精恶唑禾草灵对粳稻和籼稻生长及保护酶系的影响研究

摘要

以粳稻（郑稻18）和籼稻（绵优838）为试验材料，采用水培、盆栽及田间试验相结合，研究了水稻不同生育期对精恶唑禾草灵的敏感性及生理反应。在水稻萌发期，精恶唑禾草灵对粳稻和籼稻胚根生长的抑制中浓度（ IC50）分别为0．1687，0．1637μg/mL，表明二者在芽期对精恶唑禾草灵均较为敏感。在水稻2～3叶期喷施精恶唑禾草灵后15，30 d，籼稻的IC50分别为279．56，173．49μg/mL，而试验剂量下（12．5～400μg/mL）粳稻生长抑制率低于30％，表明粳稻对精恶唑禾草灵有较高的耐药性。在粳稻4～5叶期喷施精恶唑禾草灵，结果显示，18．45 a．i g/hm2剂量对禾本科杂草防除效果较好，且对水稻生长基本没有影响，因此，田间使用精恶唑禾草灵时需要严格控制使用剂量。精恶唑禾草灵对粳稻和籼稻GSH-Px、SOD、CAT、POD等保护酶系的影响各不相同，表明2种水稻在解毒及应对精恶唑禾草灵胁迫机制上存在着差异。%Taking Japonica ( Zheng Rice 18 ) and Indica rice ( Mianyou 838 ) as the test material and combining hydroponics,potted plants and field trials ,this study investigated the sensitivity and physiological responses of rice to Fenoxaprop-P-ethyl at different growth stages.In rice germination, the half maximal inhibitory concentration (IC50)of Fenoxaprop-P-ethyl against radicle growth of Japonica and Indica were 0.168 7,0.163 7 μg/mL respec-tively,indicating that both were more sensitive to Fenoxaprop-P-ethyl in the bud stage .For spraying fenoxaprop-P-ethyl in the 2-3 leaf stage,the half maximal inhibitory concentration ( IC50 ) of Fenoxaprop-P-ethyl against Indica rice were 279 .56 ,173 .49 μg/mL for 15 days and 30 days after treatment respectively .In contrast ,under test doses (12.5-400 μg/mL),the Japonica rice growth inhibition rate was less than 30%,indicating that the Japonica rice possesses higher resistance to Fenoxaprop-P-ethyl.In the field, both the injury effect and herbicidal activity of Fenoxaprop-P-ethyl on Japonica rice in 4-5 leaf stage at various concentrations were evaluated .The result revealed that Fenoxaprop-P-ethyl shows good preventive and controlling ability on grass weed at 18.45 a.i g/ha with no in-hibitory activity on rice growth.However,the dosage must be strictly controlled for the narrow range of application doses.The Fenoxaprop-P-ethyl has different effects on the protective enzyme system in these two types of rice such as GSH-Px,SOD,CAT,POD,indicating the differences for these two types of rice in both detoxification and mecha-nisms of response to the stress upon treatment with Fenoxaprop-P-ethyl.