Yunyan 97 was selected as the raw material. The effects of removing different number （0, 2, 3 and 4） of lower leaves on root activity, chlorophyll content, physiological features and contents of neutral aroma consti...Yunyan 97 was selected as the raw material. The effects of removing different number （0, 2, 3 and 4） of lower leaves on root activity, chlorophyll content, physiological features and contents of neutral aroma constituents in the flue-cured tobacco were analyzed. The results showed that the removal of lower leaves could significantly increase the root activity, chlorophyll content, net photosynthetic rate （Pn） and transpiration rate （Tr）, and delay the photosynthetic functional decline. Such effects were the greatest in lower leaves, followed by middle leaves and upper leaves. Moreover, the degree of the effects increased with higher number of leaves removed. After She lower leaves were removed, the water use efficiency （WUE） of leaves in the first 10 d became higher with more leaves removed. In the later periods （24 d, 38 d）, WUE decreased with more leaves removed. For the middle and upper leaves, the removal of three leaves （T2） and two leaves （T1） resulted in the highest contents of aroma constituents, respectively. For the tobaccos cultured in soil with moderate fertility under the experimental conditions, the appropriate number of lower leaves removed should be 2-3.展开更多
文摘Yunyan 97 was selected as the raw material. The effects of removing different number （0, 2, 3 and 4） of lower leaves on root activity, chlorophyll content, physiological features and contents of neutral aroma constituents in the flue-cured tobacco were analyzed. The results showed that the removal of lower leaves could significantly increase the root activity, chlorophyll content, net photosynthetic rate （Pn） and transpiration rate （Tr）, and delay the photosynthetic functional decline. Such effects were the greatest in lower leaves, followed by middle leaves and upper leaves. Moreover, the degree of the effects increased with higher number of leaves removed. After She lower leaves were removed, the water use efficiency （WUE） of leaves in the first 10 d became higher with more leaves removed. In the later periods （24 d, 38 d）, WUE decreased with more leaves removed. For the middle and upper leaves, the removal of three leaves （T2） and two leaves （T1） resulted in the highest contents of aroma constituents, respectively. For the tobaccos cultured in soil with moderate fertility under the experimental conditions, the appropriate number of lower leaves removed should be 2-3.
