【作者】 徐强；

【导师】 程智慧； 焦晓燕；

【作者基本信息】 西北农林科技大学 ， 蔬菜学， 2004， 硕士

【摘要】 硼是当今世界农业生产中普遍缺乏而又应用最广泛的微量元素之一。缺硼引起植株一系列不正常的症状。然而,目前关于硼在植株体内的原初作用仍不清楚。根据硼对植株某一器官或生理过程的影响提出了许多硼的假设功能。本研究以绿豆为材料,通过水培试验展示了不同浓度的硼对植株生长和发育的影响,旨在评估硼在植株地上部分生长和发育中作用;探讨缺硼时植物形态变化和各种生理过程变化之间的关系。生长数据分析结果表明,限制性供硼会抑制植株各个部分的生长。缺硼对植株的影响最先表现在根,且受影响的程度比地上部大。这可能是缺硼抑制了细胞分裂的结果。缺硼诱导了植株侧芽的生长,使植株失去顶端优势。这可能是缺硼抑制了生长素在植株体内极性运输或生长素氧化酶活性降低的结果。缺硼也改变了植株叶片的特征。叶片伸展受到抑制,厚度和密度增加,比叶面积(SLA)下降,叶重比(LWR)增加,脉间失绿。缺硼的叶片与供硼充足的叶片相比,累积了较多的碳水化合物,气孔导度和光合速率显著下降。叶片内碳水化合物的积累导致缺硼叶片脉间失绿。缺硼植株生长的抑制原因不是碳水化合物的缺乏。缺硼叶片的 CO2同化作用的抑制可能是碳水化合物累积的负向调控的结果。碳水化合物的累积和细胞伸展的抑制导致缺硼叶片 SLA 和 LWR 失常。植株表现的缺硼症状和体内生理生化的变化等不利影响可能因为损伤了细胞壁。本试验结果符合硼的原初作用与细胞壁结构和特性相关的假设。更多还原

【Abstract】 Boron deficiency is a widespread nutritional disorder of plants throughout the world and causes a wide variety of adverse symptoms. However the primary role of boronhas been remained unknown. Many hypotheses on the function of boron have been advancedbased on the effects of boron on a single organ of plant. The current study aimed to evaluatethe role of boron in regard to various effects on shoot growth and development in mung bean(Phaseolus aureus Roxb.). An effort has also made to analyse the relationships of differentphysiological processes when boron is deficient.Growth analysis indicated that boron limitation inhibited growth of all parts of the plant.Axillary buds were induced to grow in boron deficient plants. Foliar features were also alteredby boron deficiency: leaf expansion was inhibited, but there was increased leaf thickness,with a diminished specific leaf area (SLA), an increased leaf weight ratio (LWR) andinter-veinal chlorosis.More carbohydrate accumulated in boron deficient leaves, although reduced stomatalconductance and lower photosynthetic rate were notable in such leaves compared with thosein boron sufficient leaves. The inter-veinal chlorosis evidenced in the youngest leaf has beeninterpreted as a reflection of the carbohydrate accumulation measured in boron-deficientleaves. Thus inhibited growth of boron deficient plants is not due to shortage of carbohydrate.Inhibited CO2 assimilation of boron deficient leaves, a secondary effect of boron, might resultfrom negative regulation of carbohydrate accumulation, caused by inhibited growth in theyoungest leaf and root and reduced intercellular air-spaces, all of which may relate to the roleof boron in cell walls. Much carbohydrate accumulation and inhibited cell expansion resultedin the inhibited SLA and LWR of boron deficient leaves.The implications of deficient symptoms and physiological and biochemical alterationsare discussed. All of these adverse effects may originate from damaged cell walls when boronis deficient. The work presented here fits the hypothesis that the primary role of boron relatesto cell wall structure and properties.更多还原