【作者】 谢兆森；

【导师】 王世平；

【作者基本信息】 上海交通大学 ， 蔬菜学， 2010， 博士

【摘要】 本论文通过研究根域限制对葡萄植株树体生长和果实发育、源库器官组织结构、光合产物输导组织、源库端韧皮部超微结构、和果实糖分积累及其相关酶活性的影响,探讨了根域限制下葡萄果实生长机理和糖分积累机制,取得如下结果:1、从根域限制下葡萄源库器官生长和生物学产量的分配来看,根域限制下葡萄植株的总的生物量积累低于对照,但是根域限制下果实生物量积累占全株生物量积累的比例要高于对照,特别是在果实的第二次快速生长期,果实生物学产量占整株的比例达到最高,其中根域限制处理为39%,对照为31%。2、从根域限制下果实发育和主要营养物质积累来看,在果实整个发育期,根域限制下果皮硬度和果肉硬度均低于对照,在果实发育的第二个快速生长期,根域限制果实膨压峰值高于对照,根域限制还降低了葡萄果实果皮和果肉中的细胞壁含量,葡萄果皮中果胶含量和纤维素含量也低于对照。在果实发育的第二次快速生长期间,根域限制葡萄果实中可溶性固形物(TSS)含量高于对照,并在P≤0.05水平上达到显著性差异,果实花青素含量、总蛋白和游离氨基酸含量也是根域限制的高于对照。3、从根域限制对根、叶和果实组织结构影响来看,根域限制下葡萄植株根系吸收根表皮和皮层厚度分别为18.3μm和579.1μm,都高于对照,而中柱面积为0.004mm2,显著小比对照;根域限制下叶片厚度增加,其中根域限制为456.8μm,对照为415.4μm。叶片角质层、栅栏组织和海绵组织的厚度也是根域限制高于对照。根域限制下植株叶片主脉和侧脉的横切面直径分别为904.2μm和756.3μm,都高于对照;在果实发育的第二次快速生长期,周缘维管束和中央维管束的横切面面积为0.09mm2和0.21mm2,比对照大,根域限制果实周缘维管束数量也多于对照。4、从根域限制下染料在果实中运输与分布规律来看,在葡萄果实发育的第一次快速生长期,根域限制和对照处理的果实周缘维管束被染色数量最多,染色范围最广,染料溶液在葡萄果实中的运输速率也最高,分别为1.72cm/h和1.63cm/h。根域限制处理果实中周缘维管束和中央维管束中染料溶液的运输速度低于对照处理,但胚珠维管束中染料运输速度要高于对照,为1.32cm/h;进入生长停滞期后,根域限制和对照处理的葡萄果实中的周缘维管束被染色数目最低,染料溶液在周缘维管束和中央维管束运输速度也最低0.72cm/h和0.70cm/h;在果实的第二次快速生长期,根域限制和对照处理果实周缘维管束数目比生长滞后期增加,但低于果实发育的第一次快速生长期,根域限制果实周缘维管束染色范围、染料运输速率都高于对照处理。5、从根域限制对源(叶)和库(果实)韧皮部超微结构来看,根域限制增加了叶片细脉筛管伴胞复合体间的胞间连丝数量,说明根域限制能够促进中光合产物在叶端共质体途径的装载;在葡萄果实在第二次快速生长期,根域限制处理葡萄果实周缘维管束伴胞出现了质壁分离的现象,但是伴胞中仍在存在完整的线粒体,而且线粒体的数量高于对照,同时根域限制伴胞和周围薄壁细胞中液胞膜出现内陷和小囊胞进入,小囊胞运输是质外体卸载途径所采用的一种重要方式,根域限制处理促进果实中糖分积累与果实中伴胞和薄壁细胞的液胞中积聚了大量的小囊胞有一定的关系。6、从根域限制对葡萄果实糖分积累和相关代谢酶活性来看,葡萄果实中葡萄糖、果糖和总糖的含量都是在果实发育的第二次快速生长期迅速增加,对照果实中葡萄糖和果糖含量为56.2 mg﹒g-1FW和55.3mg﹒g-1FW,而根域限制下果实中达到了62.1 mg﹒g-1FW和65.2mg﹒g-1FW;果实进入第二次快速生长期后,果实中酸性转化酶和中性转化酶活性开始升高,根域限制果实中的酸性转化酶和中性转化酶活性都显著高于对照,但中性转化酶活性水平比酸性转化酶活性低很多。蔗糖合成酶和蔗糖磷酸合成酶活性在第二次快速生长期变化不大,根域限制和对照处理差异不显著。综上所述,根域限制抑制了葡萄树体源叶和新梢的生长,却促进库果实的生长。根域限制下,葡萄果实在第二次快速生长期(PhaseⅢ)膨大生长增加,果实主要营养物质含量提高,果实中糖含量积累增加,酸性转化酶活性增加,这些结果表明根域限制促进了果实生长,提高了果实品质。根域限制下葡萄植株根、叶和果实的组织结构,尤其是源叶和库果实输导组织结构及其韧皮部超微结构发生了相应的变化,说明了根域限制改变了葡萄源库器官的组织结构,影响了光合产物在源库两端装载和卸载。本研究结果,为根域限制栽培技术的应用和推广提供了科学依据,奠定了理论基础。更多还原

