芒果（Mangifera indica L.）果实的生理病害及其病因的研究

【作者】 张承林；

【导师】 黄辉白；

【作者基本信息】 华南农业大学 ， 植物生理学， 1997， 博士

【摘要】 本文研究了广东地区芒果果实的三种生理病害（黑顶病、小果病和内部果肉溃败病）的发病诱因,得到如下结果。 1.黑顶病的外观症状表现为果顶区域变黑。成熟前摘下果实,果柄处无乳白色的汁液流出。氟化物是黑顶病的直接诱因。田间氟化物溶液浸果试验表明,能引起芒果黑顶病的氟临界浓度范围在150-600mg L^-1之间。氟化物来自果园周围的砖厂及其它工厂。含氟雨水随重力而积聚于果顶,氟离子渗入组织产生伤害,这是黑顶病症状只出现在果顶部分的原因。连续降雨天气,相对湿度大时果实最容易发病。 2.氟化氢熏气试验证实果园中气态氟化物是小果病的直接诱因。在果实个体发育的早期,氟化物通过气孔进入果实,抑制果实生长,外观表现为果实小。显微观察结果表明,发病果实果肉细胞的细胞壁加厚。细胞已完成分裂过程,但明显小于正常果实的细胞。提示氟抑制果实生长主要是抑制了细胞的膨大生长。且这种抑制作用是不可逆的。 3.芒果果实在整个生长阶段都可吸收氟,果实中的氟主要来自果实直接吸收大气中的气态氟及溶于雨水的氟,只有少部分由叶片吸收运转而来,大部分氟积累于果皮。氟在芒果不同器官间难以运转。芒果的叶片比果实对氟为害有更强的抗性,氟为害叶片的症状为叶尖叶缘干枯。叶片吸收的氟只有少量转运到果实。上壤对氟化物有很强的固定作用。植株吸收的氟与土壤全氟及水溶性氟没有显著相关。土壤施用石灰后对土壤水溶性氟及植株含氟量无明显影响。通过土施石灰降低氟对植物的为害无显著效果。喷施钙溶液可部分地固定叶片所吸收的氟。 4.芒果内部果肉溃败病是一种主要于贮藏期间表现出来的病害。内部症状表现为果肉溃败,褐化;外观症状为果皮局部的着色不均。病果果肉糖分及抗坏血酸含量下降,酸度升高。紫花3号芒果果实自然成熟时的发病率在8%左右。乙烯催熟可大大降低果实发病率。田间施肥试验并采用DRIS法对结果进行分析发现,病害的发生与组织含钙量没有显著的相关,而可能与果肉组织养分元素的失衡有关。果园土壤平衡施肥后可显著降低果实的发病率。致病条件表现为氮镁偏多,钾硼钙偏少。更多还原

【Abstract】 The present studies were concentrated on the causes of three main physiological disorders of mango fruits, i.e., black tip, stunted fruit and internal flesh breakdown, in Guangdong. The results obtained were as follows.1. The visible symptom of black tip disorder was the darkening at the fruit stylar end. Vascular bundles of the cut pedicels secreted no milky sap when the fruit was picked before harvest. Fluoride was the direct cause of black tip disorder. Dipping fruits in fluoride solution showed that the range of fluorine concentrations which caused the disorder was about 150-600 mg kg-1. Fluorides were from the brick kilns and other factories in the vicinities of the mango orchards. Fluorine-containing rain drops gathered at the stylar end of the hanging fruit and the fluorine penetrated into the tissues caused damage to fruit. This was why the disorder symptom appeared only at the stylar end.2. The typical symptom of stunted fruit disorder was the fruit which remained small in size even at harvest. A HF fumigation cabinet experiment confirmed that the gaseous fluorine in the atmosphere was the direct cause of the stunted fruit disorder. Fluoride penetrated into tissues through stomata on the surface of peel at a considerably early stage of ontogeny and inhibited fruit growth. Although results from microscopic observations on flesh tissues showed completion of cell division in the更多还原