Analysis and Identification of Apple Rootstock SH Series by Simple Sequence Repeat Difference of Organic Acid Exudation from Roots of SH40 and Balenghaitangunder Iron-deficiency Stress Water use of apple trees on three rootstocks measured with heat pulse technique PRELIMINARY STUDY ON THE RESISTANCE MECHANISM OF APPLE ROOTSTOCK TO A STUBBY ROOT NEMATODE Differences of growth and root absorption of different apple rootstock seedlings in replant stress Difference of Organic Acid Exudation from Roots of SH40 and Balenghaitangunder Iron-deficiency Stress Growth and Physiological Characteristics of Apple Rootstock Seedlings under Hypoxia Stress Isolation and Expression of MdNCED1 Gene from Apple Rootstock SH40 Evaluation of zinc deficiency tolerance in different kinds of apple rootstocks. Analysis and Identification of Apple Rootstock SH Series by Simple Sequence Repeat