Duplication of locus coding of malate dehydrogenase in Populus tomentosa Carr.

Horizontal starch-gel electrophoresis was used to study crude enzyme extraction from young leaves of 234 clones of Populus tomentosa Carr. selected from nine provenances in North China. Ten enzyme systems were resolved. One hundred and fifty-six clones showing unusual allozyme band patterns at locus Mdh-1 were found. Three allozyme bands at locus Mdh-1 were 9:6:1 in concentration. Further studies on the electrophoretic patterns of ground mixed pollen extraction of 30 male clones selected at random from the 156 clones were conducted and it was found that allozyme bands at locus Mdh-1 were composed of two dark-stained bands and a weak band. Only one group of the malate dehydrogenase (MDH) zymogram composed of two bands was obtained from the electrophoretic segregation of pollen leachate of the same clones. A comparison of the electrophoretic patterns one another suggested that the locus Mdh-1 coding malate dehydrogenase in diploid species of P. tomentosa was duplicated. The duplicate gene locus possessed three same alleles and was located in mitochondria. The locus duplication of alleles coding malate dehydrogenase in P. tomentosa was discovered and reported for the first time. [Supported by the “Tenth Five-year Plan” National Key Project in Science and Technology (Grant No. 2002BA515B0303) and the National “863” Project (Grant No. 2002AA241071)]     

Southern pollen sired more seeds than northern pollen in southern seed orchards established with northern clones of Pinus sylvestris

Abstract

Contamination by southern pollen is a considerable problem in Scots pine (Pinus sylvestris L.) seed orchards established with northern clones. This study investigated whether the contamination was due to the competitive superiority of southern pollen by carrying out competition trials using mixtures of pollen from northern and southern populations of Scots pine. Trials were performed in a southerly seed orchard established with clones originating from northern populations. Seed paternity (siring) was determined through the analysis of allozyme variation. Southern genotypes sired significantly more seeds (76%) than their northern competitors and across all mixed-pollen crosses. Maternal genotype had no effect on seed siring success. The mean flower abortion rate was lower in southern pure-pollen crosses and mixed-pollen crosses than in northern pure-pollen crosses. The results show that local pollen may induce high levels of background pollination in southern seed orchards composed of northern genotype grafts. These results must be taken into account when aiming to produce suitable reforestation material for northern areas.     

Allozyme Variation of Picea abies in Poland

The aim of this study was to determine the levels and patterns of allozyme variation among 29 populations of Norway spruce [ Picea abies (L.) Karst.] from Poland. Thirteen investigated isoenzyme systems were encoded by 27 gene loci and, on average, 71% of the loci per population were polymorphic. The average and effective numbers of alleles per locus were 2.17 and 1.26, respectively, while the expected heterozygosity was 0.156. A relatively low allozyme differentiation among populations from north-eastern and southern Poland was observed ( F ST = 0.028, mean genetic distance D = 0.005). The results suggest that historical events and extensive gene flow played an important role in the distribution of the observed allozyme differentiation of Norway spruce in Poland.     

Lignin Characterization of Triploid Clones of Populus tomentosa Carr.

In order to understand the structural characteristics of lignin in triploid clones ofPopulus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin （MWL）, lignin carbohydrate complex （LCC） and the residual lignin from kraft pulp （KP） and sulfite pulp （SP） were isolated and analyzed by Fourier transform infrared （FTIR） spectrum and ^13C nuclear magnetic resonance （NMR）. The most diagnostic peaks were assigned and the differences were discussed. The spectral patterns reveal that triploid P tomentosa shows the specific features of hardwood from temperate areas, but in the spectrum of FTIR, the strength ratio orAl270 cm^-1 to A1226 cm^-1 is 0.88, higher than the average of hardwood from temperate areas, which will make the lignin delignification more difficult during pulping and bleaching. The LCC from triploid P tomentosa is mainly composed of xyloglucan and glucuronic acid, and other glucides have much lower ratio. In LCC FTIR, there are three peaks at 1 427, 1 329 and 1 046 cm^-1, indicating that both semi-cellulose and cellulose could exist in LCC, and that there might be relationships between cellulose and lignin. Compared with the residual lignin from KP and SP, the condensed structure in KP is more than that in SP.     

