小麦HMW-GS与戊聚糖含量及其组分的相关分析和聚类分析

分析了21个不同小麦品种的HMW_GS组成,并测定了各品种戊聚糖及其组分的含量。根据亚基评分对不同小麦品种HMW_GS等位基因位点变异和亚基组合类型与戊聚糖、各组分和组分比值进行了相关分析,又根据评分和总戊聚糖含量对这21个品种进行了聚类。结果表明,供试材料的HMW_GS组合类型有11余种;不同品种间,阿拉伯糖变异大,木糖变异小,戊聚糖含量和各组分均有较大差异;大部分指标与Glu_1位点有显著的负相关,其中Glu_D1位点大于另外2个位点;N,7,17 18和2 12亚基对戊聚糖及各组分含量影响较大,烘烤品质较好的亚基1和5 10对戊聚糖及各组分含量的贡献则较小;含有亚基组合(N,7,2 12)的大部分戊聚糖指标含量均较高;聚类分析中把这些品种分为4类,第1类可以作为饲料生产,第3类可以作为食品工业生产。     

Synthetic Evaluation of Talent Effectiveness Considering Talent Structure

Based on the widening of definition of talent effectiveness, using the indexes of talent structure and economic output types, many indexes of talent effectiveness are built up. A synthetic evaluation of regional talent utilization efficiency is presented based on principal components analyses. The result indicates that the talent utilization efficiency in east China is higher distinctly than in middle and west China and the talent utilization efficiency in middle is close to in west China without obvious hierarchy distribution     

玉米自交系及杂交种抗青枯病鉴定

1986-1989年采用自然鉴定和人工土壤接种鉴定的方法，对602份玉米材料的青枯病抗性进行了鉴定。人工接种鉴定397份，其中204份材料表现抗病。在正常年份，人工接种鉴定效果明显好于自然鉴定，但在重病区或青枯病流行年份，在尚未具备人工接种条件时，利用自然发病作为选育抗病材料仍有一定效果。玉米苗期接种青枯病重于成株期     

区域农业水资源恢复力可变模糊评价模型

区域农业水资源系统是与自然及人类活动紧密联系的复杂适应系统,不断与周围环境发生物质、能量和信息因素方面的交换和作用。以黑龙江省农垦红兴隆管理局12个农场为研究基点,运用主成分-相关分析法筛选评价指标,构建农业水资源恢复力评价指标体系,采用CRITIC法确定指标权重,结合可变模糊模型评价方法对其农业水资源系统恢复力进行评价,并利用ArcGIS技术对其进行分区,结果表明:双鸭山、八五三、北兴和八五二农场的农业水资源恢复力为Ⅱ级,饶河、二九一、五九七、红旗岭、友谊、江川、宝山和曙光的农业水资源恢复力为Ⅲ级。研究成果揭示了当地农业水资源系统力恢复情况,为农业水资源系统恢复力研究提供了一种新的研究模式。     

The Effect of Chromosome 1B/1R Translocation on the Yield Potential of Certain Spring Wheats (Triticum aestivum L.)

Nearly 50 percent of the 1988 advanced breeding lines of the CIMMYT bread wheat breeding program possess the 1B/1R homozygous translocation. Hence, a trial was conducted to estimate the effect of 1B/1R chromosome translocation on the yield potential of some of our high-yielding spring wheats, where non-limiting levels of fertility, moisture, preventive pest and disease programs were used. In conclusing the 1B/1R lines seemed to have increased their above-ground biomass yield, number of spikes per meter², 1000-grain weight and test weight. They also exhibited a slight advantage over the 1B homozygous lines on grain yield. The observed difference, however, was non-significant, as was the plant height difference observed among the two groups. Varietal comparisons indicated that the 1B/1R group headed later than the 1B group.     

Path-Coefficient Analysis of Seed Yield Components in Euphorbia lathyris L.

The interrelationships of seed yield components in Euphorbia lathyris L. have been studied by means of path-coefficient analysis. Two of seven components, ‘Number of flowers of primary inflorescence’ and ‘Number of flowers of secondary inflorescences’ proved to be of major importance through direct effects on ‘Total number of fruits’ as indicator of seed yield. Indirect effects generally arc being canalized via the same variables. Selection for seed yield is made possible through the relation between ‘Number of secondary branches’ and ‘Number of flowers of secondary inflorescences’.     

