【作者】 孟桂元；

【导师】 孙焕良；

【作者基本信息】 湖南农业大学 ， 种子科学与工程， 2009， 博士

【摘要】 本研究通过对亚麻生育后期不同打顶时间、打顶次数、打顶程度,抑芽剂种类、抑芽剂浓度、抑芽剂喷施量等田间试验,以倒伏率、倒伏指数、原茎产量、纤维品质为主要考评指标,建立了亚麻生育后期打顶抑芽防倒栽培技术体系;通过亚麻生育后期打顶抑芽防倒栽培的抗倒力学性状变化规律、形态结构特征、群体光合特征、无机营养特征的比较研究,初步探明了亚麻生育后期打顶抑芽防倒栽培高产(工艺产量)、稳产(产量原茎)、优质、高效的生理机制,主要结论归纳如下:1.亚麻生育后期打顶时间为现蕾期至初花期,以初花期打顶最好:由于田间麻株生育的差异性,至少需要两次打顶,第二次打顶应在第一次打顶后7 d内完成:打顶量以保留麻株工艺长度(即麻株基部至其梢部第一分枝处)为最好;抑芽剂如,30.2%芽敌乳油、25%芽克水剂、25%抑芽敏乳油、33%除芽通乳油等抑芽剂均有一定的抑芽效果,但以25%抑芽敏乳油最好;抑芽敏的最佳浓度为原药稀释300倍～400倍,最佳用量650 kg/hm~2～750kg/hm~2。2.打顶、抑芽、打顶+抑芽均有一定的防倒作用,但以打顶+抑芽的防倒效果最好,田间倒伏率为5.8%,较对照减少85.4%,倒伏程度也明显减轻;原茎产量略低于对照,但原茎工艺产量明显提高,高于对照23.68%,纤维强力明显增加,较对照多17.06%,纤维分裂度与对照相当。3.打顶+抑芽处理可明显降低麻株重心高度(33.14%)和倒伏指数(51.06%),增强茎秆抗折力和麻株最大承载力(46.05%和11.12%);麻株冠层重量与重心高度和茎秆抗折力分别存在密切的正和负相关性,与麻株最大承载力存在显著负相关性;说明亚麻打顶+抑芽处理能有效减少麻株冠层重量,提高麻株抗倒伏能力。4.打顶+抑芽处理后株高明显下降(25.17%),茎秆明显增粗(12.24%);分枝数、分枝长度、分枝鲜重分别减少67.50%、52.80%、94.55%;表皮皮层厚度、韧皮部厚度和木质部厚度工艺成熟期均明显增加,而髓腔直径增幅不明显。亚麻茎秆抗折力与株高、分枝鲜重存在密切的负相关性,与茎粗存在高度的正相关性,与茎秆解剖结构中表皮皮层厚度、韧皮部厚度存在极显著正相关性,与木质部厚度及髓腔大小存在显著正相关性。5.打顶+抑芽处理后初期叶面积小幅减少,中期和后期却明显增加,工艺成熟期分别是对照的2.95倍、6.06倍;处理后主茎、花和果实占总干物质的比例分别明显增加、减少,而叶占总干物质百分比影响不明显。茎秆抗折力与群体光合特性指标存在正相关性,与主茎干重呈显著正相关性,与分枝干重都呈负相关性。表明亚麻打顶+抑芽处理后改善了麻株生育后期光合特性,减少了分枝干物质重量,因而提高了麻株抗倒能力。6.打顶+抑芽处理后除活跃吸收面积(%)、比表面积较对照增幅不明显外,单株根干重、根系体积、总吸收面积和根系氧化力均明显增加;其单株氮素积累量有所减少,而单株磷素、钾素积累量有所增加;叶和茎秆中氮、磷、钾分配比例明显增多,而蒴果中分配比例明显减少。茎秆抗折力与根系特性指标存在正相关关系,与单株氮素和磷素、钾素积累量分别存在负和正相关关系,与茎秆氮素、磷素和钾素积累量呈显著正相关关系。表明亚麻生育后期打顶+抑芽处理可明显改善麻株根系特性,促进茎秆中氮、磷、钾的分配比例增加,因而有利于提高麻株的抗倒伏能力。更多还原

