涝害对甜叶菊光合及单株干叶产量的影响

利用温室盆栽法研究不同持续时间涝害对甜叶菊种质材料IS-1、QF-1、青甜杂4、JD-1、AL-4光合作用及干叶产量的影响。结果表明:随着涝害时间的持续,5份甜叶菊种质材料的叶绿素SPAD值、净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)、蒸腾速率(Tr)及单株干叶产量均表现出不同程度的变化。短时间涝害处理(Ta:5d)对SPAD值、Pn、Gs、Ci、Tr及单株干叶产量影响均不显著;但随着渍水时间的持续叶片SPAD值、Pn表现出下降趋势:在Tb(涝害处理10d)中IS-1、QF-1、青甜杂4、JD-1、AL-4的SPAD值较正常水分处理分别下降21.29%、34.57%、27.84%、23.01%、17.59%,QF-1下降最快,AL-4下降最慢;Pn较正常水分处理分别下降65.88%、78.51%、74.44%、71.68%、59.58%,QF-1下降最快,AL-4下降最慢;Gs与Tr变化趋势与Pn相似,而Ci与Pn变化趋势相反;随着涝害持续时间的持续,甜叶菊单株干叶产量出现下降趋势,不同材料相同时间涝害胁迫单株干叶产量下降幅度不同,表明不同材料对涝害的耐受力不同。

Effects of Waterlogging on Photosynthesis and Dry Leaf Yieldof Stevia rebaudina

The effects of waterlogging on the photosynthesis and dry leaf yield in the different Stevia rebaudina germplasm of:IS-1,QF-1,QTZ4,JD-1 and AL-4 were studied with the pot plant in greenhouse.The results indicated that the SPAD value of chlorophyll,net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO2 concentration(Ci),transpiration rate(Tr) and dry leaf production of stevia showed different degree changes with the continuing of waterlogging time.There was no significant change in SPAD value,Pn,Gs,Ci,Tr and dry leaf production in short-term waterlogging treatment(Ta:waterlogging for 5d),but as the time of waterlogging continuing,the SPAD value and Pn were on the declining trend:the SPAD value of the IS-1,QF-1,Qingtianza4,JD-1 and AL-4 in the treatment Tb(waterlogging for 10 days) decreased for 21.29%,34.57%,27.84%,23.01% and 17.59% than that of CK,respectively.And the Pn of different materials in treatment T2(waterlogging for 10d) showed maximum decrease,which decreased for 65.88%,78.51%,74.44%,71.68% and 59.58% than that of CK,respectively.The variation trend of Gs and Tr in all materials were as the same as to that of the Pn,but the Ci showed opposite trend with the Pn.Moreover,it indicated that there was no appreciable impact on the dry leaf yield in the mild stress(waterlogging for 5d),but with the waterlogging continuing,the dry leaf yield of per plant became lesser.There was different decreases of dry leaf yield in different materials under the same waterlogging,and it showed that different materials with different tolerance to waterlogging.