【作者】 何敏；

【导师】 黄玉碧；

【作者基本信息】 四川农业大学 ， 种子科学与技术， 2009， 硕士

【摘要】 玉米是三大粮食作物之一。近年来,我国玉米产量和种植面积都已超过小麦,是重要的粮食、饲料、化工原料来源。长期以来,骨干自交系在玉米新品种培育中发挥至关重要的作用,但骨干自交系选育和确立需要很长时间。为加快玉米育种进程,缩短育种时间,研究玉米骨干自交系形成机理,建立玉米骨干自交系早期检测体系具有重要意义。玉米叶片衰老和氮转运受编码玉米半胱氨酸蛋白酶基因See2控制,其中See2b基因对氮素的转运能力随着叶片的衰老而增强,在玉米叶片衰老过程中对氮利用起关键作用。本研究在我国玉米骨干自交系及其衍生系系谱分析基础上,以四大玉米骨干自交系(黄早四、Mol7、丹340、掖478)及其衍生系和西南地区第四轮骨干自交系18-599、08-641、21-ES共52份材料为研究对象,克隆并测定玉米See2b基因全长DNA序列,通过See2b基因的序列比对,研究其各家系中该基因突变类型及突变规律,结合叶宽、叶长、总叶片数、叶面积、成熟时保绿叶片数等重要农艺性状,进行聚类分析,为研究各家系重要基因和性状的传递规律,建立玉米骨干自交系的早期检测体系提供理论依据。主要研究结果概括如下:1.Mol7及其衍生系See2b基因的突变类型。农大178与南23232有相同的突变规律,系14与412突变规律一致,但却与其它自交系的序列突变规律不同,这可能由于在选育时有另一亲本如许053等遗传物质的渗入所致。合344突变最少,与玉米See2b基因遗传组成较其他衍生系更近。除此以外的Mol7衍生系材料的该基因具有相似的突变规律。2.黄早四及其衍生系See2b基因的突变类型。在对黄早四及其衍生系和Mol7及其衍生系的See2b基因序列比对发现,黄早四衍生系的突变类型和变异位点明显少于Mol7衍生系。推测黄早四衍生系该基因比Mol7衍生系中遗传更稳定。黄早四衍生系外显子突变主要集中在第2、第9外显子处。在第9外显子中,黄早四衍生系除K12、8723、齐401、吉856、昌7-2、文青1331、多27、⑦61外,其余21份材料与掖478、21-ES、关17均在275bp到298bp处缺失22bp序列,序列为TAGGTGAAGCAGACTTATACCA,这是一种未见报道的玉米See2b基因突变类型。由此推测这22bp碱基缺失可能会引起See2b基因突变。3.西南地区第四轮骨干自交系21-ES、08-641、18-599三者之间突变类型基本一致,且农艺水平也表明三者同被划分在一个类群。研究表明,西南地区三个骨干自交系与掖478、Mol7及其衍生系有更多的相同突变规律,其中,18-599、08-641、与掖478,Mol7及其衍生系遗传关系最近,21-ES与黄早四及其衍生系在第9外显子有相同突变。4.对农艺性状聚类发现,Mol7类群按照三个类群划分,18-599、08-641、21-ES、南23232、农大178与Mol7被划分第Ⅰ类群,系14与412被划分在第Ⅱ类群,这与前面依据分子标记建立的进化树结果基本一致,旅大红骨代表丹340与塘四平头代表黄早四都是国内主要骨干自交系,同划分在第Ⅲ类群。黄早四类群除K12与21-ES、08-641、18-599划分在第Ⅱ类群,黄野四、白野四划分在第Ⅲ类群,其余材料均与黄早四一起划分在第Ⅰ类群。更多还原

【Abstract】 Maize is one of the three good crops. Output and planting area of maize has surpassed those of wheat in recent years, making maize become important food, feed and sources of chemical raw materials. Ever since a long time ago, elite inbred lines played a key role in maize new species cultivation. However, much time is needed to breed of elite inbred lines, it is significant for accelerating breeding of maize, cutting time of breeding and studying on formation mechanism of maize elite inbred lines to create detection for maize elite inbred lines. Leaf senescence and nitrogen transport in maize are controlled by See2 gene coding cysteine protease. Nitrogen transport is enhanced along with leaf senescence controlled by homologous See2b gene, It is considered that See2b gene played a key role in nitrogen utilization in the process of leaf senescence in maize.In my study, Maize inbred lines 18-599, 08-641, 21-ES from Sichuan Agricultural University, Dan 340 from Lu DHG groups, ye478 from Reid groups, Mo17 from Lancaster group with its derivative lines, huangzaosi from Tang SPT group with its derivative lines were, totally 52, collected as experimental materials. All the materials are conducted to divide Heterotic groups through molecular methods as well as studies of Agronomic traits. And results are summarised as follows:1. It is found that Mo17 with its derivative lines have rich SNPs,Nan23232 and nongda178 were divided into the same heterotic group because of same American blood, xi14 and 412 were divided into the same heterotic group because of another material xu053. There was little mutains in he344,which was the best sameness with See2b gene.2. It is found that indels of huangzaosi and its derivative lines were poorer than those of mo17 derivative lines by analyzing the sequences of See2b genes of the two derivative lines. Then we presume that Huang and its derivative lines were relatively stable genetic. It is found that huangzaosi derivative lines except kl2, 8723, qi401, wenqingl331, duo27 and⑦61 had a same 22bp deletion segment in the nineth exon with ye478, 21-ES and guan17. And this mutation type of see2b gene had not been reported. Therefor, we could presume that the 22bp deletion segment in the ninth exon may lead to changes of see2b gene functions of maize.3. Same mutation laws is showed between 18-599,21-ES, 08-641, ye478, jie1037, and jie842, which is indicated that 21-ES and 08-641 are close to the materials which have the American Blood, while 18-599 and dan340 are divided into one group. So it is concluded that 18-599, 08-641 and 21-ES is closer to Mo17, ye478 and dan340 in blood than to huangzaosi.4. Dividing with Agronomic traits, we found that 18-599,21-ES, 08-641, nan23232, nongdal78 and Mol7 were divided in No.1 group.Xil4 and 412 were were divided in No.2 group,which are the same as those divided by SNPs in See2b gene. In huangzaisi and its derivative lines, 18-599,21-ES, 08-641 and K12 were divided in the same group,huangyesi and baiyesi were divided in the No.3 group,then others were in the same group.更多还原