| In this study, 10 maize inbred lines with different capabilities in drought resistance were evaluated for yield, morphological and physiological characters, and their relationships to drought resistance under water-stressed. The relationships between these indicators and the super-weak bioluminescence of dry / germinated seeds in different inbred lines determined with single photon count method were analyzed. Phosphate and HaO assimilations under well-water and water-stress were examined with tracer 32P and 3H. The results were summarized following:1. The yields of all inbred lines were reduced to different extent upon the drought-resistant capabilities. The yields of drought-resistant lines were influenced less in comparing with that of the drought-susceptible inbred lines. Furthermore, the drought-resistant lines had larger drought-resistant coefficient than the drought-susceptiblelines.2. Under water-stress, the leaves of drought-resistant inbred lines remained fresh and straight, while the leaves of drought-susceptible inbred lines withered. At blooming stage, the inflorescence growth in maize was postponed under water-stress, and hence resulted in the increase of the interval between stamen and inflorescence (ASI). The drought-resistant inbred lines were affected less than the drought-susceptible lines. In addition, the root/top in maize seeding, the fresh /dry of weight of maize leaves, fresh weight of maize top significantly decreased in comparison with the control under water-stress, but the drought-resistant inbred lines declined less than the drought-susceptible inbred lines.3. Under water-stress, physiological characteristics were changed. These included damaged cell membrane systems, obvious increase of relative electricity conductance ratio, lowered photosynthesis rate, lessen relative water contents, and reduced water-holding capacity in the leaves of the lines. The drought-resistant inbred lines were influenced less than the drought-susceptible inbred lines. We also observed that the transpiration rate and somatal water conservancy significantly declined in both drought-resistant and drought-susceptible lines, however, these were more affected in the drought-resistant inbred lines.4. The super-weak bioluminescence of dry seeds of different maize genotype inbred lines was not significantly associated with drought resistance (P>0.05 ), but during germinationstage under the treatments of well-water and water-stress it was significantly different among the lines. Bioluminescence counts of all interested materials in the water-stressed treatment were lower than that in well-watered treatment during germination stage. Curve simulation of the bioluminescence in the drought-resistant lines indicated a significant fitness, while the simulation in the drought-susceptible lines had a large deviation value. The super-weak bioluminescence of germinating seeds of different maize genotype inbred lines after, well-watered or water-stressed 31h and 48h was significantly associated with drought resistance (P<0.05), Therefore, we suggest that the curve fitness of super-weak bioluminescence between well-water and water-stressed conditions during germination stage can be used as one of drought-resistance indices.5. Under water-stress, in comparison with the control, the assimilated 32P and 3H were declined significantly. The amounts of assimilated 32P and 3H were different among the lines with a trend of less decrease in the drought-resistant lines. The differences may be used as one of the indexes for identifying drought resistibility.From the above results, the indicators for identifying the maize drought resistance can be summarized as follows: the interval between stamen and inflorescence (ASI) at the bloomingstage, transpiration rate at the middle of growth stage, assimilations of P and H at the seedling stage(PEG induced) were the most indexes for evaluation of maize drought resistance; fresh /dry of weight of leaves, fresh weight of top, relative...
|
PDF Full Text Request