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摘要：以大蒜为实验材料，采用水培法，研究了重金属铅和镉胁迫对大蒜根尖细胞分裂及染色体形态的影响。结果表明：重金属铅和镉均能抑制大蒜根尖生长速度，降低细胞有丝分裂指数，诱发产生微核、染色体桥和染色体断片，改变细胞核形状。根尖生长速度、细胞有丝分裂指数与重金属浓度成反比，微核率与重金属浓度成正比，相同浓度下，镉对大蒜根尖生长速度、根尖细胞有丝分裂指数及根尖细胞染色体的影响要大于铅。这说明重金属铅和镉胁迫能够降低大蒜根尖细胞分裂能力，抑制大蒜根尖细胞的生长，诱发根尖细胞染色体出现畸变现象，最终对大蒜根尖造成伤害。29560
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毕业论文关键词：大蒜根尖；重金属；细胞有丝分裂指数；微核；染色体畸变
Effects of Heavy Metals on Cell Division And Chromosome
Morphology of Garlic Root Tip
Abstract: Garlic was selected as experimental material, the effects of heavy metals such as lead and cadmium on cell pision and chromosome morphology of garlic root tip were studied with hydroponics. The results showed that lead and cadmium could inhibit growth rate of garlic root tip, reduce cell mitotic index, induce generation of micronucleus and chromosome fragment and chromosome bridge, change the shape of nucleus. Growth rate of root tip and cell mitotic index were inversely proportional to the concentration of heavy metals, the micronucleus rate was in direct proportion to the concentration of heavy metals, cadmium had greater effects on growth rate and cell mitotic index of root tip and chromosome of root tip cells than lead under the same concentration. The above showed that heavy metals such as lead and cadmium could reduce cell pision ability of garlic root tip, inhibit growth of garlic root tip cells, induce generation of chromosomal aberration of root tip cells, garlic root tip was injured in the end.
Key Words: Garlic root tip；Heavy metal；Cell mitotic index；Micronucleus；Chromosomal aberration
目 录
摘 要 1
引言 2
1. 材料与方法 2
1.1 实验材料 2
1.2 试剂和器具 2
1.3 实验方法 3
1.3.1铅胁迫液的制备 3
1.3.2镉胁迫液的制备 3
1.3.3大蒜生根培养 3
1.3.4大蒜根尖细胞有丝分裂玻片标本的制备与观察 3
1.3.5实验项目观察与测定 4
2. 结果与分析 4
2.1 不同处理下大蒜根尖生长情况 4
2.2 铅胁迫对大蒜根尖细胞有丝分裂指数的影响 4
2.3 镉胁迫对大蒜根尖细胞有丝分裂指数的影响 5
2.4 铅胁迫和镉胁迫对大蒜根尖细胞结构及染色体的影响 5
3. 结论与讨论 8
3.1 结论 8
3.2 讨论 8
参考文献 9
致谢 11
重金属对大蒜根尖细胞分裂及染色体形态的影响
引言
大蒜别名蒜、蒜头、独蒜，属于百合科葱属，以鳞茎入药。春、夏季采收，扎把，悬挂于通风处，阴干以备用。大蒜有些呈扁球形，有些短圆锥形，外有灰白色或淡棕色膜质鳞皮，剥去其鳞叶，内有6～10个蒜瓣，生于花茎的周围，茎基部为盘状，生有须根多数。每一蒜瓣外均包有薄膜，将其剥去，即可见白色、肥厚多汁的鳞片。它具有浓烈的蒜臭，辛751。原产于西亚和中亚，自从张骞出使西域，把大蒜带回国安家落户，至今已经有两千多年的历史。大蒜营养非常丰富，含有水分、脂肪、蛋白质、磷、铁、文生素C等。大蒜具有强大的杀菌能力，能消灭侵入人体内的病菌，还具有排毒清肠，预防肠胃疾病，防治肿瘤和癌症，降低血糖，防治心脑血管疾病的功能。大蒜是我们日常生活中不可缺少的调料，在烹调鱼、肉、禽类和蔬菜时有去腥增的作用，尤其是在凉拌菜时，即可增，又可杀菌。鉴于大蒜对人们生活生产的重要作用，因此本研究选择大蒜作为实验材料。