Effects Of External Copper On Grown And Metabolism Differences And Mechanism In Different Grafted Apple Trees

Frequent and long-term application of cupric fungicides (Bordeaux mixture) has contributed to accumulation of cu in orchards. The pot-planting experiment studied on the influence of the growth, metabolism of apple trees under different external copper levels. The field experiment studied on the character uptake and assimilation under field conditions by spraying Bordeaux mixture of different rate, CuSO4, Fe-EDTA etc..The aim is to provide evidence for selecting variety, amending soil and planting apple tree in Cu ammulated orchard.Researching results were as follows:The growth of new branches, chest diameter and biomass yields increased under low copper levels, but inhibited at higher levels.There is a difference in critical values, the highest ,in Matsumoto Nishiki, , is 251.79mg/kg/.Chlorophyll content and chlorophyll a, b content increase and then decrease with external copper levels.High chlorophyll content and chla/b in Matsumoto Nishiki shows that chlorophyll a is higher, chlorophyll is stable and feasible in constitutions.At high concentration external cu levels, the Carbohydrate content and NR decrease, O2- production rate and Cell electrolyte increase. But Matsumoto Nishiki have very high Carbohydrate, NR and Pro content and low O2- production rate, when new leaves in which cell electrolyte is high grows into old leaves ,the Cu toxicity can be released.At high concentration external cu levels, For Benishogon, CAT activity is improved at low concentration but inhibited at high concentration, and changes nonsynchronous and even inverse with POD activity.CAT/POD decreases apparently. With the increasing of external copper levels, the POD and CAT activity increase in synchronous,and CAT/POD is no obvious change basically.Moreover the total activity in Matsumoto Nishiki is most highest.So it has the ability to release O2- and H2O2 mostly. Ca and Fe can release the Cu toxicity on growth in different extent, decrease concentration of Cu in leaves and stems. Chla, Chla/b and carbohydrate content is increased obviously.Cell electrolyte and O2- production rate decrease. CAT/POD increases with a apparent extent, which can discompose high concentration O2- and H2O2.Spray CuSO4 on MaluspumilaMill.cv.TengmuNol and Benishogon can decrease Chlorophyll content and increase O2- production rate, but Fe can release these bad effects. Bordeaux mixture can improve Chlorophyll and active Cu and Ca content.But total Fe decreases slightly and active Fe is not affeted.Cu content increases with the external cu levels and is higher than control which shows that Ca can the toxicity affected by CuSO4.