不同品种水稻耐砷性鉴定和筛选及外源ABA对砷胁迫的缓解作用
毕业论文关键词：砷；水稻；品种筛选；脱落酸；缓解
Screening and identification of different rice cultivars for As tolerance and the alleviation of exogenous ABA on rice under As stress
Abstract：Arsenic(As) is an environmental pollutants through the food chain, screening for As-tolerant rice varieties is an important measure to reduce the As accumulation in rice. In this paper, we used hydroponic experiment for 50 varieties of As tolerance classification, and screened out the sensitive variety MRC172-9 and the high sensitive variety IR43. We studies the effect of As stress on the two cultivars. In addition, we also studied the effects of exogenous ABA on the two cultivars rice seedlings under As stress.The results showed that the As tolerance accumulation and translocation of different cultivars rice are significantly different; under As stress, relative shoot elongation(RSE), relativeroot elongation(RRE), root activity and chlorophyll content were decreased, MDAcontent was increased, and the stress effect is more obvious in the high sensitive variety; the exogenous 0.5μmol•L-1 ABA can ease the inhibitory effects of As srtess on the two kinds of rice by increasing the RSE, RRE, chlorophyll content, root activty, decreasing MDA content , shoot As concentrations and root As concentrations, and the alleviation in high sensitive variety is more obvious.
Key words: arsenic(As)；rice seedlings；varieties screening；abscisic acid；alleviation
目 录
摘要1
关键词1
Abstract1
Key words1
引言1
1 材料与方法2
1.1 材料 2
1.2 植物材料的培养与处理 3
1.2.1 水稻育苗的培养3
1.2.2 不同品种水稻耐砷性3
1.2.3 ABA对水稻幼苗砷胁迫的影响3
1.3 测定方法 3
1.3.1 样品As含量的测定3
1.3.2 根系活力的测定3
1.3.3 叶片丙二醛（MDA）含量的测定3
1.3.4 叶绿素含量的测定4
1.3.5 水稻幼苗As（V）耐性指数4
1.4 数据分析方法 4
2 结果与分析4
2.1不同品种水稻砷耐性的鉴定与筛选4
2.1.1 不同品种水稻对砷胁迫的响应4
2.1.2 不同品种水稻砷的积累和转运6
2.1.3 不同品种水稻砷耐性7
2.2 砷胁迫下外源ABA对不同砷耐性品种水稻的作用8
2.2.1 外源ABA对As胁迫下水稻幼苗地上地下相对伸长量的影响8
2.2.2 外源ABA对As胁迫下水稻叶片叶绿素的影响8
2.2.3 外源ABA对As胁迫下水稻根系活性的影响9
2.2.4 外源ABA对As胁迫下水稻叶片丙二醛的影响9
2.2.5 外源ABA对As胁迫下水稻地上地下部砷含量的影响10
3 讨论10
3.1 水稻品种砷耐性筛选10
3.2 外源脱落酸对不同品种水稻砷胁迫的缓解作用10
参考文献11
不同品种水稻耐砷性鉴定和筛选及外源ABA对砷胁迫的缓解作用
引言
砷（As）是一种大量存在于环境且可在食物链中传递的类金属元素污染物质[1]，美国有毒物质和疾病登记处（ATSDR）将其排在有害物质的第一位。砷是一种植物毒素，可以在植物体内积累。砷污染可导致农作物的减产，造成严重的经济损失；砷污染也导致砷在农作物可食部位的积累，从而导致人体摄入砷危及人体健康。故减少农作物中砷的积累量是减少砷经食物链进入人体的主要方式。作物中砷的积累量因作物的种类不同而不同，对于同种作物来说不同品种砷的积累量也不相同。由于水稻自身的生理特性及其水淹缺氧栽培模式，水稻对砷具有较强的富集能力[2]。水稻是我国第一大粮食作物，全国60%以上人口以稻米为主食，每年稻米消费量占粮食消费总量的55%左右，水稻砷污染严重威胁到我国粮食安全[3]。筛选耐砷和低砷富集型水稻品种，是目前降低水稻砷积累的重要措施。