【作者】 张鑫；

【导师】 张满让；

【作者基本信息】 西北农林科技大学 ， 农业推广硕士（专业学位）， 2019， 硕士

【摘要】 本试验以3年生‘烟富3号’高纺锤形和Y字形苹果幼树为材料,结合两种树形萌芽率、成花率、主干和主枝新梢长度、主干和主枝新梢粗度、主干和主枝新梢节间长度、主干短枝顶芽碳氮含量、主干短枝顶芽C/N、主干短枝顶芽内源激素含量及主干短枝顶芽内成花相关基因表达量的测定结果,对两种树形苹果幼树生长及成花的影响进行综合评价。本文还鉴定了5个苹果MCU基因,为进一步这研究这些MCU基因的功能奠定了基础。结果如下:1、高纺锤形苹果幼树长枝比例、主干新稍年生长量和主干新稍粗度显著高于Y字形,Y字形苹果幼树在主干的成花率和短枝比例显著高于高纺锤形。而两种树形主干和主枝上的萌芽率、主枝上的成花率、中枝比例、主枝新稍粗度、主枝新稍年生长量、主干新梢节间长度、主枝新梢节间长度无显著差异。整体上Y字形苹果幼树主干短枝顶芽C/N比高于高纺锤形。Y字形苹果树主干短枝顶芽内,ABA和ZT的含量在花后50d都高于高纺锤形,而在高纺锤形主干短枝顶芽内,GA₃和IAA的含量在花后50d和70d都显著高于Y字形。Y字形主干短枝顶芽内MdFT的表达量在花后50d比高纺锤形显著高46.47%。高纺锤形主干短枝顶芽内MdAP1表达量在花后70d明显低于Y字形。Y字形主干短枝顶芽内MdLFY的表达量在花后30d、50d和70d比高纺锤形高分别显著高出40.25%、20.10%和23.53%。在花后50d和90d,Y字形主干短枝顶芽内MdSOC1的表达量比高纺锤形分别显著高出33.33%和96.30%。本文初步探讨高纺锤形和Y字形苹果幼树的差异比较,认为Y字形苹果幼树较高纺锤形易形成结果短枝,为筛选易成花树形提供依据。然而,未能深入研究两种树形在大小年相关指标的差异,以及幼树生长环境对成花的作用。2、本研究还鉴定了苹果MCU基因家族候选成员。该家族有5个MdMCU基因,含有2-5个外显子,1-4个内含子,7个共同的保守基序,且聚为2个亚家族。五个基因均含有有关光响应和脱落酸诱导有关的顺式作用调控元件。另外,基于公开的基因表达数据表明,该家族成员在不同组织中均广泛表达。这些都为将来进一步研究MdMCUs基因的功能奠定了基础。更多还原

【Abstract】 In this study,3-year-old‘Yanfu 3’Y-shape（YS）and Tall spindle shape（TS）apple young trees（Malus?×?domestica Borkh）were used to evaluate various morphological and physiological related parameters.The germination rate,flowering rate,annual branch length,annual branch diameter,and annual branch internode length of the Y-shape（YS）and Tall spindle shape（TS）apple young trees were measured.Furthermore,the total carbon and nitrogen contents,C/N ratio,endogenous hormones content,and expression levels of flowering genes in spur buds on the main trunks were evaluated.Moreover,a comprehensive evaluation was designed to characterize the effects of tree shapes on the development and flowering of young apple trees.The findings of the present study would practically valuable for tree shape selection in apple production.We also identified five MdMCU genes,which laid the foundation for further study on the function of these genes.The main results of this study are divided into the following parts:1.The long branch ratio,new shoot diameter of main trunks,and new shoot annual growth of main trunks was significantly higher in TS apple trees as compared with YS apple trees.The YS apple trees exhibited relatively higher short shoot ratio and flowering rate on the main trunks compared with TS apple trees.We found no significant difference among the other indexes in the two studied apple tree.However,the C/N ratio in spur buds on the main trunks of YS apple was higher than TS apple trees.YS trees shared significantly higher ABA and ZT contents all in spur buds on main trunks than TS trees at 50 days after flowering.The content of GA₃ and IAA in spur buds on main trunks of TS apple trees,which were all significantly higher than YS apple trees at 50 and 70 days after flowering.In addition,the expression of MdFT in spur buds on the main trunks of YS apple trees was higher by 46.47%than TS apple trees at 50 DAF.The expression of MdAP1 in spur buds on the main trunks of TS trees was relatively lower than YS apple trees at 70d after flowering.Furthermore,we also noticed that the expression of MdLFY in spur buds on the main trunks of YS apple trees was significantly higher than TS apple trees at 30,50 and 70 DAF.The expression of MdSOC1 in spur buds on the main trunks of YS apple trees obvious higher than TS apple trees at 50 and 90 DAF.In this paper,the comparison of high spindle and YS apple young trees concluded that YS apple young trees exhibit early short branches characteristic as compared with spindle shape apple trees.This study provided a basis for screening the tree shape that forms flower buds easily.However,the exact differences between the two tree-shaped related parameters in ON-year and OFF-year,and the effect of the growth environment on young apple trees during flowering have not been investigated.2.We performed genome-wide identification,bioinformatics analysis,and gene expression profiling of MdMCU in apple.Five members of this gene family were identified and divided into two phylogenetic branches,The number of introns varied from 1 to 4 were found and seven motifs are commonly present in all MdMCUs.The upstream regions of MdMCUs all showed the presence of ABA responsive and light responsive cis-element.The results of tissue-specific expression analysis based on public data indicate that MdMCUs have wide expression profiles in various tissues.It would be laid the foundation for further functional studies of these MdMCU genes.更多还原