【作者】 曹刚；

【导师】 郁继华；

【作者基本信息】 甘肃农业大学 ， 设施作物， 2013， 博士

【摘要】 本文以黄瓜（Cucumis sativus L．）品种“银胚99”和结球甘蓝（Brassica oleraceaL.var.capitata L.）品种“8398”为试材，以LED-T8灯管精量调制光强和光质作为光源，研究了白光、红光、蓝光和不同配比的红光组合光对2种作物幼苗生长发育、光合、荧光特性、不同器官内源激素水平和叶绿体超微结构的影响。研究结果表明：1. LED红光能提高2种作物植株的生物量，并有利于促进结球甘蓝幼苗的伸长生长和叶片扩展；LED蓝光促进黄瓜和结球甘蓝幼苗的加粗生长、干物质积累和壮苗指数，且结球甘蓝幼苗矮化。与白光和单一的红、蓝光相比，LED红蓝组合光对黄瓜和结球甘蓝幼苗的生长发育表现出综合的优势，其中8R/2B下显著提升了2种作物的茎粗、株高、植株干、鲜重、壮苗指数等。2. LED蓝光和红蓝组合光均显著提高了黄瓜幼苗叶片的叶绿素及类胡萝卜素含量，红蓝组合光还能延缓叶片叶绿素含量在后期的衰减；红光培养下的黄瓜叶片叶绿素a/b在处理期间一直居高，呈阳生植物的特性。与黄瓜不同，结球甘蓝幼苗叶片光合色素的合成对光质具有选择性。红蓝组合光对结球甘蓝叶片光合色素的合成表现出极高的促进作用；红光有利于叶绿素b和类胡萝卜素的合成，叶绿素a/b值最小，呈阴生植物特性；蓝光下叶绿素a则合成较多，类胡萝卜素合成少，且叶绿素a/b值最大，呈阳生植物特性。3.黄瓜和结球甘蓝幼苗在LED红蓝组合光下叶片光系统II反应中心的开放程度较大，且光系统II吸收并能运用于光合作用的光能较多；因此，叶片的光系统II功能良好，光系统II更为健康，其中8R/2B处理下2种作物的Fv/Fm、φPSII、qP和Fv’/Fm’显著高于白光和单一红、蓝光。而LED红光下的黄瓜叶片，蓝光和白光下的结球甘蓝叶片吸收的光能不能用于光合电子传递而以热的形式耗散掉的光能多致使NPQ增高。4.在处理前期LED红光可提高结球甘蓝幼苗的净光合速率(PN)，而LED蓝光则可显著提高黄瓜幼苗的净光合速率(PN)；而在处理后期，红蓝组合光可使2种作物叶片净光合速率(PN)较高，蒸腾失水减少，水分利用效率(WUE)明显提高。此外，蓝光可诱导黄瓜和结球甘蓝叶片气孔的开放，叶片拥有较大的气孔导度(GS)。5. LED蓝光和红蓝组合光可显著提高黄瓜茎中及结球甘蓝茎和叶片中的GA3含量，且GA3含量较高可促进植株的株高、茎粗和叶片的纵、横向扩展，并促进结球甘蓝的生物量和干物质积累。LED红光可提高结球甘蓝茎和叶片中IAA含量，且IAA的含量高植株的加粗和伸长及叶片的扩展得到促进；黄瓜则在红蓝组合光8R/2B下茎和叶片中IAA含量较高，且促进植株和地上部生物量的增加。红蓝组合光下2种作物的ABA含量较低，其中8R/2B处理最低；在黄瓜中白光下ABA含量低于红光和蓝光，而在结球甘蓝中红光和蓝光下ABA含量又高于白光。且ABA也同GA3和IAA一起对植株的株高、茎粗，叶片的扩展，生物量及干物质的积累起着调控作用。6.白光不利于黄瓜叶片叶绿体的成熟，并使结球甘蓝叶绿体膨大。红光造成叶片叶绿体淀粉粒过分积累，抑制了光合产物从叶片中的输出；而结球甘蓝在红光下叶绿体光合功能面积比例增大，类囊体垛堞紧密。而在红光下红蓝组合光下，黄瓜和结球甘蓝叶片叶绿体组织结构清晰、形状规则，且类囊体垛堞加厚、连续。更多还原

