At tillering stage, spraying GA solution to the dwarf mutant could promote the elongation of the first and the second internode, but no significant effect on the length of the third internode.

The variation extent of internode length is the Maximum in population, while that of spikelet number is the minimum.

But after the abortion, the development of ZS97A pollen was impaired and the elongation rate decreased, leading to panicle enclosure by shortening the uppermost internode (UI) length.