力的生理基础,最后通过田间生产应用进行验证。旨在为玉米种子抗寒剂的研制与应用提供科学依据。主要研究结果如下：1.玉米种子活力引发药剂筛选通过单一性药剂,聚乙二醇(PEG)、赤霉素(GA3)和氯化钙(CaCl2)对种子进行引发处理,筛选出PEG可显著提高玉米种子活力,而GA：,则可显著促进幼苗生长。发芽率方面,PEG比对照(水处理)提高12.7%,但GA3、CaCl处理则分别比对照降低13.9%、46.8%。活力指数方面,PEG处理比对照显著提高21.8%,而GA3, CaCl则分别比对照降低7.5%、48.8%。株高方面,GA3、PEG、CaCl处理则分别比对照提高了26.2%、12.8%、1.3%,GA3和PEG作用明显；PEG与GA3复合引发试验的发芽率、活力指数、过氧化物酶(POD)、过氧化氢酶(CAT)等均低于PEG(对照)处理。结果表明,PEG为提高玉米陈种子活力的最优药剂。2.玉米种子活力引发药剂的田间验证出苗率,PEG处理分别比CKl(水处理)和CK2(未处理)提高了45.5%和137.0%,平均提高了91.3%,作用显著。幼苗株高、干物质积累、根冠比,PEG处理则分别比CKl和CK2平均提高了16.5%、22.6%、13.1%。田间试验与室内试验结果趋势一致,PEG为最优种子活力引发药剂,可作为进一步研究玉米种子抗寒剂的基础药剂。3.玉米种子抗寒药剂筛选单一抗寒药剂筛选结果表明,PEG处理的发芽率略低于对照(未处理),但高于其它处理,而PEG处理的活力指数、幼苗株高和幼苗鲜重则显著低于其它处理。二甲基亚砜(DMSO)、水杨酸(SA)处理的发芽率与PEG接近,但活力指数、幼苗株高和鲜重显著高于其它处理。脯氨酸(Pro)、氯化钙(CaCl2)处理的相关指标则低于对照和PEG处理。进一步以PEG为基础进行复合药剂筛选,其中PEG、DMSO和SA的组合处理的玉米种子发芽率分别比CKl(水处理)、CK2(未处理)提高了80.0%、12.5%,平均提高了46.3%。发芽势分别比CK1和CK2提高了87.5%和7.1%,活力指数则分别比CKl和CK2提高了90.5%和41.0%,平均提高65.8%。幼苗鲜重、株高分别比CK1和CK2平均提高了15.1%、7.3%,过氧化物酶(POD)、过氧化氢酶(CAT)含量分别比CK1和CK2平均提高了47.5%、40.8%。该组合处理可明显提高玉米种子抗寒性。4.玉米种子抗寒剂的优化组合通过正交试验设计,对PEG、DMSO和SA组合进行优化浓度组合筛选,确定其最佳浓度组合为PEG (20%)、DMSO (0.5%)和SA(0.007%)。该组合处理的玉米种子发芽率分别比CK1(水处理)、CK2(未处理)提高39.4%、15.0%,平均提高27.2%。活力指数则分别比CK1和CK2提高41.7%和44.6%,平均提高43.2%。株高比CK1和CK2处理平均提高9.3%。而幼苗电导率、丙二醛含量则分别比CK2降低23.5%、64.9%,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)则分别比CK2提高了10.4%、42.7%和118.0%。幼苗根活力比CK2提高48.4%,作用显著。可溶性糖、叶绿素含量分别比CK2提高32.7%、34.5%,但可溶性蛋白质略有降低(0.001%)。该组合对提高种子抗寒性具有良好的促进作用。5.玉米种子抗寒剂的田间生产应用优化抗寒剂处理2年的出苗率均明显优于对照(未处理),其中2012年比对照提高了15.4%,2013年则比对照提高了15.6%,两年平均提高15.5%。玉米幼苗株高、干物质积累、根冠比明显高于对照,而玉米种子电导率值和丙二醛含量则低于对照。玉米种子抗寒性有明显提高；最终产量表现,2012年优化抗寒剂处理比对照提高6.5%,2013年提高6.3%,两年平均提高6.4%,对玉米增产有一定促进作用。更多还原

【Abstract】 Seed vigor reflects potential ability of seed germination and seedling emergence in various conditions and is an important indicator of seed quality. Improving the vigor of seeds plays an important role in improving germination rate, withstanding the adverse environment, improving the competitive ability of seeds, enhancing cold resistance, increasing crop yield. Maize is a kind of thermophilous crop, has poor ability to adapt to low temperature. The northeast area is prone to cold and drought climate. Early sowing often encounter cold weather and late sowing is prone to drought. Study on the cold resistant agent to improve cold resistance of maize seed has important theoretical and practical significance for the early sowing,, rush-plant while the soil is damp, increasing the yield of maize. This paper selected optimal reagent to improve seed vigor firstly by using old Chuangqi518seeds as materials, through a single reagent, composite reagent priming and field verification tests. Using new Chuangqi518seeds as raw material, cold resistant agent on improving cold resistance of maize seeds by adding reagents of improving the cold resistance based on the chemicals was done. The cold resistant agent was further optimized by orthogonal test for finding the concentration ratio. At the same time, determination of morphological and physiological indexes related to the cold resistance mechanism of maize seeds and the field verification experiment were be done for providing scientific basis for the research and application of maize seed cold resistant agent. The results were as follows:1. Screening agent of maize seed vigor primingBy a single agent, polyethylene glycol (PEG), gibberellin (GA3) and calcium chloride (CaC12) of seed priming treatment, the result was that PEG can significantly improve the maize seed vigor, and GA3can significantly promote the growth of seedling. The germination rate of PEG increased by12.7%than the control (water treatment), but GA3, CaCl2treatment reduced by13.9%,46.8%. Vigor index of PEG treatment significantly increased by21.8%, while GA3, CaC12reduced by7.5%,48.8%. Plant height, GA3, PEG, CaCl2treatment increased by26.2%,12.8%,1.3%, effect of GA3and PEG was obvious; In PEG and GA3 composite