| By using the substrate cultivation methods,we analyzed the effect of the composition of nutrient solutions and supply amounts on the growth,photosynthesis index,yield,fruit quality,sugar content,and related enzymes activities of tomato and pumpkin.This can provide scientific basis and theoretical guidance for the production of farmers to achieve the purpose of suitable nutrient solutions and supply amounts so as to obtain the high quality and yield of tomato and pumpkin.The main achievements are as follows:1 Effect of the composition of nutrient solutions and supply amounts on yield and fruit quality of highly sugary tomato with coconut coir substrate.(1)Different treatments of nutrient solutions and supply amounts had a significant influence on the different growth stages and overground parts of tomato,such as plant height,stem diameter,net photosynthetic rate,stomatal conductance and intercellular CO2 mole fraction promoted with the increase of supply amount.Net photosynthetic rate reached the peak value with the A3B1 treatment,while leaf water potential reached the strongest with the A2B3 treatment.(2)Both the composition of nutrient solutions and supply amounts had a significant influence on,fruit quality and yield of tomato.For the case of single nutrient solution,vitamin C and soluble sugar descended with supply amount increasing.The soluble solid reach peak in the treatment of A1B2。(3)The sugar content of tomato was directly related with enzymes activities.Under the condition of different nutrient solutions and supply amounts,A positive correlation was found between sucrose、starch and neutral invertase activity(NI).The correlation coefficients were 0.496 and 0.610,respectively(p<0.05).A positive correlation was found between glucose and sucrose synthase activity(SS).However,there was a significant negative correlation between starch and SS.The correlation coefficients was-0.663(p<0.05).A significant negative correlation between fructose and sucrose phosphate synthase(SPS)(p<0.05)while there were no significant correlation between four kinds of sugar and AI.Based the above,indicating that the accumulation and metabolism of sugar in the tomato fruit were controlled by the NI and SPS activities mainly.Therefore,the combined action of NI and SS was the key factor affecting sugar accumulation in tomato fruit.(4)In conclusion,Yield reach the peak in the treatment of A1B2,i.e.,supply amount(A1)was 250mL,300mL in the growth and flowering period respectively.Otherwise A1B2 was the best option for improving fruit quality of tomato,i.e.,supply amount(A2)was 200mL,300mL in the growth and flowering period respectively was the best option for fruit quality.2 Effect of the composition of nutrient solutions and supply amounts on yield and fruit quality of pumpkin with coconut husk substrate.(1)Both the composition of nutrient solutions and supply amounts have influence on the plant height and stem diameter of pumpkin.The plant height reached the largest in the treatment of A3B3,which increased by 12.64%compared with A1B2 treatment.Furthermore,the stem diameter of pumpkin with A3 treatment was significantly higher than in others treatment.Net photosynthetic rate showed as:A3>A2>A1.(2)The root activity and the ratio value of free with bound water were the highest with A3B2 treatment,which increased by 57.22%.Furthermore,the growth activity and plant metabolizing was also better with A3B3 treatment.(3)The yield in amount with A2B3 treatment was the highest at 20.2 kg.hm-2,which increased by 38.12%compared with A2B1 treatment.The content of vitamin C and soluble solid in the A2B1 treatment was highest,which is benefit for the quality.Furthermore,A2B1 treatment can improve the appearance quality.(4)In conclusion,A2B3 treatment is a reasonable nutrient solution and supply amounts,i.e.,the amount of 500 ml per plant everyday in seeding stage,the amount of 1000 ml per plant everyday after the blooming stage,and the supply amount B2 in the whole life period. |
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