| With the improvement of people’s living standards,higher requirements are put forward for the diversity of wheat.Compared with Chinese wheat,American wheat has its own characteristics and advantages in high quality and stress resistance.In order to fully tap and utilize the 32 Introduced Wheat Germplasm Resources from the United States,this study intends to evaluate the utilization value of these introduced germplasm resources by investigating agronomic traits,identifying powdery mildew resistance and PEG simulated drought stress resistance,detecting appearance indicators and starch physical and chemical properties,so as to provide germplasm materials and technical support for wheat variety improvement.The main results are as follows:(1)The results of the investigation on agronomic traits showed that there were differences among the agronomic traits of different materials,and the coefficient of variation was greater than 10%.The average plant height of these materials was 102.63 cm,and the range of variation was 88.25-141.30 cm.Among them,there were 12 materials with plant height over 105 cm.The average 1000-grain weight was 30.84 g,and the variation range was23.26～45.36 g.The 1000-grain weight was generally low,and the improvement and utilization of varieties would affect the increase of yield.(2)Identification of powdery mildew resistance at seedling and adult stage.71.88% of the materials were resistant to powdery mildew at seedling stage,and 9 of them showed high or moderate resistance.59% of the materials were resistant to powdery mildew at adult stage,and the other 13 materials showed high or moderate susceptibility.The resistance to powdery mildew at seedling stage was greater than that at adult stage.The three materials numbered D30,D31 and D32 were resistant to powdery mildew at seedling stage and adult stage.The 14 materials numbered D1,D5,D8,D9,D11,D14,D15,D18,D21,D22,D23,D26,D27 and D29 showed different resistance to powdery mildew at seedling stage and adult stage.(3)The simulated drought stress tests at Germination and seedling stages showed that the relative germination rates of these materials were between 17.39% and 74.73%.Principal component analysis showed that 88.13% of the original data of resistance could be represented by three principal components.By cluster analysis,these materials were divided into five categories.There were 3 highly resistant varieties in Category I,6 drought resistant varieties in Category II,14 moderate drought resistant varieties in category III,8 drought sensitive varieties in Category IV and 3 highly sensitive varieties in category v(4)The preliminary analysis of quality characters by DA7200 near-infrared grain analyzer showed that D27 reached the standard of medium strong gluten wheat,and 22 materials reached the standard of medium gluten wheat.The variation range of crude protein content is 12.49%-15.129%,the water absorption is 52.58%-63.20%,the sedimentation value is 25.607 m L-39.477 m L,the stabilization time is 1-18.85 min,and the maximum variation coefficient of stabilization time is 50.24%.The Starch Physicochemical Properties of the tested materials showed that the changes of amylose content and amylopectin content showed an opposite trend.Amylose had a very significant correlation with gelatinization temperature,peak viscosity and dilute value,and a significant positive correlation with final viscosity and rebound value;Amylopectin has a very significant negative correlation with gelatinization temperature and solubility,and a very significant positive correlation with swelling potential,peak viscosity and dilute value,of which the maximum correlation coefficient with peak viscosity is 0.849. |
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