叶面镁营养促进妃子笑荔枝果皮着色的生理成因

以妃子笑荔枝(Litchi chinensis Sonn.cv.Feizixiao)成年树为试材,探讨叶面Mg营养调节妃子笑荔枝果皮着色的效果及其初步原因。以叶面喷Mg为处理,以喷清水为对照(CK),分别在坐果后1 d(2013年5月5日)和8 d进行叶面喷肥处理,观测果皮着色、内源激素含量和相关关键酶活性的动态变化。在坐果后15 d,Mg处理的果皮h值最低和果肉可溶性糖含量最高,克服了果皮"滞绿"现象。在果实生长发育过程中,Mg处理与CK的果皮生长素(IAA)和乙烯(Eth)含量、叶绿素单加氧酶(Pa O)和叶绿素酶(Chlase)活性在同期间均无显著差异。在坐果后11 d后,Mg处理在果皮赤霉素(GA3)和脱落酸(ABA)含量及类黄酮糖基转移酶(UFGT)活性上均显著高于同期CK,并且Mg处理使果皮ABA/GA3(含量比)高于CK。Mg处理在坐果后15 d和18 d使其果皮花色素苷含量显著高于CK,而使其叶绿素含量与CK无显著差异。可见,Mg处理克服果皮"滞绿"现象归功于果皮花色素苷含量的升高,其可能通过提高ABA/GA3值,进而刺激UFGT活性升高,从而促进果皮花色素苷合成。

The Physiological Causes of Foliar Mg Application Enhance the Fruit Pigmentation of Litchi chinensis Sonn. cv Feizixiao

Adult litchi trees cv. Feizixiao were used to study the physiological causes of foliar Mg application enhance fruit pigmentation of litchi cv. Feizixiao. Mg nutrient applied to foliarserved as the treatment with water spraying as the check(CK). The treatment was carried out on the 1st day(5th May in 2013)and the 8th day after fruit setting. The contents of 5 kinds of endogenous hormones and the activities of 3 kinds of enzymes in pericarp were detected. On the 15th day after fruit setting, the lowest h value in pericarp was coincident withthe highest contents of the soluble sugar in flesh. This help to solved the problem insynchronization of pericarp and fresh in this cultvar. During the growth and development of fruits, Mg application showed no significant effect on the contents of IAA and Eth and the enzymatic activities of Chlase and PaO in pericarp. But from the 11th day to 18th day after fruit setting, Mg treatment significantly improved the contents of GA3 and ABA and the activity of UFGT, and also the ratio of ABA/GA3 in pericarp. From the 15th day to the 18th day after fruit setting, the content of anthocyanins in pericarp of Mg treatment was significantly higher than that of CK, but the content of chlorophylls displayed no significant difference between treatment and CK. In summary, Mg treatment enhanced the biocynthesis of anthocyanins in the pericarp and therefore synchronized the maturation of pericarp and fresh of Feizixiao. During the period of fruit mature, Mg treatment may promote the pericarp anthocyanin synthesis through increase the ratio of ABA/GA3, and thus stimulate UFGT activity.