UV-B辐射对番茄花粉生活力的影响与内源激素和多胺的关系

Effects of Enhanced UV-B Radiation on Pollen Activities of 2 Tomato Cultivars in Terms of Endogenous Hormone, Polyamine and Proline Levels in Stamens

以成熟期不同的两个番茄品种同辉(早熟型)和霞光(晚熟型)为试材,模拟兰州地区12％和20％臭氧层减薄时增强的UV- B辐射(分别为T1=2．54 KJ·m-2·d-1和T2=4．25 KJ·m-2·d-1),研究了大田条件下增强UV-B辐射对其花粉生活力的影响以及雄蕊中4种内源激素(IAA、GAs、ZR和ABA)和多胺(Put、Spm和Spd)及脯氨酸的变化。结果表明:辐射抑制了同辉的花粉萌发和花粉管伸长,但只降低了霞光的花粉萌发率;两种辐射明显降低了两品种番茄雄蕊中的GAs含量,同时造成同辉雄蕊中Put和Spd含量明显增加,Spm和Put／Spd+Spm比值显著降低;霞光中3种多胺含量都显著减少,导致高辐射时Put／Spd+Spm比值上升;同辉番茄雄蕊的脯氨酸含量不受影响,但高辐射使霞光番茄雄蕊的脯氨酸含量降低。实验表明,两品种番茄花粉生活力的变化与增强UV-B辐射下雄蕊中GAs水平、Spm含量以及脯氨酸含量的减少有关。雄蕊中多胺和脯氨酸含量变化对UV- B辐射的响应说明霞光品种对UV-B辐射更敏感。

The effect of enhanced UV-B radiation on pollen activities, endogenous hormone -（indole-3-acetic acid （IAA）, gibberellic acid （GA）, zeatin riboside （ZR）, abscisic acid （ABA）） content and free polyamine and proline levels was studied in stamens of 2 tomato cultivars, Tonghui （TH） and Xiaguang （XG）, which differ in ripening date. Culti- vars were exposed to UV-B radiation at＇ambient （as a control）, ambient plus 2.54 KJ·m^-2·d^-1 （T1） and ambient plus 4. 25 KJ·m^-2·d^-1（T2） levels （simulating a 12% and 20% ozone depletion, respectively, at Lanzhou, 36°N, 103°E, at summer solstice） under field conditions. Both pollen germination and pollen tube growth were inhibited in TH, whereas only pollen germination was affected in XG with 2 doses of UV-B radiation. Endogenous GA level declined markedly in stamens of both cultivars. In stamens of TH, both Put and Spd levels increased, whereas Spm level and the ratio of Put to Spd＋Spm decreased. In stamens of XG under T2 treatment, Decreased Put, Spm and Spd content resulted in a high ratio of Put to Spd＋Spm in stamens of XG under T2 treatment. The proline level did not change in stamens of TH but decreased in stamens of XG with high UV-B radiation. Thus, change in pollen activity was associated with reduced GA, Spm and proline levels caused by enhanced UV-B radiation in stamens of both tomato cultivars. Change in polyamine and proline levels in response to UV-B radiation indicated that XG might be more sensitive to UV-B stress.