High semi-lethal temperature and heat tolerance of tea chrysanthemum.

摘要

High semi-lethal temperature and heat tolerance of seedlings of four tea chrysanthemum cultivars from tissue culture and field, respectively, were investigated using electrical conductivity method. There was a sigmoid function between the rate of injured leaf cells and treatment temperature after the leaves had been treated by gradient high temperature from 25 to 70 degrees C with 5 degrees C interval. The logistic equation was used to determine the semi-lethal temperature LT₅₀ ( degrees C) for tea chrysanthemum cultivars to determine the inflexion point of the curve. The semi-lethal temperature of tea chrysanthemum seedlings cultivated in field was 57.39, 51.83, 55.67 and 57.00 degrees C for C. morifolium 'Hangbaiju', C. indicum var. aromaticum, C. morifolium 'Boju', and C. morifolium 'Gongju', respectively. The semi-lethal temperature of tea chrysanthemum seedlings of tissue culture was 47.83, 44.37, 46.09 and 47.57 degrees C for 'Hangbaiju', C. indicum var. aromaticum, 'Boju', and 'Gongju', respectively. The heat tolerance of four cultivars of tea chrysanthemum from tissue culture and field respectively was in the same descending order: 'Hangbaiju', 'Gongju', 'Boju', and C. indicum var. aromaticum. This research provides basis for introducing and obtaining the heat-tolerant somaclonal variations of tea chrysanthemum.