Effects Of High Temperature Stress On Growth And Development Of Salvia Splendens

Salvia splendens, also known as Pau Red, is attached to the Labiatae Salvia perennial herbs, often for annual cultivation. Its slender inflorescence, bright colors, long flowering, and strong adaptability make it become the most common cultivated herb flowers in our cities and landscapes.In order to understand the impact on growth and development of Salvia splendens under high temperature stress at different growth stages, various cultivars, including the own cultivar 'Shenzhou Hong' and imported varieties of 'Di Wang' and 'Huo Fenghuang', were employed to conduct series experiments: sowing periods experiment and high temperature stress test. Flowering and some morphological, physiological and biochemical trails were assayed.The main results were concluded as follows:(1)High temperature had less effect on the beginning of flowering, but greater impact on the flowering quality and survival rate at different growth stages. The flowering rate was increased with delaying the planting time when the sowing period was from April 10 to May 25.(2) The plant growth rate, flowering rate, survival rate and other Morphological parameters can be used as indicators for evaluating the heat-resistance of Salvia splendens, high temperature stress on the growth of a Salvia splendens is mainly reflected in the growth rate droping, the flowers survival rate poor, color change shallow, etc.; heat-resistance of the three tested varieties was arranged as 'Phoenix', 'Divine Red', 'Emperor'.(3) Changes of peroxidase (POD) activity in plant in a certain extent reflect the relative strength of heat resistance. Under high temperature stress, peroxidase (POD) activity increased, the changes of heat-resistant varieties are less than that of heat-sensitive varieties.(4) Under high temperature stress, catalase (CAT) activity decreased, heat-resistant varieties are less change than heat-sensitive varieties. But the strength of heat-resistance has little relationship between heat-resistant varieties.(5) Under high temperature stress, the relative content of chlorophyll decreased, the changes of heat-resistant varieties are greater than that of heat-sensitive varieties.(6) Under high temperature stress, the content of leaf proline increased significantly, the changes of heat-resistant varieties are less than that of heat-sensitive varieties.