增强UV-B辐射对两个烤烟品种主要化学成分的影响

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-2·d-1和T2 8.50 kJ·m-2·d-1),研究了大田条件下增强UV-B辐射对两个烤烟品种烟叶常规化学成分、质体色素和酚类含量的影响,为揭示UV-B辐射对烤烟化学质量特征的影响机理提供理论依据.结果表明:两种UV-B辐射明显降低了两个烤烟品种的水溶性糖和邻苯二酚含量,同时造成两个烤烟品种全氮、全钾、游离氨基酸、质体色素和类黄酮明显增加.增强UV-B辐射对两个烤烟品种烟碱含量的影响不同,增强UV-B辐射使“云烟87”的烟碱含量增加,使“红花大金元”烟碱含量降低.水溶性糖和总氮含量变化对UV-B辐射的响应说明“云烟87”品种对UV-B辐射更敏感.

Effects of enhanced UV-B radiation on basic chemical compositionsof two flue-cured tobacco cultivars

The effects of enhanced UV-B radiation on basic chemical components,chromoplast pigment and phenols contents were studied in the leaves of two flue-cured tobacco cultivars — "Yunyan 87"(Y87) and "Honghuadajinyuan"(HD).Selected cultivars were exposed to UV-B radiation at ambient(control,CK),ambient plus 5.30 kJ·m-2·d-1(T1) and ambient plus 8.50 kJ·m-2·d-1(T2) levels that respectively simulated 24.65% and 39.53% ozone depletions under summer solstice field conditions in Kunming City(located at 25°04’N and 102°73’E).The study was meant to provide theoretical basis for the formation mechanism of chemical qual-ity of flue-cured tobacco leaves in different ambient UV-B regions.Water soluble total sugar and catechol levels declined markedly in leaves of both cultivars with two doses of UV-B radiation compared with CK.However,total nitrogen,potassium,free amino acids,chromoplast pigment and flavonoid levels increased in leaves of both cultivars.While nicotine level increased in the leaves of Y87,it decreased in the leaves of HD under two doses of UV-B radiation compared with CK.Changes in water soluble total sugar and total nitrogen levels in response to UV-B radiation suggested that Y87 was more sensitive to UV-B stress than HD.