小麦新品种“绵阳26”主要性状与产量的关系

对87个试验点的资料分析，绵阳26的主要性状与产量的回归方程为：y=-1084．3321＋5．265x1 9.0142x2＋5.2486x3＋8.3796x4＋6．3627x5。经偏回归和偏相关分析，产量构成因素中，千粒重，有效穗对绵阳26的产量贡献和影响最大（b'4=1．2769．b'2=1．1272，R2y0=0．7287，R4y0=005689）；而千粒重、有效穗、穗粒数之间为负相关，存在着不同程度的制约关系。在本资料现有产量的基础上，稳定千粒重，主攻穗数和穗粒数的提高，是发挥绵阳26高产潜力的决定因素。     

Selection for Seed Yield in Lolium perenne L.*

Components of seed yield were estimated for each set of 100 plants derived from six varieties of Lolium perenne. Significant differences between the varieties were found for all components of seed yield, but the range was broader within each variety. An indirect selection of seed yield using the character seeds per spike produced a selection response similar to that obtained by direct selection on high seed yield per plant. A direct and indirect selection of characters estimated in small, drilled plots of topcross off-springs (F₁) was less successful than the selection based on the single plants. Spearman rank correlation coefficients between the single plants and their offsprings did not show significant agreement for seed yield. But altogether the results indicated that the increase of seed yield/area was about 6 % when 10 % of the best plants were selected.     

Predicting the relative effectiveness of direct versus indirect selection for oat yield in three types of stress environments

Summary In breeding crop varieties for stress environments, it must be decided whether to select directly, in the presence of stress, or indirectly, in a nonstress environment. The relative effectiveness of these two strategies depends upon the genetic correlation (r _g ) between yield in stress and nonstress environments and upon heritability in each. These parameters were estimated for grain yield of 116 random oat lines grown in nonstress, P-deficient, N-deficient, and late-planted environments. Estimates of r _g between yield in nonstress and yield in P-deficient, N-deficient, and late-planted environments were 0.52±0.24, 1.08±0.16, and 0.06±0.24, respectively. No consistent relationship between heritability and environment mean yield was observed. Direct selection in the presence of stress was predicted to be superior for yield in low-P and late-planted environments, but indirect selection in high-N environments was predicted to be as effective as direct selection in producing yield gain in low-N environments. These results confirm that neither high-yield environments nor environments in which the heritability of yield is maximized are necessarily optimum when the goal is to maximize yield gain in stress environments.Dep. of Agronomy, Iowa State Univ., Ames, IA 50011; USA, Journal Paper no. 13101. Project 2447.     

Genetic variation in seed production and its components in four cultivars of the pasture grass Setaria sphacelata

Variation in seed production and its components was investigated between and within four cultivars of the pasture grass Setaria sphacelata, in two experiments over two years, as a basis for future cultivar improvement. The study sought to determine the basis for the considerable differences in seed production of the four cultivars Nandi, Narok, Solander and Kazungula, to determine the extent of genetic variation in the four cultivars in attributes which contribute to seed yield, and to investigate genotypic consistency in seed production over years and seasons. Each experiment comprised 50 genotypes of each cultivar. In the first experiment, plants were harvested a set number of days after median flowering date whereas in the second experiment, which was unreplicated, each genotype was harvested a set number of days after it had flowered. In the first experiment, seed yields were generally highest for Kazungula, lowest for Narok and intermediate for Nandi and Solander. All measured attributes contributing to seed yield exhibited a high order of variation between and within cultivars, but the basis for the large difference in seed yield per plant between cultivars was tiller fertility rather that total tiller number. Averaged over the four harvests, there was a six fold to > 100–fold intra-cultivar genetic range in seed production, associated with differences in tiller fertility, which were associated with differences in date of first flowering. Broad sense heritability for seed yield averaged 0.68 for the four cultivars and showed little change over the four harvests. Genotypes which produced high seed yields in summer were also more productive of seed in autumn and the 0ore productive genotypes in the first year were also more productive in the second year. Cultivars differed in the relative importance of factors which contributed to the high seed yield of high-yielding genotypes. In the second experiment, genotypes with a high seed yield also generally had the highest tiller fertility, even though all genotypes were harvested the same number of days after first flowering. Within-cultivar correlations in seed yield between the two experiments were generally significant and the elite 20% of genotypes from this experiment had 1.2–2.9 times the seed yield of the same genotypes with a very different harvesting regime in the first experiment. It is concluded that opportunities exist in all four cultivars for improvement in seed production and that the selection criterion offering the best opportunity for advance would be fertile tiller number. In Narok, Solander and Nandi, this would result in increased tiller fertility, whereas in Kazungula, it would result in an increase in total tiller number. This revised version was published online in July 2006 with corrections to the Cover Date.