BIOCHEMICAL EVALUATION FOR WEAK-LIGHT TOLERANCE OF VARIOUS TOMATO (SOLANUM LYCOPERSICUM L.) CULTIVARS IN CHINA

Enhancement in vegetable cultivation technologies remarkably popularized the construction and use of energy-saving sunlight greenhouses. Ten tomato cultivars in Central Plain of China were used as experimental materials. The effects of weak light stress (50% of normal light density) on the activities of SOD, POD and CAT were determined. Its effect on chlorophyll contents, soluble sugar, soluble protein, proline, and MDA were detected. Dry matter accumulation, fruit setting rate, average fruit weight/fruit and average yield per plant were also measured to observe their changes due to weak light stress. Correlation analysis and main factor analysis were conducted on the coefficients for weak light tolerance of all individual indices using DPS software. The D value of weak light tolerance of cultivar "Xinfen No. 8 '' (cultivar 5) was maximum, and that of "Jinguan No. 5 '' (cultivar 7) was minimum. Tomato cultivar "Xinfen No. 8" exhibited the strongest weak-light tolerance, whereas cultivar "Jinguan No. 5 '' (cultivar 7) showed the weakest weak-light tolerance. This research provides necessary reference for tomato breeding under weak light conditions.