Study On Classification, Uptake-characteristics And Regulation Of Root Architecture In Apple Stock

The classification of root architecture (RA) of apple stock, and the effect of nutrient elements, soil-texture types, plant growth regulator and container types on root architecture and its uptake characteristics with seedling and perennial Malus hupehensis(Pamp) Rehd taken as materials have been studied in this article, by using the combined methods of paper-culture, water-culture, sand-culture and soil-culture in pot. The results are as the follows:1. The root architecture types of young apple tree may be classified 5, namely"RA of more shallow branch"(MSBRA),"RA of less lateral root and far explortion for nutrition"(LFERA),"RA of branches evenly distributed"(BEDRA),"RA of nutrient layer split"(NLSRA) and"RA of linear and thin lateral roots and round primary root"(LTRRA). The root system may also be classified"root groups", as the"branch groups"of the above ground part. The root groups of the young apple tree may be classified 8, namely"Hair root group and high uptake","Thin and short root group", Thin and long root group","Middle-thick and short root group","Middle-thick and long root group","Thick and short root group","Thick and long root group"and"Big root group", and its types and structures are an important factor to decide the types of root architecture.There may be 8 types of RA in young seedling of Malus hupehensis (Pamp) Rehd, namely"No lateral root"type,"Lateral roots gathering upper primary root"type,"Lateral roots gathering upper and middle of primary root"type,"Lateral roots gathering on the middle of primary root"type,"Lateral roots gathering lower primary root"type,"Lateral roots gathering on middle and lower of primary root"type,"Lateral roots gathering upper and lower of the primary root"type and"Lateral roots evenly-distributed on primary root"type.2. The root activity of the"no lateral root"RA type is lowest, that of the"lateral roots evenly-distributed on primary root"type is highest. The Imax value of P-uptake of the type of RA"lateral roots gathering upper of primary root"is highest; the Km value of P-uptake of the type of RA"lateral roots gathering upper and middle of primary root"is highest; the Km value of P-uptake of type of RA"lateral roots evenly-distributed on primary root"is lowest.In the young tree of M. hupehensis (Pamp) Rehd., the root activityies of the RA types ranged from the highest to lowest are the"RA of less lateral root and far explortion for nutrition"(LFERA), the"RA of more shallow branch"(MSBRA) and the"RA of root system nutrient layer split"(NLSRA). The nutrient uptake rates of P, Ca, Fe and Zn in soil of different...