initiator experiment, germination rate, vigor index, peroxidase (POD), catalase (CAT) were lower than the PEG (control) treatment. The results showed that, PEG was the best medicine to improve seed vigor of old maize seed.2. The field verification test of maize seed vigor priming agentThe seedling emergence rate, PEG increased by45.5%and137%than CK1(water treatment) and CK2(untreated), the average increase of91.3%,effect is significant. The plant height, dry matter accumulation, root shoot ratio, PEG treatment respectively increased by16.5%,22.6%,13.1%than CK1and CK2. The results of field test and laboratory test are consistent, PEG is the optimal seed vigor priming agent, can be used as the basis medicament for further research of maize seed cold resistant agents.3. Screening of maize seed cold resistant agentsSingle cold drug screening results showed that the germination rate of PEG treatment was slightly lower than the control (untreated), but higher than other treatments, and vigor index, seedling height and fresh weight of seedlings were significantly lower than other treatments. The germination rate of two dimethyl sulfoxide (DMSO), salicylic acid (SA) treatment was close to PEG, but the vigor index, seedling height and fresh weight was significantly higher than other treatments. Proline (Pro), calcium chloride (CaC12) correlation index was lower than control and PEG treatment.Experiment of composite medicament screening was be done on the basis of PEG, germination rate of maize seed of PEG, DMSO and SA combined treatment increased by80%and12.5%than CK1(water treatment), CK2(untreated), the average increase of46.3%. Germination potential respectively increased by87.5%and7.1%than CK1and CK.2, the vigor index respectively increased by90.5%and41%than CK1and CK2, the average increase of65.8%. Seedling fresh weight, plant height increased by15.1%,7.3%than CK1and CK2, peroxidase (POD), catalase (CAT) content increased by47.5%,40.8%than CK1and CK2. The combined treatment can significantly improve the cold resistance of maize seed.4. The optimization of maize seed cold resistant agentThrough the orthogonal experimental design, optimized concentration combinations on PEG, DMSO and SA was screened, its optimal concentration combination was PEG (20%), DMSO (0.5%) and SA (0.007%). The germination rate of combined treatment of maize seed respectively increased by39.4%,15%than CK1(water treatment), CK2(untreated), an average increase of27.2%. Vigor index respectively increased by41.7%and44.6%than CK1and CK2, the average increase of43.2%. Plant height averagely increased of9.3%than CK1and CK2. And the MDA content, conductivity of seedling respectively reduced23.5%,64.9%than CK2, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) content respectively increased by10.4%,42.7%and118%than CK2. The root vigor of seedling increased by48.4%than CK2, effect was significant. The content of chlorophyll, soluble sugar respectively increased by32.7%,34.5%than CK2, but the soluble protein decreased slightly (0.001%). This combination had a good effect on improving cold resistance of seeds.5. Application of field production of maize seed cold resistant agentThe germination rate of two years of optimization of cold resistant agent was significantly better than the control (untreated), which in2012increased by15.4%than the control, in2013increased by15.6%than the control, two years averagely increased by15.5%. Maize plant height, dry matter accumulation, root shoot ratio was higher than that of the control, but the corn seed and MDA content was lower than those of control. Maize seed cold resistance is obviously improved; The final yield performance of optimization cold resistant agent processing, increased by6.5%in2012, increased by6.3%in2013than control, two years averagely increased by6.4%. Optimization cold resistant agent had a certain effect on maize yield.更多还原