留叶数目和方式对烤烟生长及光合特性的影响

通过田间试验,比较了不同留叶数目和方式对洛阳烟区豫烟6号(Nicotiana tabacum cv.Yuyan No.6)叶片生长及光合特性的影响。结果表明,留叶数目影响了烟株底叶离地高度、株高、株型,以留叶18~20片/株处理的烟株底叶离地高度和株型较为适宜;留叶数目显著影响了上部叶的叶面积,但对中部叶、下部叶的叶面积影响较小。随着留叶数目的增多,上3叶的叶面积逐渐减少;留叶数目还影响下部叶和上部叶的叶绿素含量与光合性能,但对中部叶没有显著影响。随着留叶数增多,下3叶的叶绿素含量、光合速率、蒸腾速率和气孔导度逐渐减少,胞间CO2浓度逐渐增加;留叶22片/株时,上3叶的叶绿素含量、光合速率、蒸腾速率和气孔导度最大。同一留叶数条件下,2次留叶处理的叶面积、光合速率、蒸腾速率和气孔导度比1次留叶略小,但没有显著差异。建议在洛阳烟区种植豫烟6号品种以现蕾期1次留叶18片/株为宜,这有利于烟株各部位叶片的协调发展。

Effects of Number and Pattern of Remained Leaf on Growth and Photosynthetic Characteristics of Flue-cured Tobacco

A field experiment was conducted to investigate the effects of number and pattern of remained leaf on growth and photosynthetic characteristics of flue-cured tobacco (Nicotiana tabacum L.cv.Yuyan No.6) in Luoyang region.The results showed that,the height between ground and the lowest leaf,plant height,and plant type were affected by the number of remained leaf.Remaining 18 leaves and 20 leaves is more suitable when compared to other remained leaf treatments.Number of remained leaf had significant effect on leaf area of upper leaves,but had no significant effects on medium leaves and lower leaves.With the increasing number of remained leaves,the third upper leaf area decreased.For lower leaves and upper leaves,number of remained leaves had significant effect on chlorophyll content and photosynthetic characteristics,but no significant effect of medium leaves.For the third lower leaf,with the increasing number of remained leaves,chlorophyll content,photosynthetic rate,stomatal conductance and transpiration rate decreased;and the intercellular CO2 concentration increased.For the third upper leaf,the chlorophyll content,photosynthetic rate,stomata1 conductance and transpiration rate were higher in the treatment with 22 remained leaves than in other treatments.The pattern had no significant effect on leaf area and photosynthetic characteristics.The results suggested that the one-time remained 18 leaves at flower budding stage is more appropriate for N.tabacum Yuyan No.6 in Luoyang region.