摘要
采用胁迫强度为pH2.0,2.5,3.0,3.5,4.0,4.5,5.0的模拟酸雨和具显效剂量的稀土镧[La(Ⅲ)]复合处理水稻种子,置于常温下萌发,测定镧对不同酸雨胁迫强度下种子萌发和呼吸指标的影响。结果表明,1.0mg/L的La(Ⅲ)溶液浸种对水稻种子萌发有稳定促进作用,被确定为显效剂量。在高强度酸雨(pH2.0~2.5)胁迫下,水稻种子的各项萌发指标均为0,低强度酸雨(pH3.0~5.0)对种子萌发影响较小,当胁强为pH2.0时,La(Ⅲ)浸种无明显效果,胁强为pH2.5时,La(Ⅲ)浸种能促进部分水稻种子萌发,胁强为pH4.0时,La(Ⅲ)浸种处理的各项萌发指标接近或超过对照,促进作用较明显。进一步测定La(Ⅲ)对特定剂量酸雨胁迫下呼吸作用的影响表明,经La(Ⅲ)浸种后种子呼吸速率显著增强,呼吸商更接近1。由此可见,La(Ⅲ)对种子萌发的促进作用可能与La(Ⅲ)浸种能提高种子呼吸速率,增加糖类呼吸基质等有关。
The effects of Lanthanum ( La (Ⅲ) ) on germination and respiration of rice seeds under acid rain (AR) stress were studied with seven simulated AR concentrations of pH 2.0, 2.5, 3.0, 3.5, 4.0,4.5 and 5.0 and a dominant dosage of La (Ⅲ). The results showed that 1.0 mg/L of La (Ⅲ) solution had a marked stable and pro- moting effect on seed germination among the seven concentrations from 0.5 to 30.0 mg/L of La (IIl) , thus it was designated as the dominant dosage. When the seeds were treated only with AR, no seed germination occurred under the stress of pH 2.0 - 2.5 AR, but when the seeds were treated with the stress of pH 3.0 - 5.0 AR, the seed ger- mination was little affected. When the seeds were treated by AR with La (Ⅲ), it was found that La (Ⅲ) had a certain promoting effect on seed germination at the pH 2.5 AR stress intensity, and all germination indexes recov- ered as close to or even higher than those of the controls at pH 4.0 AR stress intensity, indicating a remarkable effect of La (Ⅲ) on enhancing germination of seeds. The results of respiration tests of the treatments showed that the treatments by soaking seeds with La ([II ) had a significantly higher respiratory rate than those without La (Ⅲ), and their respiratory quotients were closer to 1, indicating that the promoting effect of La (Ill) on seed ger- mination could be related to increase of respiratory rate and strengthening of the capacity of using carbohydrates.
出处
《杂交水稻》
CSCD
北大核心
2008年第5期69-72,共4页
Hybrid Rice
基金
国家发改委稀土专项基金项目(IFZ20051210)
江苏省教育厅"高等学校大学生实践创新训练"项目(20070730)
关键词
镧
酸雨胁迫
水稻
种子萌发
呼吸作用
Lanthanum
acid rain stress
rice seed
germination
respiratory