Effect Of Different Day And Night Temperature On Tomato Endogenous Hormones, Nutrient And Growth In Flowering Stage

Taking tomato variety of Jinguan 5 as material, the study design DIF treatment on tomato growth in flowering stage, and set 3 daily mean temperature (18℃,25℃ and 32 ℃) and 3 DIFs (0℃,6℃ and 12℃), to research the dynamic changes of endogenous hormones, soluble sugar and free amino acids contents, dry matter accumulation and growth indexes systematically, then study and compare the response of these indexes to DIF. The results can provide theoretical basis for optimal temperature regulation in facility tomato production. The main research contents are as follows:At the daily mean temperature of 18℃ and 25 ℃, IAA and ZT content reach highest at 6℃ DIF; GA3 content reach highest at 12℃ DEF. At the daily mean temperature of 32℃, IAA and ZT content reach highest at 6℃ DIF; GA3 content was not remarkable difference among the treatments.In flowering stage, tomato soluble sugar and free amino acids content changed regularly with the shift of the growth center. Carbon metabolism and nitrogen metabolism were in a mutual coordinated condition. Total soluble sugar and free amino acids content nearly showed the same changes, reach highest at 12℃ DIF at the daily mean temperature of 18℃; reach highest at 6℃ DIF at the daily mean temperature of 25℃. Total soluble sugar content reach highest at 6℃ DIF and total free amino acids content reach highest at 12℃ DIF at the daily mean temperature of 32℃. In separate organ, soluble sugar and free amino acids content showed difference.Growth and hysiological activities of tomato requires different suitable temperature. Tomato root absorption area, plant height and stem diameter reach highest at 6℃ DIF. Root activity reach highest at 0℃ DIF. Leaf area showed difference among the treatments.Through comprehensive compare of all DIF treatment,21℃/15℃ treatment promoted the highest endogenous hormones which hastening growth, accumulated the highest dry matter and was best for growth of leaf, stem and root.28℃/22℃ treatment promoted the highest soluble sugar and free amino acids content in organs. The study suggested that in suitable temperature range, appropriate rise of DIF was benefit for plant growth, while beyond the suitable temperature range, a over large DIF can quite inhibit growth, and reduced nutrient synthesis and accumulation.