毛白杨种内过氧化物同工酶变异

用聚丙烯酰胺凝胶电泳分离了105份毛白杨的过氧化物同工酶，经三年重复，共获8种酶谱，表现了毛白杨种内遗传多型性。第一种酶谱是毛白杨种的主要酶谱型，占全部试材的85．7％，同属一种酶谱型的材料，其形态性别及生长习性都有明显差异，曾被定为新种、变种或变；不同酶谱材料的形态分歧应晚于酶分子水平的分歧。将8种酶谱的相似系数值进行聚类，第Ⅰ、Ⅱ、Ⅲ、Ⅳ类酶谱因发生较早可聚为一类，此类是毛白杨的主要类。第Ⅴ、Ⅵ、Ⅶ、Ⅷ种酶谱是近代毛白杨与派内几个种进行多元化、多地、多次杂交的新类型。     

杨树种质SSR指纹数据库构建

【目的】构建林木种质资源指纹数据库是林木种质材料遗传鉴定的前提,也可为林木杂交育种提供清晰的遗传学背景。【方法】选取亲缘关系较远的8份杨树无性系材料筛选SSR引物,基于TP-M13-SSR技术进行SSR-PCR扩增,采用ABI3730XL毛细管电泳系统检测PCR扩增产物,利用GeneMarkerV1.91进行基因分型,Cervus3.0.7估算多态信息含量(PIC)和各位SSR位点无效等位基因频率(pN),POPGENE3.2估算各SSR位点上的等位基因数目(Na)、Shannon信息指数(I)和观测杂合度(HO),NTSYS-pc2.1进行遗传聚类分析。【结果】共筛选出13对条带清晰、重复性好的SSR引物,共扩增出89条多态性条带,单个位点上的等位基因数目为2~12个,平均值为6.5个;Shannon’s信息指数(I)为0.13~1.91,平均值为0.97;多态信息指数(PIC)为0.19~0.81,平均值为0.56;观测杂合度为0.06~0.76,平均值为0.40。聚类分析结果表明,参试的无性系种质材料分为3类,第一类为南林系列无性系;第二类为中林108杨、中潜1号、中潜3-2、中驻2号、中驻4号、中驻6号、中驻7号、中驻8号、浙7、中皖1号、中皖2号、丹红杨、A65/27、南抗4、南抗3;第三类为湘林系列无性系。【结论】TP-M13-SSR分子标记技术能有效地鉴别杨树无性系种质,明晰无性系间亲缘关系,遗传聚类的结果与其谱系关系基本一致。研究结果为杨树无性系种质鉴定及进一步开展杨树杂交育种奠定了基础。     

2个引进杨树无性系的硬枝扦插试验

以宁夏仁存渡护岸林场引进的截叶毛白杨、毛新×毛白73两个无性系的1年生硬枝为材料,以新疆杨为对照进行硬枝扦插试验,采用ABT-1号生根粉对插穗进行处理,比较其扦插生根情况。结果表明:2个无性系的杨树及新疆杨采用不同处理时,插穗生根情况不同;ABT-1生根粉处理的截叶毛白杨插穗在500 mg·L^-1浓度时愈伤组织形成率最大,达58.33%;毛新×毛白73枝条在600 mg·L^-1浓度时愈伤组织形成率最大,为41.67%。未用ABT-1生根粉处理的截叶毛白杨、毛新×毛白73和新疆杨的生根率高于处理过的。不同品种的杨树扦插生根率存在极显著差异,新疆杨生根率高达82.14%,高于截叶毛白杨与毛新×毛白73的,更适合进行扦插扩繁。     

枫香同工酶遗传多样性分析

对取自枫香16个群体的幼嫩叶片样品采用垂直板聚丙烯酰胺电泳技术进行了同工酶分析.结果表明:(1)群体间的遗传结构差异显著.在所分析的6个酶系统共6个位点中,各个位点的等位基因频率变化从0～1不等,16个群体中有9个群体存在稀有基因,6个群体存在特有基因,一共发现了4个稀有基因,3个特有基因;(2)枫香群体水平每位点等位基因数总平均为3个,每位点有效等位基因数总平均为1.855 7个,多态位点百分率总平均为100％,观察杂合度总平均为0.582,期望杂合度总平均为0.443,Shannon信息指数总平均为0.711 0.从整体上看,群体内的杂合子超过了哈代-温伯格平衡所要求的比例,杂合子过量.(3) UPGMA聚类分析显示,枫香16个群体中分为2大类,第1大类就是福建建瓯,其他15个群体即为第2大类.在第2大类中遗传距离较远的群体是重庆丰都、安徽黄山,它们与本类群体中其他13个群体的遗传距离较远,而该13个群体间的遗传距离较近,因此可以看出,福建建瓯与其他群体间的遗传距离是最远的,16个群体基本上呈现按地理距离聚类的趋势,与地理分布格局较吻合.     

