Through scanning electron microscope and optical microscope, a compara- tive study on morphological features and anatomical characters of the leaves of some pear cultivars （strains） was carried out. The results showed that the size and shapes of leaf epidermal cells were different, stomatal apparatuses were distributed in the hypodermis, the shapes of stornas were mainly oval, and these of ＇Jinxiang- shui＇ were long oval; the stomatal type was irregular, the cultivar with the maximum density of leaf stomas was ＇Jinxiangshui＇, and the minimum was ＇Aishanli＇. The thickness of palisade tissues and spongy tissues of different pear cultivars （strains） was different, the maximum thickness of palisade tissues of ＇Aishanli＇ was 105.5 iJm, and the maximum thickness of spongy tissues of ＇Jinxiangshui＇ was 98.4 IJm. The ratios of palisade tissues to spongy tissues from high to low were ＇Qiuyueli＇, ＇Zaoxiangshui＇, ＇Aishanli＇, ＇Hongjinqiu＇ and ＇8404＇. The differences on these mi- cromorphological characters among different pear cultivars （strains） had important significance to the identification of the cultivars and the early choice of breeding.
利用简化基因组测序技术—特异性位点扩增片段测序技术(Specific-locus amplified fragment sequencing,SLAF-seq)对509份苹果属植物种质进行测序,获得586454个SLAF标签,其中多态性SLAF标签463612个;经过序列比对,根据完整度>0.94、次要等位基因频率(MAF)>0.05,过滤筛选得到46460个多态性单核苷酸(SNP)位点;基于这些SNP位点构建苹果属植物不同种的系统发生树并分析主成分。结果表明,通过SLAF-seq技术能够在全基因组范围内快速开发高通量的SNP标记,并直接用于苹果属植物种质资源遗传多样性研究中。34种509份苹果属植物的多样性水平较高(He=0.318,I=0.488,Ae=1.520),在多于1份试材的种群中,变叶海棠的遗传多样性水平最高,中国苹果的遗传多样性水平最低。综合聚类分析和主成分分析结果表明,供试苹果属植物分为5个基本的类群,Ⅰ山荆子类群,Ⅱ苹果属植物野生种类群,Ⅲ苹果栽培品种类群,Ⅳ以中国苹果、八棱海棠、花红、楸子和海棠花为主的类群,Ⅴ新疆野苹果类群。野生种丽江山荆子、山楂海棠、陇东海棠、变叶海棠、花叶海棠、滇池海棠和沧江海棠聚类比较紧密,栽培种之间的亲缘关系相对较近,栽培品种与东方苹果和森林苹果等野生种聚在一起,新疆野苹果与中国原产苹果属栽培种的亲缘与起源演化关系有待于进一步考究。
