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[Objective] anscriptomes of Hippophae rhamnoides subsp. mongolica cv ‘Xiangyang’ were analyzed to design primers and develop EST-SSR (Expressed Sequence Tags-Simple Sequence Repeat) markers.[Method] The primers were designedand the SSR was developed based on the Expressed Sequence. 179 pairs of primers were validated randomly.[Result] 17 383 SSR-ESTs (SSR-containing EST) were identified. Of the total EST-SSRs, the mononucleotiderepeat was the most dominant type, accounting for 62.77%, followed by dinucleotiderepeats and trinucleotiderepeats, accounting for 21.82% and 13.77%, respectively. AT and AG were the most abundant dinucleotide motifs; AAG, ATC and ATA were repeated dominant motifs in trinucleotide. Based on these SSR-ESTs, 9 291 pairs of EST-SSR primers were designed; 179 pairs of primers were randomly selected and compounded for PCR amplification, among which 142 loci were amplified successfully. Amplificationproductions of 92 loci were genotyped using the DNA analyzer, of which 40 loci (43.48%) were

[目的]本研究通过对蒙古沙棘＂向阳＂品种的转录组序列进行SSR引物开发,为沙棘亲本分析、遗传多样性和遗传育种等研究提供支持。[方法]利用已测得的转录组序列进行分析和筛选,整理具有SSR位点的序列,进行引物设计,随机挑选179条引物进行验证。[结果]得到具有SSR位点的EST序列17 383条,其中,单核苷酸、二核苷酸和三核苷酸重复基元分别占62.77%、21.82%和13.77%;二核苷酸重复基元类型以AT和AG为主,三核苷酸重复基元类型以AAG、ATC和ATA为主。9 291条序列设计出扩增EST-SSR位点的引物,随机合成的179对引物中,142对扩增成功,选取其中92个位点的扩增产物上机检测,40个SSR位点（43.48%）呈现多态。对扩增稳定且峰图清晰的17个多态位点的进一步分析,得到蒙古沙棘天然群体在各位点的观测杂合度（HO）为0.083 0.875,期望杂合度（HE）为0.180 0.750。[结论]本研究开发出的EST-SSR标记,为后期进行沙棘属植物遗传多样性分析、遗传图谱构建及分子育种等研究提供了重要支持。

[Objective] To resolve the controversy over the phylogenetic position of Chosenia arbutifolia in Salicaceae.[Method] The whole chloroplast genome sequences of C. arbutifolia was determined by next-generation sequencing, and the phylogenetic position of C. arbutifolia was investigated by comparing its sequences with all available complete chloroplast genome sequences from the genera Populus and Salix.[Result] The total genome was 155, 661 bp, consisting of two single-copy regions separated by a pair of inverted repeats (IRs) of 27, 455 bp. The large single-copy (LSC) and small single-copy (SSC) regions spanned 84, 536 bp and 16, 215 bp, respectively. The total GC content of the chloroplast genome was 36.68% and 113 unique genes were annotated, including 79 protein coding genes, 30 tRNA genes, and four rRNA genes. Twenty genes were duplicated in the inverted repeat regions, 14 genes contained one intron, and three genes (rps12, clpP, and ycf3) contained two introns.[Conclusion] A phylogenetic tree constructed f

[目的]为探讨额河杨和银灰杨天然杂种的起源机制,[方法]应用18对SSR标记,从分子水平上对新疆额尔齐斯河流域杨属植物的种间关系进行分析研究。[结果]表明：（1）SSR系统发育树将整个流域天然杨属植物分为两大类群,即黑杨派和青杨派为一类,白杨派为一类;（2）白杨派派内系统聚类图显示,银白杨、欧洲山杨、银灰杨三个树种均有较大的遗传分化,特别是杂种银灰杨似乎更大;（3）黑杨派和青杨派的UPGMA分类图显示,青杨派和黑杨派分属于2个分支,其中,青杨派内部分化相对简单,分为2支,均为典型的苦杨;黑杨派内部的分化较为复杂,可分为4类,包括典型的欧洲黑杨、额河杨和回交子代。[结论]杂种额河杨具有更多的欧洲黑杨的遗传成分,因此,将额河杨放到黑杨派是正确的。

To explore the hybrid origin mechanism of Populus × jrtyschensis and P. canescens, the phylogenetic tree based on nuclear microsatellite markers (SSR) analysis was structured. The result show that the natural Populus populations can be classified into two groups, the one is Section Leuce, and the other is Section Aigeiros and Section Tacamahaca. In Section Leuce, significant genetic differentiation was found in the populations of Populus alba, P. canescens and P. tremula, especially the crossbreed Populus (P. canescens). A UPGMA phylogenetic tree shows that Section Aigeiros and Section Tacamahaca can be divided into two groups. Compared with Section Tacamahaca, the genetic differentiation in Section Aigeiros is more complex, and they can be further divided into four subgroups, including P. nigra, P. × jrtyschensis and their backcross progeny. It is confirmed that P. × jrtyschensis should be classified as Section Aigeiros based on their smaller genetic distance. [目的]为探讨额河杨和银灰杨天然杂种的起源机制,[方法]应用18对SSR标记,从分子水平上对新疆

