【作者】 谢宗周；

【导师】 邓秀新；

【作者基本信息】 华中农业大学 ， 果树学， 2008， 硕士

【摘要】 柑橘存在很多自然变异,其中部分芽变材料和嵌合体资源可直接应用于新品种选育。本研究对田间自然产生的两个柑橘新材料进行了品质检测,并采用形态学和SSR、AFLP及SSAP等标记技术对两者的来源及与相近品种的差异进行了遗传鉴定,结果显示两者均为柑橘新种质,都可能直接作为新的优良品种资源应用于生产实践。其中,广西的‘鹿寨蜜橙’为甜橙芽变,遗传性状稳定;而江西赣南的脐橙/温州蜜柑嫁接疑似嵌合体发生在以温州蜜柑为中间砧以枳为基砧的高改脐橙园中,果实外观似脐橙,果肉色泽则与温州蜜柑类似。1.‘鹿寨蜜橙’成熟果实风味浓,可固含量高达15%,可滴定酸含量低于0.5%,其中,果糖(63.03mg/g)、蔗糖(43.49mg/g)、葡萄糖(72.19mg/g)含量均高于其相近品种冰糖橙,柠檬酸、奎宁酸、苹果酸含量也高于后者。形态学观察表明,其叶形指数、气孔密度、气孔纵径与冰糖橙的差异显著,叶形比冰糖橙更接近椭圆,气孔密度更高,花药和胚囊发育正常。SSAP标记显示,‘鹿寨蜜橙’与冰糖橙相比存在1个多态性位点。表明‘鹿寨蜜橙’是不同于冰糖橙的芽变新种质,可以直接作为品种资源加以利用。2.本研究收集到的柑橘嫁接嵌合体为华盛顿脐橙(Citrus sinensis Osbeck cv.Washington)与温州蜜柑(C.unshiu)的嵌合体。形态学,细胞学,生理生化和分子标记等分析表明,嵌合体中由L1层细胞决定的性状,如汁囊、气孔长度等都与温州蜜柑相似,而由L2层细胞决定的性状如花粉形态、育性和种子数量则与华盛顿脐橙相似。高效液相色谱(HPLC)分析果肉所含的类胡萝卜素组成成分,结果表明嵌合体和温州蜜柑的果肉具有相同的类胡萝卜素种类,主要类胡萝卜素均为β—隐黄质(β-cryptoxanthin)。SSR和cpSSR分析表明:该嵌合体的核基因组和叶绿体基因组分别同时具有华盛顿脐橙和温州蜜柑所有的带形。综合以上结果,推断它是由华盛顿脐橙和温州蜜柑构成的周缘嵌合体,其L1层来源于温州蜜柑,L2/L3层来源于华盛顿脐橙;该嫁接嵌合体分别具备了各自亲本的优良性状,有可能成为新的鲜食品种。更多还原

【Abstract】 Spontaneous mutation often occurs in Citrus orchards,Some bud mutation and chimera can be directly used for breeding.Here we analyzed the quality of two field bud sports and identified their genetic background and differences to related cultivars by morphological observation and molecular marker,such as SSR(Simple sequence repeat),AFLP(Amplified fragment length polymorphism) and SSAP(Sequence-specific amplification polymorphism).The results indicated both were new germplasms and could be applied to the industry as elite cultivars.’Luzhai’ sweet orange(Citrus sinensis),a bud mutant of sweet orange found in Guangxi,has stable genetic traits;a putative chimera of navel orange(Citrus sinensis)/Satsuma mandarin(Citrus unshiu),found in top-worked navel orange orchard(using Poncitrus trifoliate as the rootstock and Satsuma mandarin as inter rootstock),has fruits with appearance resembling ’Washington’ navel orange and the pulp color similar to Satsuma mandarin.Main results are as followed:1.The flavor of ’Luzhai’ sweet orange mature fruit is of rich flavor.The content of TSS is about 15%,however,that of TA is lower than 0.5%.Besides the higher content of fructose,sucrose,and glucose than those of ’Bingtang’ sweet orange at 63.03 mg/g,43.49 mg/g and 72.17 mg/g respectively,the content of quinic acid,malic acid and citric acid are also much higher than those of ’Bingtang’ sweet orange.There oxists significant difference in the phylliform index,the stoma density and stomatal longitudinal diameter between ’Luzhai’ sweet orange and ’Bingtang’ sweet orange,but was not in the transverse diameter.In morphology,the phylliform of ’Luzhai’ sweet orange is almost elliptical, with higher stoma density and different stoma size,the anther and megaspore are normally developed as well.SSAP analysis indicated that polymorphism locus existed between ’Luzhai’ and ’Bingtang’ sweet orange.2.A graft chimera was discovered which originated from the top work of ’Washington’ navel orange(Citrus sinensis) scion onto Satsuma mandarin(Citrus unshiu). The graft chimeras and their donors were investigated in morphology,cytology, biochemistry as well as by molecular markers.Some characters of the chimera,such as juice sacs,stoma length,which were determined by L1 cell layer,were similar to those of Satsuma mandarin,while other characteristics determined by L2 cell layer resembled ’Washington’,including pollen morphology and fertility and seeds number.The extract from the fruit pulp of chimera and their donors was studied using HPLC.The results indicated that the mature fruit of the chimera had the same carotenoids profile as Satsuma mandarin,in whichβ-cryptoxanthin accumulated predominantly in the juice sacs.SSR and cpSSR analysis suggested that both nuclear and chloroplast genomes of the chimera were composed of its donor plants respectively.Based on the results above,we concluded that the chimera was a periclinal chimera consisting of L1 derived from Satsuma mandarin and L2/L3 from ’Washington’ navel orange.It combined the valuable traits of its donor plants and could be used as a commercial cultivar for the fresh market of citrus industry.更多还原