[The discovery and genetic analysis of dwarf mutation 99CDAM in Brassica napus L].

ABSTRACT

The plant height of rapeseed varieties has increased more than 20 cm due to wide application of heterosis, which leads to high risk of lodging at late stages of rapeseed development. Using dwarf genes to decrease plant height is an effective approach to resolve the lodging problem. A dwarf mutation 99CDAM with plant height of about 85 cm was discovered from a Brassica napus line which had selfed for many years. The mutation 99CDAM has good characters of early flowering and rich branches, as well as better yield and quality traits, which can be stably inherited, so 99CDAM has important value in Brassica napus breeding. Genetic analysis on reciprocal crosses between 99CDAM with high-stalk lines 2091, 7045 and 7350, and the F2BC1 and F23 populations derived from the cross between 2091 with 99CDAM indicated that the genetic model of dwarf genes in 99CDAM was obviously different from what had been reported before. The mutation 99CDAM was controlled by three pairs of recessive dwarf genes and showed a maternal effect..