| Abstract: | Two mutants possessing elongated uppermost internode, Xieqingzao eB-1 (XQZeB-1) and Xieqingzao eB-2 (XQZeB-2), were identified from M 2 population of Xieqingzao B-line (XQZB) treated with γ-ray. The proportion of uppermost internode length to entire culm length of XQZeB-2 and XQZeB-1 were 65.3%and 54.8%, respectively. Compared with the original XQZB, the increased length of uppermost internode of XQZeB-2 contributed to the total increased culm length by 90.2% as well as XQZeB-1 by 53.3%. Genetic analysis showed that the characters of elongated uppermost internode in the two mutants were governed by one pair of recessive gene respectively. The recessive gene of XQZeB-1 is allelic to the reported eui , but that of XQZeB-2 is non-allelic to it by allelic test. Therefore, the elongated-uppermost-internode gene of XQZeB-2 is a new gene, designated as eui2. Microsatellite markers RM258, RM269, RM271 and RM304, which were linked with eui2 and located on chromosome 10, were identified. The genetic distances from the four markers to eui2 were 12.0 cM, 12.9 cM, 35.1 cM, 1.4 cM, respectively. It could be concluded that eui2 gene was located on the middle of the long arm of chromosome 10. |
