Homoeological relationships between the f chromosome of Brassica rapa and the e chromosome of Brassica oleracea

Eight plants of the putative double monosomic addition line (DMAL, 2n= 20) were developed by crossing a monosomic chromosome addition line of radish [f(A)‐type monosomic addition line (MAL) (2n= 19)] carrying the f chromosome of Brassica rapa (2n= 20, AA) with another [e(C)‐type MAL (2n= 19)] having the echromosome of Brassica oleracea (2n= 18, CC). The homoeological relationships between the two alien chromosomes were investigated by morphological, cytogenetic and random amplified polymorphic DNA (RAPD) analysis. Seventeen morphological traits that were not present in the radish cv. ‘Shogoin’ were observed in both MALs and these traits were substantially exhibited in DMAL plants. At the first metaphase of pollen mother cells (PMCs), the two parental MALs showed a chromosome configuration of 9II +1I, demonstrating impossibility of recombination between the R and the added chromosomes. The DMALs formed 10II in approximately 73% of PMCs, with one bivalent showing loose pairing between two chromosomes differing in size. In an attempt to identify the two MALs by RAPD‐specific markers using 26 selected random primers, 13 and 20 bands were specific for the f(A)‐type and the e(C)‐type MALs, respectively; 12 bands were common to both MALs (26.7%). In conclusion, the f chromosome of B. rapa is homoeologous to the e chromosome of B. oleracea. The genetic domain (genes) for 17 morphological traits are linked to each homoeologous chromosome bearing 27% of the corresponding RAPD markers.     

基因型和供体植株生长环境对大白菜游离小孢子胚胎发生的影响

１７个用于大白菜常规育种的基因型在ＮＬＮ－１３液体培养基中进行游离小孢子培养，结果有１６个基因型经由小孢子胚胎发生途径获得小孢子胚。这些基因型包括从早熟晚熟的各种类型。各基因之间在小孢子胚胎发生频率方面存在很大差异，产量最高的两个基因型Ｔ１１和ＣＣ１１，平均每百花蕾分别达３５９２８和３４１３２个胚。供体植株生长环境对小孢子胚胎发生具有明显影响；在１０／２０℃（液／昼）的部分控温温室生长的供体植株，     

Analysis of spaced-plant and micro-plot performance for yield-related traits in octoploid and hexaploid primary triticales

Summary Twenty-nine primary triticales (x Triticosecale Wittmack), derived from homozygous, uniform wheat and rye inbreds, were evaluated (i) to assess wheat, rye and interaction effects for yield-related characters, (ii) to estimate correlations between these characters, and (iii) to investigate the possibility of predicting micro-plot performance from early spaced-plant tests. The triticales (12 octoploid, 17 hexaploid) were tested under space-planting and in micro-plots in three-replicate, randomized block designs in 1983 and 1984, respectively. In general, hexaploid triticales performed significantly better than octoploids. Strong wheat and wheat x rye interaction effects were found, making it difficult to predict the performance of primary triticales from their constituent parental genotypes. At both ploidy levels under space-planting kernel weight per spike showed significant positive correlations with spikelets per spike, kernels per spikelet, and 1000-kernel weight. No significant associations were detected between spaced-plant and micro-plot performance for octoploids, indicating severe disorders at this ploidy level. In hexaploid triticales spikes per plant, kernel weight per spike, and kernels per spikelet observed in spaced-plants appeared to be useful indicators of grain yield in micro-plots.     

A forage grass and small grain legume plant collecting expedition in South East Poland, 1990

Summary The Plant Genetic Resources Unit (PGRU) of the Institute of Grassland and Environmental Research, Welsh Plant Breeding Station (IGER, WPBS), UK, and the Plant Genetic Resources Section of the Plant Breeding and Acclimatization Institute (PBAI), Poland, carried out a joint collecting expedition in Poland between 25 August and 7 September 1990. The expedition was unique in that it was the first time that vegetative sampling had been applied to the perennial forage grass and legume populations of south east Poland. The expedition focused on seminatural vegetation in agriculturally managed situations and detailed collection site data on management systems was obtained from landowners.Samples were collected from 62 sites. Vegetative collections of Lolium spp. (37 populations) and Trifolium spp. (56 populations), and seed collections of Festuca spp. (32 populations) were made by the IGER team (Table 2). The PBAI team made 59 separate seed collections, mainly of Leguminosae.The expedition covered four geographical subregions of south east Poland. (See Fig. 1). These were the Nizina Mazowiecka south of Warszawa, the Wyzyna Malopolska with the town of Kielce at its centre and the Beskidy Zachodnie and Beskidy Wschodnie regions of the Carpathian mountains.A diverse range of habitats was sampled covering a broad range of altitude agricultural management systems and ecological conditions. Polish agriculture is faced with the problems of a rapid orientation to a market economy and it is likely that the diverse range of habitats encoutered will be reduced as agricultural practices change. This will lead to genetic erosion of the unique forage grass and legume populations to be found in Poland.Abbreviations ECP/GR European Co-operative Programme on Crop Genetic Resources - IGER Institute of Grassland and Environmental Research - PBAI Plant Breeding and Acclimatization Institute - PGRU Plant Genetic Resources Unit - WPBS Welsh Plant Breeding Station     

Perceived risk, displacement and refuging in brown bears: positive impacts of ecotourism?

