[Effects of nutrient solution supply amount on yield, quality and volatile matter of tomato]

We examined the effects of different amounts of nutrient solution supply on the yield, quality and volatile substances of tomato fruit by substrate cultivation. Using tomato cultivar 'HL2109' as experimental material, four treatments were set, including Control: irrigating with 117 L pure water for each plant; T₁: irrigating each plant with 39.0 L of nutrient solution; T₂: irrigating each plant with 58.5 L of nutrient solution; T₃: irrigating each plant with 117 L of nutrient solution. The quality and volatile substances of tomato fruits were determined by using chemical method and SPME-GC-MS technique. The results showed that the yield per plant and the gross production increased and then decreased with the increases of nutrient solution supply. The yield of T₂ was the highest among all treatments. The yields of T₁, T₂ and T₃ were 29.3%, 72.6% and 47.0% higher than that in Control, respectively. The irrigation water use efficiency of T₁ was the highest and T₂ took second place, though the difference being not significant. The soluble solids content and sugar acid ratio of tomato fruits in T₂ were the highest, and the flavor and quality were significantly improved. The content of ascorbic acid and soluble protein gradually increased with the increases of nutrient solution supply. The contents of total soluble sugar and reducing sugar were first increased and then decreased, both being highest in T₂. Using GC-MS analysis, a total of 69 volatile compounds were detected. The total content of volatile compounds from T₁, T₂ and T₃ were higher than that in Control, which presented as T₂﹥T₁﹥T₃﹥CK. Among them, the content of volatile compounds from T₂ was 6971 μg·kg^-1, which was 1.97 times higher than that in the Control. The content from T₃ was 4070 μg·kg^-1, being 0.73 times of that in the Control. The contents of 1-Pentene-3-one, 6-Methyl-5-hepten-2-one, hexanal, hexanoic acid, Phenylacetaldehyde and cis-3-hexenal were highest in T₂ among all treatments. Moreover, the content of characteristic volatile compounds, the quantity and total content of volatile compounds were highest in T₂. Taken together, the T₂ treatment (irrigating each plant with 58.5 L of nutrient solution) had the best effects, with the quality and content of volatile compounds in tomato fruit being improved.