Study On Growth And Development Of Tobacco Root And Chemical Regulators

From 1998 to 2000 ,by pot and field experiment, the study of growth and development of Tobacco root , the relationship between tobacco root and upward part and the effect of regulators were carried out. The best combined regulator was selected .The results were showed as follows:First, there was a relationship between the emergency of different type roots and their growth and the emergency of leavies. adventicious root emerged when the first leaf came out, the first lateral root emerged when the second leaf came out, the second lateral root emerged when the five leaf came out . In the field period ,both the length and the weight of root corresponded with Logistic equation, the number of roots correspond with power equation.The correlation of root weight* root number'With leaf number> leaf area and plant height were extremely significant, but not significant with content of sugar and total N.Second, the dynamic change of root activity was a curve with two peaks, they appeared respectively at 30 days and 80 days after being replanted. The dynamic change of nicotine and K in different organ were consistent .with that of root activity. The content of K in stem and leaf appeared decline tendency, but still had a small peak at the later stage , correspond with the rising tendency of root activity at the later stage. The activity of different lateral roots acted at different stage ,at the procedure time the activity of adventicious root and the first lateral root were stronger than that of the second lateral root ,the root activity in upper soil layer was stronger than that of in the underside. At the laterstage , the activity of different lateral roots were supplemented by each other.Third, by the use of three kinds of chemical regulators-ABT4, FA and FeSO4 ,the length and the weight of root were increased, the growth of leaf were accelerated, the root activity were improved, the contend of Nicotine and KaO were increased, the sugar/N . sugar/nicotine and N/nicotine were got coordinated therefore ,the quality of tobacco became better. But the different regulators had a different effect at the different stage. ABT4 mainly influenced the length and the weight of root and mainly acted at earlier stage. FA had a steady influence at later stage and FeSO4 mainly influenced the activity of root , the absorption of K and synthesis of nicotine .Forth, among the nine kinds of combined regulators, the morphic of root were extremely improved by spraying leaf with ABT4 (10ppm), irrigating root with FA (lOOppm) and mixing up soil with FeSO4(5g). With that treatment ,a strong root tribe can be formed. The root activity^ the accumulation of nicotine and K were distinctly enhanced by spraying leaf with ABT4 (30ppm),irrigating root with FA(300ppm),mixing up soil with FeSO4(8g) .