Abstract: In order to study the coordinated regulation mechanism of plant growth regulator on winter wheat root growth and yield formation under rain-fed condition, a field experiment was conducted to determine effects of different treatments (the mixture of uniconazole and chlormequat chloride and water control) on yield formation, population quantity and root growth of winter wheat under rain-fed condition in the North China Plain.These results suggested that plant growth regulator significantly increased spike number and grain yield, but had no marked effect on spikelet number per spike and kernel numbers per spike.Plant growth regulator could promote the tillering of winter wheat before winter and enhance population quantity in early growth stage.Under plant growth regulator treatment, winter wheat root length and root surface area per plant were decreased significantly, however, root diameter, root number, root weight and root/shoot ratio per plant were significantly increased.At tillering stage, plant growth regulator had effect on winter wheat root length density in 0-30 cm soil layer and root weight density in 0-50 cm soil layer but had no effect in the deep soil layer.Plant growth regulator could coordinated regulated root growth and tiller formation of winter wheat, which contributed to shape reasonable population structure and increase yield.

Key words: Winter wheat, Root, Yield, Tillering, Plant growth regulator

CLC Number: 

• S512.01