Branching And Anatomical Structure Of Wheat Seedlings Root System

Root anatomical structure has a great impact on his function of soil nutrient and water acquisition, and it changes with age of root segment. Thus when the anatomical structure and function of different roots are studied, the comparison should be made between root segments of same age. In order to find the morphological mark of root age, root morphology, emergences of lateral roots, formation of root primordia, and anatomical structure were studied in wheat seedlings of winter wheat (Triticum aestivum L., var NongDa 189) cultured on sand in culture room. Formation of root primordia was observed with olefin section made and anatomical structure was analyzed on section. Influence of phosphorus deficiency on root anatomical structure was also studied.The results showed that formation of both lateral roots and their primordia required a given thermal time; the root axis of same age (expressed as thermal time accumulation) had same lateral root number, this indicated that number of lateral root may be used as morphological mark of age of the mother root axis. The diameter of later xylem vessel of the seminal root and first pair of primary roots were greater than these of second and third pairs. There was a linear relationship between diameter of root and these of later xylem vessel. Under P deficient conditions, the formation of lateral root prmordia took more thermal time; the thermal time for the formation of lateral root primordia was significantly less than other root axis. And the root dry matter, root/shoot rate and main axis elongation rate also be influenced. Root system anatomy structure changes have not been found in this study.