scholarly journals Quantitative genetic analysis in Phalaris tuberosa I. The statistical theory of open-pollinated progenies

1965 ◽  
Vol 6 (3) ◽  
pp. 360-370 ◽  
Author(s):  
B. D. H. Latter
Keyword(s):  
Growth Rate ◽  
Statistical Theory ◽  
Genetic Analysis ◽  
Maternal Effects ◽  
Seed Weight ◽  
Open Pollination ◽  
Quantitative Genetic ◽  
Commercial Population ◽  
Seedling Growth Rate ◽  
Self Fertilization

The present series of papers is concerned with the variation shown by date of ear emergence, seed weight, and measures of seedling growth rate in the Australian Commercial population of Phalaris tuberosa L. In this first communication, the statistical theory necessary for the interpretation of the available experimental observations is developed. The treatment involves a consideration of the effects of partial self-fertilization under open-pollination, of phenotypic assortative mating, and of maternal effects, on the expectations of the observed covariances among relatives.

scholarly journals Quantitative genetic analysis in Phalaris tuberosa II. Assortative mating and maternal effects in the inheritance of date of ear emergence, seed weight and seedling growth rate

1965 ◽  
Vol 6 (3) ◽  
pp. 371-386 ◽  
Author(s):  
B. D. H. Latter
Keyword(s):  
Growth Rate ◽  
Genetic Variation ◽  
Assortative Mating ◽  
Maternal Effects ◽  
Seedling Growth ◽  
Seed Weight ◽  
Correlated Response ◽  
Environment Interaction ◽  
Additive Genetic Variation ◽  
Seedling Growth Rate

The variation shown by the Australian Commercial population of P. tuberosa in respect of date of ear emergence, seed weight and seedling weight has been analysed, and the interrelationships among the variables characterized. All three characters show appreciable additive genetic variation, in the sense that approximately seven generations of artificial selection would be sufficient to push the population mean for each trait beyond the range shown by introduced ecotypes.Apart from the positive association between seed weight and seedling weight due to maternal influence, the three variables are to a large extent genetically independent in this locally adapted interbreeding population. It is therefore probable that the negative ecotypic correlations between seedling growth rate and date of ear emergence, and between seed weight and date of ear emergence, would rapidly be dispelled under random mating in a synthetic population.Under open-pollination, date of ear emergence has been shown to be subject to phenotypic assortative mating of degree ρ = 0·78, approximately 53% of the variation being additive genetic. Variation in seed weight within the strain is extensive, with a heritability of 0·79. Neither character shows evidence of important genotype × years interaction.Variation in seedling weight involves an appreciable genotype × environment interaction component, and has a heritability of only 0·17 which includes variation due to genetically determined maternal effects. The correlation between the seed weight of an ovule parent and the ‘ true’ mean seedling weight of the derived maternal half-sib group is of the order of 0·57. It has been estimated that the correlated response per generation in seedling weight, due to selection for seed weight, is 0·54 times that expected from direct selection.

Influence of stress during soybean seed fill on seed weight, germination, and seedling growth rate

1991 ◽  
Vol 71 (2) ◽  
pp. 373-383 ◽  
Author(s):  
D. L. Dornbos Jr. ◽  
R. E. Mullen
Keyword(s):  
Growth Rate ◽  
Water Stress ◽  
Seed Yield ◽  
Seed Weight ◽  
Soybean Seed ◽  
Seed Number ◽  
Individual Seed ◽  
Small Seed ◽  
Seedling Growth Rate ◽  
Seed Fill

Water and high air-temperature (AT) stresses that occur during soybean (Glycine max (L.) Merr.) seed fill greatly reduce seed yield, but their effects on seed germination and vigor are less clear. The objective of this study was to determine the effect of water stress at optimum and high AT during seed fill on soybean seed yield and individual seed weight, and the subsequent germination and vigor of the seed. At daytime ATs of 27 and 35 °C in 1985 and 29 and 33 °C in 1986, control, moderate, and severe water-stress treatments were imposed by differential irrigation throughout seed fill on greenhouse-grown plants. Water stress intensity, measured by accumulating stress degree days (SDD) during seed fill, increased linearly as the volume of irrigation water declined. The weight and number of seed produced by each plant, and individual seed weight, declined linearly as SDDs accumulated at each AT. Water stress at optimum ATs reduced seed number more than individual seed weight, but water stress at high ATs reduced individual seed weight more than seed number. Water or high AT stress caused fewer larger seed and more small seed to be produced. The germination percentage and vigor of the harvested seeds was reduced by water stress and high ATs, but by a smaller proportion than yield or seed number. Individual seed weight, germination, and seedling growth rate were strongly correlated when reduced by water and high AT stress. Severe stress during seed fill caused soybean plants to exceed their capacity to buffer seed number, shifting seed weight distributions towards a larger proportion of small seed, resulting in poor seed lot germination and vigor. Key words: Soybean, germination, vigor, drought, high temperature, heat stress

scholarly journals Quantitative Genetic Analysis of Growth Rate in Avocado

2007 ◽  
Vol 132 (5) ◽  
pp. 691-696 ◽  
Author(s):  
Haofeng Chen ◽  
Vanessa E.T.M. Ashworth ◽  
Shizhong Xu ◽  
Michael T. Clegg
Keyword(s):  
Growth Rate ◽  
Genetic Analysis ◽  
Tree Growth ◽  
Growth Rates ◽  
Fruit Set ◽  
Tree Height ◽  
Persea Americana ◽  
Trunk Diameter ◽  
Quantitative Genetic ◽  
Quantitative Genetic Analysis

