【作者】 常源升；

【导师】 许雪峰； 韩振海； 张新忠；

【作者基本信息】 中国农业大学 ， 果树学， 2014， 博士

【摘要】 苹果果形与果实大小是苹果外观品质的重要指标之一,本试验以红玉×金冠杂交F1为试材,连续调查2008年和2009年果实纵径、横径和单果重的表型数据,对F1代果实纵径、横径进行遗传分析,并和单果重,果形指数进行相关性分析,随后用SSR和SNP图谱对果实纵径,横径,单果重,果形指数做了QTL分析,对遗传效应大的QTL区段预测了可能的候选基因。果实单果重、果实横径、果实纵径在2008年和2009年两年表型数据的次数分布图均呈单峰的正态分布,表明这三个性状是微效多基因控制的数量性状。果实纵径在2008年和2009年的广义遗传力分别为：91.1%和81.9%,果实横径在2008年和2009年的广义遗传力分别为93.2%和85.3%,说明2009年比2008年的环境效应大。将2008年和2009年共有的单株的果形和单果重数据做相关相分析,两年结果都表明,果实纵径和果实横径正相关(r>0.75)；果形指数与果实横径负相关(r-0.19；r=-0.17),与果实纵径正相关(r=0.48；r=0.42),且相关系数的绝对值纵径要比横径大,说明果形指数主要由果实纵径决定；果实大小与果实横径(r=0.87；r=0.89)、纵径均呈显著正相关(r=0.76；r=0.78),果实横径与果实大小的相关系数要比纵径与果实大小的相关系数大,表明果实大小主要取决于果实横径；果实大小与果形指数不相关(r=-0.033；r=-0.084)。分别用SSR(242个SSR标记)图谱和SNP(3476个SNP标记)图谱对2008年和2009年两年连续数据QTL分析,采用区间作图,SSR图谱在全基因组阈值LOD≥2.8下,果实大小、果实纵径、果实横径、果形指数共检测到19个QTLs,在SNP图谱全基因组阈值LOD≥3.5下,检测到16个QTLs。在单条染色体阈值条件下,SSR图谱中果实大小与果实纵径连锁的QTL有4个,与果实横径连锁的QTL有6个；果形指数与果实纵径连锁的QTL有2个,与果实横径连锁的QTL有1个。在全基因组阈值条件下SNP标记图谱中果实大小与横径重合QTL有1个；果形指数与果实纵径重合的QTL有1个；果实大小与果形指数不存在相关的QTLs。果实大小与果形指数不存在相关性,同时QTL也没有检测到二者重合或连锁的QTL,说明果实大小与果形指数属于不同的遗传基因控制。对遗传效应较大的QTLs(LOD>3.50)进行基因预测,最终得到与果实横径和单果重相关的基因3个,位于LG3上；果实纵径基因2个,位于LG7上；果形指数基因14个,位于LG11上。更多还原

【Abstract】 Fruit size and shape are important external quality traits in commercial crops, in this study, The progeny of cross between the apple cultivars ’Jonathan’ and ’Golden Delicious’ were used to analyse the inheritance of fruit length and diameter, correlation of fruit size, shape, length and diameter in two successive years.. We also dected the QTLs for fuit size, length, diameter, shape index by a SSR and SNP linkage maps, then the candidate genes predicted according to the QTL interval.Fruit size, length, diameter are followed a normal distribution in2008and2009, indicated they are controlled by polygenes without major gene segregation.The broad-sense heritability of fruit length and diameter were estimated as91%and93%, respectively in2008; and as82%and85%in2009. These values indicated that fruit length and diameter were easily affected by environmental in2009.Fruit length and diameter were significantly correlated in both2008and2009(r>0.75). FSI was positively correlated with fruit length (r=0.48; r=0.42), and negatively correlated with fruit diameter (r=-0.19; r=-0.17). The absolute values of correlation coefficients between FSI and fruit length were larger than those between FSI and fruit diameter, suggesting that length was a more pronounced trait than diameter. Both length (r=0.76; r=0.78) and diameter (r=0.87; r=0.89) were positively correlated with fruit size, though the correlation was stronger for diameter, indicating that fruit size (weight) was more a function of diameter than of length. No significant correlation was detected between FSI and fruit size (r=-0.033; r=-0.084).By the SSR linkage map19QTLs for fruit size, shape, length, and diameter were identified at the whole-genome level based on a LOD threshold≥2.80in both sampling years and16QTLs detected by SNPs linkage maps at the LOD≥3.50.In SSRs linkage map,4QTLs and6QTLs for fruit size were overlapped or closely associated with QTLs for fruit length and diameter, respectively,2QTLs and1QTL for fruit shape index were linked the QTLs for fruit size and diameter. Meanwhile, by SNPs linkage map, there are1QTL for fruit size coincided with the QTL for fruit diameter and1QTL for fruit shape index tightly linked the QTL for fruit length.No significant correlation was detected between FSI and fruit size and none of the QTLs for fruit size mapped to the same region as QTLs for fruit shape, implying that fruit size and shape are under independent genetic control.We predicted the interval genes for QTLs which dectected at the LOD≥3.50by the SNPs linkage map and3candidate genes (located on LG3) for fruit diameter and size,2genes (located on LG7) for fruit length, and14genes (on LG11) for fruit shape index obtained which may be controlled the trait.更多还原