外源亚精胺对盐碱胁迫下番茄果实品质及挥发性成分的影响

本实验以"金棚朝冠"番茄为试材,研究外源喷施0.25 mmol/L亚精胺(spermidine,Spd)对75 mmol/L复合盐碱溶液(Na Cl、Na_2SO_4、NaHCO_3、Na_2CO_3浓度比为1∶9∶9∶1,pH 8.6)胁迫下番茄果实产量、品质的影响,利用顶空固相微萃取-气相色谱-质谱联用技术测定番茄果实挥发性物质成分和相对含量。实验分4个组:正常营养液浇灌+0 mmol/L Spd(CK组);正常营养液浇灌+0.25 mmol/L Spd(CS组);75 mmol/L复合盐碱溶液+0 mmol/L Spd(S组);75 mmol/L复合盐碱溶液+0.25 mmol/L Spd(SS组)。结果表明:盐碱胁迫条件下,喷施Spd可以显著提高番茄果实中VC、可溶性糖和番茄红素含量(P0.05),降低果实中有机酸和硝酸盐含量(P0.05),提高果实品质;同时显著提高了番茄的单株产量与单果质量(P0.05),保证番茄的高产。盐碱胁迫减少了果实挥发性物质数量和特征芳香物质的相对含量,喷施Spd缓解了胁迫对挥发性物质的相对含量和数量的影响。因此,盐碱胁迫条件下,喷施Spd可以提高番茄果实品质、增强果香、增加产量、降低不利因素对番茄果实品质和产量的影响。

Effects of Exogenous Spermidine on Tomato Fruit Quality and Volatile Compounds under Salinity-alkalinity Stress

The study was designed to investigate the effects of spraying exogenous spermidine (0.25 mmol/L) on fruit yield, quality and volatile compounds in tomato cultivar Jinpengchaoguan. Plants were exposed to 75 mmol/L salinity-alkalinity stress c(NaCl):c(Na2SO4):c(NaHCO3):c(Na2CO3) = 1:9:9:1. Four treatments were performed: 0 mmol/L salinity-alkalinity plus 0 mmol/L Spd (CK), 0 mmol/L salinity-alkalinity plus 0.25 mmol/L Spd (CS), 75 mmol/L salinity-alkalinity plus 0 mmol/L Spd (S), and 75 mmol/L salinity-alkalinity plus 0.25 mmol/L Spd (SS). The results showed that applying 0.25 mmol/L Spd (SS) significantly improved fruit VC (P < 0.05), soluble sugar and lycopene contents and yields (P < 0.05). Under salinity-alkalinity stress the organic acid and nitrate contents were reduced significantly (P < 0.05). Headspace solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) was used to analyze the volatile substances of tomato fruits in different treatments. Our results illustrated that salinity-alkalinity stress could decrease the total number of volatile substances and the relative contents of characteristic aroma compounds, and this effect could be mitigated by spraying Spd. Therefore, spraying Spd can reduce the adverse effects caused by salinity-alkalinity stress, resulting in improved fruit quality and aroma, and increased fruit yield.