The effects on the MDA content in the leaves
Under different light intensities, the MDA content in the leaves of the six mangrove species showed significant differences (P< 0.01; Figure 5). The MDA content in the leaves of theK. obovata , A. marina, and the R. stylosa seedlings showed a gradually increasing trend, with the smallest low light stress observed under the G1 treatment along with relatively low MDA values. The MDA content in the leaves of the A. corniculatum , C. tagal , and the B. sexangula seedlings first decreased and then increased, with the least low light stress under the G2 treatment and a relatively low MDA value. These results indicate that too high or too low light intensity can increase the low light stress of seedlings and thus increase the MDA content.
Under different flooding times, the MDA content in the leaves of the six mangrove species all had significant differences (P < 0.01). The MDA content in the leaves of K. obovata , A. marina , A. corniculatum , R. stylosa , C. tagal , and the B. sexangula seedlings all first decreased and then increased. The stress on the K. obovata , C. tagal , and theB. sexangula seedlings the was the lowest under the T2 treatment, along with relatively low MDA values. The A. marina , A. corniculatum , and the R. stylosa seedlings were under the lowest stress under the T3 treatment, and their MDA content was also lower. These results indicate that too long or too short flooding times can increase the stress on the seedlings, resulting in an increasing MDA content in the leaves.
Under different seawater salinities, the MDA content in the leaves of the six mangrove species showed significant differences (P< 0.01). The MDA content in the leaves of the K. obovata , C. tagal , and the B. sexangula seedlings all showed a gradually increasing trend, with the lowest stress under the S1 treatment and lower MDA values. The MDA content in the leaves of theA. corniculatum , A. marina , and the R. stylosaseedlings first decreased and then increased; the seedlings showed the lowest stress under the S2 treatment, and their MDA content was also lower. These data indicate that too high or too low seawater salinity can increase the stress on the seedlings, resulting in an increasing MDA content in the leaves.