【Abstract】 Cucumber (Cucumis sativus L.) cultivar “yinpei99” and head cabbage (Brassica oleraceaL.var.capitata L.) cultivar “8398” were selected as materials. LED-T8lamp which can preciselymodulate light intensity and light quality were used as the light source. The experimentexplained effects of white, red, blue, red and blue combination light on growth and development,photosynthesis, fluorescence characteristics, the endogenous hormones levels in differentorgans and chloroplast ultrastructure of the two kinds of crop seedling. The main results are asfollows:1. The red LED light can not only improve plant biomass but also be propitious to promotethe elongation growth and leaf expansion of head cabbage seedlings. On the contrary, the blueLED light is beneficial for diameter increment, dry matter accumulation and increasing seedlingindex of cucumber and head cabbage seedlings, meanwhile, head cabbage seedlings weredwarfed. Compared to a single light source, the combination of red and blue LED light showedintegrate advantages on the growth and development of cucumber and head cabbage seedlings,in which the treatment8R/2B significantly improved stem diameter, height, dry and freshweight and seedling index of two kinds of crop.2. Under the blue LED light and a combination of red and blue light conditions, thecontent of chlorophyll and carotenoid of cucumber leaves significantly increased. What’s more,a combination of red and blue light can delay the attenuation of the chlorophyll content in thelatter. Under the red LED light treatment, the chlorophylla/b content of cucumber leavescontinuously stayed the highest, which shows the characteristics of the light-demanding plant.Unlike cucumber, the photosynthetic pigment synthesis of head cabbage seedlings leavesindicated selectivity for light qualities. A combination of red and blue light had a stimulatingeffect on photosynthetic pigment synthesis of head cabbage leaves. The red light is conduciveto the synthesis of chlorophyll b and carotenoid, moreover, it can minimize the chlorophylla/bratio, which shows characteristics of shade plants. The two kind crops under the blue lighttreatment appeared the reverse phenomena that more chlorophyll a synthesized, less carotenoidsynthesized and chlorophylla/b ratio reached maximum, which shows the characteristics of thelight-demanding plant.3. With a combination of red and blue LED light treating, the degree of openness of theblades photosystem II reaction center of cucumber and head cabbage seedlings is bigger than that of other different light treatments, and the energy which photosystem II absorbed, used inphotosynthesis, is more than that of other different light treatments. Therefore, the leavesphotosystem II function well and the photosystem II is healthier. Under8R/2B compound lighttreatment, these parameters Fv/Fm, φPS II, qP and Fv’/Fm’of two kind crops were significantlyhigher than those of treatment with the single light source. The light energy absorbed bycucumber leaves treated with red LED light and head cabbage leaves treated with blue andwhite LED light cannot be used for photosynthetic electron transport instead dissipated in formof heat energy resulting from increasing NPQ.4. In the early stage of treatment, the red light can improve the net photosynthetic rate (PN)of head cabbage seedlings, while the blue light can significantly elevate the net photosyntheticrate (PN) of cucumber seedlings. In the later stage, a combination of red and blue light canmake two kind crops leaves elevate net photosynthetic rate (PN), reduce transpiration water lossand significantly improve water use efficiency (WUE). In addition, the blue light inducedstomata opening of cucumber and head cabbage leaves, the leaves had a larger stomataconductance (GS).5. The blue LED light and a combination of red and blue LED light can significantlyimprove GA3content of cucumber stems,also in head cabbage stems and leaves. In addition,higher GA3content can promote plant height, stem diameter and leaf vertical and horizontalexpansion, and stimulate the biomass and dry matter accumulation of head cabbage. The redLED light can improve the IAAcontent in the stems and leaves of head cabbage, and the higherIAA content promoted plants bold and elongation and leaf expansion. The IAA content in thestems and leaves of cucumber is higher under compound light8R/2B conditions, which canmake shoot biomass increased. The ABAcontent of two crops is low with a combination of redand blue light treatment, which appears lowest under8R/2B treatment. The ABA content incucumber with white light treatment is lower than that with the red or blue light treatment, theresult in head cabbage shows the same. The ABA associated with GA3and IAA plays aregulatory role on plant height, stem diameter, leaf expansion, biomass and dry matteraccumulation.6. The white light was not conducive to cucumber chloroplast mature, but made headcabbage chloroplast enlarged. The red light caused excessive accumulation of chloroplast starchgrains, which inhibited the output of photosynthetic products from the leaves. Under the red light, the chloroplast photosynthetic area proportion of head cabbage was larger, thylakoid bodybattled closely. Under a combination of red and blue light, the chloroplast organization ofcucumber and head cabbage leaves had clear structure, regular shape and thick and continuousthylakoid body battlement.更多还原