【作者】 张玉；

【导师】 柯永培；

【作者基本信息】 四川农业大学 ， 作物遗传育种， 2013， 硕士

【摘要】 玉米是我国重要的粮食作物,其产量的高低在国民经济中起着举足轻重的作用。控制玉米轴色性状的基因与产量性状相关联。因此,研究一个新的轴色突变体的遗传特性,明确其遗传方式对玉米育种应用具有重要意义。本研究以经辐射诱变获得的玉米红轴突变体698-3R为材料,比较分析了与原白轴自交系698-3的主要性状差异；通过遗传交配设计,对该突变体的轴色性状进行遗传鉴定,以期明确其遗传规律；并利用SSR-BSA法对控制轴色的基因进行了初步定位。主要研究结果如下：1.表型性状研究表明,突变体698-3R穗轴颖表现为红色,自交系698-3穗轴颖为白色。其他农艺性状方面,与自交系698-3相比,698-3R的叶夹角缩小,说明其株型更紧凑；雄穗主轴缩短,二级分枝数减少,雄穗总体变小,有利于籽粒产量的提高；穗长和百粒重显著减小,行粒数显著增加,秃尖长度显著变短,单株产量显著增加,与前人研究红色穗轴与玉米高产量有相关性的结果一致。2.遗传分析结果,所有正反交F1植株均表现为红轴,表明698-3R的红轴性状受细胞核的显性基因控制；经χ2检验,各正反交回交群体及F2分离群体的红轴株数和白轴株数的分离比例全部符合一对基因遗传的理论期望比例,表明该突变体的轴色性状受一对核基因控制,并且突变体698-3R红轴类型对白轴类型为显性遗传,将该基因暂定名为C(t)。3.通过SSR-BSA分析,将C(t)基因初步定位在第一染色体短臂上的SSR标记phi095与umc1452之间,与phi095相距3.9cM,与umc1452相距7.1cM。本研究所定位的控制698-3R穗轴红色素的C(t)基因与前人研究P1基因的SSR引物phi095相近,说明该基因与控制果皮色和轴色的主要基因P1之间存在紧密连锁。然而,该红轴突变基因C(t)与P1基因的同源性还有待于进一步研究。更多还原

【Abstract】 Maize is the most important crop in China; the yield has a significant influence to the national economy. The gene that controls the maize cob color was associated with the yield. Hence, it would be great significant to the maize breeding by researching the genetic characters of a new cob color mutant and knowing it’s inheritable mode. The major characters of698-3R, a mutant with red cob derived from inbred line698-3by irradiation, was comparatively analyzed to the original maize inbred line698-3with white cob color; The genetic identification of cob color mutant was carried out using genetic mating design, expect to clear on the inheritance; and the gene controlled cob color was mapped preliminary by SSR-BSA. The main results were as follows:1. Phenotypic character researches showed that, the cob glume of698-3R is red while inbred line698-3is white. On the other agronomic characters, compared with inbred line698-3,698-3R has smaller degree of leaf angle, indicate that is a compact plant type; and also698-3R have shorter spindle length, secondary branch number decrease, smaller tassel, that is beneficial to increase yield; ear length and100-kernel weight were significantly reduced, kernel numbers significantly increased, barren ear tip length significantly shorten, hence the yield increased significantly. The results are consistent with the previous research result that red cob color is associating with the high yield.2. The genetic analytic result showed that, all the F1plants of reciprocal crosses have red cob, indicated the red cob was controlled by nuclear dominance gene, the segregating ratio of red cob plants to white cob plants in the F2and backcross population with reciprocal crosses are correspond to the theory expect ratio of a single gene inherent, demonstrate the red cob trait of698-3R was governed by a single dominance gene, and it is temporary named as C (t).3. The C (t) gene is preliminary positioned between the SSR markers phi095and umc1452through the SSR-BSA analysis; it was located on the short arm of chromosomel. The gene C (t) is linked to phi095with genetic distance3.9cM, and umc1452with genetic distance7.1cM. The C (t) gene controlled red cob color of698-3R in this study is closed to the SSR primer phi095of P1gene, indicated that C (t) gene is closely linked to major P1gene which control pericarp color and cob color in previous research. However, the homology between this red cob mutant gene C (t) and P1gene needs further investigation.更多还原