Identification Of Aphid Resistance Of 30 Wheat Varieties In Different Ages And Its Relationship With Correlation Analysis Of Agronomic Characters

The production of wheat has an important impact on China’s food security,and the occurrence of diseases and insect pests will cause great production losses to wheat,among which wheat aphids are frequent and serious pests in wheat producing areas,which will reduce the yield and quality of wheat.In order to control wheat aphids economically and effectively,the aphid-resistant varieties of wheat were identified and screened,and the relationship between agronomic traits,quality traits and aphid resistance was explored,which laid the foundation for the subsequent wheat aphid-resistant breeding work.In this study,the number of dominant wheat aphids（Sitobion avenae Fab.）was investigated under indoor and outdoor conditions for 30 wheat varieties bred in different years,and the aphid-resistant types of wheat were determined by aphid ratio method and fuzzy recognition method.Four agronomic traits of different wheat varieties were measured in the field:spike density,loss rate of 1000-grain weight,plant height and awn length,and whether they can be used as indicators of wheat aphid resistance was analyzed.At the same time,the sedimentation value,crude protein,moisture and other quality traits of wheat were quickly determined and analyzed by near-infrared analyzer.The results show that:1.The aphid resistance of wheat is obviously different with different varieties.The six wheat varieties that showed moderate resistance both indoors and outdoors were:Han 6172,Zhoumai 16,Kaimai 18,Zhoumai 18,Shaanxi 538 and Xinong 558,and the seven wheat varieties with low resistance were:Xinong 6028,Fengchan 3,Aifeng 3,Xiaoyan 107,Xiaoyan 168,Shaanxi 229 and Youbang 9987.Other varieties showed aphid sensitivity.2.The identification results of indoor and outdoor aphid resistance are basically consistent,and the identification results of aphid resistance by aphid quantity ratio method and fuzzy recognition method are highly consistent.The four varieties,Shaanxi 160,Shaanxi nong981,Xinmai 13 and Xinong 389,all showed low susceptible indoors and low resistance outdoors.The other 26 varieties showed the same resistance to aphids indoors and outdoors,accounting for 86.67%of the total.Shaanxi 160 and Shaanxi nong 981 changed from low resistance（aphid quantity ratio method）to moderate resistance（fuzzy recognition method）,and Aikang 58 changed from moderate susceptible（aphid quantity ratio method）to low susceptible（fuzzy recognition method）.Only three varieties had different identification results,and the other 27 varieties had the same identification results,accounting for 90%of the total materials.3.When divided by different ages of breeding wheat,the aphid resistant materials and aphid sensitive materials accounted for almost half of each other,and there was no obvious difference between years.Besides,the number of wheat aphids changes with the time as follows:the daily average number of aphids of all varieties increases with the extension of inoculation date,the initial growth rate of aphid number of aphid-resistant varieties is low,and the latter growth rate is slow,instead the initial growth rate of aphid number of aphid-sensitive varieties is high,and the latter growth rate is fast.In the field,the daily average number of aphids increased gradually from early March,increased sharply from early April,reached the peak in late April or early May,and then decreased gradually.The number of aphids in the field mainly varies with the amount of nutrients in wheat fields.4.The results of correlation identification between agronomic traits and aphid resistance shows that the spike density of different wheat varieties has a very significant negative correlation with the ratio of aphid amount at adult stage(correlation coefficient:-0.475^**),and the stepwise regression equation of the spike density to aphids ratio is:Y1=2.057-0.294X1;The loss rate of 1000-grain weight is positively correlated with the ratio of aphid amount(correlation coefficient:0.472^**),and the stepwise regression equation of the loss rate of 1000-grain weight and the ratio of aphid amount is:Y2=1.422+2.700X2;There is no significant correlation between plant height,awn length and aphids ratio.5.The sedimentation value,crude protein,starch,gluten,water,stability time,water absorption rate,formation time,extensibility and other quality traits of wheat are different due to different wheat varieties,and there are also differences among different aphid resistance grades.According to the aphid resistance of different wheat varieties identified in this study,wheat materials with certain aphid resistance have relatively high sedimentation value,crude protein,gluten and water.Therefore,aphid resistant germplasm has great utilization value for wheat quality breeding,and its application prospect is also broader.The results of statistical analysis show that the aphid resistance of wheat varies greatly with different varieties,and there is no obvious difference in aphid resistance among different years of breeding wheat.In the identification of wheat aphid resistance,indoors or outdoors,the aphid quantity ratio method or fuzzy recognition method has little effect on the overall identification results and the identification types are generally consistent.According to the occurrence rule of wheat aphids,the number of wheat aphids can be investigated from early March to late May.The spike density of wheat can be used as an auxiliary index for selecting traits of wheat resistance to wheat aphid,and the loss rate of 1000-grain weight reflects the damage caused by wheat aphid to wheat production to a cert ain extent.The aphid resistance of wheat is related to its quality traits,so aphid resistance breeding should be combined with quality breeding.