【作者】 国艳梅；

【导师】 于广健； 顾兴芳；

【作者基本信息】 东北农业大学 ， 蔬菜学， 2003， 硕士

【摘要】 黄瓜是世界各国的主要蔬菜作物之一，而我国是世界上黄瓜种植面积最大的国家。近年来，随着国内保护地黄瓜的大面积推广利用，黄瓜苦味的问题愈来愈突出，因苦果不能食用常造成极大的经济损失。因此，选育无苦味黄瓜，对于改善黄瓜品质，提高经济效益具有重要意义。深入了解苦味性状的遗传规律，获得遗传模式信息，对于指导育种工作将具有很重要的现实意义。而分子标记辅助育种（MAS）通过找到与苦味基因紧密连锁的分子标记可在苗期鉴定，简工节本，大大缩短育种进程。本论文以三种不同苦味类型（营养部分与果实都苦BiBiBtBt，营养部分苦BiBibtbt和营养部分与果实都不苦bibibtbt）的纯合自交系为试材，通过对F₁、F₂代表现型分离比例分析得到苦味基因的遗传规律。用亲缘关系较远的黄瓜自交系新泰密刺（国内保护地主栽品种，含苦味基因Bi）和38（荷兰温室黄瓜血统，含bi基因）作为亲本，配制F₁，自交获得F₂代群体为材料，采用先进的AFLP技术，筛选与苦味基因紧密连锁的AFLP分子标记。主要结果如下： 1．当Bt不在遗传背景出现时，Bi／bi在F₂代表现为简单的3:1分离比例，不受Bt基因的影响。但当Bibi为杂合状态，不但营养部分是苦的，果实也是苦的。F₁代的果实和营养部分都是苦的，F₂代营养苦：果实与营养都苦：不苦分离比例为1:2:1。 2．当bi不在遗传背景中出现时，Bt／bt在F₂代表现为简单的3:1分离比例。F₁代果实与营养部分都是苦的，F₂代果实和营养部分均苦与只是营养苦的分离比为3:1，表明Bt基因是独立遗传的。 3．当bi、Bt均在遗传背景中出现，遗传分离比例较复杂，bi对Bt存在隐性上位作用。F₁代果实与营养均苦，F₂代果实与营养均苦与只是营养苦与都不苦的分离比例为11:1:4。 4．用BSA方法通过AFLP技术对控制营养部分的苦味基因Bi／bi进行引物筛选，通过对192对选择性扩增引物的筛选，找到了两个有效引物，分别是：E-AT+M-CTC（简称E4M6）和E-TA+M-CTA（简称E5M5）。其中E4M6引物组合筛选的多态带型是：在分子量标准240bp处，苦味池有较明显的条带，不苦味池只有较浅的条带，且条带位置略偏下。E5M5的多态带型是在分子量标准140bp左右，不苦味池有明显条带，而苦味池在此处无带。计算得出E4M6与苦味基因Bi之间的遗传距离为15.0cM，E5M5与bi之间的遗传距离为18.8cM。更多还原

【Abstract】 Cucumber is one of the main vegetable in the world. We have the largest cucumber planting area. In the recent years the problem of bitterness of cucumber fruits has become more and more serious in dependent territory which caused economic losses. Therefore it is of significant importance to study the inheritance mode about bitterness. Molecular markers are considered to be one of the most useful tools to assist in the selection of nonbitter plant during the period of seedling and then shortening breeding process. One aim of this research is to ascertain the genetic regulation of bi and Bt and their interaction by studying three F2 population of three inbred lines(the genotype is BiBiBtBt,BiEJibtbt and bibibtbt respectively). Another aim is to find AFLP markers linked to the bitter gene using a F2 population. The main results are as follows:l.Bi/bi segregation ratio is 3:1 that abstained by tasting the vegetative and fruit was 1 vegetative bitter :2 vegetative and fruit bitter:! nonbitter when the bt gene was not segregating in the F2 progeny.When the genotype is Bibi,not only the vegetative is bitter but also the fruit is bitter.2.The Bt/bt was inherited as a single gene when bi was not segregating in the cross. The genetic information was also abstained by tasting F2 population. The F2 progeny segregation frequency fit a ratio of 3 vegetative:! nonbitter fruit.3.The genetic segregation is comprehensive when bi and Bt gene were in the same genetic background. The interaction mode is epistatic that has not been reported previously.The two genes was inherited in a ratio 11:1:4.4.Two AFLP markers were identified to be linked with the bitter gene and nonbitter gene by screening 192 pair of primers. The genetic distance with the bitter gene was 15.0cM and with the nonbitter gene was 18.8cM respectively.Graduate: Guo Yanmei Major: Olericulture Supervisor: Prof.Yu Guangjian更多还原