遮阴对双色木番茄幼苗生理特性的影响

为探讨遮阴对双色木番茄生长的影响,对双色木番茄幼苗在100%自然太阳光(NS,CK)、46.4%NS、11.8%NS和5.6%NS处理下的生理指标进行研究。结果表明:相对电导率和丙二醛(MDA)、游离脯氨酸(Pro)、可溶性蛋白含量均随光照强度的下降先下降后上升,在46.4%NS时出现最小值,可溶性糖含量则呈不断下降的趋势;超氧化物歧化酶(SOD)、过氧化物酶(POD)活性随光照强度的下降先下降后上升,均在46.4%NS时出现最小值;光饱和点(LSP)、光补偿点(LCP)、暗呼吸效率(Rd)、最大净光合速率(Pmax)、净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)均随光照强度的下降呈不断下降趋势;表观量子效率(AQY)和水分利用效率(WUE)则表现为随光照强度的下降,先升高后降低,分别在11.8%NS和46.4%NS时最高;叶绿素含量随光照强度的下降不断上升,叶绿素a/b则逐渐下降,Fv/Fm和Fv/Fo均先上升后下降,在46.4%NS时达到最大值。双色木番茄幼苗主要通过提高Pro、可溶性蛋白和叶绿素含量,加强SOD、POD活性,降低LSP、LCP和Rd,增大AQY和WUE来适应弱光环境。将各项指标进行隶属函数分析,综合评价后得出46.4%NS下的双色木番茄幼苗生长最佳。

Effects of shade on the physiological characteristics of Solanum wrightii seedlings

To investigate the effects of shade on the growth ofSolanum wrightii,physiological indicators ofS.wrightiiseedlingsunder 100%natural sunlight(NS,CK),46.4%NS,11.8%NS,and 5.6%NS were assessed.We found that the relative conductivity,and content of malondialdehyde(MDA),free proline(Pro),and soluble protein first decreased with decreasing transmittance,thenincreased.These parameters reached an apparent minimum at 46.4%NS.Soluble sugar content decreased with decreasingtransmittance.The activity of superoxide dismutase(SOD)and peroxidase(POD)first decreased,then increased with decreasingtransmittance.Minimum activity occurred at 46.4%NS.Light saturation point(LSP),light compensation point(LCP),darkrespiration rate(Rd),maximum net photosynthetic rate(Pmax),net photosynthetic rate(Pn),transpiration rate(Tr),and stomatalconductance(Gs)tended to decrease as transmittance decreased.Apparent quantum yield(AQY)and water use efficiency(WUE)initially increased,then decreased with decreasing light transmittance.The maximum values of these parameters occurred at 11.8%NS and 46.4%NS,respectively.As transmittance decreased,chlorophyll content increased,and chlorophyll a/b ratio decreased,Fv/Fm and Fv/Fo both increased at first,then decreased,with a maximum at 46.4%NS.In summary,S.wrightiiseedlings increasetheir content of Pro,soluble protein,and chlorophyll,and their levels of SOD,CAT,and POD activity.They also reduce LSP,LCP,and Rd,and increase AQY and WUE to adapt to low light environments.Membership function analysis indicated that thegrowth of theS.wrightiiseedlings was best under 46.4%NS.