Mapping Of Lfy Gene Controlling Leafy Trait In Maize

Lacking of germplasm resources was the leading problem of the maize breeding in our country, we should unceasingly supply the new germplasm and expand to make use of the germplasm , for this we can keep maize breeding and production leap a new stair in our country. In this research leafy maize material is a new-type of germplasm derived from U.S.A with a high photosynthesis efficiency. Leafy maize had 8 to 25 leaves above the ear, and better stalk strength much taller than non-leafy maize and more flourishing root, their stalk was stalwart, their resistance was strong . For leafy maize had more than 20 leaves above the ear, it had characteristic which the ordinary maize did not have. In order to uses well this idioplasm resources, it is necessary to study heredity of leafy trait.F2 separation population generated from inbred line Y53 (16L) crossed Y53 (4L) was used in this study. The number in brackets represented the leaf number above the ear. This study aimed at the fine-mapping of Lfy gene which controls the maize leaf number above the ear. Based on the primary analysis results of Lfy gene, we selected SSR markers near the target gene for mapping and linkage analysis of Lfy gene. The results were described in detail as following.1. Analysis of leaf number above the ear in F2 population. The result indicated that the leafy trait was the quantitative characteristic. The leafy trait was controlled by major genes and minor genes, it was not by the simple gene, also was not together by the completely equivalent minor genes.2. SSR primer selection. According to the primary mapping results of Lfy gene, this study selected ten pairs of SSR markers near the target gene for fine mapping. Totally, there were five pairs of SSR primers, that was umc1363, umc1071, umc2012, umc1977 and umc2224 showing polymorphism between two parent lines.3. Linkage analysis of SSR markers and Lfy gene. Marker umc1071 was linked with marker umc1363, the genetic distance was 19.2 cM. Marker umc1363 was linked with marker umc2012, the genetic distance was 16.8 cM. Marker umc1977 was linked with marker umc2224, the genetic distance was 18.8 cM. The genetic distance between markers umc2012 and umc1977 was 16.2 cM. Markers umc1363 and umc2012 were close linked with Lfy gene, the genetic distance was 4.0cM and 12.8cM, respectively.4. Based on the synteny of maize and rice, SSR marker umc1363 was located in AC14426 region in chr 3 of rice. There were some QTLs related to rice leaf development in this region. It may be safely concluded that Lfy gene plays an important role in leaf number above the ear and plant height in maize. Moreover, Lfy gene may regulate the leaf development process, including leaf senescence, among others.