Effects of three different flooding periods on some anatomical, morphological and biochemical changings in maize (Zea mays L.) seedlings.

摘要

Flooding stress has many important morphological and biochemical effects on plants. Because of the importance of determination the effects of flooding on the plants and understanding of the tolerance mechanisms, in this research Four-days-old maize (Zea mays L.) seedlings (cv. single cross 704) were exposed to 4, 7 and 10 days flooding stress. At the end of each treatment the roots and shoots of the seedlings were harvested separately. To show the some anatomical, morphological and biochemical changings of the flooding on plants, cross sections of the roots and shoots were studied with light microscope. There was no clear changing in the tissue structures' of leaves and stems of different treatments in comparison with controls, but in the roots of plants aerenchyma had been developed under stress condition especially in the mesocotyl region. The roots of flooded plants grow towards the soil surface despite positive geotropism of control roots. The chlorophyll a and b content and the ratio of chlorophylls a/b have been decreased but the amounts of soluble sugars have been increased in both the roots and shoots of seedlings. We conclude that flooding influences plants growth and life and development of the aerenchyma and vegetative roots help to plants to adapt itself to stress condition. So it is very important to know which plants are sensitive or tolerant and what are the tolerance mechanisms in the different plants to succeed in agricultural efforts.