林业科学
林業科學
임업과학
Scientia Silvae Sinicae
2015年
7期
84-90
,共7页
刘方春%马海林%马丙尧%杜振宇%井大炜%邢尚军
劉方春%馬海林%馬丙堯%杜振宇%井大煒%邢尚軍
류방춘%마해림%마병요%두진우%정대위%형상군
干旱胁迫%根际促生细菌%蜡样芽孢杆菌%核桃苗%光合
榦旱脅迫%根際促生細菌%蠟樣芽孢桿菌%覈桃苗%光閤
간한협박%근제촉생세균%사양아포간균%핵도묘%광합
drought stress%plant growth-promoting rhizobacteria ( PGPR )%Bacillus cereus%walnut seedlings%photosynthesis
【目的】研究干旱环境下接种根际促生细菌( PGPR)对植物光合特性的影响，为 PGPR 在干旱逆境中的应用提供依据，为干旱地区造林及植被恢复提供技术支撑。【方法】采用盆栽试验，以产细胞分裂素的蜡样芽孢杆菌 L90为供试 PGPR 菌株，以核桃苗为供试植物，利用 LI-6400便携式光合作用仪研究中度干旱胁迫及干旱复水条件下接种 L90对核桃苗叶片光合参数的影响。【结果】干旱胁迫( DR)及干旱环境下接种L90对核桃苗叶片的净光合速率(Pn)、气孔导度(Gs)、胞间 CO2浓度(Ci)及叶绿素(Chl)含量影响显著。整个胁迫期间，同正常浇水处理相比，DR 处理核桃苗叶片的 Pn和 Gs分别下降21.78%和29.47%，而接种 L90处理仅下降11.62%和23.84%，干旱环境下接种 L90可显著提高 Gs，缓解干旱对 Pn的抑制。除干旱胁迫初期外，随着干旱胁迫时间的增加，L90缓解干旱对 Pn的抑制效果逐渐增强。随着干旱胁迫时间的延长，DR 处理核桃苗叶片的 Ci迅速降低后持续升高，而 Gs持续降低，其光合性能同时受气孔因素和非气孔因素的限制；接种 L90后核桃苗叶片的 Ci和 Gs持续降低，其光合性能主要受气孔因素限制。一定强度的干旱能够造成核桃苗叶片中 Chl 的分解或流失，在胁迫末期，同对照处理相比，DR 处理核桃苗叶片的 Chl 含量显著降低9.22%；同 DR 处理相比，L90处理叶片 Chl的含量显著增加9.49%，干旱环境下接种 L90显著抑制了干旱胁迫后期 Chl的降解。恢复供水后，同正常浇水处理相比，DR 处理的 Pn，Gs和 Chl 含量分别降低9.46%，10.29%和5.86%，Ci增加8.72%；同 DR 处理相比，接种 L90处理的 Pn，Gs和 Chl 含量分别提高7.01%，12.15%和5.81%，基本恢复到对照水平。接种 L90有利于核桃苗叶片光合功能的快速恢复。【结论】干旱胁迫下，植物叶片的 Pn，Gs和 Chl含量均有不同程度的降低，而干旱环境下接种产细胞分裂素的蜡样芽孢杆菌 L90能够在一定程度上抑制这种降低，延缓水分胁迫下非气孔因素对植物叶片 Pn的限制，且更有利于恢复供水后叶片光合功能的恢复。
【目的】研究榦旱環境下接種根際促生細菌( PGPR)對植物光閤特性的影響，為 PGPR 在榦旱逆境中的應用提供依據，為榦旱地區造林及植被恢複提供技術支撐。【方法】採用盆栽試驗，以產細胞分裂素的蠟樣芽孢桿菌 L90為供試 PGPR 菌株，以覈桃苗為供試植物，利用 LI-6400便攜式光閤作用儀研究中度榦旱脅迫及榦旱複水條件下接種 L90對覈桃苗葉片光閤參數的影響。【結果】榦旱脅迫( DR)及榦旱環境下接種L90對覈桃苗葉片的淨光閤速率(Pn)、氣孔導度(Gs)、胞間 CO2濃度(Ci)及葉綠素(Chl)含量影響顯著。整箇脅迫期間，同正常澆水處理相比，DR 處理覈桃苗葉片的 Pn和 Gs分彆下降21.78%和29.47%，而接種 L90處理僅下降11.62%和23.84%，榦旱環境下接種 L90可顯著提高 Gs，緩解榦旱對 Pn的抑製。除榦旱脅迫初期外，隨著榦旱脅迫時間的增加，L90緩解榦旱對 Pn的抑製效果逐漸增彊。隨著榦旱脅迫時間的延長，DR 處理覈桃苗葉片的 Ci迅速降低後持續升高，而 Gs持續降低，其光閤性能同時受氣孔因素和非氣孔因素的限製；接種 L90後覈桃苗葉片的 Ci和 Gs持續降低，其光閤性能主要受氣孔因素限製。一定彊度的榦旱能夠造成覈桃苗葉片中 Chl 的分解或流失，在脅迫末期，同對照處理相比，DR 處理覈桃苗葉片的 Chl 含量顯著降低9.22%；同 DR 處理相比，L90處理葉片 Chl的含量顯著增加9.49%，榦旱環境下接種 L90顯著抑製瞭榦旱脅迫後期 Chl的降解。恢複供水後，同正常澆水處理相比，DR 處理的 Pn，Gs和 Chl 含量分彆降低9.46%，10.29%和5.86%，Ci增加8.72%；同 DR 處理相比，接種 L90處理的 Pn，Gs和 Chl 含量分彆提高7.01%，12.15%和5.81%，基本恢複到對照水平。接種 L90有利于覈桃苗葉片光閤功能的快速恢複。【結論】榦旱脅迫下，植物葉片的 Pn，Gs和 Chl含量均有不同程度的降低，而榦旱環境下接種產細胞分裂素的蠟樣芽孢桿菌 L90能夠在一定程度上抑製這種降低，延緩水分脅迫下非氣孔因素對植物葉片 Pn的限製，且更有利于恢複供水後葉片光閤功能的恢複。
