Evaluation Of Resistance Level Among Different Oats Cultivars Varieties To Rhopalosiphum Padi

Oat is an important food and feed crop and a characteristic advantageous crop in the northern region of China.It has important value in adjusting the agricultural industry structure,ensuring food security,improving the nutritional health of the whole population,improving the ecological environment,and promoting agricultural efficiency.Aphids are one of the important pests in oat production in China and around the world.They are widely distributed and occur in large quantities,directly or indirectly causing severe yield reduction in oats.Screening and applying insect resistant varieties is one of the most cost-effective measures for controlling oat aphids.This study focuses on the Rhopalosiphum padi,and comprehensively evaluates the aphid resistance level of main oat varieties grown in different oat planting areas through field resistance identification,population life table construction,feeding behavior analysis,and determination of physiological and biochemical substance content in oats.The main research results are as follows:1.Oat varieties of aphid resistance identification field30 oat varieties were evaluated for aphid resistance using the aphid quantity ratio method.The resistance of the tested oat varieties to aphids showed six levels:Dingyou No.3,Qinghai 444,Qingyin No.2,Baiyan No.7,and Mcngyan No.3,among which five varieties were highly resistant;Five varieties,including Yankc 2,Qinghai Tian,Dingyou No.4,Qingyan No.1,and Neiyan No.5,are medium resistant;Five varieties,including Sun God,Yellow Oat,Leader,Baylor,and Mengsiyan No.2,have low resistance;Six varieties,including Mengsiyan No.1,Bayan No.7,Baiyan No.2,Bayan No.1,Caoyou No.1,and Mengyan No.2,are low susceptible;Two varieties,Bayou No.14 and Bayan No.5,are considered moderate;Seven varieties,including Bayou No.1,Aiwo 126,Bayou No.5,Furuizhi,Bayou No.3,Bayou No.18,and Yanwang,are highly susceptible.2.The effect of different oat varieties on the growth and development of Rhopalosiphum padiIn order to clarify the growth and development status of the grain constricted aphid on different resistant oat varieties in the field,a single head feeding method was used to construct an experimental population life table.The results showed that the net reproductive rate(R0),average generation cycle(T),and population doubling time(DT)of aphids on Bayou No.1,Baiyan No.2,Neiyan No.5,and Mengsiyan No.1 were relatively low,while the intrinsic growth rate(rm)and weekly limit growth rate of aphids on sweet crops in Qinghai were relatively low(λ)Higher,0.482 and 1.620,respectively.The intrinsic growth rate(rm)and weekly limit growth rate of aphids on Mengyan No.2(λ)The highest values were 0.587 and 1.799,respectively,and cluster analysis of life table parameters showed that Bayou No.1,Baiyan No.2,Neiyan No.5,Mengsiyan No.1,Qinghaitian,and Yanwang were not conducive to the population development of Hegu constricted aphid,indicating that the above varieties have strong resistance to it.3.The effect of different oat varieties on the feeding behavior of the grain constrictor aphidIn order to determine the aphid resistance and insect resistance sites of different oat varieties,the feeding behavior of aphids was measured using spike potential technique.The results showed that aphids had the most occurrences of np waves(9.27)and the longest duration of np waves(43.23 minutes)in Qinghaitian,and the longest duration of F waves(27.00 minutes)in Bayan No.7;When aphids feed on Yan Wang and Aiwo 126,the average duration of El wave(5.24 minutes)and E2 wave(37.52 minutes)are the longest,indicating that the above varieties have strong resistance in the leaf epidermis,mcsophyll tissue,and phloem,and are in the category with strong aphid resistance in the cluster analysis results.In addition,There was a significant correlation(P<0.05)between some waveform parameters and life table parameters of different oat varieties consumed by Rhopalosiphum padi.4.Physiological and biochemical substance content of different oat varietiesTo accurately evaluate the resistance of oat varieties to aphids,colorimetric and high-performance liquid chromatography methods were used to determine the content of physiological and biochemical substances.The results showed that the nutrient contents of varieties Aiwo 126,Qinghai 444,Bayou No.18,and Baylor were significantly lower than those of Baiyan No.2,Bayou No.1,Mengsiyan No.1,Yanke No.2,and Dingyou No.4,respectively;Except for the content of Dingbu,the content of all secondary metabolites in Bayou No.18 was significantly higher than that in Baiyan No.2.Based on clustering analysis of physiological and biochemical substance content,Yanke No.2 and Neiyan No.5 showed poor overall performance,while other oat varieties showed strong overall performance.At the same time,the intrinsic growth rate and weekly growth rate of aphids on oats were significantly positively correlated with the content of soluble sugars,soluble proteins,and amino acids in the body of oats(P<0.05),and negatively correlated with the content of secondary metabolites such as total phenols,tannins,and total flavonoids.5.Comprehensive evaluation of aphid resistance levels in different oat varietiesBased on the life table parameters,feeding waveforms,and plant physiological and biochemical content of Rhopalosiphum padi on different oat varieties,cluster analysis was conducted.The results showed that Baiyan No.7,Baiyan No.2,Mengsiyan No.2,Dingyou No.4,Yanwang,Mengsiyan No.l,Bayou No.18,Bayou No.1,Beile,and Qinghaitian had strong comprehensive resistance to aphids.