W-默科特单性结实能力与果实不同部位四种内源激素含量的关系

Relationship between Parthenocarpy Ability and Content of 4 Endogenous Hormones in Different Fruit Parts of W-murcott Tangor

为了探讨植物内源激素对单性结实的影响,本研究选取兼性单性结实能力较强的柑橘品种‘w-默科特’为试材,对其进行授粉和不授粉处理,观测胚珠和果实发育以及生理落果过程,同步以HPLC法测定不同处理的果实各部位内源激素的含量。结果表明,32~39DAF(花后天数)是W-默科特胚珠发育的关键时期,胚珠形态出现明显的差异。25-50DAF正好与柑橘生理落果主要发生期对应,胚珠中ABA含量最高,且未授粉W-默科特显著高于授粉W-默科特,败育胚珠可能是果实中ABA的主要来源部位;同期的促生长类激素,胚珠中ZT含量与果肉比较接近,低于果皮,但GA3、IAA含量明显低于果肉,未授粉W-默科特和授粉W-默科特则高低互现,总体差异较小。均值处理后的激素比值T综合展示了两类激素间的变化关系,在25?50DAF,未授粉W-默科特整果的T值较授粉W-默科特整果更高,这可能是果肉或果皮产生了更高的生长类激素,克服了败育胚珠产生的较高ABA,减少了生理落果,保障了W-默科特单性结实。本研究结果为进一步研究柑橘单性结实和前期生理落果提供了数据参考。

In order to investigate the effect of parthenocarpy in citrus, and explore the effect of plant endogenous hormones on parthenocarpy in citrus, endogenous hormones were measured by HPLC in different parts of pollinated and non-pollinated fruits of W-murcott tangor which has a strong facultative parthenocarpic ability, meanwhile,the ovule and fruit development as well as physiological fruit drop process were observed. The results showed that 32~39 DAF(day after flowering) is a critical period for W-murcott tangor ovule development, significant difference in ovule morphology was found. During 25~50 DAF, which is corresponding to the main citrus physiological fruit drop period, the ABA content in the ovule was the highest, and the ABA content in the unpollinated W-murcott tangor was significantly higher than the pollinated W-murcott tangor. The aborted ovule may be the main source of ABA in the fruit. During the same period, the content of ZT in ovules was close to that in pulp, but lower than that in peel. However, the content of GA3 and IAA in ovules was significantly lower than that in pulp, and the overall difference was small between unpollinated W-murcott tangor and pollinated W-murcott tangor. The hormone ratio after homogenization treatment was named as T value, which showed the relationship between the two types of hormones comprehensively. At 25~50 DAF, the T value of the unpollinated W-murcott tangor whole fruit was higher than that of the pollinated W-murcott tangor whole fruit, which may be the result of more growth hormones produced in unpollinated W-murcott tangor pulp or peel. More growth hormones overcame the function of higher ABA produced by the abortive ovule and leaded to a reduced physiological fruit drop and guaranteed successful parthenocarpy of W-murcott tangor. The results provided a reference for the further study of citrus parthenocarpy and early physiological fruit drop.