增强UV-B辐射对两个烤烟品种生长和叶片解剖结构的影响

Effects of intensified UV-B radiation on growth and anatomical structure of two flue-cured tobacco cultivars

以云南两个烤烟主栽品种云烟87和红花大金元为试验材料,模拟昆明地区24.65%和39.53%的臭氧衰减时增强的UV-B辐射(分别为T1=5.30 kJ m-2d-1和T2=8.50kJ m-2d-1),研究了大田条件下增强UV-B辐射对两个烤烟品种生长和上部叶解剖结构的影响。结果表明:增强UV-B辐射对两个烤烟品种株高和茎粗的影响都是以低UV-B辐射最大。UV-B辐射增强对红花大金元节距的影响和对其株高的影响相同。UV-B辐射增强使云烟87的节距有减小的趋势。随着UV-B辐射强度的增加,红花大金元品种的叶长、叶宽和叶面积都增加。云烟87的叶长、叶宽和叶面积在低UV-B辐射强度最大。与对照比较,低UV-B辐射增强促进了两个烤烟品种叶面积系数、单位叶面积重和单叶重的增加;而高UV-B辐射增强降低了两个烤烟品种单位叶面积重和单叶重,增加了叶面积系数。栅栏组织厚、叶片厚、栅栏组织厚与海绵组织厚比值及栅栏组织厚与叶片厚比值都是以低UV-B辐射最大。从增强UV-B辐射对两个烤烟品种的株高、节距和叶面积的变化结果看,红花大金元对UV-B辐射的耐性比云烟87的要强。低UV-B辐射增强能促进烤烟生长,有利于改善两个烤烟品种叶片组织结构。

Effects of intensified UV-B radiation on growth and anatomical structure were studied in leaves of two flue cured tobacco cultivars, Yunyan 87 （Y87） and Hongda （HD）. Plants were exposed to UV-B radiation at ambient （as a control）, ambient plus 5.30 kJ m-2d-1 （TI） and ambient plus 8.50 kJ m-2d-1 （T2） levels （simulating a 24. 65% and 39.53% ozone depletion, respectively, at Kunming, 25°04＇N, 102°73＇E, at summer solstice） under field conditions. Plant height and stem diameter exposed to low UV-B radiation were the largest, whereas to high UV-B radiation were the least. Influential tendencies of UV-B radiation on internode and plant height of HD were the same. Internode of Y87 wasdecreased as UV-B radiation enhanced. Length, width, and leaf area of HD were increased as UV-B radiation en hanced, whereas those of Y87 were the largest under low UV-B radiation treatment. Low UV-B radiation promoted in crease in leaf area index, weight per unit leaf area, and weight per leaf of both cultivars. Compared to control, high UV B radiation decreased weight per unit leaf area and weight per leaf of both cultivars, and increased leaf area index. Thickness of palisade tissues, leaf thickness, ratio of palisade tissues thickness to spongy and to leaf thickness under low UV-B radiation were the largest , whereas those under high UV-B radiation were the least. Change in plant height, inter node and leaf area in response to UV-B radiation indicated that Y87 is more sensitive to UV-B stress. Low UV-B radia tion can improve zrowth and anatomical structure of tobacco leaves.