Effects of Different Rootstocks on Growth and Mineral Elements in Leaf of Grafted Pecan Seedlings

The seedlings of 'Pawnee', 'Stuart', 'Mahan' and 'Jinhua' were used as rootstocks to graft the scion of 'Pawnee'. The influence of rootstock types on the growth index and mineral element content of leaf of grafted pecan(Carya illinoinensis) seedlings through different rootstocks of grafting combinations were analyzed. The results showed that the survival rate of seedlings grafted on 'Pawnee' and 'Stuart' was more than 90%, and had the dominate position on growth indexes such as root diameter, scion height, scion diameter, leaf fresh weight, leaf area, leaf perimeter, and internode length; the comprehensive score was in order of 'Pawnee/Pawnee', 'Pawnee/Stuart', 'Pawnee/Mahan' and 'Pawnee/Jinhua'. From June to September, nitrogen content in leaf was the highest in 'Pawnee/Pawnee', which was 15.47 g/kg; 'Pawnee/Mahan' had the widest range of variations of phosphorus content, which decreased 13.78% in leaf; in terms of potassium content and C/N ratio, 'Pawnee/Jinhua' had the highest value which was 10.69 g/kg and 45.84 in leaf respectively. Nitrogen content in leaf expressed significantly positively correlated with scion height, scion diameter; potassium content and C/N ratio expressed significantly negatively correlated with scion height. It can be seen that the effects of different rootstocks on growth and mineral elements content of leaf of grafted pecan seedlings was obvious: the grafted seedling using the 'Pawnee' as rootstock had a great advantage in the grafted survival rate, affinity and growth potential, which showed the best growth; the seedlings grafted on 'Pawnee' and 'Stuart' with stronger growth potential had greater ability to accumulate the element nitrogen in leaf, but showed weaker level on element phosphorus, potassium and C/N ratio.