【作者】 赵书岗；

【导师】 张玉星；

【作者基本信息】 河北农业大学 ， 果树学， 2004， 硕士

【摘要】 水杨酸是植物体内普遍存在的内源信号分子之一，已被确认为是一种新型的植物激素，具有重要的生理生化作用。良好的授粉受精是生产优质果品的基础，而酚类物质代谢会直接对果实品质产生重要影响，因此研究水杨酸对二者的作用，对提高果品质量具有重要的意义，同时还可进一步揭示水杨酸的生物学意义。本试验以鸭梨和雪梨为试材，研究了水杨酸在授粉受精及果实酚类代谢过程中的作用。主要研究结果如下： 1．鸭梨花器官中含有SA，并且在其开花过程中，SA的含量有一显著高峰，出现在开花第二天，最高值达266.58μg·g^-1 FW，而后呈逐渐下降的趋势，在第五天略有升高，但幅度不大。 2．盛花期喷施0.02 mmol·L^-1 SA处理可显著提高鸭梨的座果率。0.0002、0.2 mmol·L^-1 SA处理可提高鸭梨花后两周的座果率，但六月落果后与对照差异不显著。 3．鸭梨开花期间，乙烯的释放速率为跃变型，跃变高峰出现在开花的第二天，外源喷施0.0002、0.002 mmol·L^-1 SA处理可降低这一高峰，0.02、0.2 mmol·L^-1 SA处理可完全抑制乙烯高峰，使其释放速率始终维持在一个较低的水平。 4．在花期喷施不同浓度SA均可提高鸭梨雌蕊中GA₃的含量，0.0002、0.002、0.02 mmol·L^-1 SA处理可降低鸭梨雌蕊中ABA的含量，0.0002、0.002 mmol·L^-1 SA处理可降低IAA的含量，仅有0.2 mmol·L^-1SA处理可提高IAA、ABA的含量。 5．用SA液体培养鸭梨花枝研究表明，0.002、0.02 mmol·L^-1SA处理可提高雌蕊中POD、SOD的活性，降低MDA、O₂^-·的积累，延缓其衰老；0.0002 mmol·L^-1SA处理对POD、SOD有短期的促进作用，可暂时缓解MDA、O₂^-·的积累；0.2 mmol·L^-1SA处理抑制SOD、POD的活性，提高MDA、O₂^-·的水平，从而加速雌蕊衰老。 6．0.0002、0.002、0.02mmol·L^-1SA处理均可提高鸭梨及雪梨花粉生活力，并且促进花粉的萌发及花粉管的伸长。 7．0.0002、0.002、0.02 mmol·L^-1SA处理可显著拮抗EGTA对花粉萌发及花粉管生长的抑制作用，而且与正常情况相比，其花粉的萌发率高，花粉管生长速度快，采用LaCl₃与SA培养花粉有同样的效果。采用CaCl₂与SA共同培养可湮没SA对花粉的促进作用，仅有个别SA浓度处理，花粉的萌发率及花粉管的生长速度仍显著高于对照。 8．0.0002、0.002、0.02 mmol·L^-1SA处理可显著拮抗LiCl及新霉素对花粉萌发及花粉管生长的抑制作用，在LiCl及新霉素浓度较高的情况下更为显著。 9.在果实采收前一个半月，连续喷施0.02 mmol·L-’sA处理可降低果实中酚类物质的含量，抑制PPO的活性，减少木质素含量、果点数量和减小石细胞大小。0.002、O.OZmmol·L’’SA处理可提高果实中POD酶的活性。更多还原

【Abstract】 Salicylic acid (SA) is an endogenous signal substance that exists universally in the plant, which has been confirmed as a new hormone, and plays a crucial role in regulation of physiology and biochemistry action. Good pollination and fertilization is the basis of high-quality fruit; On the other hand, metabolism of phenols can directly affect the fruit quality. Therefore it has an important significance to improving the quality of fruit and revealing biology sense of salicylic acid by studying the effect of SA on the two aspects. This experiment studied the effects of SA on pollination, fertilization and phenol metabolism in Ya-li pear and Xue-li pear. The main results were as follows:1. SA existed in the flower of Ya-li pear. With blooming there was a marked peak of SA content and it appeared at the day after blooming, the maximal value attained 266.58 μg.g-1 FW. Then the content of SA dropped gradually, and ascended within a narrow range at the fifth day after blooming.2. It improved the rate of fruit setting by spraying 0.02 mmol.L-1 SA in florescence. Spraying 0.002 and 0.2 mmol.L-1 SA can only improve the rate of fruit setting after two weeks of bloom, yet there was unobvious divergence between treatments and control after June drop.3. The releasing rate of ethylene was a jump pattern in florescence, the peak appeared at the day after blooming. It was reduced by spraying 0.0002 and 0.002 mmol.L-1 SA, and was inhibited and maintained in a low level all along by 0.02 and 0.2 mmol.L-1 SA.4. Spraying SA of different concentrations in florescence resulted in the increase of endogenous GAs content of Ya-li pear pistil. ABA content was reduced with spraying 0.0002, 0.002, 0.02mmol.L-1 SA. IAA content was also reduced by 0.0002 and 0.002 mmol.L-1 SA. Only spraying 0.2 mmol.L-1 SA that improved the contents of IAA and ABA in the pistil.5. With 0.002, 0.02mmol.L-1 SA liquid cultivating Ya-li pear flower branchs, it prolonged the life of pistils, enhanced the activity of peroxidase (POD), supereoxide dismutase (SOD) and decreased the content of malondialdehyde (MDA), superoxide anion radical (O2-). There was only a short-term increasing effect on 0.0002 mmol.L-1 SA on the two enzymes, so the accumulation of MDA and O2 was relieved temporarily. Pistil apolexising was accelerated under the concentration of 0.2 mmol.L-1 SA treatments, meanwhile the POD and SOD activity were inhibited, MDA and O2 contents were raised.6.The treatments of 0.0002,0.002,0.02 mmol.L-1SA improved the pollen activity of Ya-li pear and Xue-li pear, moreover accelerated germinating of pollen and extending of pollen tube.7.0.0002, 0.002, 0.02 mmol.L-1 SA treatments antagonized the inhibition of EGTA on germination of pollen and extending of pollen tube, and the same to LaCl3. But the accelerating action of SA on pollen was neglected by using CaCl2; only individualtreatment of SA was obviously higher than control.8. The inhibitions of LiCl and Neomycin on germination and extending of pollen tube were antagonized by 0.0002, 0.002, 0.02mmol.L-1 SA, it was more marked at the situation of higher concentration of LiCl and Neomycin.9.The result showed that successive spraying 0.02mmol.L-1 SA inhabited polyphenoloidase (PPO) activity during mature period of fruit and decreased the number of fruit spots, the size of stone cell, content of phenols and lignin. But 0.002 and 0.02 mmol.L-1 SA treatments improved the activity of POD in fruit.更多还原