栽培因子对白肋烟叶片组织结构的调控

Effects of Main Cultural Factors on the Microstructure of Leaf Tissues

研究表明:叶厚、栅厚、海厚、组织比、上表皮厚度等与烟叶品质和产量关系较密切的关键特征基本上都是TN86>KY907>TN90>KY908>K26>KY8959,因而应以TN86,KY907,TN90的叶片组织结构较好.叶厚、栅厚、海厚、组织比、栅厚/叶厚及上下表皮厚度与栅栏组织细胞宽度等均随种植密度增加、封顶期后移和留叶数增多而呈下降趋势,但从低水平至中等水平的降幅很小,而从中水平至高水平的降幅较大;随施N量加大而呈上升趋势,低N至中N的升幅远大于中N至高N的升幅,施N量的作用大于种植密度,封顶期的效应远大于留叶数,且各项观测值均随叶位升高而增加.因而以18000株/hm2,施N300kg/hm2,全田50%现蕾后5d一次性封顶和留叶21-22片的试验组合的叶片组织结构较理想.叶片组织结构的关键特征均以完熟时最大、过熟时最小、初熟时在二者之间,下、中、上各叶位分别在封顶后第三、四、五周达完熟状态,兼顾各叶位宜在第4周砍收.

The results showed that the correlation of thickness of leaf, palisade tissue, sponge tissue and upper epidermis with the quality and yield was TN86 〉 KY907 〉 TN90 〉 KY908 〉 K26 〉 KY8959. So the leaf structure of TN86, KY907 and TN90 was better than others. The thickness of leaf, palisade tissue, sponge tissue, palisade / sponge, palisade/leaf, upper and lower epidermis and width of cell of palisade tissue decreased with the increase in growth density, the delay of topping stage and increase in the remained leaf number. The extent of decline was smaller from lower level to middle level than from middle to higher. The above leaf microstructure parameters was enhanced with increase in N fertilizer, but the extent of increase was larger from lower N to middle N than from middle to higher. The effect of N fertilizer was more obvious than growth density, and topping stage was more obvious than remained leaf number. These leaf micro structure parameters increased with the leaf position upward. Therefore, leaf might have a ideal leaf structure when the plants have the following culture measures ： growth density 18 000 plant/hm^2, N 300 kg/hm^2, topping only once at the time when 50% flower bud growing up to 8 - 10 cm and 20 - 21 remained leaf/plant. The leaf key structure feature was largest at the leaf mature stage, middle at pre-leaf mature stage and smallest at post-leaf mature stage. The leaf mature stage of lower, middle and upper position leaf were 3, 4, 5 weeks after topping, so it would be better to chop harvest the tobacco at 4 weeks after topping.