氯对烤烟农艺性状和叶绿素荧光参数的影响

Effect of Chlorine on Agronomic Traits and Chlorophyll Fluorescence Parameters of Flue-cured Tobacco

以烤烟品种K326和云烟85为材料,研究不同供氯水平对烤烟生长、相对叶绿素含量及叶绿素荧光参数的影响。结果表明:适量的氯对烤烟农艺性状有一定的改善作用。两个品种叶片相对叶绿素含量均在旺长期最高,且各时期在低氯水平(0～40 kg/hm^2)下,相对叶绿素含量较高。供氯水平在20～60 kg/hm^2范围内,随供氯水平提高,最小荧光(Fo)、非光化学猝灭(NPQ)不断增加,实际光合速率(Y[Ⅱ])、潜在光合速率(Fv/Fm)不断降低,PSⅡ反应中心关闭程度(1-q P)呈先降后增趋势。供氯水平在80～100 kg/hm^2,NPQ趋于平缓,1-q P持续增加。这表示在低氯水平(0～40 kg/hm^2)下光合器官功能旺盛,而高氯水平(60～100 kg/hm^2)则产生胁迫造成光系统Ⅱ的破坏。因此,低氯水平(0～40 kg/hm^2)较适宜烤烟的生长。试验中两烤烟品种均在供氯水平20～40kg/hm^2时,有利于改善烟株的农艺性状,提高烟叶的光合特性,使烤后烟叶氯含量在优质烟叶生产的标准范围内。

The effects of different levels of chlorine application on growth,relative chlorophyll content and chlorophyll fluorescence parameters of flue-cured tobacco were studied with K326 and Yunyan 85 as materials. The results show that moderate chlorine application could improve the agronomic traits of flue-cured tobacco. The relative chlorophyll content of the two flue-cured tobacco varieties reached the highest at vigorous growing stage,and the relative chlorophyll content was higher at the low chlorine level (0-40 kg /hm^2 ). The levels of chlorine supply between 20-60 kg /hm^2 ,with the increase of chlorine level,minimum fluorescence (Fo ) and non photochemical quenching (NPQ) were increased,the actual photosynthetic rate (Y[Ⅱ]) and potential photosynthetic rate (Fv /Fm ) were decreased,and the degree of PSⅡ reaction center closure (1-qP) decreased first and then increased. The non-photochemical quenching (NPQ) tends to be gentle and the closure of PS II reaction center (1-qP) increases continuously in the range of 80-100 kg /hm^2 chlorine supply. This indicates that photosynthetic organs function vigorously at low chlorine levels (0-40 kg /hm^2 ),while high chlorine levels (60-100 kg /hm^2 ) cause damage to photosystem II. Therefore,low chlorine level (0-40 kg /hm^2 ) is more suitable for the growth of flue-cured tobacco. The chlorine level of 20-40 kg /hm^2 is beneficial to improve the agronomic traits of tobacco plants,improve the photosynthetic characteristics of tobacco leaves,and make the chlorine content of roasted tobacco leaves within the standard range of high-quality tobacco production.