不同钾肥用量对“重阳红”桃果实挥发性物质的影响

Effects of Different Potassium Fertilizer Rates on Volatiles of “Chongyanghong” Peach Fruit

为探讨钾肥对桃果实挥发性物质的影响,对陕西主栽"重阳红"桃采用放射沟施肥法进行不同用量的钾肥处理,不施钾肥的为对照,采用固相微萃取-气相色谱-质谱联用技术测定了其挥发性物质成分和含量。4种处理桃果实中共检测出82种挥发性成分,主要由醛类、酯类、醇类、烯烃类和酮类等物质构成,其中共包含了12种特征香气物质且它们的相对含量从低到高的顺序为K3(0.93 kg/株)<K2(0.70 kg/株)<对照(0)<K1(0.47 kg/株)。此外,施钾肥提高了桃果实中醛类、烃类和酮类物质的相对含量,降低了醇类和酯类物质的相对含量。不同钾肥用量之间对桃果实的香气影响不同,施0.47 kg钾肥果实的"果香型"香气物质的相对含量最高,其中对香气含量贡献最大的为顺-3-乙酸己酯;而施0.70 kg钾肥果实的"青香型"香气的相对含量最高,但果香味相对最淡;同时,施0.47 kg和0.93 kg钾肥桃果实中均存在"花香型"香气成分,因而香气成分表现更为丰富。因此,施0.47 kg钾肥可以使桃果实的果香味浓厚且香气物质丰富。

Radial furrow fertilization method was used to investigate the effect of different potassium fertilizer rates on volatiles of ＂Chongyanghong＂ peach fruit as a major cultivar grown in Shaanxi province using peaches without potassium fertilization as the control. Solid phase microextraction-gas chromatography-mass spectrometry（SPME-GC-MS） was used to determine the composition and contents of volatile aroma components. A total of 82 volatiles were detected in the control（CK） and three treatment（K1, K2 and K3） groupds, mainly including aldehydes, esters, alcohols hydrocarbons and ketiones. Meanwhile 12 characteristic aroma components were identified and the order of their relative contents in four groups was as follows： K3 K2 CK K1. In addition, compared with control, the potassium fertilizer increased the contents of aldehydes, hydrocarbons and ketiones, but decreased the contents of alcohols and esters. Different volatiles were detected among different potassium fertilizer rates, the content of fruity aroma compounds in fruits from the application of 0.47 kg of potassium fertilizer was the highest,（Z）-3-hexyl acetate making the largest contribution to the aroma. The content of green aroma compounds in 0.70 kg potassium fertilizer fruits was the highest, but with light fruity. Flowery aroma components existed in peach fruits grown in the soils fertilized with 0.47 kg and 0.93 kg of potassium, respectively, thus having a richer aroma. Therefore, applying 0.47 kg of potassium fertilizer can make peach fruity aroma richer.