Effects of Water Stress on the Growth and Chlorophyll Fluorescence Characteristics of Moringa oleifera Seedlings

PurposeThe effects of water stress on the main characters and photosynthetic parameters of Moringa oleifera seedlings were studied, and the relationship between water stress and photosynthesis and physiological indexes of M. oleifera was revealed, which provided a theoretical reference for cultivation management and resistance screening of M. oleifera.

MethodWe potted M. oleifera PKM1 under five different water content levels: optimal water content (TA), mild water stress (TB), moderate water stress (TC), severe water stress (TD), extremely severe water stress (TE), which were controlled by weighing the soil and pots.

Result(1) Under water stress, the plant height, stem diameter, leaf number, leaf dry weight, stem dry weight, root dry weight, leaf area, root water content, root length, root width and root thickness of M. oleifera seedlings decreased, the crown ratio increased. (2) Under water stress, the chlorophyll content of M. oleifera seedlings showed a decreasing trend; F_o is increasing, however, F_v, F_m, F_v/F_m, F_v/F_o, qP and rETRmax all were decreased.

ConclusionWe can conclude that moderate water stress is conducive to the growth of M. oleifera seedlings. Under the condition of drought stress, high photosynthetic capacity and root-shoot ratio of M. oleifera are the important physiological basis for drought resistance.