Nutrient deficiency affects root architecture of young seedlings of Malus hupehensis (Pamp) Rehd. under artificial medium cultivation

Chinese. 试图建立营养与根构型变化的模型，塑造苹果理想根构型，提高果树营养利用效率和进一步探讨营养元素在根构型构建过程中的作用机理。采用滤纸培养系统研究了营养元素缺乏对湖北海棠[Malus hupehensis（Pamp.）Rehd.]根构型的影响。湖北海棠实生幼苗根构型可分为8种类型。完全营养液中培养的植株根构型以“侧根集中分布在主根中上部”类型为主，生长介质分别缺磷、钾和钙时，植株根构型均以“侧根集中分布在主根上部”的类型为主，而“侧根集中分布在主根中上部”根构型减少；但缺磷时，根构型呈现“侧根集中分布在主根两端”的植株比例增加，“侧根集中分布在主根中部”的类型减少，根构型类型呈现多样化；缺钾时，“无侧根”植株比例增加，“侧根集中分布在主根中部”类型减少，并且“无侧根”、“侧根集中分布在主根上部”和“侧根集中分布在主根中上部”3种根构型的植株占97.9%，根构型类型简单。分别缺铁、镁和锌时，虽然植株根构型均以“侧根集中分布在主根中上部”类型为主，但拥有“侧根在主根上均匀分布”根构型的植株增加。缺氮介质中生长的植株根构型以“侧根在主根上均匀分布”类型为主，根构型类型呈现多样化。营养元素缺乏与湖北海棠幼苗根构型的改变有很大的关联，湖北海棠因缺乏不同营养而形成相应各异的根构型类型。

English. The project aimed to establish models between root architecture (RA) changes and the nutrition, mold ideal root architectures of apple trees. It also intended to improve the nutrient uptake efficiency and to further explore the functional mechanism of nutrient elements during the course of RA construction。The cultivation system of filter paper was used to research nutrient deficiency on RA of Malus hupehensis(Pamp.) Rehd. Researchers found there may be 8 types of RA. In a complete Hogland solution, the main type of RA is “lateral roots gathering upper and middle of primary root”. With the lack of P, K or Ca, the main type of RA is “lateral roots gathering upper primary root”, and the “lateral roots gathering upper and middle of primary root” of RA decreases. But when short of P, the “lateral roots gathering upper and lower of the primary root” increases, and the type of “lateral roots gathering on the middle of primary root” decreases, with the types of RA diversified, Under K-deficiency, the type of “no lateral root” increases and “lateral roots gathering on the middle of primary root” types decrease, and the percentage of “no lateral root”, “lateral roots gathering upper primary root” and “lateral roots gathering upper and middle of primary root” types accounts for 97.9% in all, with the types of RA simplified. Lacking Fe, Mg or Zn, the main type of RA is “lateral roots gathering upper and middle of primary root”, but the “lateral roots evenly-distributed on primary root” increases; the main type of RA is “lateral roots evenly-distributed on primary root” under the condition of N-deficiency, and the types of RA turn out to be diversified. There is a close relationship between nutrient deficiency and RA changes. Owing to various forms of nutrient deficiency, correspondingly different types of RA have been produced.