【作者】 张利军；

【导师】 王忠民； 杨铁钊；

【作者基本信息】 新疆农业大学 ， 作物遗传育种， 2004， 硕士

【摘要】 本文分别在实验室和大田条件下研究了烟草种子引发回干的生理效应及技术指标，和烟草种子在萌发与幼苗生长过程中提高抗寒性的调控技术及生理学基础。初步研究表明：1、对烟草种子进行引发, 引发72 h回干处理的烟草种子萌发率最高，催芽后48 h萌发率达到93%，比对照（正常种子）提前了72 h。同时当萌发至72 h，从切片上看种子的胚乳层因被消耗而变薄，胚根突破种皮，此时期的回干种子从外观上可以看到突破种皮微露的白色胚根。随着萌发时间的延长，回干种子的胚根上出现的黄色区域越明显，且呈现萎缩状态。萌发率也随着萌发时间的延长而降低。这可能是过度引发损害了生长点，黄色萎缩区域是坏死区域。因此烟草种子引发的最佳终止期是72 h。2、经过引发回干处理的种子再进行催芽时，种子内的蛋白质、可溶性蛋白、淀粉等大分子物质被均衡利用，其含量变化较平稳；游离氨基酸、可溶性糖等一些有利于萌发、提高种子活力的物质含量较高。3、烟草种子经三种化学物质处理后的萌发试验表明：第一，所选三种化学物质处理的烟草种子均有抗低温的作用；第二，在抗低温效果上，三种化学物质都有各自最佳的浸种浓度；第三，三种化学物质的浸种时间都以48 h为宜；但以浓度为0.5 mmol·L-1水杨酸（SA）浸种48 h的效果最佳，与对照相比达到极显著差异。4、0.5 mmol·L-1的水杨酸（SA）处理过的烟草种子，其幼苗在常温下POD、CAT和SOD的活性比对照高，MDA的含量比对照低，但都不显著。经低温胁迫3 d后，处理组中的POD、CAT和SOD的活性比常温下低但显著高于对照组，MDA的含量比常温下高但显著低于对照。表明SA可能通过保护酶系统，降低活性氧的伤害来提高烟草幼苗的抗寒性。-----------------------------------------基金项目：河南省烟草专卖局重点科技攻关项目（HYKJ200201） <WP=9>5、水杨酸和引发回干两种处理结合的丸化种子在试验室内萌发，处理组的种子在萌发后6 d萌发率达到80%后，对照此时刚有种子萌发。在大田中的萌发结果，处理组的烟草幼苗长势较好。表明，水杨酸和引发回干两种处理结合可提高烟草种子的抗寒性及萌发速度。更多还原

【Abstract】 In this thesis，experiments under both lab and field were conducted to study the physiological effects and technical index of priming and drying treatment and chemical regulating technology and physiological basis of enhancement of chilling-tolerance during tobacoo germination period． The result showed that： 1、The tobacco seeds were treated by priming and drying．The result showed that the highest germination ratio of seed was of the seed by priming 72 hour and drying treatment． Its germination ratio reached to 93% when the seed bourgeoned to 48 hours and the was earlier 72 hours than contrast．From the microtome the albuminous cells became thin because they were consumed and the radicle grew out the seed coat when the tobacco seeds were treated for 72 hours．And from the exterior of the drying seeds the white radicle can be seen in this period． With the Time of seed bourgeon , there was a yellow dot can be seen on the radicle of tobacco seeds and this yellow dot would become clear and wither and the germination ratio decreased．Probably the seed growing dot was damaged because of excessive priming and the yellow dot be necrosis dot． So the best closing date of priming and drying treatment on tobacco seeds was 72 h after priming． 2、In the second germination progress after priming and drying treatment，the content change of protein，soluble protein and starch which was used balanced in the <WP=11>process of seed bourgeon was stabler and the content of free amino acid and soluble sugar in seed which benefit seed bourgeon and improve seed vitality was higher than that in the contrast seed． 3、Tobacco seeds were treated by three different chemical substances．The result showed：The tobacco seeds were treated by three substances all can resist chilling．From effects on chilling-tolerance，the best concentration of soaking seeds of three substances was different．The most suitable time of soaking seeds about three substances to resist chilling was 48 hours．The substance had a striking chilling-tolerance effect was SA(concentration： 0.5 mmol·L-1；treating time：48 h) and the effect reached to marked difference compared with CK．4、Compared with seedlings who seeds treated by water，the activities of POD，CAT and SOD in seedling who seeds treated by SA （0.5 mmol·L-1）were higher and the content of MDA was lower but not striking different．However，compared with the CK，the activities of POD，CAT and SOD in SA treatment were higher and the content of MDA was lower after chilling-stressed 3 d and reached to a striking difference．This indicated that enhancement of the chilling tolerance of tobacco seedling by SA was probably from enhancing activities of protective enzymes during chilling stress．5、The priming and drying tobacco pelleted seeds were treated by SA． In lab，when the germination rate of treated seeds reached to 80% after sowed 6 d，the CK began to germinate．In field，tobacco seedlings grew better than CK． This indicated that SA and priming and drying treatment could improve tobacco seedling chilling tolerance and pick up the seed germination speed．更多还原