不同水稻品种种子萌发对酸雨胁迫的响应

Responses of Seed Germination of Different Varieties of Rice to the Acid Rain Stress

采用室内试验方法,研究了pH2.0、2.5、3.0、3.5、4.0、5.0模拟酸雨对徐稻3号、镇稻9424、新品5356等3个品种水稻种子萌发的影响。结果表明,3个品种的发芽(率)势、发芽(活力)指数随胁迫强度增加(pH5.0￣3.0),呈先增后减的变化;pH2.5时仅有异状发芽,pH2.0时不发芽。3者的发芽(率)势、发芽(活力)指数等均与胁迫时间(1￣7d)呈显著负相关(异状发芽率呈正相关)。综合分析认为,酸雨对3个水稻品种的伤害阈限为pH2.5￣pH3.0,胁时为2￣4d,3个水稻品种对酸雨抗性存在一定差异,即徐稻3号与镇稻9424的抗酸雨能力略强于新品5356。

In order to study the effects of acid rain on seed germination of different varieties of rice, three varieties of rice （O. sativa） seeds including Xudao 3, Zhendao 9424 and Xinpin 5356 were treated with simulated acid rain（SAR） at pH 2.0, 2.5, 3.0, 3.5, 4.0 and 5.0 for 7 d. The percentage of seed germination, germination energy, germination index and vigor index of these three varieties initially increased and then decreased with the decrease of pH value from 5.0 to 3.0. Rice seeds only germinated abnormally at pH 2.5 and didn＂ t shoot up at pH 2.0 at all. Further, at pH 2.5, there was a significantly negative correlation between stress time （1-7 d） and the values of percentage germination, germination energy, germination index and vigor index while a positive correlation between stress time （1～7 d） and the percentage of abnormal germination. Moreover, the germination threshold values for these varieties were all between pH 2.5 and 3.0. The stress time when the difference of the five indices between each treatment and CK was significant was 4 d, 2 d, 2 d, 2 d, 4 d for Xudao 3 and Zhendao 9424, and 3 d, 2 d, 2 d, 2 d, 4 d for Xinpin 5356 respectively. Xudao 3 and Zhendao 9424 had stronger resistance than Xinpin 5356 to acid rain stress.