穗上多叶玉米自交系LY-1的遗传特性研究

利用外引玉米杂交种通过多年连续自交获得1份穗上叶片数为7～10片的自交系LY-1。研究该材料穗上叶片数的遗传特性,分别将其与3个不同穗上叶片数材料L583、LS-1和昌7-2不同遗传背景的自交系杂交,获得3个衍生的后代分离群体。通过穗上叶片数、株高、穗位高和穗高系数的分析,结果表明,F_1的穗上叶片数介于双亲之间,偏高亲值,没有明显杂种优势,表现出不完全显性遗传特性。株高、穗位高以及穗高系数均表现超高值亲本,具有极强的杂种优势。相关分析结果表明,穗上叶片数与穗高系数呈极显著的负相关,株高与穗上叶片数、穗位高以及穗位高与穗高系数均呈极显著正相关。从各性状的遗传力来看,3个群体株高和穗位高的平均遗传力较高,均在75%以上;其次是穗高系数;穗上叶片数的遗传力仅为62.43%。因此,利用LY-1作为多叶资源进行种质改良和新品种选育,可降低穗位相对高度,提高植株的抗倒伏能力。

Study on Genetic Characteristic of an Inbred Line LY-1 with Multiple Leaves above Ear in Maize

An inbred line LY-1 with 7-10 leaves above the ear was developed from an introduced maize hybrid by continuous selfing. In order to study the genetic characteristic of the number of leaves above ear, the line LY-1 as the male was respectively crossed with three different inbred lines L583, LS-1 and Chang7-2 as the females to obtain their progenies and segregation populations. Four traits with leaves above the ear, plant height, ear height and the coefficient of ear height were analyzed. The results showed that the number of leaves above ear in F1 was between the corresponding parents and close to the high parents, and has no obvious heterosis. It appeared incomplete dominant inheritance for the number of leaves above ear, but the plant height, ear height and coefficient of ear height in F1 were higher than those of the high parents and existed extremely strong heterosis. The analysis of correlation illustrated that significantly negative relations existed between the number of leaves above ear and coefficient of ear height, but the relations between plant height and the number of leaves above ear, and ear height, between ear height and coefficient of ear height, are highly positive. According to the heritability of each trait, the average heritability of plant height and ear height were higher with over 75%, the following was the coefficient of ear height, but the heritability for the number of leaves above ear was the lowest with only 62.43%. Therefore, leafy inbred lines LY-1 could be used as a resource with multiple leaves above ear to improve germplasms and develop new varieties, and enhance the lodging resistance of plants by reducing the relative ear height in maize.