【作者】 丁伟；

【导师】 马凤鸣；

【作者基本信息】 东北农业大学 ， 作物栽培与耕作学， 2004， 博士

【摘要】 20世纪90年代后，磺酰脲类等超高效化学除草剂的开发应用占据农药市场，代表着化学除草剂的发展方向。在玉米、大豆、小麦、油菜、水稻五大作物中磺酰脲类除草剂已广泛应用。由于磺酰脲类除草剂中的一部分品种在土壤中残留时间长，对后茬敏感作物毒害很重，而甜菜(Beta Vulgaris L．)又是最敏感作物。因此，磺酰脲类除草剂的广泛应用，给甜菜生产轮作造成严重障碍，同时也限制了此类超高效除草剂的应用。本文利用目前国内外甜菜品种资源，对甜菜耐磺酰脲类除草剂基因型进行筛选，并在耐性基因筛选基础上研究其耐性机理，为解决甜菜生产磺酰脲类除草剂造成的轮作障碍及其合理利用耐性基因提供理论依据。通过研究得出如下结论： 1．首次筛选出1个对豆磺隆具有耐性的甜菜品系NE02-1。上年土壤中豆磺隆含量在3.7ppb以下时，经过一年降解对次年耐性甜菜NE02-1生产不会造成危害，但对敏感甜菜生产则危害严重；用7.5 ga.i.／hm~2豆磺隆茎叶处理时，耐性甜菜仍然可以恢复正常生长。 2．耐性甜菜NE02-1根系活力在豆磺隆施用量0.5 ga.i.／hm~2-1.0ga.i.／hm~2时降幅较小，叶绿素含量呈增加趋势，使甜菜具有较强的光和作用能力；豆磺隆7.5ga.i.／hm~2叶面喷施3天后，耐性品系NE02-1叶绿素含量开始增加，并在短时间内恢复至正常水平。根系活力降幅较小，6天后开始恢复生长。 3．耐性甜菜幼苗根系受到豆磺隆胁迫时，叶片中POD、SOD均表现降低后增高趋势，MDA含量呈现增高后降低变化；豆磺隆茎叶处理后，耐性甜菜SOD活性前3天表现为降低趋势，以后SOD活性增加并达到正常状态。POD活性在茎叶处理后第6天明显高于对照，而敏感甜菜则持续降低。MDA含量虽然呈现增高趋势，但与敏感甜菜相比增加幅度较小。耐性甜菜在豆磺隆胁迫下抗氧化酶保持较高活性，清除了活性氧对甜菜造成的危害，是耐性甜菜品系NE02-1对豆磺隆耐性增强的原因之一。 4．耐性甜菜NE02-1内源激素在豆磺隆胁迫下，短时间即可恢复并维持相对平衡，三种促进型激素IAA、GA及Zr与敏感甜菜相比保持较高的含量，ABA含量较对照略有降低。而敏感甜菜IAA、GA含量呈现降低趋势，Zr含量始终维持较低水平，并且ABA含量明显增高。耐性甜菜体内三种促进型激素与ABA比值明显高于敏感甜菜，因而维持了耐性甜菜体内激素的相对平衡，对于耐性甜菜在豆磺隆胁迫下保持正常生长具有重要作用。 5．耐性甜菜根系及叶片对豆磺隆吸收与敏感甜菜无差异，但传导至根部的豆磺隆明显低于敏感甜菜。 6．耐性甜菜对豆磺隆的降解速度大于耐性中等品系，耐性甜菜对体内豆磺隆短时间的快速降解，使得受豆磺隆毒害时间短是其耐性增强的重要原因。 7．在豆磺隆胁迫下，耐性甜菜叶片及根中具有较高的GST活性及GSH含量。较高的GSH含量及GST活性，使缀合豆磺隆能力增强。这是耐性甜菜对豆磺隆解毒的重要途经。 8．耐性甜菜在豆磺胁迫下，与敏感甜菜相比保持较高的氨基酸含量。豆磺隆对耐东北农业大学农学博士学位论文性甜菜三种支链氨基酸缘氨酸、亮氨酸及异亮氨酸抑制作用不同，对异亮氨酸抑制作用最明显，对撷氨酸及亮氨酸抑制作用不明显。 9.豆磺隆胁迫下，耐性甜菜品系NE02一IALS活力明显增加，与敏感甜菜品系相比，耐性甜菜品系ALS活力在甜菜生育过程中表现较高水平;叶面喷施豆磺隆后，耐性甜菜品系ALS始终表现较高活力.在豆磺隆胁迫下，耐性甜菜品系NE02一1豆磺隆作用靶酶ALS活力增加是对豆磺隆耐性增强的关键原因。更多还原

