【作者】 程志强；

【导师】 刘志敏； 刘文革；

【作者基本信息】 湖南农业大学 ， 蔬菜学， 2008， 硕士

【摘要】 西瓜内富含人体内必需的次生代谢物质,如番茄红素（Lycopene）、L-瓜氨酸（L-citrulline）、维生素C（Vc）。本论文以二倍体、三倍体、四倍体西瓜品种为试材,对西瓜中瓜氨酸、番茄红素、Vc等功能性成分做了研究:西瓜果实中瓜氨酸的提取与测定;果实成熟过程中番茄红素、瓜氨酸、Vc含量的变化;不同瓤色西瓜品种中番茄红素、瓜氨酸、Vc的含量差异;不同倍性（同源四倍体、二倍体、三倍体）西瓜果实中番茄红素、瓜氨酸、Vc含量差异,为高番茄红素、高瓜氨酸、高Vc含量的西瓜品种选育与栽培奠定了一定的理论基础和实践指导。1.西瓜果实中L-瓜氨酸的测定方法探讨:本实验研究了西瓜果实及西瓜皮中L-瓜氨酸的提取工艺及分光光度测定方法。结果表明,当选用无水甲醇-6MHCL（v/v=9:1）为提取剂,瓜瓤或瓜皮与提取剂的比例为1:1:5,提取温度55℃,活性炭用量10g,提取时间20分钟时提取效率最高。根据L-瓜氨酸在强酸溶液中与二乙酰一肟的专一显色反应及反应复合物在490nm处吸光度与L-瓜氨酸浓度呈线形关系的特点,建立了一种准确、简便、灵敏的L-瓜氨酸的分光光度测定方法。2.西瓜果实发育过程中功能性成分的变化:本试验以2个西瓜品种的纯合二倍体及其人工诱导的同源四倍体、三倍体为材料,测定了不同倍性西瓜果实发育过程中番茄红素、瓜氨酸、Vc及相关因素pH、可溶性固形物含量的变化,为功能性西瓜育种和栽培提供理论依据。采用分光光度法测定番茄红素,二乙酰一肟分光光度法测定瓜氨酸,碘量法测定不同生长期番茄红素、瓜氨酸、Vc含量。结果表明:三个品种果实中番茄红素的含量随果实的生长发育有相同的变化趋势,授粉后15天的幼果番茄红素含量极低(0.2～0.6mg.100g^-1),授粉后的25～28天是番茄红素急剧增加的时期,完熟期番茄红素含量最高,过熟期番茄红素含量缓慢减少;瓜氨酸的含量随果实的生长发育有大致相同的变化趋势,授粉后15天的幼果瓜氨酸含量较低,授粉后的20～28天是瓜氨酸快速增加时期,31-34天瓜氨酸增加到达最大值,37-40天瓜氨酸进入缓慢下降期;Vc含量变化规律基本相同,幼果期、成熟期较高,果实膨大期较低,且呈“V”型变化曲线。3.不同倍性西瓜功能性成分的差异:以10个西瓜品种为试材,测定了其同源二倍体、三倍体、四倍体果实成熟期番茄红素、L-瓜氨酸、Vc含量的差异。结果表明:不同倍性西瓜中番茄红素、L-瓜氨酸、Vc含量的差异较大,其中XQ、M2、太谷花皮、郑三4个品种,其四倍体或三倍体中番茄红素的含量均是其二倍体的1.7倍以上;太谷花皮、02B4两个品种,其四倍体或三倍体中L-瓜氨酸的含量是其二倍体的1.65倍,M2四倍体中L-瓜氨酸的含量是其二倍体的1.85倍;02B4品种,其三倍体Vc的含量是二倍体的2.03倍;M2品种,其四倍体Vc的含量是二倍体Vc含量的1.49倍。8组材料中,三倍体或四倍体的Vc含量高于二倍体（P＜0.05）。4.不同瓤色功能性成分的差异:本试验以多个相同倍性不同瓤色的西瓜品种为试材,分别对二倍体、三倍体、四倍体不同果肉颜色的番茄红素、L-瓜氨酸、Vc含量的差异作了初步研究。结果表明,二倍体、三倍体品种中黄瓤果肉的L-瓜氨酸含量高于红瓤品种,四倍体品种中黄瓤果肉的L-瓜氨酸含量低于红瓤;二倍体品种中黄瓤果肉的Vc含量最高,其次是白瓤和红瓤,三倍体、四倍体黄瓤品种的Vc含量均高于红瓤品种;二倍体、三倍体、四倍体黄瓤品种的番茄红素的含量均低于红瓤品种;二倍体白瓤果肉中番茄红素含量为0。更多还原

