【作者】 李微；

【导师】 陶龙兴；

【作者基本信息】 中国农业科学院 ， 作物， 2011， 硕士

【摘要】 本试验选用NaCl和NaHCO3作为盐胁迫,设置几个不同的盐浓度梯度,对所选的粳稻种子进行盐胁迫处理,分别测定不同处理下种子萌发和幼苗生长时的各项农艺指标和生理生化指标,探讨水稻种子萌发和苗期生理因素内在的相关性,以明确盐胁迫对水稻种子及幼苗生长发育影响的根源,为盐碱地科学种植水稻,选择优质抗盐种子提高盐碱地水稻单产能力提供一定的理论依据,为水稻抗性育种提供参考指标。本试验结论如下：1.低浓度的盐胁迫对水稻种子的发芽有略微的促进作用,盐浓度大于1%时表现出抑制作用。盐浓度小于0.5%时,对各品种发芽率的影响是不大的；盐胁迫的浓度大于0.5%时,盐浓度越大,各品种的发芽率越低。0.7%的盐浓度是抗盐性强弱品种在发芽率上表现差异的临界浓度,当盐胁迫浓度大于0.7%时,抗盐性弱的品种的发芽率会迅速降低,抗盐性强的品种的发芽率平缓下降。盐胁迫对其它发芽阶段指标的影响规律与芽率类似。2.盐胁迫对水稻幼苗农艺性状指标株高、根长、根数的影响规律是一致的,即低浓度的盐胁迫促进水稻幼苗农艺性状的生长,高浓度的盐胁迫抑制生长,抗盐性品种株高、根长、根数的值明显优于其它品种,在盐浓度较高时,差异更加明显。水稻在受到盐胁迫时株高、根长、根数等农艺性状指标的变化情况可以作为抗盐能力的依据。3.盐胁迫对水稻生理生化指标的影响规律抗盐性弱的品种外渗电导率的值高,受到盐胁迫伤害的程度大。抗盐性强的品种外渗电导率的值低,受到盐胁迫伤害的程度小。外渗电导率的值与水稻的抗盐性成反比。随着盐胁迫浓度的增加,各品种水稻幼苗叶片内的脯氨酸含量、SOD活性、MDA含量显著增加,而可溶性糖含量、叶绿素含量显著下降。抗盐性强的品种幼苗叶片内的脯氨酸含量、SOD活性、可溶性糖含量、叶绿素含量高,MDA含量低；抗盐性弱的品种幼苗叶片内的脯氨酸含量、SOD活性、可溶性糖含量、叶绿素含量低,MDA含量高。更多还原

【Abstract】 In the test, NaCl and NaHCO3 were used as salt stress, several different salt concentration gradients were set, seeds of indica rice and japonica rice were treated with salt stress, seed germination and seedling growth of the various agronomic parameters and physiological and biochemical indexes were measured under different treatments, inherent relativity of seed germination and seedling physiological factors were discussed. in order to clear reason of salt stress effect on rice seed and seedling growth and development. This would provide theoretical basis on scientific planting rice on saline alkali soil, on selecting seed which had high-quality resistant salt and increased yield, and provide reference index of resistance breeding of rice. The test results were as follows.1. Low concentration of salt stress slightly simulated effect on germination of rice seed. Germination of rice seed showed inhibitory effect when more than 1% salt concentration. Germination rate of different varieties was slightly influenced when less than 0.5% salt concentration; and germination rate of different varieties was more and more lower along with the increasing of salt concentration when more than 0.5% salt.0.7% salt concentration was critical concentration which germination rate showed differences on strong and low resistant salt varieties. When more than 0.7% salt concentration, germination rate of varieties which were weak resistant salt would decrease quickly, and germination rate of varieties which were strong resistant salt would gently decreased. Effects of salt stress on impact law of other germination stage indicators were similar to bud rate.2. Effect law of salt stress on agronomic traits of plant height, root length, root number of rice seedling was consistent. Low concentrations of salt stress would promote growth agronomic traits of rice seedling, and high concentrations of salt stress would inhibit growth. Plant height, root length, root number value of varieties which were strong resistant salt were significantly better than other varieties, when the salt concentration was high, the differences were more pronounced. Change situation of plant height, root length, root number and other agronomic traits indexes when rice was salt resistance could be used as the basis of salt resistant ability.3. Effect law of salt stress on physiological and biochemical indexes of riceVarieties which were weak resistant salt were high exosmosis conductivity, affected more degree hurt salt resistance.However, Varieties which were strong resistant salt were low exosmosis conductivity, affected smaller degree hurt salt resistance. Extravasais conductivity was inversely proportional with salt resistance of rice.As concentration salt stress increased, the proline content, SOD activity, MDA content of varieties leaves of rice seedling increased significantly, while the soluble sugar content, chlorophyll content decreased.leaves of rice seedling of varieties which were strong resistant salt were high proline content, SOD activity, soluble sugar content, the chlorophyll content, were low MDA content. Leaves of rice seedling of varieties which were weak resistant salt were low proline content, SOD activity, soluble sugar content, the chlorophyll content, were high MDA content.更多还原