钼酸铵对‘千玉6号’甜瓜果实营养品质和挥发性物质的影响

Effect of Ammonium Molybdate on Nutritional Quality and Volatile Substances of Muskmelon‘Qianyu No.6’

钼是植物生长发育和营养品质形成所需的重要微量元素之一,为实现甜瓜优质生产,采用袋式基质栽培方式,灌溉营养液中四水合钼酸铵设置0、0.02和0.04 mg/L共3个梯度(分别记为M0、M1和M2),利用化学方法和顶空固相微萃取-气相色谱-质谱联用技术测定成熟期果实营养品质和挥发性物质成分含量,以此探讨钼酸铵对‘千玉6号’薄皮甜瓜果实营养品质和挥发性物质的影响。结果表明,甜瓜果实可溶性蛋白质、可溶性固形物、硝酸盐和还原糖含量均随钼酸铵施用浓度增加而先升后降,游离氨基酸含量与其相反,可滴定酸和抗坏血酸含量则与钼酸铵浓度呈正相关。钼酸铵用量对甜瓜果实芳香成分及含量影响明显,0.04 mg/L钼酸铵处理果实检出的28种香气成分总含量为447.89μg/kg,香气种类和含量均低于其他处理,但其检出酯类物质占比达61.79%,高于其他处理;同时,0.04 mg/L处理特征香气物质种类最多,包含8种物质,分别为丁酸乙酯、2-甲基丁酸乙酯、2-甲基乙酸丁酯、乙酸己酯、1-辛烯-3-醇、(E,Z)-3,6-壬二烯-1-醇、(Z)-6-壬烯-1-醇和(Z)-6-壬烯醛,总相对含量高于其他处理,达49.26%。综上,施用0.04 mg/L四水合钼酸铵能够有效提高基质培薄皮甜瓜果实营养和风味品质,可作为甜瓜基质栽培优质生产钼肥施用浓度。

Molybdenum is one of the important trace elements for plant growth and formation of nutritional quality.To meethigh-quality production needs of melons,the matrix bag culture method was used to find the appropriate concentration of molybdenum fertilizer,the effect of ammonium molybdate tetrahydrate on the nutritional quality and volatile substances of melon fruit was discussed.The thin-skinned melon variety‘Qianyu No.6’was used as the material,three levels of ammonium molybdate tetrahydrate[(NH4)2MoO4·4H2O]at 0,0.02 and 0.04 mg/L were set.Chemical methods and headspace solid-phase microextraction-gas chromatography-mass spectrometry were used to determine the nutrient quality and volatile components.The results showed that thecontent of soluble protein,soluble solids,nitrate and reducing sugar in the fruits first increased and then decreased with the increase of the concentration of ammonium molybdate.On the contrary,the content of titratable acid and ascorbic acid was positively correlated with the concentration of ammonium molybdate;the amount of ammonium molybdate had great influence on the aroma components and content of melon fruit;under treatment of 0.04 mg/L ammonium molybdate,the total content of 28 aroma components detected in the fruits was 447.89μg/kg,and boththe detected aroma types and contents were lower than other treatments,but its detected esters accounted for 61.79%,which was higher than other treatments.At the same time,0.04 mg/L treatment had the most of the aroma substances,which included 8 substances,namely ethyl butyrate,ethyl 2-methyl butyrate,butyl 2-methyl acetate,hexyl acetate,1-octene-3-ol,(E,Z)-3,6-nonadien-1-ol,(Z)-6-nonen-1-ol and(Z)-6-nonenal,a total relative content was 49.26%,and it was higher than other treatments.In conclusion,the application of 0.04 mg/L ammonium molybdate tetrahydrate can effectively improve the nutrition and flavor quality of muskmelon fruit,and it can be used as the optimum concentration of molybdenum fertilizer for high-quality production of melon.