Morphological and AFLP-Based Genetic Diversity in Rosa platyacantha Population in Eastern Tianshan Mountains of Northwestern China

Morphological and AFLP-based genetic analyses of six natural populations of Rosa platyacantha in the Eastern Tianshan Mountains of Xinjiang in Northwestern China were performed. Nested analysis of variance models(ANOVA) showed that there were significan differences(P > 0.05)in morphological traits among and within the populations of R. platyacantha. The phenotypic variation coefficien(CV) of the traits varied from9.78% to 37.71%, confi ming the abundant phenotypic variations in the species. The average value of the phenotypic differentiation coefficien(Vst) was 27.50%, indicating a lower phenotypic diversity among populations than within populations. Principal component analysis(PCA) showed that the two decisive traits of ANH and TAW contributed to the proportion of 97.19% in the 1st principal component(PC), suggesting that the phenotypic variations of the traits primarily originated from the achene characters. The percentages of polymorphic loci(PPL), Nei's genetic diversity index(h) and Shannon information index(I) were highly similar among populations, with average values of 63.96%, 0.2361 and 0.3506,respectively. Moreover, the gene differentiation(Gst) and estimated value of gene fl w(Nm) were 8.10% and 5.6766, respectively, indicating very low genetic diversity among populations. Clustering analysis based on morphological traits and AFLP markers showed that the populations were mainly grouped with similar altitudes and geographic distances, respectively. The Mantel test revealed that there was no significan correlation between the phenotypic and genetic diversity among populations, implying a possible influenc of environments on the genotypes of R. platyacantha.

新疆东天山地区宽刺蔷薇居群表型多样性分析

对新疆东天山地区6个宽刺蔷薇(Rosa platyacantha)居群进行叶片、花序、果实、种子等11个表型性状的遗传多样性分析,结果表明:宽刺蔷薇各表型性状无论在居群间还是在居群内均表现出显著或极显著差异,存在丰富的表型多样性。6个居群11个性状的平均表型分化系数为27.50%,表明居群内多样性较居群间多样性更为丰富。各表型性状平均变异系数为16.51%,离散程度相对较低。对表型性状进行的变异系数多重比较和主成分分析均显示,果实相关性状的变异是造成宽刺蔷薇表型变异的主要来源。性状相关性分析进一步发现,生殖生长与前期的营养生长并无明显相关关系。聚类分析结果表明,6个宽刺蔷薇居群的表型性状并没有严格依地理距离聚类,而是受到遗传因素与环境条件特别是海拔高度因子的共同影响。

不同试剂解除天山野生蔷薇种子休眠的效果

为野生蔷薇的训化繁育提供参考,以天山野生的腺齿蔷薇(Rosa albertii Regel)、密刺蔷薇(Rosa spinosissima L.)和宽刺蔷薇(Rosa platyacantha Schrenk)的种子为材料,低温层积后采用高锰酸钾(KMnO_4,浓度0.1%、0.2%和0.3%)、硫酸铜(CuSO_4,浓度0.1%、0.2%%和0.3%)和萘乙酸(NAA,浓度50mg/L、100mg/L和150mg/L)3种试剂不同浓度浸泡处理后进行培养,50d后种子无发芽时统计发芽率。结果表明:3种试剂几乎没有打破腺齿蔷薇的休眠,可打破密刺蔷薇和宽刺蔷薇的休眠,宽刺蔷薇的发芽率高于密刺蔷薇,高锰酸钾和硫酸铜处理效果优于萘乙酸,其中以KMnO_4处理密刺蔷薇、宽刺蔷薇的效果最好,0.2%KMnO_4处理密刺蔷薇的发芽率最高,为26.7%;0.2%和0.3%KMnO_4处理宽刺蔷薇的发芽率最高,均为33.3%。

不同海拔来源宽刺蔷薇的光合日变化及其生理机制

以来源于不同海拔高度的3个新疆宽刺蔷薇1年生实生苗为材料,在引种地北京测定光合作用日变化以及13:00的荧光参数、抗氧化生理指标。结果表明,来源不同海拔的宽刺蔷薇植株都在9:00以后出现净光合速率的持续降低,在上午受到气孔限制,中午则主要受非气孔限制,即PSⅡ反应中心活性的影响。各植株在13:00均受到不同程度的光抑制,与来源中、低海拔植株相比,来源高海拔的植株PSⅡ反应中心活性与热耗散能力均显著降低,即发生了更显著的光抑制效应;POD、APX酶活性以及AsA/DHA等酶类和非酶类抗氧化物质在高海拔来源植株中显著升高,以抵抗光氧化胁迫,但仍然造成了过剩的活性氧累积以及植物组织的膜脂过氧化伤害。

生于蔷薇果实上的葡萄孢属1新种和亚隔孢壳属1新记录种

从新疆伊犁哈萨克自治州的巩留县和霍城县采集到4种野生蔷薇果实的病害标本,采用常规组织分离法和单孢分离法获得2株Botrytis属真菌和3株Didymella属真菌。通过形态学特征并结合系统学分析手段明确了菌株的分类地位。结果表明:来源于宽刺蔷薇Rosa platyacantha果实的2个病害菌株为新种—宽刺蔷薇葡萄孢Botrytis roplatyacae R.Ma,L.J.Hou.,该种与卡罗来纳葡萄孢B.caroliniana和拟蚕豆葡萄孢B.fabiopsis亲缘关系较近,但其产生的菌核为黑色,不同于B.fabiopsis产生的灰色菌核,且分生孢子(2.58~3.90×1.48~1.94μm)明显小于B.caroliniana(7.3~14.7×5.7~9.1μm)。从腺齿蔷薇R.albertii、腺果蔷薇R.fedtschenkoana和弯刺蔷薇R.beggeriana果实病害上分离到的3个菌株均为蔷薇亚隔孢壳黑斑病菌Didymella aliena,该菌为中国新记录种且首次在蔷薇属植物上报道。