Physiological Effects Of The New Plant Growth Substance-L-Glutamic Acid On Litchi

After spraying L-glutamic acid with different concentration on Litchi in its different period, we studied the physiological effects of L-glutamic acid on the Litchi, observed the changes of the contents of chlorophyll and sugar, the dry weight, the activity of IAA oxidase, perxidase(POD), polyphenol oxidase(PPO), cellulose. The results showed:1. When gultamic acid concentrations were at 0.02⁰.5g/L,the chlorophyll content rose with the increase of glutamic acid concentration. When the concentration over 1.0g/L, glutamic acid has inhibition on the chlorophyll. All glutamic acid can enlarge the net photosynthetic unit and the soluble sugar content and dry weight, and can decrease the internal CO₂ concentration in the leaves.2. L-glutamic acid at low concentration cannot inhibit the growth of the braches, but they can make the leaves green. When the concentrations of L-glutamic acid were higher than 2.0g/L, they can kill the gentle leaves. But when the lengths of the braches were over 5cm, no one can inhibit its growth, insides "kongshaoling".3. From the census of the activities of enzymes, we can see that: L-glutamic acid with high concentration can promote the enzymes' activity such as IAA oxidase, peroxidase (POD), polyphenol oxidase (PPO), cellulose. After treated with 2.0g/L and 4.0g/L L-glutamic acid, the IAA were decomposed mostly. The high activity of the PPO manifest the strong aspiration of the leaves and more energy was cost. Except the POD has the same action as IAA oxidase action in leaves, it also has one action as PPO-can oxide the phenol. The cellulose can make the leaves fall from the tree. The high concentration treated, the more easy the leaves fall. Content of malonadehyde in leaves was increased with the concentration of L-glutamic. Malonadehyde (MDA) is the index of the peroxidation of membrane-lipid. The more the leaves were hurt, the high content of MDA in the leaves. Treated with 1.0g/L glutamic acid, the enzymes activity and the content of MDA were decrease at the 5^th d, the leaves return to normal.