Genetic differences between autochthonous and breeding populations of common cypress (Cupressus sempervirens L.) in Greece

Individuals were selected for resistance against the imperfect fungus Seiridium cardinale Wag in six common cypress populations (Cupressus sempervirens L.) in Greece. A total of 109 resistant clones and 140 trees from their base populations were surveyed at several allozyme loci. The comparison yielded information on changes in genetic variation due to artificial selection. The genetic structure of the breeding populations was similar to their base populations. Nevertheless, the number of rare alleles among the resistant clones had decreased, showing a similar trend at most loci and for most comparisons. Possible implications for breeding strategies are discussed.     

Studies on isoenzyme polymorphism in Fomes annosus1

33 Isolates of Fomes annosus (Heterobasidion annosum) were analysed for their isoenzyme pattern of the enzyme Lactate Dehydrogenase (E.C. 1.1.1.27), Malate Dehydrogenase (E.C. 1.1.1.38), and Laccase (E.C. 1.10.3.2). For lactate dehydrogenase and malate dehydrogenase, a conspicuously high degree of variation in the isoenzyme pattern was found, indicating a rather high degree of genetic variability in the loci coding for these enzymes. The isoenzyme spectrum of laccase, however, was the same in all the strains which were tested.     

白皮松天然群体遗传多样性的等位酶分析

采用8种等位酶对白皮松4个天然群体的遗传多样性和遗传分化进行了研究.在4个群体中共检测到10个基因位点,15个等位基因,其中6个位点为多态位点;群体总体水平多态位点比率P=60%,平均有效基因数A=1.92,平均期望杂合度He=0.106,种群平均遗传距离为0.006 8.南漳白皮松群落平均等位基因数A=1.9,平均有...     

Background pollination in Pinus sylvestris seed orchards

The proportion of background pollen grains in the seed crops of two Pinus sylvestris seed orchards in Central Finland was estimated with the aid of multilocus allozyme markers. The orchards studied were more than 30 years old and in full pollen production. For the bulked seed crops of the seed orchard with southern clones the estimated average of background pollination over four years was 26%. There were statistically significant differences between years. No significant heterogeneity in the degree of background pollination between clones was found. Among single ramets there was significant heterogeneity in the estimated contamination rates, but the variation was not related to position in the orchard. For the seed orchard with northern clones the bulked seed crop was studied only for one year and the level of background pollination was found to be 33 %. These estimates are fairly high, but lower than for many other orchards. Background pollination at this level will cause losses in expected genetic gains. Part of the seeds from northern orchards will not be adapted to the intended area of use.     

表达豇豆胰蛋白酶抑制剂转基因杨树的蛋白检测

对转豇豆胰蛋白酶抑制剂基因的三倍体毛白杨杂种 [(毛新杨×毛白杨 )×毛白杨 ]的可溶性总蛋白和胰蛋白酶抑制剂蛋白的含量进行测定 .结果发现 ,与未转基因植株相比 ,所有供试转基因株系叶片中的总可溶性蛋白含量明显增加 ,但老叶的含量高于嫩叶 ,这表明转基因株系可溶性总蛋白含量增加可能是CpTI基因表达的结果或由于外源基因导入后引起杨树基因组中某些自身基因的表达所致 .转基因株系叶片中有较高含量CpTI,而对照叶片则检测不到CpTI,这进一步证实了CpTI基因已在转基因株系中得到稳定表达 .进一步比较发现 ,在供试的 5个无性系中 ,TG0 7、TG0 4和TG71在总蛋白含量和CpTI含量增加较为明显 .另外 ,聚丙烯酰胺凝胶电泳胶分析发现 ,与未转基因植株相比 ,在所有供试转基因株系叶片中均出现一条分子量为 11.3kD的清晰蛋白带     

Evidence for the adaptive significance of allozymes in forest trees

Positive correlations between allozyme heterozygosity and fitness measures, primarily growth and fecundity, have been reported for a number of forest tree species. Because the amount of variation in growth explained by allozyme genotype is usually on the order of only a few percent, there has been little effort made towards using electrophoretic screening of allozymes as a tool in early selection on seedlings in production nurseries. We review the progress made in studies of heterozygosity in forest trees, focusing on how recent studies have utilized careful experimental design to allow testing of hypotheses as to the causative nature of the heterozygosity-fitness phenomena. We discuss evidence suggesting a deleterious nature for rare allozyme alleles, and present a case of apparent balancing selection across life history stages acting to maintain rare alleles in Pinus taeda. We also review the apparently common trend in natural stands toward increasing heterozygosity over time, and suggest how gains might be made through artificial selection based on allozyme survey data.     

