茄子株高性状鉴定与遗传分析

以长茄高代自交系125 和126 构建的茄子6 个不同世代的遗传群体〔P₁、P₂、F₁、F₂、 B₁（125×F₁）、B₂（126×F₁）〕 为试材,利用主基因+ 多基因混合数量性状遗传模型对茄子的株高性状进行多世代遗传联合分析。结果表明：供试亲本株高 性状差异显著,分离世代株高性状数值均呈单峰的偏正态分布,属于数量性状遗传。多世代遗传联合分析结果显示茄子株高 性状的最适遗传模型为C-0 模型,不存在主基因遗传效应,表现为多基因控制的加性- 显性- 上位性遗传模式。采用二阶 遗传参数进一步分析株高的多基因遗传效应,结果显示,茄子分离世代F₂、B₂ 的多基因遗传率分别为49.24%、22.77%,茄 子株高以多基因遗传为主。     

6个籼型两系不育系的主要农艺性状配合力分析

[目的]通过对6个籼型两系不育系的配合力及遗传率分析,探讨其育种利用情况。[方法]以6个籼型不育系与6个恢复系为材料,采用不完全双列杂交(NCⅡ)设计,配制36个F1,对8个农艺性状进行配合力及遗传率分析。[结果]不育系的各性状一般配合力方差均达显著或极显著水平,这6个不育系对所配组合的株高、单株谷重等8个性状的影响均有明显差异;WA918S是一个较理想的不育系,新二S可利用其一般配合力,广茉S、1892S可利用特殊配合力,从而选育出强优势组合。[结论]该研究为合理利用这些不育系提供理论支持。     

Testing genetic determinism in rate of hoof growth in pigs using Bayes Factors

Excessive growth and consequent deformity of hooves is a frequent disorder in some purebred pig populations. A test to detect possible genetic determinism related with this phenomenon was performed using the Bayes Factor (BF). Data were available for females from three purebred selection lines: Landrace (561 records), Pietrain (183) and Large White (225). Animals were scored in four categories, according to the overall growth rate of their hooves. A Bayesian analysis was performed separately for each line using a threshold model with a probit approach, and Bayes Factors between models with and without additive genetic effects were computed. Results from the three lines showed that models exhibiting genetic variability were much more probable than those that did not include a genetic component, with BF values of 312, 35 and 40 (and posterior probabilities of 0.99, 0.97 and 0.98), respectively, for the Landrace, Pietrain and Large White lines. Monte Carlo estimates of posterior means of heritabilities were medium to high (0.25, 0.41 and 0.38, respectively), and the highest posterior density region for heritability at 99% did not include zero in any of the three lines. These results allow us to conclude that genetic determinism has an important influence upon the rate of hoof growth in the pig. A potential genetic response can be achieved in the populations analysed, but further studies are needed to determine the genetic architecture of hoof growth disorders in pigs.     

Fragrance heritability in Hybrid Tea roses

Most of the Hybrid Tea roses that are sold as cut flowers are non-scented, despite the long-standing interest of the perfume industry to rose scent. In the absence of comprehensive knowledge on the genetic and biochemistry of volatile biosynthesis in roses, we decided to characterize a Hybrid Tea progeny obtained from parents that emit very different scents. First, we identified the 11 most abundant volatile compounds synthesized by the progeny, and a short review is given for each one that describes their occurrence in the genus Rosa, in the parents and the studied progeny. We have then used statistical analysis on the distribution of volatiles among individual progeny members to unveil the laws of segregation of the scent traits in this cross. As a general rule, the quantity and quality of volatile compounds was lower in the progeny members. Variations in scent quality were mostly linked to the quantity of monoterpenes that was present. Offsprings emitting a pleasant fragrance were, in practice, found to be rare.     

Genetic Variance and Covariance Patterns of Growth and Survival in Northern Pinus sylvestris

The amount of additive genetic and environmental variance for tree height and field survival, and the genetic relationship between the traits were estimated using data from half-sib progenies of Swedish and Finnish Scots pine (Pinus sylvestris L.) plus-trees, assessed in 18 single-tree plot progeny trials. The progeny trials were established in northern Sweden and comprised 9-13-yr-old, Finnish polycross progenies or Swedish open-pollinated progenies. In total across the trials, 71?630 individual trees from 888 families were included in the study. At the overall level, the additive genetic coefficient of variation ranged between 3.1 and 16.3% for height and between 0 and 27.9% for survival, with averages of 9.5% and 14.2%, respectively. Narrow-sense heritabilities were moderate to low, with averages across trials of 0.11 for height and 0.06 for survival. At the within-population level, estimates of genetic correlation between height and survival were mostly large and positive, with an arithmetic mean and standard error across trials of 0.47±0.39.     

