Genetic Analysis For Plant Height Of A Semi-dwarf Mutant And Mapping Of Eui Gene In Rice

Plant height is one of the important agronomic traits in rice. According to the plant height, rice may be divided into two types-tall rice and dwarf rice. Common tall rice has an unimportant value in rice breeding and production because of lodging. While recessive tall rice regarded as the fourth element in hybrid rice production has an important value in practical use. So far, there are 10 recessive tall mutants reported, and the plant height is mainly controlled by eui1 or eui2 gene. Compared to tall rice, dwarf rice has higher lodging resistance and a greater harvest index, allowing for application of more nitrogen fertilizer. Thus so far, a great deal of studies have been made on the dwarf trait of rice, and over 70 dwarf genes named 'd' and semi-dwarf genes named 'sd' have been reported. But the semi-dwarf gene mainly used in production is the sd-1 gene. As the same dwarf gene used widely, there exist a risk of genetic singleness. So it is highly important to find and identify new dwarf genes.02428h derived from a semi-dwarf material 02428 in somatic cell culture was a recessive tall mutant. 02428ha derived from a recessive tall mutant 02428h was a semi-dwarf and late maturing mutant with eui gene. In this paper, the characters and genetic model of plant height of the semi-dwarf mutant were analysed. Allelism tests had been done between 02428ha and several rice cultivars with semi-dwarf gene. The mapping eui and preliminary screening of candidate gene also had been done. The main results were as follows:The plant height of 02428ha was about 113.9 cm, and its all internodes length and panicle length were shorter than them of 02428h But the reduction of the 1st internode in reverse order was the main cause that made the plant height of 02428ha predominantly shorter than that of 02428h. Owing to the reduction of flag leaf sheath length, the panicle-neck length of 02428ha was longer than that of 02428. Genetic model of plant height of 02428ha was studied using the hybrid progenies by crossing 02428ha with 02428h and 02428. The plant height of F₁ progenies by crossing 02428ha with 02428h was similar to that of high value parent 02428h. 02428ha had the panicle-neck elongated as 02428h did. The plant height and panicle-neck length of F₁ progenies on crossing 02428ha...