| dc.description.abstract | Leaf early senescence caused by nutrition deficiency is one of the major limitation reasons in the
world crop production. Potassium (K) is one of important nutrient elements in crop growth, which
modifies dozens of enzyme activations and controls stomatal movement of photosynthesis. The
yield and quality of maize (Zea Mays L.) have been limited due to K deficiency in plough layer soil.
However, the mechanism of K deficiency tolerance is not fully understood in maize. In this study,
two inbred lines, 099 (tolerance to potassium deficiency) and 835 (sensitive to potassium deficiency)
were carried out to investigate the variations of chlorophyll content, photosynthetic and
chlorophyll fluorescence parameters related with senescence under different K+ concentrations in
maize at seedling stage. The results showed that the Chlorophyll a, b and (a + b) of 835 were significantly
decreased under different K deficiency treatments, whereas those of 099 were remained
normal. In addition, 099 showed a lower stomatal restriction and higher electronic transition capacity
under different K deficiency treatments. The variations of F0, Fv/Fm, ΦPSⅡ, qP and NPQ in 835
were largely higher than those in 099. These results indicated that the inbred line 099 tolerance to
K deficiency could keep chlorophyll content to maintain photosynthesis and to alleviate the injury
of PSII under K deficiency condition. This study should contribute to explaining the physiological
mechanism tolerance nutrition deficiency and improving breeding program in maize. | en_US |