Ecotourism is a rapidly growing industry with unknown impacts on viewed wildlife that may require novel management action. We examined the impact of viewing activities on the behaviour of brown bears (Ursus arctos) in coastal British Columbia.Domination of the best feeding sites and human avoidance by large male bears has consistently been reported. We, however, saw displacement in time rather than space - during the viewing day large males were less active than at other times, while females with cubs tended to be more active.In each year, females with cubs spent similarly high proportions of their time fishing when people were present. In years with large male activity, less time was spent fishing when people were absent. When freed from the potential threat of large male bears, females with cubs showed no measurable impact of controlled human activity.Human presence at a feeding site impacts the behaviour of brown bears, but not as expected. Temporal avoidance of human activity by large males was observed; indications that they departed upon satiation, before the arrival of morning tours, however, suggests that there was little energetic impact. By displacing large males, viewing activities created a temporal refuge, enhancing feeding opportunities for subordinate age/sex classes. With the strong positive relationships between mean female mass and litter size, this may in turn increase population productivity.     

Sources of winter hardiness in wild lentil

Summary In high altitude areas (> c. 850 m elevation) in west Asia and north Africa, lentil (Lens culinaris) is grown as a spring crop to avoid severe winter cold. But late fall-sown lentil with winter hardiness has higher yield potential in these areas. In this study a total of 245 accessions of wild lentil, 10 of cultivated lentil and three accessions of Vicia montbretii (syn. L. montbretii) were evaluated for winter hardiness in Syria and Turkey during the 1991/92 season. The absolute minimum temperatures were-16°C in Syria and-18.9°C in Turkey and the susceptible indicators were killed at both locations showing that the cold was sufficient for screening. Although winter hardiness was assessed as percentage of survived plants in Syria and as a visual damage rating on a 1–9 scale in Turkey, there was agreement between the winter hardiness ratings with a correlation of r=–0.56, P<0.001. Accessions of L. culinaris ssp. orientalis exhibited the highest level of winter hardiness, on average; whereas accessions of L. nigricans ssp. ervoides were the most susceptible. Correlations revealed that winter hardiness was concentrated among accessions originating from high elevation areas.     

Moderate impacts of plant invasion and management regimes in coastal hind dune seed banks

Plant invaders may directly or indirectly affect ecosystem resilience through their impact on soil seed banks. The invaders, and the application of control measures, change seed bank dynamics by altering the number of seeds entering and leaving the seed bank. We tested the impact of bitou bush (Chrysanthemoides monilifera ssp. rotundata), on the seed bank. We examined seed banks in heavily-invaded, sparsely-invaded and managed dunes, where bitou bush biomass had been controlled. While management of bitou bush may have reduced the density of bitou bush seeds in the soil, it did not reduce the richness of other weed species. Native tree species richness was significantly higher in seed banks of sparsely-invaded than either heavily-invaded or managed sites, perhaps indicating a permanent shift in community structure following invasion. However, remaining indices of native seed bank diversity were similar across all invasion categories, indicating that seed banks of many native species were unaffected by both invasion and management. While examination of seed banks is informative in assessing past and potential community dynamics, low similarity between the standing vegetation and seed bank at all sites indicated that many hind dune species had other storage or regeneration modes and seed banks cannot be relied upon for comprehensive dune restoration.     

Variation and genetic diversity for gliadins in Spanish spelt wheat accessions

Gliadin composition has been analysed in 403 accessions of spelt wheat (Triticum aestivum ssp. spelta); 61 different patterns were found for the -gliadins, 44 for the -gliadins, 19 for the -gliadins and 15 for the -gliadins. A subset of 333 accessions belonging to fifty populations from Asturias, North of Spain, showed high levels of genetic variation (A = 3.89, P = 0.88, Ne = 3.35 and He = 0.553), indicating that 82.5% of the genetic variation was within populations, and only 18.5% among populations. Thirty-five of these populations presented more of five accessions, in this new subset the values of genetic variation were higher that those of fifty populations (A = 4.49, P = 0.91, Ne = 3.80 and He = 0.595). The genetic variation within populations was 59.7% of the total, and 40.3% among populations, which could be associated to fixation effects of some alleles by genetic drift.     

菜心ISSR-PCR反应体系的优化

以菜心（Brassica campestris L．ssp．Chinensis Var．utilis Tssen．et Lee．）为材料,对影响ISSR-PCR扩增结果的因素如Mg^2＋、Taq DNA聚合酶、dNTPs、Primer、模版DNA的浓度及引物退火温度、延伸时间和循环次数进行了探讨,确立了适合菜心ISSR-PCR分析的最佳反应体系和PCR扩增参数：在25pL反应体系中含10×buffer 2．5μL,2．0mmol／LMg^2＋,0．5U Taq DNA聚合酶,0．2mmol／LdNTPs,0．5μmol／L引物,30ng模板DNA．PCR扩增程序：94℃预变性3min;94℃变性1min,49．7～56℃退火（退火温度随引物不同而定）1min,72℃延伸45s,40个循环;72℃延伸5min．     

大白菜叶球相关性状的QTL定位与分析

 应用 35 2个标记位点的大白菜AFLP和RAPD图谱和一套品种间杂交获得的重组自交系群体 ,采用复合区间作图的方法 ,对大白菜叶球相关的 7个农艺性状进行QTL有定位及遗传效应研究。结果表明 ,在 14个连锁群上检测到 33个QTL ,其中控制生育期的有QTL 3个 ,控制外叶数的QTL有 3个 ,控制球高的QTL有 7个 ,控制球径的QTL有 5个 ,控制球叶数的QTL有 4个 ,控制球重的QTL有 4个 ,控制荒重的QTL有 7个。另外 ,估算了单个QTL的遗传贡献率和加性效应 ,其加性效应各不相等