Sensitive Difference Of Bispyribac-sodium In Rice And The Improving Role Of Additives On Its Herbicide Effects

Bispyribac-sodium is one of the pyrimidine salicylic herbicides which is developed by Japanese Combinatorial Chemistry Industry Kabuskiki Kaisha in 1988.Bispyribac-sodium can inhibit the chain amino acid(isoleucine,leucine,valine)biosynthesis,and interfer the cell division,result in sensitive plants stopping growing and getting chlorosis,until death to achieve the purpose of weeding.This paper takes the rice(Oryza sativa)as the main research objective,determineing the different sensitivity between Oryza sativa L.subsp.japonica S.Kato,Oryza sativa L.subsp.indica S.Kato and Oryza sativa L.subsp.hybrid rice S.Kato after bispyribac-sodium treated and analyzing the mechanism of different sensitivity.The adjuvants were added to explore a new way to improve the efficacy and avoid phytotoxicity.In order to provide theoretical basis and technical guidance for bispyribac-sodium so that it can be used safely and efficiently.The main results as follows:1.It showed different sensitivity significantly in different types and leaf stages of rice to bispyribac-sodium.At the same leaf stage,japonica including Nanjing45,Sidao 11 were highest sensitivity to bispyribac-sodium,indica including Nanjing 11,Yangdao 26 took the second place,and hybrid rice including Lingyou6362,Guangliangyou 192 were the lowest.Along with the leaf stage growing,the sensitivity of rice to bispyribac-sodium to rice decreased gradually.All the types of rice showed higher sensitivity in 1-1.5 leaf stage than that in 2-3 leaf stage and4-5 leaf stage after bispyribac-sodium treated.2.After 3 g.ai./667m2 bispyribac-sodium treated,the cell membrane permeability of rice leaves and stems changed.The innibition effect of bispyribac-sodium on indica's leaves and stems were less than japonica.Bispyribac-sodium treatment could destroy the chloroplast of rice,reducing the content of chlorophyll.After treated,the chlorophyll contents of the rice were increased after decreased firstly.And the TBARS contents were decreased after increased firstly.GSH contents were fell to the lowest after 5 d after treatment and increased equal to the control treatment 7 d after treatment.GSSG contents and GST activity reached to the highest after 5 d after treatment and then recovered to normal.The changes of chlorophyll and TBARS content verified the injury of herbicide bispyribac-sodium on rice.And it showed consistency with the apparent phenomenon;while,GST activity and GSH content showed consistency too.It is said that there might be a complementary role in detoxification.3.The stress effect of bispyribac-sodium treatment on rice was significantly alleviated after exogenous GSH and NAC pretreated;Meanwhile,the injury of rice was increased after DEM and BSO pretreatment,and then adding exogenous GSH will reverse the process.Much indicates that,in the case of the toxicity of bispyribac-sodium to rice,if GST wants to play the role of detoxification,it must use GSH as the substrate;Together,GSH itself may also play centain degree of oxidative defense function.4.Addition of GY-Tmax 0.3%(w/w)significantly improved the security of bispyribac-sodium on rice,while the addition of GY-T1201 0.3%(w/w)or GY-S903 0.03%(w/w)had no significant effect on the safety of bispyribac-sodium.Addition of GY-Tmax 0.3%(w/w)or GY-T1201 0.3%(w/w)and GY-S903 0.03%(w/w)significantly improved the control effect of bispyribac-sodium on Echinochloa glabrescens,especially addition of GY-Tmax 0.3%(w/w),which was the most obviously synergistic effect.Addition of GY-Tmax 0.3%(w/w)or GY-T1201 0.3%(w/w)and GY-S903 0.03%(w/w)had no significant control effect of bispyribac-sodium on Eclipta prostrata.