云南红豆杉天然种群遗传多样性研究

采用垂直板式聚丙烯酰胺凝胶电泳，检测了云南红豆杉（Taxus yunnanensis)雌配子体的5种等位酶，并以10个基因位点编码的5个酶系统，分析了滇西北3个云南红豆杉天然种植的遗传多样性与遗传分化。结果表明，群体的多态位点比例是0．77；群体的平均杂合性观察值是0．302；预期值为0．3320；每个基因位点发现的等位基因数是2．05，有效等位基因平均数是1．466。对10个基因位点的基因多样性测定表明，种群间的分化占14．66％。总的基因多样性约85％产生于种群内。群体间的平均遗传距离是0．118。     

Effects of Planting Density on Growth of New Clones in Populus tomentosa

Effects of seven planting densities on the growth and tree form of nine 5-year-old new clones in Populus tomentosa were studied. The plantations, arranged with completely random block design, were located in Wuzhi County, Henan Province.Results indicated that effects of planting density on the diameter at breast height (DBH), individual volume and growing stock increment of all new clones in P. tomentosa were significant at the 1% level of probability, effects of planting density on the tree height increment of new clones B2 and B31 and on the live branches height (LBH) increment of new clones B5 and B30 were significant at the 5% level of probability, while the interaction between planting density and clone was not significant at the 5% level of probability. It was concluded that the degree of differences among new clones within the same planting density was different with different planting densities and traits. For short rotation industrial timber, clones B 1, B3, B4, B5, B7, B9, B31 were suitable with the density of 1 000-2 500 trees per hectare, while for bigger diameter timber, clones B1, B3, B4, B7, B9, B31 could be used with the planting density of 660-833 trees per hectare. Clonal repeatability was also different in different planting densities.     

Phytopbthora cactorum on walnut seedlings in Italian nurseries

Phytophthora cactorum was consistently isolated from basal stem tissues of walnut seedlings affected by collar and root rot. The isolates were identified on the basis of morphological and cultural characteristics and of electrophoretic patterns in polyacrylamide slab gels of total native mycelial proteins and isozymes (arylesterase, malate dehydrogenase, acid and alkaline phosphatase). The electrophoretic phenotypes of walnut isolates were identical or very similar to those of P. cactorum isolates from different hosts (apple, loquat, pineapple-guava and strawberry). In pathogenicity tests, P. cactorum isolates from walnut proved to be highly pathogenic for seedlings of English walnut (Juglans regia) and moderately pathogenic for seedlings of eastern black walnut (Juglans nigra); moreover, they did not rot apple seedlings, suggesting host-specificity. Poor soil drainage and excessive irrigation can be considered as predisposing factors to collar and root rot incited by P. cactorum.     

蔗糖质量分数和pH值对樟子松花粉发芽率的影响

pH值水平和蔗糖质量分数是影响花粉发芽的重要条件，本文用三个pH值水平和三种蔗糖质量分数共9种组合，分别对来自三个无性系的樟子松花粉的发芽率进行了测定、比较、分析，结果表明，pH值为5．5、蔗糖质量分数为10％的培养基最适合樟子松花粉发芽。     

毛白杨抗虫、感虫无性系树皮内酶活性的初步研究

对14年生抗虫、感虫毛白杨无性系树皮内过氧化物酶(POD)和多酚氧化酶(PPO)的酶活力进行了比较分析，结果表明抗、感虫无性系间树皮内多酚氧化酶的酶活力差异显著，抗虫无性系大于感虫无性系；而感虫无性系内的过氧化物酶的酶活力大于抗虫无性系，但二者差异不显著，多酚氧化酶的酶活性与抗虫性有一定的关系，是造成抗性差异的原因之一，可以将多酚氧化酶活性作为毛白杨抗性育种的一个指标。     

Restriction map and polymorphisms of nuclear ribosomal genes of Populus balsamifera

Balsam poplar (Populus balsamifera) clones from five populations, which were collected along a transect from northern Wisconsin to the northern tree line, were evaluated for polymorphisms in nuclear ribosomal DNA. For this purpose, a restriction map was constructed using four six-cutter enzymes in single and double digests of genomic DNA. After electrophoretic separation on agarose gels and Southern transfer, blots were hybridized to non-radioactively labeled heterologous rDNA probes of soybean. Among populations, variation was detected in the length of the intergenic spacer between the tandem repeats of the coding regions and in the degree of methylation of one restriction enzyme recognition site. Based on a comparison of the derived restriction map of balsam poplar and other poplars, high homology was evident in the rDNA coding regions among species, whereas the intergenic spacer varied slightly in both length and number of restriction sites.