Gibberellin biosynthesis inhibitors help control plant height for improving lodging resistance in E. Tef (Eragrostis tef)

Abstract

Eragrostis tef, a tall stature and highly nutritious cereal grown in East Africa, has a serious lodging problem that reduces its productivity considerably. Certain plant-growth regulators are known to restrict growth and consequently improve lodging resistance in cereals by affecting gibberellin biosynthesis. The effect on height of growth regulator chlormequat chloride (CCC) was determined for varieties Gea Lammie with a short phenotype and DZ-01-196 with a tall phenotype. Chlormequat chloride decreased plant height by 27% in Gea Lammie and by 46% in DZ-01-196. More detailed analysis of growth regulator application by including Paclobutrazol (PBZ) on the tall tef variety DZ-01-196 revealed that both CCC and PBZ reduced culm length, but had no effect on internode diameter. Chlormequat chloride at 100 mM especially reduced the length of the lowermost internodes. Treatment with CCC on the other hand did not increase panicle-bearing tillers, but grain yield in CCC-treated plants was comparable to non-treated control. The regulation of gibberellin biosynthesis could therefore be a key target for improving lodging resistance in Eragrostis tef.