大赖草和新麦草物种专化DNA重复序列研究Ⅱ在小麦族中分布的多态性

大赖草和新麦草中克隆的５个ＤＮＡ重复序列与小麦族不同物种ＤＮＡ进行Ｓｏｕｔｈｅｒｎ杂交。结果表明,这５个重复序列在Ｌｅｙｍｕｓ属（赖草属）和Ｐｓａｔｈｙｒｏｓｔａｃｈｙｓ属（新麦草属）中的丰度与小麦、大麦和黑麦相差悬殊,可以作为这２个属染色体的分子标记检测其导入小麦、大麦和黑麦后的踪迹,尤其是ｐＬｒ６４７对这２个属专化性更强,应优先选用。另外,结合本研究结果对小麦族有关种属染色体组的进化问题进行了讨论。     

小麦族10种禾草叶片可消化性及矿物质含量的差异

利用扫描电镜及能量分散型荧光X射线新技术分析小麦族10种多年生禾草叶片的可消化性和矿物质含量.结果表明,供试草种叶片可消化性的高低顺次是:老芒麦>野大麦>航道冰草=加拿大披碱草>蒙农杂种冰草>诺丹冰草>肥披碱草≥新麦草=披碱草>蒙古冰草.叶片中7种矿物元素含量变幅为:Mg 0.21%～0.57%、Si 0.90%～3.31%、P 0.27%～0.3%、S 0.3%～0.0%、Cl 0.21%～0.52%、K1.44%～3.0%、Ca 0.42%～0.98%,草种间差异显著.     

小麦族内的核质互作研究进展

本文从核质基因型互作、细胞质与染色体互作、细胞质与染色体（片段）互作和细胞质基因与细胞核基因互作４个层次综述了小麦族内核质互作研究的最新进展及其小麦遗传育种学的拓展,提出了小麦族内核质互作研究的重点领域－核质杂种的遗传变异、新型核质杂种的创制和杂种优势利用,并展望了这一领域的研究前景。     

Levels and distribution of allozyme and RAPD variation in populations of Elymus fibrosus (Schrenk) Tzvel. (Poaceae)

To study the magnitude and nature of genetic variation in E. fibrosus, the levels and distribution of allozyme and RAPD variations were investigated in populations collected from Finland and Russia. The results obtained from the allozyme and RAPD studies were compared to each other in 10 of the populations. The allozyme analysis showed that 6 of 12 presumed loci (50%) were polymorphic within the species, while the mean number of polymorphic loci within populations was 4.8%. The mean number of allele per locus for the species was 1.5 and 1.05 across the populations. Genetic diversity at the species level was low (H _es = 0.025), and the mean population genetic diversity was even lower (H _ep = 0.007). Both these values were much lower than the average for other Elymus and self-fertilising species. The largest proportion of the total allozyme diversity was found among, rather than within the populations (G _ST = 0.70). The allozyme genetic distances between the populations did not reflect geographic distances. Cluster and principal coordinates analyses revealed the same allozyme relationship patterns among the populations. A comparison of allozyme and RAPD variation in 10 of the populations showed differences in the amount of genetic variation. The RAPD analysis revealed higher levels of variation (A _p = 1.19, P _p = 20.3 and H _ep = 0.09) than the allozyme one) A _p = 1.06, P _p = 5.8 and H _ep = 0.008). For both markers, the largest proportion of the total gene diversity was found among the populations studied (G _st = 0.63 for RAPDs and G _st = 0.65 for allozyme). In contrast to the allozyme analysis, the RAPD based genetic distances did reflect geographic distances. The cluster and principal coordinates analyses showed different grouping of populations for each data set. There was a positive, but not significant, correlation (r = 0.41) between the genetic distance matrices resulting from these markers. Regional comparison revealed that the Finnish populations had a higher diversity than the Russian ones. Generally, this study indicates that E. fibrosus contains low genetic variation in its populations. The results are discussed in the context of conservation of the species.     

小麦族植物分类及开发利用

小麦族植物是禾本科植物中最重要的一大类群,包括人类主要粮食作物小麦,以及大麦、黑麦等许多具有优良农艺性状的植物种类。对小麦族进行全面的系统学研究,建立合理的分类系统,是开展该族其他研究工作的理论基础。笔者系统介绍了国内外小麦族分类简史、分类现状和进展,深入分析了小麦族植物种质资源的开发利用,最后提出进一步合理利用和保护小麦族中野生近缘物种,发掘抗病抗逆基因,创制小麦新品种和改良牧草,使之最大限度发挥麦族物种粮饲兼用的特点。     

4种禾本科小麦族植物微观形貌特征比较研究

[目的]研究小麦族4种植物花粉粒和气孔的微现特征的异同,并探讨花粉粒和气孔大小与染色体组倍数的关系。[方法]通过扫描电镜对二倍体长稳偃麦草、中阍偃麦草、普通小麦、和八倍体小偃麦的花粉粒和叶表面的微观形貌特征进行了比较。[结果]4种植物在花粉粒形态、大小、表面突起,萌发孔和叶表面气孔大小方面存在一定的差异,其中二倍体长穗偃麦草与其他3种植物的花粉粒和气孔的微观特征差异明显。可见,小麦族二倍体物种与六倍体物种、八倍体物种在花粉粒和气孔的微观特征方面有明显差异,但六倍体和八倍体物种之间差异不明显。[结论]用花粉粒和气孔的一些微观特征作为鉴别二倍体和六倍体、八倍体等染色体组倍数相差较大的物种有一定的依据。     

小麦族旱麦草属植物的RAPD研究初报

以来自我国新疆和中东地区的１１份旱麦草属种质资源为材料，进行了随机扩增多态性ＤＮＡ分析。结果表明，旱麦草属植物在选定条件下每个反应可扩增形成４．９条带，每个引物在１１份材料及２个普通小麦对照品种中可扩增出１０．４条不同的谱带。该属植物与普通小麦的比较研究发现，二者之间的遗传进化关系较远，ＲＡＰＤ揭示的遗传相似系烽仅为０．３２５－０．４６１。     

The diversity of head-scab resistance in Triticeae and their relation to ecological conditions

1507 accessions from 93 species of 18 genera in Triticeae were screened for resistance to initial infection and resistance to pathogen spread with multi-floret and single-floret injection inoculation methods respectively. The accessions with high resistance were mainly found in perennial genera: Roegneria, Hystrix, Agropyron, Kengyilia and Elymus. Based on differences in resistance, 18 genera screened in Triticeae could be classified into five groups. The species with high resistance were mainly distributed in humid ecological environments. This revised version was published online in July 2006 with corrections to the Cover Date.     

小麦族拟鹅观草属研究进展

综述了拟鹅观草属植物的分类历史、形态特征和地理分布以及对拟鹅观草属植物的细胞学标记、染色体组分析、分子生物学标记、对赤霉病的抗性等方面的研究进展     

Molecular mapping of major genes and quantitative trait loci determining flowering time in response to photoperiod in barley

Two major genes (eam8 and eam10) and two quantitative trait loci (QTL) determining flowering time in barley were associated with restriction fragment length polymorphism markers. The loci eam8 and eam10 were found to map in regions of chromosomes 1HL and 3HL, respectively, already estimated from previous classical linkage analyses. While investigating doubled haploid lines of a spring habit barley mapping population, two QTL for flowering time were detected on chromosomes 1HL and 7HS, respectively, when the material was grown under long photoperiod conditions. When growing the same lines under short photoperiod, no QTL were discernible. Allelic and homoeologous relationships with flowering time loci described earlier in barley and other Triticeae species are discussed.