我国南方冬油菜机械化生产农艺研究进展

油菜机械化生产是我国油菜生产发展的方向,近年来在南方冬油菜区进行了适合机械化生产的油菜品种筛选和鉴定,农机和农艺配套技术试验示范。本文综述了在油菜机械直播和机械移栽、抗倒伏措施及理想株型构建、施肥技术、病虫草害化学防治、化学催熟技术、机械收获技术等方面的研究概况,并探讨了存在的问题及今后的研究方向。

油菜短柄叶光合衰退及其对产量的影响

以中双9号、中油杂11号和华油杂14号油菜为材料,测定花后短柄叶光合速率及生理指标,探讨短柄叶光合衰退与叶绿素含量等因素之间的关系及其对油菜产量的影响。结果表明,油菜短柄叶光合速率随叶片衰老而逐渐降低,1,5-二磷酸羧化酶(RuBPCase)、可溶性蛋白和叶绿素含量,以及超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性均呈现出下降趋势,膜脂过氧化作用产物丙二醛(MDA)在叶片光合功能衰退过程中含量逐渐上升。油菜叶片光合衰退与RuBPCase含量、可溶性蛋白含量、叶绿素含量和SOD活性存在显著相关关系,表明光合速率的下降可能与油菜叶片衰老过程中N含量、叶绿素降解及蛋白质合成受抑制相关;SOD和CAT水平逐渐降低及MDA含量升高也表明,叶片衰老过程中氧自由基胁迫抑制光合作用。叶片光合作用与油菜单株产量的相关关系分析结果表明,油菜短柄叶光合速率,特别是短柄叶衰退的中后期光合速率是影响油菜产量的重要因素。

Influences of 5-ALA Application on Winter Oilseed Rape (Brassica napus L.) Growth before Winter

[Objective] The aim of this paper is to investigate the influences of exogenous 5-aminolevulinic acid （5-aLA） application on the growth and mechanism of winter oilseed rape （Brassica napus L.） before winter. [Method] For this purpose a split-plot experimental design with four treatments of seed soaking with 0,25,50 and 75 mg/L ALA solution （CK,A1,A2 and A3） was carried out from October 2009 to January 2010 in order to observe the influences upon the growth and relevant physiological indexes of Zhongshuang 9. [Result] Seed soaking with ALA solution significantly promotes the growth of double-9 before winter,which is probably due to the fact that ALA application enhances its photosynthesis,absorption of nutrients,and its anti-oxidation abilities. The research also finds that ALA treatment notably increases its photosynthetic pigment contents,root activities,leaf nitrate reductase activities,soluble sugar contents,antioxidase activities,and significantly decreases malondialdehyde（MDA） content. [Conclusion] These results indicate that seed soaking with 50 mg/L ALA solution might have a potential application in increasing the productivity of winter oilseed rape in agricultural management.

Dynamics of Essential Metal Elements Contents in Winter Oilseed Rape during Cold Acclimation

[Objective]The paper was to investigate the dynamics of essential metal elements（Ca,Mg,Fe,Mn,Zn and Cu）contents in winter oilseed rape（Brassica napus L.）during cold acclimation,and to reveal the effects and mechanisms of essential elements in cold resistance of oilseed rape.[Method]Three varieties with different cold resistance including Zhongshuang No.11（ZS,freezing sensitive variety）,Ganyouza No.1（GY）and Jinyuyou No.1（JYY,freezing tolerant varieties）were used in the study,and the changes of necessary metal elements in these oilseed rapes during cold acclimation were studied.[Result]The concentration of metal elements in oilseed rape had significant changes during cold acclimation,and the difference between varieties was significant.In plant roots,the concentrations of Ca,Mg,Fe,Mn,Zn and Cu were significantly increased,this might because that low temperature made the transpiration decreased,thus blocking the upward transport of elements.In plant shoots,the concentrations of Ca,Mg and Zn were significantly decreased,while the concentrations of Fe and Mn were significantly increased;the change extent of various elements in ZS variety was the largest.[Conclusion]Maintaining the stability of Ca,Mg and Zn concentrations and increasing Fe,Mn and Cu concentrations in plant shoots might be benefit for increasing the cold tolerance of winter oilseed rape.

ALA Altered ABA Content of Winter Oilseed Rape(Brassica napus L.)Seedling

[Objective] The paper was to explore the impact of 5-aminolevunic acid（ALA）treatment on growth of winter oilseed rape（Brassica napus L.）seedlings and its mechanism.[Method] The effects of ALA on abscisic acid（ABA）contents in plant organs and xylem saps were investigated through hydroponic experiment.Four treatments including seed soaking with 0,25,50 and 75 mg/L ALA solutions（CK,A1,A2 and A3）for 6 h were set in the test.[Result] In addition to A3 treatment which made the dry weights of oilseed rape seedlings slightly decrease,after seed soaking with ALA,dry weights,net photosynthetic rate（Pn）,transpiration rate（Tr）and stomatal conductance（Gs）of plants significantly increased compared with control.ABA concentrations in plant shoots and xylem saps increased in different levels after seed soaking with ALA.[Conclusion] The increasing endogenous ABA contents might be an explanation for promotion effect of ALA application on the growth of winter oilseed rape seedling.