【Abstract】 Development and applying of some kinds of super high effective herbicides such as sulfonlureas occupied the herbicide market after the year1990 in 20th century.It represented the direction of herbicide development. Sulfonlureas herbicides were have been widely used in five big crops such as corn,soyben,wheat and rapeseed.Some kinds of sulfonlureas herbicides was long residue in soil and seriously damaged the sensitive rotation crops.Sugarbeet(Beta vugaris L) is the most sensitive crop .Widely use of sulfonlureas had brought obstacle in sugarbeet rotation and in the same time restricted the application of this super high effective herbicides also.In this paper,we used china and outside sugarbeet varieties to select tolerant sugarbeet gene type to sulfonlureas herbicides and studied on its tolerant mechanism in order to resolve the obstacle in sugarbeet rotation and provide theory basis in reasonable use of the tolerant gene. We concluded following results:l.One tolerant sugarbeet variety had been firstly selected.Its growth was unaffected after a year when soil chlorimuron-ethyl was under3.7ppb,but the sensitive variety was damaged seriously, while chlorimuron-ethyl was sprayed in 7.5ga.i./hm2 on the leaf of tolerant sugarbeet, its growth can remain normally after several days.2.Root activity of tolerant variety NE02-1 was slightly decreased when soil chlorimuron-ethyl was 0.5ga.i./hm2-1.0 ga.i./hm2.Chlorophll content showed increasing trend and made the tolerant variety had higher photosynthesis ability.Three days after spraying chlorimuron-ethyl , chlorophll content of the tolerant sugarbeet was increased and recovered formal level in short time. The root activity slightly decreased and recovered formal growth after 6 days.3.Under the stress of chlorimuron-ethyl in root, POD and SOD activity in the tolerant sugarbeet seedlings showed firstly decreasing and then increasing trend;MDA content was firstly increased and then decreased in short time.Three days after spraying chlorimuron-ethyl, SOD activity in the leaf of tolerant variety showed decreasing trend then SOD activity begin increasing and arrive at normal level.At the same time, SOD activity of the sensitive sugarbeet was continuously decreased and MDA content showed increasing trend,but the increasing scope of the tolerant variety was little compare with the sensitive sugarbeet varieties.lt is one course that resistant oxidant enzyme keep high activity in tolerant sugarbeet variety so as to clarify the super oxide which is harmful to sugarbeet4.Endogenous hormones content of the tolerant variety recovered in short time and remained relatively balance under chlorimuron-ethyl stress .three advancing hormons 1AA,GA and Zr remained higher content compare with sensitive sugarbeets, ABA content was lower relatively.On the contrary the endogenous hormons of sensitive sugabeets maintain lowerlevel and ABA content was striking increased.Three advancing endogenous hormons content divided by ABA content in tolerant sugarbeet was distinct higher than the sensitive sugarbeet.It remained the balance of endogenous hormons content relatively and it is important to the tolerant variety remain formal growth under stress of soil chlorimuron-ethyl.5.There was no difference in chlorimuron-ethyl absorption by root system and leaf between the tolerant and sensitive variety,but the sensitive variety transferred more chlorimuron-ethyl to its root after spraying chlorimuron-ethyl.6.Chlorimuron-ethyl degradation in tolerant variety was quicker than sensitive variety. Rapid degradation of chlorimuron-ethyl in tolerant variety at short time makes tolerant sugarbeet uninjured and it was the important cause to increase tolerance to chlorimuron-ethyl.7.The tolerant sugarbeet has higher GST activity and GSH content in root and leaf under stress of Chlorimuron-ethyl.This increased the conjugation ability to chlorimuron-ethyl..It is important way to dispel toxin of chlorimuron-ethyl in tolerant sugarbeet variety.8.The tolerant variety remained higher amino acid content under c更多还原