摘要
为给氰草津在麦田的安全利用提供理论依据,分别在冬前、起身、孕穗和抽穗4个时期喷施不同剂量的氰草津,通过目测小麦药害程度、测定光合作用及叶绿素荧光参数和产量等方法探讨氰草津在小麦田适用的时期和剂量。结果表明,冬前及次年小麦起身期喷施氰草津675~1 350g·hm-2（有效成分）,小麦表现0~1级药害,小麦产量与对照无显著差异。孕穗期及抽穗期使用氰草津,小麦表现2级以上药害,并减产40%以上。对光合作用及叶绿素荧光参数测定表明,起身期喷施中、低剂量氰草津,药后3d对小麦叶片净光合速率（Pn）、胞间CO2浓度（Ci）、气孔导度（Gs）、蒸腾速率（Tr）、气孔限制值（Ls）、PSⅡ最大光合效率（Fv/Fm）、光下实际量子产量（ΦPSⅡ）和光合电子传递速率（ETR）等参数有不同程度的影响,药后10d恢复到与对照相当的水平,说明起身期喷施氰草津675~900g·hm-2对小麦光合作用影响较小,安全性较高。孕穗期及抽穗期喷施不同剂量氰草津,造成小麦叶片Pn、Gs、Fv/Fm、ΦPSⅡ、ETR等参数显著下降,表明小麦叶片PSⅡ光反应中心受到损伤、电子传递受阻和光合量子捕获能力下降等非气孔因素导致光合能力和原初反应能力降低,最终造成小麦严重药害并减产。以上结果表明,氰草津安全使用期为冬前及小麦起身期,安全剂量为900g·hm-2以下,非安全期使用及过高使用剂量会对小麦产生严重药害。
To determinate the safety of cyanazine in wheat field,cyanazine with doses ranged in 675- 1 350 g · hm -2 were sprayed on wheat at 4 stages of before the winter,during double ridge stage,boo- ting stage and heading stage. The phytotoxicity and influences on photosynthesis, fluorescence and yields to wheat were examined. When cyanazine was used at before the winter or during double ridge stage,the growth and yield of wheat were little affected. The effect on phototsynthesis of wheat was limited and restorable in 10 days when about 675~900 g· hm-2 cyanazine was used at double ridge stage while became unrecoverable as 1 350 g · hm- 2 of cyanazine was sprayed at the same stages. As used at booting stage or heading stage of wheat,the cyanazine might caused serious phytotoxicity and the Pn ,Gs ,Fv/Fm ,ФPSⅡ ,ETR of wheat were extremely declined and couldn＇t restorable in short time. It showed the light reaction center of wheat PS Ⅱ was injured and reaction activity was descended.The electron transfer was suffocated and photosynthetic quantum capture ability was declined. The a- bove non-stomatal factor declined the photosynthesis ability and the original response ability of wheat, which lead to serious yield loss at last. The above result showed that the safe-use period of cyanazine was before the winter or during double ridge stage and the safe threshold dose of cyanazine was 900 g· hm-2 on wheat.
出处
《麦类作物学报》
CAS
CSCD
北大核心
2015年第5期714-721,共8页
Journal of Triticeae Crops
基金
国家公益性行业(农业)科研专项(201203098)
NSFC-河南人才培养联合基金项目(U1204321)
关键词
小麦
氰草津
药害
光合作用
荧光参数
产量
Wheat
Cyanazine
Phytotxicity
Photosynthetic characteristics
Fluorescence parame- ters
Yield
