Pft2 , pft3 and pft4 respectively , were isolated from a fe - deficiency root cdna expression library of malus xiaojinensis by screening library for three times using fe ( ii ) - transporter of maize as a probe , then two representative clones ( ptfl and ptf2 ) were sequenced 主要结果如下： 1 、用标记的玉米fe ( )转运蛋白基因片段为探针，对约120000pfu的文库进行筛选，经过三轮筛选，最后获得4个单一的阳性克隆cdna ，分别命名为ptf1 、 ptf2 、 ptf3和ptf4 。
2 sequences were analysed and compared in genbank : ptfl is 494bp and ptf2 is 763bp in longth , the deduced proteins consist of 88 and 172 amino acids respectively , these cdna - clones encode the same gene - fe ( ii ) - transporter . 3 southern blotting showed that fe ( ii ) - transporter was a single copy in malus xiaojinensis genome and it was also existed in malus baccata and malus zumi 2 、根据测序的结果，将所得序列在genbank中进行同源性比较，结果如下： ptf1长为494bp ， ptf2长为763bp ，分别编码88个和172个氨基酸，属于小金海棠fe ( )转运蛋白基因的两个不同长度的基因片段，是同一个基因。
The study was undertaken to isolate fe ( ii ) - transporter cdna and related binding protein cdna under fe - deficiency stress from a fe - deficiency root cdna expression library of malus xiaojinensis by screening library using maize fe ( ii ) - transporter cdna and wheat tamre - bp cdna as a probe . the main results as follows : 1 out of approximately 120000 plaques , four positive cdna clones encoding fe ( ii ) - transporter proteins , designated pftl - 本试验以苹果属小金海棠( malusxiaojinensischengetjiang )为试材，利用玉米fe ( )转运蛋白基因片段以及小麦金属反应元件结合蛋白tamre - bpcdna为探针，筛选小金海棠缺铁根cdna表达文库，目的在于克隆苹果铁高效基因型小金海棠的fe ( )转运蛋白基因以及与缺铁胁迫相关的结合蛋白基因。
In order to explore the method of new stock micropropagation , the micropropagated plantlets of malus pruniolia var . ringo were used as material to culture in designed sugar - free culture box with environmental control system for studying their rooting ability , photosynthesis and root morphogenesis , and compared with those cultured in sugar - containing culture system 摘要为了探索新的砧木快速繁殖的方法，以圆叶海棠离体新梢为供试材料，采用自行设计的无糖培养箱和环境控制系统，进行无糖培养生根研究，比较无糖培养与有糖培养海棠离体新梢光合指标和根系形态指标之间的差异。
Biodiversity in addition has become a hot point of recent study . many researches on species diversity of mains millerwere reported , the studies on genetic diversity were rarely reported , especially for the species such as malus toringoides hughes , which is rich in morphological and genetic diversity 遗传多样性和生态环境多样性、景观多样性和人文多样性等几个方面，而苹果属植物物种多样性的研究比较多，但种内的多样性及其类型分化的研究少有报道，对于形态和遗传物质多样性都相当丰富的变叶海棠更是如此。
If the eight new species published in recent years were included , there are thirty - one malus species in china . they cover geographically all the twenty - nine provinces , municipalities and autonomous regions of china with one of exception of hainan province . the most densely populated areas are sichuan > yunnan and shanxi province , which have 24 , 17 and 15 species respectively 中国至少有23种，如果加上近年发表的8个新种，则种类数目达31个，主要分布在除海南省以外的全国30个省、市和自治区，尤其以中国的云南、贵州、四川、甘肃和陕西等分布种类较多；其中分布种类占前3位的省分别是四川、云南和陕西，拥有种的数目分别为24种、 17种和15种。
The root system of malus toringoides is so developed that it can grow on prior soil and in cracks of rock . like malus transitoria , malus toringoides tolerant to draught and can grow on sunny dry slope , rocks of steep cliffs , barren stone area , roadsides and field sides . malus toringoides was also adapted to habitat shade and can grow normally gorges of hill , and even on sides of brook and river , where water often attack on 变叶海棠根系发达，能穿透坚硬的土层和岩石裂缝，它具有喜光耐旱的特点，在阳坡、凸坡、悬崖峭壁、瘠薄坚硬的石谷子地、道路两旁和农耕地边都能正常生长，与花叶海棠近似；变叶海棠也具有喜湿耐阴的特点，在深山峡谷、甚至在根系长期经受洪水侵袭的溪边、河岸也能正常生长，与陇东海棠近似。
Abstract : the ecological benefits on various bunds planted with vegetation were studied using fuzzy comparison analysis method ， the results showed that the bunds of amorpha fruiticosa ， biomass ， caragana korshinskii are relatively good ， especially the bund of amorpha fruiticosa is the best ， whereas the bund of malus spectabilis is somewhat insuperior to any other bunds 文摘:通过对几种生物埂生态效益的模糊对比分析结果表明，紫穗槐、黄花菜、柠条埂的生态效益相对较好，尤其是紫穗槐埂为最优，而海棠埂则稍差一些。
In the main area populated by malus toringoides hughes , malus kansuensis and ( or ) malus transitoria were found occasionally . the fact of the three species " convergence in western sichuan and southern gansu shows their close relation - ships geographically . their different distribution indicate their geographical replacements , of subflora forest vegetation of china - himalayas , in which many new and old species co - existed 在变叶海棠的主要分布区内，有陇东海棠和花叶海棠（或其中之一）的零星分布，它们在四川西部和甘肃南部汇集，表现为地理亲缘；其分布区的分异表现为地理替代，该地区植物区系成分新老兼备。