【Abstract】 Watermelon is a natural and rich source of beneficial secondary plant substance for human.Such as Lycopene,L-citrulline,Vc.Many watermelon varieties include diploid, triploid and tetraploid were employed to study The lycopene,L-citrulline and Vc contents and its changes during watermelon fruits development.It served as a theoretical fundamental and guide of breeding and cultivating watermelon with high lycopene, L-citrulline and Vc contents.1 A discuss about the method of L-citrulline determining in watermelon friuts:In this study,the extracted technology and spectrophotometry determination of citrulline in watermelon were established.The results showed that the highest efficiency of citrulline could be extracted with MeOH:6MHCl（v/v=9:1）with active carbon 10g in a bath for 20 min,followed by heating at 55℃.1:1.5 radio of sample and extractor,,.According to the special color development reaction between L-Citrulline and Diacetyl monoxime in the strong acid solution and the linear relationshio feature which reactive compoud color varied with L-citrulline consistency.The precise,convenient and sensitive method of The pectrophotometry determination of citrulline was set up.2 The changes of functional ingredient in watermeon fruits development:A total of 2 watermelon（Citrullus vulgaris） cultivars（FANZU NO.2,XQ,M2） include 2x,3x,4x were selected.The lycopene,L-citrulline and Vc contents changes were determined during their fruits development.All changes curves of functional ingredients contentsof three ploidy cultivars were similar.The lycopene content were very low(0.2～0.6mg.100g^-1)after 15 days of artificial pollination The 25～28 days after artificial pollination was the period of lycopene sharp increasing and it was the highest in ripe period.The changes in overripe watermelon decreased slowly.The L-citrullline content were very low after 15 days of artificial pollination.The 20～28 days after artificial pollination was the period of sharp increasing and it would reach the peak value at 31～34 day after artificial pollination.It began to fall slowly after 37～40 days after artificial pollination.The Vc contents in young fruit and maturation in watermelon were higher.The lycopene、L-citrulline and Vc contents in 10 ripe fruits include diploid,triploid and tetraploid was determined.The results showed that The lycopene、L-citrulline and Vc contents contents were significant difference in different ploidy watermelon.The lycopene,L-citrulline and Vc contents in triploid or tetraploid were higher than in dipoidy in eight cultivars.It is significantly differenent（P＜0.05）.3 The difference of functional ingredient in different ploidy watermelon:A total of （Citrullus lanatus）Cultivars were selected.The lycopene,L-citrulline and Vc contents in 10 watermelon ripe fruits include diploid,triploid and tetraploid was determined.The results showed that The lycopene,L-citrulline and Vc contents were significant difference in different ploidy watermelon.The lycopene,L-citrulline contents in triploid or tetraploid were higher than in diploid in eight cultivars.The Vc contents in triploid or tetraploid were higher than in diploidin nine cultivars.It is significantly differenent（P＜0.05）.4 The difference of functional ingredient in different colour flesh:Many different colour flesh with same ploidy watermelon（Citrullus lanatus） cultivars were selected.The lycopene,L-citrulline and Vc contents of different colour flesh in ripe fruits of their diploid,triploid and tetraploid were determined.The results showed that The L-citrulline contents of yellow flesh was more than that of red flesh in diploid and triploid watermelon. The results in tetraploid is oppisite.The Vc contents of yellow flesh in diploid is the most, the second is white flesh and the third is red flesh.The Vc contents of yellow flesh were more than that of red flesh in triploid and tetraploid.The lycopene contents of yellow flesh were lower than that of red flesh in diploid triploid tetraploid.The Lycopene of white flesh in diploid is zero.更多还原