几个杜仲无性系光合特性比较研究

Photosynthesis Characteristics of Clones of Eucommia ulmoides

利用Li-6400便携式光合系统仪、光合助手软件（Photosyn Assist）等,在陕西杨凌对9个杜仲品系（品种）日光合速率（Pn）、光合有效辐射（PAR）、最大净光合速率（Pmax）、表观光量子效率（Φ）、暗呼吸速率（Rd）、光补偿点（LCP）、光饱和点（LSP）等进行了测定或计算,结果为,杜仲无性系日光合速率变化曲线在5月、9—10月呈单峰曲线,6—8月呈双峰曲线;在光饱和下的最大净光合速率Pn存在差异,依次为无性系6号〉8号=5号〉7号〉4号〉秦仲2号〉2号（〉为显著性大于,p〈0.05;=为差异不显著）,光辐射强度高于1 200μmol·m-2s-1时4、5、6号无性系降Pn低明显,而7、8号无性系及秦仲2号品种变化不大;杜仲无性系光补偿点LCP值为11.9-30.1μmol·m^-2s^-1,从低到高排列为4号〈5号〈6号=2号〈8号=7号〈秦仲2号;光饱和点LSP值为286-522μmol·m^-2s^-1,从高到低排列为6号〉8号〉5号=7号〉4号=秦仲2号〉2号;暗呼吸速率Rd值为0.583-1.86mol·m^-2s^-1,从低到高依次为4号=6号（6号=5号）〈5号〈2号〈8号=7号〈秦仲2号;最大净光合速率Pmax值为16.1-22.6μmol·m^-2s^-1,由高到低排列次序为8号〉7号=秦仲2号=6号（秦仲2号=6号=5号）〉5号〉4号=2号;表观光量子效率Φ值为0.039 3-0.0618,由高到低次序为秦仲2号（=2号）（2号=7号）〉7号=8号〉5号〉4号〉6号;在以光合能力作为良种选择参考指标时,8号、6号、秦仲2号无性系可优先予以考虑。

Portable photosynthesis system Li-6400 and Photosyn Assist were applied to determine diurnal net photosynthetic rate（Pn）,photosynthetically active radiation（Par）,maximum net photosynthetic rate（Pmax）,apparent quantum yield（Φ）,dark respiration rate（Rd）,light compensation point（LCP）and light saturation point（LSP）of nine clones of Eucommia ulmoides Oliv.The result showed that Pn curve during May and September to October has one peak while from June to August has two peaks;Pmax are different following the order No 6〉No 8〉No 5〉No 7〉No 4〉Qinzhong No 2〉No2（No difference at p〈0.05）.Pmax of clones No 4,No 5and No 6declined significantly at the intensity of radiation 1 200μmol·m^-2s^-1,and no significant changes to clones No 7,No 8and Qinzhong No 2.LCP of these clones is 11.9-30.1μmol·m^-2s^-1,following an order No 4〈No 5〈No 6=No 2〉No 8 =No 7〈Qinzhong No2.LSP is 286-522μmol·m^-2s^-1,with an order No 6〉No 8〉No 5=No7〉No4=Qinzhong No2〉No2.Rd is 0.583-1.86mol·m^-2s^-1,with an order from low to high：No4=No 6〈No 5〈No 2〈No 8=No 7〈Qinzhong No 2.Pmax is 16.1-22.6μmol·m-2s-1,with an order from high to low：No 8〉No 7=Qinzhong No 2=No 6（Qinzhong No 2= No 6= No 5）〉No 5〉No 4=No 2.apparent quantum yield（Φ）is 0.0393-0.0618,with order from high to low Qinzhong No 2（=No2）（No 2=No 7）〉No 7=No 8〉No 5〉No 4〉No 6.Based on the photosynthetic proper-ties,clones No 8,No 6and Qinzhong No 2are prioritized selection for consideration.