苹果砧木根系发育对高pH胁迫的响应及其内源激素调控机理

西北黄土高原地区是我国苹果生产的最大产区和最佳产区，但是，土壤pH值偏高并不断加重已经成为该产区除干旱之外影响苹果园肥料利用率进而影响果实产量和品质的另一重要因素，因此，急需开展苹果根际高pH胁迫相关研究，尤其是根系的响应及其调控机制。本研究以具有无融合生殖特性且耐碱性不同的苹果砧木为试材，进行根际高pH胁迫，研究苹果砧木在根际高pH胁迫下根系形态结构、根毛发育、根尖显微结构及其细胞衰亡等方面的变化，以及根系内源激素的时空分布，揭示苹果砧木根系生长发育对根际高pH胁迫的响应及内源激素调控根系发育的机理，这对苹果抗逆砧木育种、苗木繁育和优质高产栽培具有重要意义，有利于促进我国北方苹果产区果业持续发展，同时也将丰富苹果抗逆生物学理论。

The Northwest Loess Plateau is the largest and the best area of apple production, however, the pH value of soil is rising gradually. High pH of soil has become another important factor except for drought which affected the utilization rate of fertilizer and the fruit yield and quality of apple garden in this region. Therefore, it is urgent to carry out some research on high pH stress of apple, especially on the responses of root and the regulation mechanism. So, different apple rootstocks with apomixis ability and different tolerance to alkali will be used as materials exposed to high pH stress of rhizosphere. The root morphological structure, root hair development, root microscopic structure and its cell decay of apple rootstocks under high pH stress will be studied,together with the temporal and spatial distribution of endogenous hormones. The aim is to reveal the responses of root growth and development to high pH stress and the regulation mechanism of endogenous hormones for root growth and development. This study will be very important to resistant breeding of apple rootstock, seedling propagation and cultivation for high yield and high quality of apple, and be conducive to promote the sustainable development of apple industry of north China. The results will also enrich the anti-biological theory of apple.