【Abstract】 In this thesis, effects of root restriction on the growth of grape vine and berry, the anatomical structure of source and sink organs, conducting tissue of phloem ultrastructure, and sugar accumulation and its relative enzymes activity were studied. This study explored the mechanism of berry growth and development, and the sugar accumulation. The main results were indicated as follows:1 In terms of effects of root restriction on the biomass allocation of grape vine, the total biomass accumulation of grape vine under root restriction was less than control, but the biomass accumulation of grape berry under root restriction was more than control treatment. Root restriction inhibited the growth of leaf and shoot, decreased the aboveground biomass accumulation of grape vine, but increased the biomass accumulation of grape berry; the biomass accumulation of grape cluster took up 39% for root restriction, and 31% for control.2 In terms of the berry development and main nutriments accumulation in berry under root restriction, during all stages of berry growth, the firmness of berry and berry skin under root restriction were lower than control treatment. During phaseⅢ, the berry turgor pressure under root restriction had higher peak value compared with the control treatment, but the cell wall content of flesh and berry skin under root restriction was lower than control treatment. Root restriction also decreased the pectin and cellulose content. During phaseⅢ, the TSS content under root restriction was higher than control treatment, showed a significant difference at P≤0.05 level with control treatment; root restriction also increased the anthocyanin content, the total protein content and free amino acid content.3 In terms of anatomical structure of root leaf and berry, root restriction increased the thickness of epidermis and cortex, 18.3μm and 579.1μm respectively, but the cross sectional area of pericycle of absorbing root was 0.004mm2 for root restriction, which was significantly less than control; the thickness of leaf for root restriction and control treatment were 456.8μm and 319.4μm respectively, root restriction also increased the cutin layer thickness, stockade tissue thickness, and sponge tissue thickness. The diameter of leaf main vein and side vein under root restriction were 904.2μm and 756.3μm, which were longer than control treatment; the cross-sectional area of dorsal and central vascular bundle under root restriction were 0.09mm2 and 0.21mm2, the amount of central vascular bundles in grape berry under root restriction was also more than control.4 In terms of the transport and distribution rule of dye stuff in grape berry under root restriction, during phaseⅠ, the dorsal and central vascular bundles were colored mostly under root restriction and control treatments, and the speeds of dye stuff transport in vascular bundles were the highest among three phases of berry development, the speeds for root restriction and control treatment were 1.72cm/h and 1.63cm/h respectively; after phaseⅡ, the distribution of dye stuff decreased under root restriction and control treatments, the amount of colored vascular bundles and speeds of dye stuff transport decreased under both two treatments the speeds in central vascular bundles were 0.72cm/h and 0.70cm/h respectively; during phaseⅢ, the distribution of dye stuff increased under root restriction and control treatments, but lower than phaseⅠ.5 In terms of the changes of unltrastructure of source organs and sink organs, The number of plasmodesmata between companion cell (CC) and sieve element (SE) in minor vein under root restriction is more than control treatment, this showed root restriction promoted the symplast transport in leaf; During the second rapid growth phase of the grape berry, CC under root restriction showed more serious plasmolysis. Cytoplasmic contents such as vesicles were fused into the vacuole of which the tonoplast nearly disappeared in the phloem parenchyma cells, and cytoplasmic contents in fruit cells produced under root restriction became denser than the control treatment.6 Total sugar content of berry under root restriction was higher than that of control berry. The peak concentration of glucose and fructose in grape berries from the control plants was 56.2 and 55.3mg﹒ g-1FW, while concentration in root restriction berries was 65.2 and 62.1 mg﹒g-1FW, which was higher than in control. Acid invertase (AI) activity, which increases with berry development, was significantly higher in root-restricted berries than in control berries. Neutral invertase (NI) activity showed a similar trend to AI, but the amount of NI activity was lower than AI in both treatments. Sucrose phosphate synthase (SPS) and sucrose synthase (SS) activity changed slightly with berry development, and there was no significant difference in SS and SPS activity between root restriction and control treatments. Therefore, AI appears to be the key enzyme induced by root restriction that explains the higher sugar content found in grape berry produced under root restriction.From all above,root restriction decreased leaf growth, but promoted the berry growth. During phaseⅢ, root restriction promoted the berry expanding growth, increased the main nutriment content and AI enzyme activity, these results explain why root restriction could improve berry quality. Root restriction led the change in anatomical structure of root leaf and berry, especially the ultrastructure of the phloem in leaf and berry, these results showed that root restriction changed the anatomical structure of source and sink organs, led to the pathway of photosynthate loading and unloading. Therefore, the findings of the present study may provide a scientific base for promotion of root restriction.更多还原