| Oats are rich in variety and are a cultivated crop worldwide.Selenium is an essential trace element to maintain normal physiological function of human.The production of selenium-rich oats will play a very important role in selenium supplementation for residents in China.Therefore,it could provide reliable material guarantee for the development of functional oats foods to reveal the accumulation rule of selenium in oats,and to evaluate and screen excellent comprehensive characters oats varieties based on quality and yield after spraying selenium.In this experiment,24 oats varieties were used as research materials.At heading stage of oats,three spraying concentrations were set: sodium selenite dosage was 0g·hm-2,8 g·hm-2,16 g·hm-2(pure selenium content 0 g·hm-2,35.896 g·hm-2,71.792 g·hm-2 respectively).After spraying selenium,the sampling were choose to determine the selenium content of root,stem and leaf,panicle and grain from 24 oats varieties at flowering,filling and maturity stages,which aimed to reveal the selenium accumulation rule in oats.And the effects of spraying selenium on the contents of protein,fat,β-glucan and yield of 24 oats varieties were analyzed.Furthere the comprehensive characters for 24 oats varieties were evaluated based on the contents of selenium,protein,fat,β-glucan and yield treated with 80 g·hm-2 sodium selenite.The main research results were as follows:1.The mean selenium content in roots,stems,leaves,panicles and grains of 24 oats cultivars increased with the increase of selenium application content in this experiment.The selenium content was the highest in the root without selenium treated;however,the selenium content was the highest in the leaves after spraying selenium.The mean selenium content in leaves sprayed with 80 g·hm-2 and 160g·hm-2 sodium selenite increased by 266.78% and 452.40%,respectively,compared with that without selenium treated at flower stage;by 266.78% and 452.40%,respectively,at filling stage.The increase of selenium content in grain at mature stage was only lower than that of leaf.Under the same selenium concentration,the difference of selenium content in panicles among 24 oats varieties was the greater at flowering and filling stages,but the difference of selenium content in grains among 24 oats varieties was the greater at maturity stage.The difference of selenium content in roots among 24 oats varietiesremained lesserin growth periods.There was a significant positive correlation between spraying selenium concentration and grain selenium content of 24 oats cultivars with r = 0.896.2.When 80 g·hm-2 sodium selenite was sprayed,the grain selenium content of 24 oats varieties all were within the safe range of selenium content limited by China.The cultivar No.10（Pinyan 1）with the highest selenium content was 0.300 mg·kg-1 in grains.However,when 160 g·hm-2 sodium selenite was sprayed,the grain selenium content of 24 oats varieties all exceeded the safe upper limited by China.3.Selenium was mainly accumulated in the nutritive organs of oats at flowering and filling stages under different spraying selenium concentrations,howerer,selenium accumulation was the highest in panicles at maturity stage.But under spraying 0 g·hm-2,80 g·hm-2 and 160 g·hm-2 sodium selenite the mean seleniumaccumulation in grains of 24 oats cultivars was only 30.04%,41.79% and 38.13% of panicle respectively.Spraying selenium could increase significantly the mean selenium accumulation in every organs of 24 oats cultivars at different growth stages.The selenium accumulation increased with the increase of selenium application content in this experiment.4.The mean protein and fat content of 24 oats cultivars were not affected by spraying selenium.The mean β-glucan content of 24 oats cultivars was increased by spraying sodium selenite with 80 g·hm-2,whereas decreased with 160 g·hm-2.There was no significant correlation between selenium concentration and protein content or fat content of 24 oat varieties,but there was a significant positive correlation between selenium concentration and β-glucan content.The variation levels of protein,fat and β-glucan contents i of 24 oat cultivars also were changed by spraying selenium.5.There was no significant difference in yield of the 24 oats varieties between sprayed sodium selenite with 0 g·hm-2 and 80 g·hm-2.The yield of five oats varieties by sprayed sodium selenite with 160g·hm-2 were significantly lower than those without sodium selenite ttreated.There was no significant correlation between spraying selenium concentration and yield of 24 oats varieties.6.Correlation analysis showed that there was a significant positive correlation between selenium content and fat content or β-glucan content,but no significant correlation between selenium content and protein content or yield.7.The top five varieties of the ranking of comprehensive index by principal component analysis based on selenium content,quality traits and yield of 24 oats varieties after spraying selenium were No.9（Baiyan 10）,No.3（Baiyan 3）,No.5（Baiyan 5）,No.10（Pinyan 1）and No.2（Baiyan 2）in turn.8.The clustering analysis showed oats varieties wree clustered as three groups based on the grain selenium content after spraying selenium.The mean grain selenium content was the highest（13 varieties）in Ⅲ varieties groups,also grain selenium content was relatively stable in that.24 oats varieties wree clustered as three groups based on protein,fat and β-glucan content.The mean β-glucan content and fat content all were the highest（5 varieties）in Ⅱ varieties groups,also β-glucan content and fat content were relatively stable in that;The mean protein content was the highest（6 varieties）in Ⅲ varieties groups,also protein content was relatively stable in that.24 oats varieties wree clustered as four groups based on yield.InⅡvarieties group,there were two varietied with the highest yield,which were No.13（Bayou 1）and No.15（Bayou 18）.24 oats varieties wree clustered as four groups based on grain selenium content,quality traits and yield,which could be divided as: high grain selenium andβ-glucan content（3 varieties）,high yield（7 varieties）,high protein content（6 varieties）and high fat content（8 varieties）groups respectively.9.GYT biplot analysis based on yield and considering grain selenium,protein,fat and β-glucan content showed thatthe top five oats varieties of the ranking of comprehensive value after after spraying selenium were No.10（Pinyan 1）,No.23（Banner）,No.24（OA1576-4）,No.11（Pinyan 2）and No.9（Baiyan 10）in turn. |
