关键词: 施氮量, 复合沙培番茄, 氮代谢酶活性, 果实品质, 产量, 综合评价

Abstract: In order to explore the optimal nitrogen application amount and its physiological functions on promoting high yield and high quality of composite sand cultured tomatoes, tomato variety of ‘Maofen 812’ was used as the experimental material, five nitrogen application treatments with 0 (N0), 143 (N1), 285 (N2), 428 (N3) and 571(N4) kg·hm-2  were set up. The effects of different nitrogen application treatments on the activities of nitrate reductase (NR) and glutamine synthase (GS) in tomato leaves, as well the fruit quality and yield of tomato were analyzed. The results showed that appropriate amount of nitrogen fertilizer was helpful to increase the activities of nitrogen metabolism enzymes in tomato leaves, thus improve fruit quality and yield. Compared with N0 treatment, the NR and GS activities of N3 treatment were increased by 42.79% and 182.93%, respectively. The vitamin C content, soluble protein content, soluble sugar content, soluble solids content and yield of N3 were increased by 70.90%, 6667%, 25.00%, 27.25% and 58.38% than those of N0 treatment, respectively. Principal component analysis, membership function method and comprehensive evaluation showed that the comprehensive ranking of different treatments was N3 > N4 > N2 > N1 > N0. Therefore, 428 kg·hm-2 was recommended as the fertilization standard for the cultivation of compound sand-cultured tomatoes, which provided theoretical basis for nitrogen fertilizer management of compound sand culture tomato.

Key words: nitrogen application rate, compound sand culture tomato, nitrogen metabolism enzyme activity, fruit quality, yield, comprehensive evaluation