【목적】연구간한배경하접충근제촉생세균( PGPR)대식물광합특성적영향，위 PGPR 재간한역경중적응용제공의거，위간한지구조림급식피회복제공기술지탱。【방법】채용분재시험，이산세포분렬소적사양아포간균 L90위공시 PGPR 균주，이핵도묘위공시식물，이용 LI-6400편휴식광합작용의연구중도간한협박급간한복수조건하접충 L90대핵도묘협편광합삼수적영향。【결과】간한협박( DR)급간한배경하접충L90대핵도묘협편적정광합속솔(Pn)、기공도도(Gs)、포간 CO2농도(Ci)급협록소(Chl)함량영향현저。정개협박기간，동정상요수처리상비，DR 처리핵도묘협편적 Pn화 Gs분별하강21.78%화29.47%，이접충 L90처리부하강11.62%화23.84%，간한배경하접충 L90가현저제고 Gs，완해간한대 Pn적억제。제간한협박초기외，수착간한협박시간적증가，L90완해간한대 Pn적억제효과축점증강。수착간한협박시간적연장，DR 처리핵도묘협편적 Ci신속강저후지속승고，이 Gs지속강저，기광합성능동시수기공인소화비기공인소적한제；접충 L90후핵도묘협편적 Ci화 Gs지속강저，기광합성능주요수기공인소한제。일정강도적간한능구조성핵도묘협편중 Chl 적분해혹류실，재협박말기，동대조처리상비，DR 처리핵도묘협편적 Chl 함량현저강저9.22%；동 DR 처리상비，L90처리협편 Chl적함량현저증가9.49%，간한배경하접충 L90현저억제료간한협박후기 Chl적강해。회복공수후，동정상요수처리상비，DR 처리적 Pn，Gs화 Chl 함량분별강저9.46%，10.29%화5.86%，Ci증가8.72%；동 DR 처리상비，접충 L90처리적 Pn，Gs화 Chl 함량분별제고7.01%，12.15%화5.81%，기본회복도대조수평。접충 L90유리우핵도묘협편광합공능적쾌속회복。【결론】간한협박하，식물협편적 Pn，Gs화 Chl함량균유불동정도적강저，이간한배경하접충산세포분렬소적사양아포간균 L90능구재일정정도상억제저충강저，연완수분협박하비기공인소대식물협편 Pn적한제，차경유리우회복공수후협편광합공능적회복。
[Objective]Plant growth-promoting rhizobacteria ( PGPR ) are rhizosphere inhabitants that can promote plant growth and suppress diseases. The study of PGPR effect on photosynthetic characteristics will provide scientific basis for application potential under drought stress and technical support for afforestation and vegetation ecological restoration in arid environments. [Method]A pot experiment was conducted in order to evaluate the effects of PGPR on the photosynthetic characteristics under drought conditions. A dominant species of PGPR with the ability to produce cytokinins,namely Bacillus cereus L90,was selected to use in this study. Walnut ( Juglans regia ) seedlings were inoculated with B. cereus L90 and then subjected to moderate soil drought stress. The net photosynthesis rate ( Pn ) , stomatal conductance (gs),intercellular CO2 concentration (Ci) and chlorophyll (Chl) content of the walnut seedlings were measured with a LI-6400 portable photosynthesis system and a portable chlorophyll meter. [Result]The results indicated that drought stress and B. cereus L90 inoculation had significant effects on the Pn,Gs,Ci and Chl content of walnut leaves. Compared with the control,the Pn and Gs under drought stress ( DS) were significantly decreased by 21. 