Resistance Of Different Variety Of Spring Rape At Seedling Stage And Effects Of Seed Dressing With Imidacloprid

Spring rape is one of the main oil crops in the region of Inner Mongolia,and Phyllotreta humilis Weise is one of the most serious pests in seedling of spring rape.Spring rape in the seedling could be affected hugely by this pest.That is the best way to control the pest and ensure the yield of spring rape that spring rapes of resistance to P.humilis are selected.Resistance mechanism and physiological and biochemical responses of spring rapes were studied.First,host selection of P.humilis to three spring rapes and Lepidium apetalum were tested through olfactory.In the same time,the growth,nutrition materials,4 defense enzymes and yields were also determined among three spring rapes.On the other hand,chemical control was used in this area and seed dressing was one of the main measures.On the base of these results,Dahuang rape was selected to dressing with imidacloprid,and the effects of imidacloprid to Dahuang rape were tested.The main results are as follows:1 Y-olfactometer was used to test the selection of P.humilis to odor of three rapes and L.apetalum.Compared with the air,P.humilis was attracted by four plants evidently,and the selection rates were 6.5,7.5,8.3 and 8.2 for Space meng IV,Dahuang,L.apetalum and Qingyou 14 respeetively.When three rapes compared with L.apetalum,P.humilis was attracted by L.apetahm obviously.The selection rates of P.humilis to L.apetalum were 8.0,7.7and 7.8 compared with Space meng P.humilis,Dahuang,and Qingyou 14.Compared among three rapes.P.humilis was attracted mostly by Qingyou 14,then Dahuang.Space meng IV was the most resistance rapes among three rapes.2 The growth and nutrient of different varieties of rape were determined.The results showed:(1)The height of rape in the seedling stage was measured.The height of was taller than heights of Dahuang and Qingyou 14.The heights of Space meng ?,Dahuang and Qingyou 14 were 8.5cm,7.1cm and 5.5cm respectively when 28 days after rape sprouted.The leaf area of Space meng ? was higher than that of the other two types of rape.In the final twenty-eighth days,leaf area of Space meng IV and Dahuang rape were higher than that of Qinghai oil 14.The leaf area of Space meng IV was the highest and value was 66.44cm2,followed by 60.79cm2of Dahuang.It was the smallest of Qingyou 14,and it was 55.39cm2.The fresh weight of three rapes were also tested,the results were as follows:Dahuang(0.37g)>Space meng IV(0.33g)>Qingyou 14(0.31g)respectively.There was no difference significantly between them.(2)The soluble sugar content of Space meng ? was lower than that of other two rapes significantly.The soluble sugar content of Space meng IV was 1.13mg/g,andThe protein content of Space meng ? was 3.26mg/g,and it was lower than that of Qingyou 14 and Dahuang significantly.The protein content of Dahuang was 3.53mg/g,and it was 3.44mg/g about Qingyou 14.(3)The yields of three types of rape had been tested for three years since 2014.The yield of Space meng IV was higher than that of other two rapes significantly in three years.3 The activities of three defense enzymes were determined about three types of rape.The activity of PLA in Space meng ? was 62.67 u/g min,and it was higher than that of other two rapes significantly.There was no significant difference of the activity of PLA between Dahuang and Qingyou 14.The activity of PPO in Space meng IV was 26.44 u/(g·min),and it was higher than that of Dahuang and Qingyou 14 significantly.The activity of PPO(21.33 u/g·min)in Dahuang was higher than that of PPO(16.22u/g·min)in Qingyou 14 significantly.Forever,The activity of POD in Qingyou 14 was 13.33 u/(g·min),and it was lower than that of Space meng IV and Dahuang.There was no significant difference in activity of POD between Space meng ? and Dahuang.The activities of SOD in three rapes were also measured.It was 100.43 ?/g·min in Space meng ?,and 83.76 u/(g·min)for Dahuang,70.94 u/(g·min)for Qingyou 14.There was significant difference between them.4 Effects of seed dressing with imidacloprid on Dahuang were measured.They were promoted significantly that height,leaf area,fresh weight and nutrients of Dahuang treated by imidacloprid in seedling stage.Yield of Dahuang treated with imidacloprid increased significantly compared with control.And It was same in 4 defense enzymes.