Evaluation Of Zinc Efficiency Of Different Varieties Of Oats And Response To Low Zinc Stress

Oat is a grain and feed crop,which is rich in nutritional value and has high health care effect.Zinc is one of the important factors affecting the yield and quality of oats.The ideal choice to solve the zinc deficiency in soil is to screen and cultivate oat varieties with high zinc absorption and utilization efficiency.Thus study on the difference of zinc efficiency and physiological response of different oat varieties to low zinc stress has important theoretical and practical significance for the genetic improvement of zinc nutritional traits of oat and cultivation of oat varieties with high zinc efficiency.First of all,this study made clear the suitable concentration and time of low zinc stress for evaluating the differences of oat varieties with different zinc efficiency under liquid culture.Then,by liquid culture experiment,the differences of zinc absorption and utilization of 30 oat varieties with large genetic differences were evaluated.Finally,oat extremely Zn-efficient varietiy Jinyan 2004 and Zn-inefficient varietiy 8202 were selected as experimental materials to explore the differences of root morphological adaptability and root exudates between zinc efficient and inefficient oat varieties under low zinc stress.The main results are as follows:(1)Through the analysis of the effects on the growth and zinc accumulation of different oat varieties under different zinc supply levels.When the low zinc concentration is 10-8 mol/L and the low zinc stress time is 25 d,under the condition of liquid culture,it is most appropriate to evaluate the difference of zinc efficiency of different oat varieties at seedling stage.(2)According to the clustering of zinc efficiency of different oat varieties,30 oat varieties were divided into three groups.7,8,15,19 and 24 were zinc efficient oat varieties.13,16,18,22,25,26,27,28,29 and 30 were zinc inefficient oat varieties,and the other 15 varieties were moderately sensitive.(3)Low zinc stress hinders the growth and reduces the dry matter quality of oats.The root morphological adaptability of Zn-efficient varietiy Jinyan 2004 was significantly stronger than that of Zn-inefficient varietiy 8202 under low zinc stress.The Zn-efficient varietiy Jinyan 2004 could increase the zinc absorption capacity of roots under low zinc stress.These are achieved by increasing root configuration parameters such as maximum root length,total root length,total root tip number,surface area,volume and so on.(4)The proton secretion and plasma membrane ATPase activity of Zn-efficient varietiy Jinyan 2004 were significantly higher than those of Zn-inefficient varietiy 8202 under low zinc stress.The results showed that the ability of Zn-efficient varietiy Jinyan 2004 to acidify rhizosphere soil was stronger than that of Zn-inefficient varietiy 8202,and its tolerance to low zinc stress was stronger.