78% and 29. 47%. However,the decreases with inoculation of B. cereus L90 were only 11. 62% and 23. 84%, respectively. Therefore,B. cereus L90 inoculation was able to relieve negative effects of DS on Gs and Pn. The relieving effect of B. cereus L90 inoculation on DS increased along with the prolonged period of stress after the initial stage of drought. The Ci of walnut leaves in DR treatments decreased significantly at the initial stage,and then continuously elevated,whereas the Gs continuously declined. The result suggested that the reductions in net photosynthetic rate resulted from both stomatal and non-stomatal limitations. In B. cereus L90 treatment,Ci and Gs decreased continuously,indicating that the Pn reductions mainly resulted from stomatal limitations. The Chl contents of leaves decreased with drought stress. In the late period of drought stress,the chlorophyll content of walnut seedlings in DR treatment significantly decreased 9. 22%,compared with the control. However,the chlorophyll content with inoculation of B. cereus L90 was 9. 49% higher than that of the DS. B. cereus L90 inoculation could significantly decrease the decomposition of chlorophyll content under drought stress. In re-watering after DS,the Pn,Gs and Chl content were still lower than the control,by 9. 46%,10. 29%and 5. 86%,and the Ci was higher than the control by 8. 72%. However,re-watering the drought-stressed seedlings inoculated with B. subtilis increased Pn,Gs and Chl contents to the control’s level,and the contents were higher than the DR seedlings by 7. 01%,12. 15%,5. 81%,respectively. The photosynthetic ability of B. cereus L90 inoculated seedlings was more easily recovered to the level of control after re-watering.[Conclusion]The present study demonstrated that Pn,Gs and Chl content of walnut leaves significantly decreased due to water stress. Cytokinin-producing,B. cereus L90 inoculation under drought conditions could alleviate non-stomatal limitations and interfere with the suppression of net photosynthetic rate. Additionally,L90 is conductive to the photosynthetic ability recovery of walnut leaves after re-watering.
