| Peanut is an important oil crop in China,and provide vegetable oil and high quality protein,which has high economic value.At present,peanut is widely planted in Huang-Huai-Hai area,and insect pest is the key factor reducing peanut production.In recent years,piercing-sucking pest,such as Frankliniella occidentalis,has been one of the most important peanut insect pest.The long-term use of chemical pesticides resulted in resistance of F.occidentalis.Therefore,screening and planting insect-resistant peanut varieties provide resources for green production of peanuts.Base on monitoring the occurrence regularity of F.occidentalis in Baoding area,In this study,90 peanut varieties were selected as materials to evaluate the resistance to F.occidentalis at the seedling stage.The resistant varieties of F.occidentalis were obtained,and the physical and chemical indicators of the resistant and susceptible varieties were analyzed,which provided a basis for determining the resistance mechanism of the resistant varieties to F.occidentalis.The main results are as follows:1.The monitoring results of the population dynamics of F.occidentalis in the peanut field from 2019 to 2020 showed that the main peak of the occurrence of F.occidentalis is concentrated in the peanut seedling to the flowering stage in Baoding of Hebei province.The first peaks occurrence in early June,the peak period came from mid-June to mid-July,and the peaks came from late July to September.The peak period occurred on 4th July,2019,with the highest number of insects reaching 2542,and on 22th June,2020,with the highest number of insects reaching 6759.2.According to the damage index of peanut leaves and insect quantity ratio,90 peanut varieties were screened against F.occidentalis.Field test results showed that different varieties have obvious differences in resistance to F.occidentalis.67 resistant varieties to and 23 susceptible varieties were screened,including 1 high-resistant variety,24 resistant varieties,42 medium-resistant varieties,18 susceptible varieties and 5 highly susceptible varieties;In 2020,25 resistant varieties to F.occidentalis and 5 susceptible varieties were screened,and 16 peanut varieties resistant to F.occidentalis were finally obtained,accounting for 53.3%of the identified materials.One high-resistant variety Tianfu 22,with the damage index is 16.25,and 4 resistant varieties,namely Quanzhou 1111,Fenhua 8,Tianfu 25,and Puhua 28,with the damage index from 17.25 to 20.58.11 copies of medium-resistant varieties with the damage index ranges from 21.08 to 25.92.There were 5 highly susceptible varieties,namely Yannonghua 04,Heyou 133,Weihua 18,Yannonghua 06 and Weihua 21.with the damage index from 31.08 to 38.17.3.The leaf disc method was used to determine the indoor selectivity of F.occidentalis to 30 different peanut varieties.The results showed that the selectivity of F.occidentalis to different peanut varieties was significantly different,the number of insects on the leaves of the high-resistant variety Tianfu 22 was the least after 0.5 h and 2 h,1 and 3 respectively;9 insects on the leaves of high-susceptible variety Weihua 21,these demonstrated that F.occidentalis showed different feeding selectivity to different variety.4.The 25 resistant to F.occidentalis peanut varieties and 5 highly susceptible varieties were screened according to physical and chemical indicators,including leaf thickness,chlorophyll content,wax content,soluble sugar,soluble protein,total phenol content,and total flavonoid content,the resistance determination of related physical and chemical indicators,and correlation analysis was conducted on the damage index of peanuts and the biochemical indicators.The results showed that the wax content,total phenol content,and total flavonoid content were significantly negatively correlated with the leaf damage index,and the correlation coefficients were-0.800,-0.704 and-0.707 respectively).The soluble protein content and the damage index showed an opposite trend,which were positively correlated,with a correlation coefficient r=0.797;However,there was no significant correlation between the leaf thickness,chlorophyll content,soluble sugar content and the damage index of different peanut varieties(the correlation coefficients were r=0.373,r=0.288,r=0.461,respectively).These results indicate that the waxy content,total phenol content and total flavonoid content of anti-thrips peanut varieties are higher,but the soluble protein content is lower.5.The yield of 30 selected peanut varieties was measured.The results showed that the yield had significant difference among different varieties difference.The yield of anti-thrips peanut varieties Tianfu 22,Quanzhou 1111,Fenhua 8,Tianfu 25,Puhua 28 and so on,were ranging from 3127.11 kg/hm2 to 3506.15 kg/hm2,and Quanzhou 1111 had the highest yield with 3506.15 kg/hm2.The pods yield of highly-susceptible varieties Yannonghua 04,Heyou 133,Weihua 18,Yannonghua 06,and Weihua 21 ranged from 2481.75 kg/hm2 to 2595.44 kg/hm2.Although some varieties have higher leaf damage index,the yields did not decrease significantly,we speculate it may be due to the stronger compensation ability of the varieties themselves. |
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