Screening Of Selenium-enriched Methods For Tea Seedlings And The Effect Of Nitrogen And Selenium Interaction On Tea Yield And Quality And Selenium Absorption

Selenium is an essential element in animals and plants,and it is the "king of cancer" among trace elements.Studies have reported that in animals,organic selenium has lower toxicity than inorganic selenium.Not only is it preserved in tissues more than inorganic selenium,but its bioavailability in humans is also higher than inorganic selenium.However,the area of selenium-rich soil in China is limited,and the supply of natural selenium-rich products cannot meet the needs of Chinese citizens.Therefore,it is necessary to use the biological selenium-enriched method to convert artificially added inorganic selenium into organic selenium,and to use tea as a selenium carrier is scientific and safe.In this paper,the indoor hydroponic test was used to screen the selenium-enriched tea method,and then the best selenium application method was foliar application of selenium in the field,and the technology was optimized through interaction with nitrogen,and finally through the selenium content,quality and yield of tea And other indicators to determine the best selenium application combination.The experimental results are as follows:1.After two different selenium application methods were applied to the first-age tea seedlings of Longjing 43 and Shuchazao tea varieties,the selenium content in the tea leaf was higher by 0.0776 than the control in terms of selenium content in tea.mg/kg,foliar application of selenium was 7.2298 mg/kg higher than the control;Longjing 43 rhizosphere selenium application was 0.2489 mg/kg higher than the control,and foliar application of selenium was 12.8586 mg/kg higher than the control.Therefore,selenium application of selenium increased the selenium content of tea significantly more than that of rhizosphere;in terms of the adsorption capacity of selenium,both rhizosphere application and foliar application of selenium showed that Longjing 43 was stronger than Shucha earlier.2.The effect of selenium enrichment in different leaf positions of Longjing 43 one-foot tea seedlings is different.The measurement results show that regardless of selenium application in the rhizosphere or foliar application,the selenium content in Longjing 43 shows the1st-2nd leaves>3rd-4th leaves> 5th to 6th leaves> 7th to 8th leaves> 9th to 10 th leaves;selenium application in the rhizosphere The 1st to 2nd leaves have a selenium content of0.2735 mg/kg and the 9th to 10 th leaves have a selenium content of 0.1113 mg/kg Foliar application of selenium: The content of selenium in leaves 1 to 2 can reach 13.3380 mg/kg,and the content of selenium in leaves 9 to 10 can reach 6.1525 mg/kg.It can be seen that the young parts of tea seedlings have a better effect on the enrichment of sodium selenite.3.Selenium can increase the activities of SOD,POD,CAT,and APX in tea seedlings,and can increase the content of chlorophyll a,chlorophyll b,and carotenoids in fresh tea leaves within a suitable concentration range.And in terms of improving the antioxidant capacity and photosynthetic pigment content of tea seedlings,selenium selenium application is more effective than rhizosphere selenium application.4.Adopt selenium selenium application method,design a two-factor three-level orthogonal experiment,in the field experiment to study the effect of nitrogen and selenium interaction on tea yield,the study found that: appropriate concentration of selenium can increase tea 1 bud 1leaf,1 bud 2 The length of leaves,1 bud 3 leaves,40 mg/L selenium can significantly advance the germination period of tea,but 80 mg/L selenium has no significant effect on the advancement of tea germination period,but two concentrations of selenium have 1 bud of tea One-leaf,one-bud two-leaf,one-bud three-leaf hundred bud weight,germination density and total fresh leaf yield have a significant reduction effect.5.Foliar application of selenium significantly improves the sensory evaluation and functional components of tea;in terms of appearance,selenium application of leaves can make the tea more slender and firmer than the control,and the color of the tea is more green and aroma More intense;in terms of tea quality,selenium can increase the content of caffeine and free amino acids in tea,40mg/L selenium slightly promotes the content of tea polyphenols in tea,and 80mg/L selenium improves the content of tea polyphenols in tea It showed obvious inhibitory effect,but selenium reduced the quality of water leaching in tea,and selenium had a significant effect of reducing the phenol-ammonia ratio of tea,which could reduce the bitterness of tea.6.The cumulative amount of selenium in tea is directly proportional to the concentration of selenium application.0.5% nitrogen can promote the accumulation of selenium content in the first batch of tea picked after selenium application,and 1% concentration of nitrogen has Inhibition;tea was picked for the second time on the 40 th day after selenium treatment,and it was found that the 1% concentration of nitrogen had no effect on the inhibition of tea selenium accumulation.7.In the two-factor three-level orthogonal experiment,it is concluded that: A3B3 is the optimal treatment combination to improve the sensory evaluation and quality components of tea;A3B1 is the optimal treatment combination to increase the tea yield;A2B2 is the optimal treatment to increase the selenium content of tea combination.According to the national selenium-enriched tea standard,comprehensive safety,economy,nutrition and other aspects are considered,and A2B2,namely nitrogen concentration 0.5% + selenium concentration40mg/L,is considered as the best treatment combination of artificial selenium-enriched tea technology.