【Abstract】 By studying on different topping time,topping number,topping extent and the type,concentration,spraying volume of inhibiting bud agent at growth later stage in flax under field experiment,the anti-lodging cultivation technology of topping and inhibiting sucker at growth later stage in flax was established using lodging rate,lodging index,the original stem yield,fiber quality appraisal as the main indicators.This paper ascertained preliminary physiological characteristics of high-yield(original stem yield),high-quality,highly efficient of anti-lodging cultivation of topping and inhibiting sucker at growth later stage in flax through comparatively study of lodging resistances mechanical characteristics changes,morphological structure characteristics,group photosynthetic characteristics and inorganic nutrition characte-ristics.The main results were as follows:1.The topping time at growth later stage in flax is ranged from squaring period to the beginning of flowering and the best topping time is early flowering period.It need at least twice topping and the second topping time should be completed in 7 d after the first topping;It’s better to retain the length of main strains(ie strains base to its first branch).The maleic agent such as 30.2%yawei EC,25%yake grams water,25%yiyamin EC,and 33%chuyatong EC,etc all have some inhibition sucker effect,but 25%yiyamin EC is the best;The best concentration of yiyamin EC is 300 to 400-fold dilution and the best dosage is 650～750 kg/hm~2.2.Topping,inhibition sucker,topping + inhibition sucker would have some anti-lodging effect,but topping + yiyamin had the best anti-lodging effect.Its field lodging rate was only 5.8%,reduced 85.4%comparing with the control.Its raw stem yield was slightly lower than the control,but process output was significantly(23.68%) higher than control.Fiber strength was 17.06%higher than the control and fiber splitting was corresponded to that of control.3.Topping+yiyamin obviously reduced center of gravity height(33.14%) and lodging index(51.06%) and enhanced breaking resistance of stem,the maximum weight carrying capacity of flax(46.05%and11.12%).Flax canopy weight was significantly positively and negatively correlated with center of gravity height and breaking resistance of stem respectively. It was negative correlated with the maximum carrying capacity of flax,which showed topping + yiyamin can effectively reduce canopy weight and improve stem capacity of lodging resistance.4.The plant height decreased significantly(25.17%) and stem diameter increased 12.24%. The number of branches,branch length and fresh weight of branches reduced 67.50%,52.80%, 94.55%respectively after topping +yiyamin.The thickness of epidermis cortex,phloem and xylem increased significantly,but the diameter of medullary cavity was not obviously incremental.Stem breaking resistance was significantly negative correlated with plant height and branch fresh weight and was significantly positive correlated with stem diameter.It was also significantly positive correlated with the thickness of epidermis cortex and phloem and was positive correlated with xylem thickness and cavity size.5.The leaf area reduced slightly at initial stage and increased significantly at mid-and latter-of topping+yiyamin treatment,which was 2.95,6.06 times than the control at mature stage respectively.Stem,flowers and fruits of the proportion of the total dry matter were significantly increased,reduced respectively and the change of leaf percentage of total dry matter was not obvious after topping+yiyamin.Stem fracture resistance was positively correlated with indicators of group photosynthetic characteristics and was significantly positively correlated with stem dry matter.It was negatively correlated with branch dry matter.These showed that the improvement of photosynthetic characteristics and reduction of branch weight after topping+yiyamin treatment at growth later stage can increase the capacity of lodging resistance.6.The change in active absorption area(%)and specific surface area of roots was not obvious,but the root dry weight per plant,root volume,total absorption area and root oxidation power increased significtively after topping+yiyamin.The nitrogen accumulation per plant was slightly reduced,but phosphorus and potassium accumulation per plant increased.The nitrogen, phosphorus and potassium distribution ratio of leaf and stem increased obviously,and proportion of capsule fruit in the distribution decreased significantly.Stem fracture resistance was positively correlated with indicators of root characteristics and was positive and negative correlated with per plant nitrogen and phosphorus,potassium accumulation respectively.It was significtively positive correlated with nitrogen and phosphorus, potassium accumulation of stem.All these indicated the improvement of root characteristics and increase of nitrogen,phosphorus and potassium accumulation of stem can increase lodging resistance in flax.更多还原