油松优树子代测定及遗传增益的初步研究

通过对５３０株油松优树子代林内８２９个家系（次）生长疸的测定，初步选出了较为优良的油松家系，并对不同来源的优树家系和单株的树高及地径的遗传率进行了估算。     

南方春大豆不同播季主要农艺性状的变化及其遗传研究

本文以１２个南方春大豆早熟品种（系）和１２个中熟品种（系）为材料，进行春，秋播试验，研究主要农艺性状的秋播变异率，遗传变异系数，遗传力和遗传进度，结果表明：１，两熟期组秋播变异率平均，除分枝起点为负值以外，其它１１个性状在２．３６％－５２．８８％之间，说明秋播对为结性状均有一定影响；熟期组之间各性状秋播变异率的大小亦存在较大差异，如秋播对早熟组株高，主茎节数，结荚节数，结荚高度，主茎荚数和百粒重的     

Resin canal traits relevant for constitutive resistance of Norway spruce against bark beetles: environmental and genetic variability

The influence of genetic determination and environment on the variability of secondary resin canal traits was investigated on 15–19-year-old Norway spruce (Picea abies (L.) Karst.) clones grown in Lower Austria (Pressbaum and Ulmerfeld) and southern Sweden (Knutstorp and Hermanstorp). Eleven and 20 clones were present on the two Austrian and the two Swedish sites, respectively. The sites differed in their water availability, as indicated by different annual precipitation and soil type. Resin canal traits measured were the number of epithelial cells per canal, the number of resin canals per unit tangential wood surface area, the mean resin canal area and the total resin canal area per unit tangential wood surface area. The latter three traits are known to be related to the constitutive resin flow of Norway spruce.

Environment had an influence on the variability of resin canal traits but the most important factor for the variability was the tree’s genetic disposition. Within countries, clones from the drier sites (Pressbaum and Hermanstorp) showed significantly smaller resin canals. Trees from Pressbaum also had smaller total resin canal areas than trees from Ulmerfeld. The number of epithelial cells and the number of canals did not differ between sites.

Resin canal traits had wide genetic variation and high broad sense heritabilities (H²), with values between 0.28 and 0.82. Highest heritability values were reached for the number of epithelial cells and the number of canals (H² > 0.8). Genotypic correlations across trials were high for the resin canal traits and approached 1 in both the Austrian and the Swedish trials, indicating that there was little genotype by environment interaction for these traits and thus the ranking of clones was very similar in the different environments.

The number of epithelial cells, the mean area and the total resin canal area showed either moderately significant positive genotypic correlations with tree growth traits or none at all.

In a breeding context, our results are encouraging and indicate that high constitutive defence potential against bark beetles, such as Ips typographus, is not aligned with low volume growth. But it should be taken into consideration that environment and forestry practices can also have an impact on the resin reservoir provided by the radial resin canals.     

Age trends in the genetic parameters of wood density and the relationship with growth rates in hybrid larch (Larix gmelinii var. japonica × L. kaempferi) F1

Age trends in variance components and heritability of overall wood density, earlywood and latewood density, and latewood proportion were investigated in 29-year-old trees of 19 full-sib families of hybrid larch (Larix gmelinii var. japonica × Larix kaempferi) F₁. The age–age correlation and optimum selection age for these traits were also estimated and genetic and phenotypic correlations between wood density and radial growth rate were calculated for each growth ring. Intraring wood density data were obtained using X-ray densitometry. The coefficient of additive genetic variance was stable over all ages, whereas the coefficient of environmental variances gradually decreased with increasing age, resulting in increases in heritability estimates with age for overall density. The latewood proportion had the highest heritability estimates at all ages, ranging from 0.44 to 0.66. Overall density and its various components at 28 years of age showed strong genetic correlations with their respective traits at all younger ages. Optimum selection ages for the wood density traits ranged from 8 to 14 years, at which point maximum gain efficiencies per year were obtained. There were negative correlations between wood density and radial growth rate at early ages, although these relationships tended to be weaker with increasing age. These results suggest that selection at a young age is effective for wood density, but particular care must be taken in selecting trees with an improved radial growth rate because rapid growth will result in a low-density wood product, especially in the early growth period.     

裂叶红麻的光合器官数量性状与麻皮产量相关性分析

对６个裂叶红麻品种（系）不同光合器官的数量性状与干皮产量作了相关分析。结果表明总叶数、７裂叶数及麻皮长和麻皮宽的光合器官之间及与干皮产量之间的相关都是显著的，而圆叶数、３裂叶数及５裂叶数与干皮产量相关不显著。总对数、７裂叶数及麻皮长的数量性状其广义和狭义遗传力都很低．表明主要光合器官的表现易受环境影响，注意选择圆叶数性状可能有助于培育高产品种。