Physiological Response of Paspalum notatum’s Leaf and Root under Persistent Drought Stress

To investigate the correlation and difference between Paspalum notatum’s leaf and root under drought adversity,this study tested the physiological responses of wild Paspalum notatum’s leaf and root under 0(CK),1,3,5,7,14,21,and 28 d drought stress treatment.These physiological responses include osmotic regulating substance,antioxidant enzyme activity,malonaldehyde content,cell membrane permeability,and chlorophyll content.According to the results,the soluble protein content,proline concentration,malonaldehyde content,cell membrane permeability and CAT activity in Paspalum notatum’s leaf and root tended to increase with the prolongation of drought stress;the soluble sugar content and SOD activity first increased and then decreased;POD dropped gradually;the contents of chlorophyll a,b and total chlorophyll first declined,then mounted,and lastly dropped again.During the early stage of drought stress,SOD and CAT acted as the main antioxidant enzymes in Paspalum notatum’s leaf and root.However,with the aggravation of drought stress the predominant antioxidant enzymes became SOD in the root system whereas CAT and POD in the leaf.It implicates drought has a strong influence on root’s CAT and leaf’s SOD and POD.Leaf is the major organ regulating the osmosis and photosynthesis of Paspalum notatum.The findings can provide a useful theoretical basis for improving Paspalum notatum’s drought tolerance.

猪大肠杆菌的分离鉴定及药敏试验

为了解贵州省猪源大肠杆菌对抗生素耐药的情况,有效防控猪场大肠杆菌性拉稀和腹泻。本试验采集2018—2019年贵州省5个市县规模猪场/养殖户的粪便和样品1 202份,经分离培养和生化鉴定,获得大肠杆菌532株,药敏试验结果显示大部分大肠杆菌分离株对抗生素多重耐药,这对指导贵州大肠杆菌病防治具有重要的临床意义。