打顶后施用生长素(IAA)和钾肥对烤烟碳氮代谢的影响

Effects of applying indole-3-acetic acid (IAA) and potassium on carbon and nitrogen metabolism of flue-cured tobacco after topping

研究了不打顶(T1)、打顶(T2)、打顶+追施K_2SO_4(T_3)、打顶+涂抹生长素1次(T4)、打顶+追施K2SO4+涂抹生长素1次(T5)、打顶+追施K2SO4+涂抹生长素2次(T6)等6种调控措施对烤烟碳氮代谢的影响。结果表明:由打顶当天到打顶后30d,烤烟淀粉酶活性总体上表现为下降后又略有上升的趋势,转化酶(INV)活性则逐渐降低;2种酶活性均以T6最高,T1最低,且差异达到极显著水平;除T1外,各处理在打顶后的淀粉含量逐渐升高,总糖含量则呈现上升后又逐步下降的变化,至打顶后30d,淀粉和总糖含量均以T6最高,T1最低;随生育时期延长,硝酸还原酶(NR)活性和蛋白质含量均表现为逐渐下降的趋势。打顶后30d,T6的NR活性和蛋白质含量均为最高;在打顶后30d,以T5的NR/INV比值最大。打顶当天在顶端涂抹生长素,同时追施K2SO4肥,可促进烤烟生长和碳氮代谢。

This paper studied the carbon and nitrogen metabolism of flue-cured tobacco under effects of six treatments, i. e., no topping （T1）, topping （T2） , topping ＋ topdressing K2SO4 （ T3 ）, topping ＋ spraying IAA （ indole-3-acetic acid） 1 time （ T4 ）, topping ＋ topdressing K2SO4 ＋ spraying IAA 1 time （ T5 ）, and topping ＋ topdressing K2SO4 ＋ spraying IAA 2 times （ T6 ）. The results showed that from the day of topping to the following 30 days, the amylase activity of flue-cured tobacco had a trend of decreasing first and increasing slightly then, while invertase （INV） activity decreased gradually. The activities of these two enzymes were the highest in T6 and the lowest in T1, with a significant difference. Except in T1, the starch content in all treatments increased gradually, and the total sugar content increased first but decreased then. At the 30th day after topping, the starch and total sugar contents were the highest in T6 , and the lowest in T1. Nitrate reductase （NR） activity and protein content had a decreasing trend with the growth of tobacco, and were the highest in T6 at the 30th day after topping. Treatment T5 had the highest ratio of NR/INV after 30 days of topping. Spraying IAA at the top of tobacco plant on the day of topping combined with K topdressing could promote the growth and the carbon and nitrogen metabolism of flue-cured tobacco.