番茄黄化基因Netted Viresce(NV)的遗传定位及生理特性研究

Physiological Characteristics and Genetic Mapping of Tomato Yellow Leaf Gene Netted Viresce(NV)

以玛娜佩尔为受体亲本,以野生番茄潘那利LA0716为供体亲本,通过多代回交构建近等基因系。对近等基因系中黄化突变(nv)植株和野生型植株的表型性状和主要农艺性状进行分析,并测定叶绿素含量、净光合速率等;利用透射显微镜观察叶绿体超微结构。以回交系BC6为母本与nv植株进行回交,同时BC_6植株进行自交,观察并统计BC_7及BC_6S_1群体植株的表型,分析遗传规律;利用BC_7S_1分离群体进行基因精细定位,结合高通量基因组重测序,筛选仅在黄化突变位点目的区域内的SNP位点,并结合基因注释分析候选基因。结果表明:与正常植株相比,黄化植株表现植株矮小、叶片窄小、叶色黄化,叶片的叶绿素含量、净光合速率显著降低,气孔导度、胞间CO_2浓度、蒸腾速率显著升高。叶绿体超微结构观察显示,黄化植株叶绿体数目减少,类囊体的基粒片层和基质片层未完全分化,垛叠不整齐。遗传分析表明,玛娜佩尔黄化性状受1对隐性核基因控制;利用CAPS和In Del分子标记将NV基因定位于9号染色体标记In D-09-4-1和HP63/64之间,物理距离为51 Mb。玛娜佩尔基因组重测序数据可利用率高,数据比对分析得到7个与光合作用相关的基因。

Near-isogenic lines derived by back-crossing were developed by using‘Manapal’as the recipientparent and wild-type tomato‘Spennelllii LA0716’as a donor parent.Ten‘Manapal’plants and10wild type(WT)NIL plants were selected to analyze their main agronomic traits,and measure chlorophyll content andphotosynthetic characteristics.The ultra-structure of chloroplast was observed with transmission microscope.The segregation ratios of the seedlings with normal and yellow leaves in BC7and BC6S1populations were calculatedand used for genetic analysis of nv.The BC7S1population was used for fine mapping of nv.The SNPs within theregion of nv were identified by the alignment re-sequencing result of‘Manapal’and wild type tomato materials.Compared to WT plant,nv plant height was lower,nv leaves were narrower,its leaf color is yellowing.Thecontent of chlorophyll,net photosynthetic rate were remarkably reduced.Stomatal conductance,inter-cellularCO2concentration and transpiration rate significantly went up in nv plants.In addition,the number of chloroplastsof nv plants was reduced.The grana lamellae and stroma lamellae of thylakoid stacking were not fully differentiatedand irregularly arranged.These results suggested that the yellow leaf trait was controlled by a single recessive gene.The gene NV was mapped in a51Mb region on chromosome9,between InDel makers09-4-1and HP63/64.Seven genes related to photosynthesis were identified in this region.