Strawberry (Fragaria×ananassa Duch.) is rich source of dietary antioxidants, minerals and nutrients. Dietary antioxidants have been known as beneficial for enhancing the fitness, preventing certain diseases and even mitigating the effects of ageing. The objectives of the present study were to determine variability and inheritance of antioxidants, to identify antioxidant rich and productive genotypes, and to suggest suitable breeding approaches. The genotypes, namely Ofra, Chandler, Festival and Camarosa showed higher concentrations of dietary antioxidants and therefore could be useful in future breeding. Results indicate that the effect of the genotypes on antioxidant contents is stronger than that of the environment. The high heritability (>80%) and low genetic advance as percentage of mean (<40%) for ascorbic acid and β-carotene contents could be improved by heterosis breeding. However, selection and hybridization would be effective tools to enhance the phenols and anthocyanin content, and yield potential as these traits showed high heritability (>80%) and high genetic advance as percentage of mean (>40%). Positive direct effect on fruit yield was highest for phenol content (0.609) which is also fairly close to its correlation coefficient (0.765) indicating that a direct selection based on phenol content would be most effective and that the phenol content could be used as a reliable biochemical marker to identify the productive genotypes having higher amounts of dietary antioxidants. The information could also be used for developing antioxidant rich cultivars, i.e. ‘Breeding Strawberry for High Antioxidants’. 相似文献
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. 相似文献
Data from a trial of 36 families at Little Wittenham, North Oxford was used to assess growth traits and stem form in common
ash (Fraxinus excelsior, L.). The trial followed a design described by Barnes (Silv Genet 44(2–3):81–88, 1995) as the Breeding Seedling Orchard (BSO).
The objectives of the study were to determine variation in growth and form traits and estimate genetic parameters of families.
Assessments conducted at 3–8 years for height, diameter at breast height (dbh), straightness and forking showed significant
differences (P < 0.05) among families with Guys (19), Settrington (34), Overbury (23) and Grimthorpe (36) being the best performers while
Coleford (3 and 5) Gwynedd (27) and Bacheiddon (32) were the least performers. At the overall level, the additive genetic
coefficient of variation (CVA) ranged between 10.2 and 12.7% for height and 1.5 and 2.1% for dbh. Height had a high genetic correlation (rg = 0.85) with dbh whilst forking had low correlation (rg = 0.25) with height. Estimates of heritability decreased with age from
= 0.62 at 3 years to = 0.30 at 8 years for height while values for dbh decreased from = 0.48 at 4 years to = 0.27 at 8 years. Some genetic gains are possible despite the low genetic variation among families; height had the greatest
potential of genetic gain (12.5% at 8 years). Results suggest that early selection of superior families of Fraxinus excelsior appears to be feasible and it could be possible to achieve simultaneous improvement in both growth and form. 相似文献
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. 相似文献
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. 相似文献