The Inhibitory Effects Of Bionics Signal Molecule On Nitrate And Nitrite Of Tobacco Leaves

Nitrate and nitrite are the precursor of obacco carcinogen -tobacco-specific nitrosamines (TSNA). Restraining the content of NO3-, NO2- is one of the method to restraining the content of TSNA. Insect feeding or mechanical injury (such as topping) can activate the system of tobacco plants of defense responses, changing the absorb and translation of N from tobacco. Based on the study of the interaction of tobacoo and insect, the bionics signal molecule (BSM) from tobacco feeding oligophagous pests oral secretion,were applied to the top of caulis of diverse types of tobacco after topping, studying on the interaction of BSM and NO3-, NO2- and interaction effects of bionics signal molecule and the cultivation factors, such as varieties, and topping time. This Study based on the best way to use BSM, which provide a new way to regulate tobacco alkaloids.Thesis work are summarized as follows:1. Determined and analyzed the content of NO3-, NO2-content and NR activity on flue-cured tobacco and burley tobacco in the whole growth process of plants in various parts. Analyzed the effect of BSM on the content of NO3- , NO2- and NR activity after topping. The results show that; the central tobacco leaf and root NO3- content reach maximum in the fast growing period, reaches a minimum after topping 25d; tobacco central leaf and root get lowest levels of NO2- in topping period and reach the maximum in the 15d after topping.; The NR activity in tobacco central s reached the minimum in the 25d after topping. Root NR activity within decreasing gradually in the first five days after topping,reached minimum after topping 25d. Middle leaves of burley tobacco in different periods of NO3-content get the maximum in topping period, reach the minimum at 25d after topping .The content of NO3- in root sreach the maximum in the fast growing period and reached the minimum in the 25d after topping; The NO2-content of middle leaves in burley tobacco reach the maximum in the fast growing period reached the lowes in the 25d after topping . NOcontent of root reach the maximum in the fast growing period reached the lowes in the in the topping period; NR activity of the central leaves and root in burley tobaccoreach the lowes in plant period reach the maximum the 5d after topping,2. The effect of using BSM on flue-cured tobacco after topping of different topping time. The exprriment from the year 2008 and 2009 were show that: K326 and 9717 varieties of tobacco flue-cured tobacco, treated with BSM after topping, the content of NO3-and NO2- in leaves were in decreased degrees, compared with the matched group. 2008 results show that: K326 and 9717 varieties of tobacco flue-cured tobacco dealed with BSM after topping, K326 middle leaves decreased NO2- more, fell to 43.3%, the content of NO3- in the upper leaf of 9717 decreased the most, up 31.5%. 2009 results show that: the treatment of BSMa on NO2- were more effective than NO3-; besides the content of NO3- in the middle leaves, the use of BSMa made better effect on the early blossoming topping group than full bloom topping group.3. The effect of the use of BSM of burley tobacco. The results showed that: the use of BSM after could reduce the content of NO3- and NO2- in the leaves of burley tobacco with differenct conditions. The experiment of Hubei in 2008 show that the higher content of BSM got better result. That is to say, the result put up concentration effect. The use of BSM got better result in the content of NO3-and NO2- in the iddle leaves then the upper. The experiment of Hefei in 2008 show that the use of BSM got better result in the content of NO2- then NO3-, and made better effect on the early blossoming topping group than full bloom topping group.