沙棘抗旱性是多因素作用的结果，如果只利用单因素／单项指标评价其抗逆性，则具有一定的片面性。本研究对干旱胁迫下4个沙棘品种的多项生理生化指标的变化进行比较分析，并通过主成分分析和综合评价发现：乡土中国沙棘（河北丰宁种源）品种的抗旱性最强，引进大果沙棘-乌兰格木品种的抗旱性最差，引进的4个沙棘品种抗旱能力强弱的排序为：丰宁（0．619）〉楚伊（0．445）〉向阳（0．390）〉乌兰格木（0．274）。净光合速率、蒸腾速率、气孔导度、叶水势、谷胱甘肽还原酶和脱落酸的含量可作为沙棘抗旱性的判定指标。随着干旱胁迫的加剧，与对照相比，4个引沙棘品种的净光合速率、蒸腾速率、气孔导度和叶水势均下降，而超氧化物歧化酶活性、细胞膜透性、谷胱甘肽还原酶和四大激素均上升，这说明干旱逆境胁迫影响了沙棘正常的生长发育过程，同时通过内在的生理生化指标的改变来增加其自身对逆境胁迫的抵抗能力。这些将为沙棘抗旱树种的筛选和进一步的杂交育种提供依据。

应用SSR标记技术,对新疆齐斯河流域河谷分布的白杨派树种银白杨、银灰杨和欧洲山杨天然居群的克隆结 构、克隆多样性和遗传多样性进行研究.结果表明：欧洲山杨、银白杨和银灰杨均有很强的克隆繁殖特性.欧洲山杨、银白杨居群的克隆多样性均比较高,Simpson指数分别为0.987和0.983.与欧洲山杨相比较,银白杨居群具有较低的遗传多样性,Shannon信息指数分别为1.068 9和0.324 9,Nei多样性指数平均为0.505 6和0.211 2.欧洲山杨和银白杨居群间的遗传一致度均较高,变幅分别为0.778 1～0.9544和0.975 1～0.9946,反映出其超长距离的基因流特性,超强的基因流阻止了银白杨和欧洲山杨居群的遗传分化.研究发现,银白杨和欧洲山杨分别有95％和89.98％的遗传变异存在于居群内.

To explore the development regularity from shoot to stem, the culms in different developmental stages and portions of Moso bamboo (Phyllostachys heterocycla cv. pubescens) were studied by anatomy analysis. The resu!ts of histological observations indicated that the rapid development of culms mainly presented in longitudinal direction, which was dominated by cell division and cell elongation. In the initial stage of growth, numerous cell nuclei could be seen in parenchyma and fiber cells-an obvious sign of cell division-indicating the presence of meristematic tissue when cell division dominated the culms development. As the culm developed, the number of nuclei declined, until there were almost no detectable nuclei in the late stages of development. The development of culm was dominated by cell division in the initial stages and by cell elongation in the middle and late stages. The development, maturation and aging in different parts of the culm were studied systematically from the basal to the top internode. T

Along the Erqis River, there are various natural Populus forests, which include Section Leuce in Populus, such as Populus alba, Populus canescens and Populus tremula. Clonal diversity and structure were studied using nuclear microsatellite markers. The results showed that clonal reproduction was the primary reproduction strategy of these Populus populations. The populations of P. alba and P. tremula had an abundant clonal diversity and the mean Simpson's index were 0.983 and 0.987, respectively. Compared with the P. tremula, Populus alba had lower genetic diversity and their Shannon' index were 1.068 9 and 0.324 9, Nei' index were 0.505 6 and 0.211 2, respectively. The genetic consistency was high among populations, and variation range were 0.778 1 0.954 4 in P. tremula, 0.975 1 0.994 6 in Populus alba. It suggested they had long-distance gene flow and prevented genetic differentiation among P. alba and P. tremula population. In addition, genetic diversity indicated that the genetic variation occurred within

The drought resistance of Hippophea rhamnoides relates to the effects of multiple factors. It is one-sided to evaluate its resistance using single factor (single indicator). The drought resistance based on physiological and chemical indices in four H. rhamnoides species was evaluated by principal components analysis and subordinate function analysis. The results showed that the native species (H. rhamnoides ssp. Sinensis, Fengning; FN) had the strongest drought resistance compared with the other three exotic species (H. rhamnoides ssp. Mongolia, Xianyang, XY; H. rhamnoides ssp. Mongolia, Chuyi, CY; and H. rhamnoides ssp. Mongolia, Wulangemu,WL). The H. rhamnoides L. Wulangemu had the weakest drought resistance. And the capacity of drought resistance of the four species is gauged as follows: FN (0.619) > CY (0.445) > XY (0.390) > WL (0.274). It was also found that the net photosynthetic rate, transpiration rate, stomatal conductance, leaf water potential, glutathione reductase and ABA content could be used as