Growth redundancy of winter wheat root system in irrigated arid area
干旱灌区冬小麦根系的生长冗余

By the method of root hand-removal,a tube experiment was conducted to study the morphological characteristics of root system and the relationships between root system and aboveground part of two winter wheat varieties collected from Hexi irrigated area of Gansu Province.The results indicated that at earlier growth stage,the growth of the wheat varieties with their roots partly removed was inhibited to a certain extent.Compared with CK,the root/shoot ratio and other root indices of root-removed wheat were decreased,and more decrement was observed with the roots more removed.At latter growth stage,the overcompensation effect of root system occurred.For the varieties with their roots removed,the spike length,spike mass,grain number per spike,and grain mass on the main stem and tillers were bigger than CK,and the removal of 1/4 roots had more advantages to main stem,while 1/2 roots removal was more beneficial to tillers.It was considered that under adequate irrigation,at least 1/4 of winter wheat roots could be redundant.