The authors report a quantitative genetic analysis of avocado (Persea americana Mill.) growth rate, flower abundance, and fruit set. The data are based on a total of 204 different genotypes of progeny of ‘Gwen’ avocado. Each was replicated four times, with two replicates planted in each of two locations in southern California (Irvine and Riverside). Data were collected over 4 years (consecutive) on tree height, canopy diameter, and trunk diameter, representing three distinct measures of growth rate. Growth data were found to fit a linear regression over years, so the slope (growth rate) was used in the analyses. In addition, 2 years of data on flower abundance and 1 year on fruit set were also collected. Quantitative genetic analyses of these data showed that broad-sense heritability (H) was 35.5%, 30.3%, and 26.6% for tree height, canopy diameter, and trunk diameter respectively; and 33.8% and 23.0% for flowering abundance and fruit set respectively. No genotype-by-location effect was noted for growth rate; however, flower abundance and fruit set showed a relatively weak genotype-by-location effect (21.9% and 17.1% respectively). The H estimates are low, probably as a result of sources of uncontrolled environmental error associated with variation in initial planting dates, but fall within the range that should permit quantitative trait locus analyses. The authors also found a moderate positive correlation between tree growth rates and fruit set, but none between growth rates and flower abundance. Different pollen parents have significantly different impacts on tree growth rates, flower abundance, and fruit set.

scholarly journals Evaluation of Seed Nut Size as Index of Selection for Superior Seed Quality Attributes in Two Biotypes of Cashew (Anacardium occidentale)

2015 ◽  
Vol 72 (1) ◽  
pp. 69-81
Author(s):  
T. O. Kehinde ◽  
M. A. Adebisi ◽  
A. O. Alegiledoye ◽  
O. O. Ajani ◽  
K. A. Shofuyi
Keyword(s):  
Growth Rate ◽  
Seed Germination ◽  
Seedling Growth ◽  
Seed Weight ◽  
Seed Quality ◽  
Seed Length ◽  
Seedling Vigour ◽  
Seedling Growth Rate ◽  
Seed Width ◽  
100 Seed Weight

Abstract Quality seed nuts are germane to propagation of the cashew plant. Seed nut fraction and genotypes have been identified to influence seed quality of crop plant. Unexpectedly, seed size effect has not been well documented in Brazilian and local biotypes of cashew grown in Nigeria. An experiment was initiated to investigate the effect of three nut sizes and two biotypes of cashew on seed quality (physical and physiological) traits. Seed nut were collected from three cashew plants of the same age of each of the biotypes and were allowed to stay for 60 days after collection. The experiment was carried out in a factorial arrangement laid out in a completely randomized design with three replicates using two factors (nut size and biotypes) in 2011 cropping season in both laboratory and screen house tests. Data were collected on physical characters such as seed length, seed width, 100 seed weight and seed imbibition rate while physiological characters were seed germination and early vigour traits. Data obtained were analysed statistically using Tukey HSD test at 5% probability level. The result revealed that some of the characters were significantly different from one another. Seed nut fraction and biotype had considerable effect on seed length, seed width, seed imbibition rate and 100 seed weight. The two factors (nut size and biotype) interaction had profound effect on seed width only. On seed physiological quality, biotype effect was significant on seedling fresh and dry weights and seedling growth rate whereas seed nut size had considerable effect on seed germination, seedling vigour index, seedling fresh weight and seedling growth rate. The interaction effect of nut size and biotype recorded significant effect on the above four characters. Brazilian biotype had superior physical characters (seed length, width and weight) but with low imbibitions rate while medium and large nut sizes gave the highest seed germination and seedling vigour. Also, medium and large nuts had the highest seedling fresh weight whereas the highest seedling growth rate was recorded with small size seed. However, large, medium and small nut sizes of local biotype had the highest imbibition rate, whereas small, medium and large nut size of Brazilian biotype gave the highest 100 seed weight. On seedling emergence, large nuts of local biotype recorded the highest seedling emergence and seedling vigour index. Medium nuts of the two biotypes of cashew are recommended for cashew seed multiplication. Further research on physiology of cashew nut sizes during storage and osmo and hydro priming treatment effect are necessary and therefore advocated.

scholarly journals Assessing risk of the natural regeneration of introduced conifers or wilding spread

2008 ◽  
Vol 61 ◽  
pp. 91-97 ◽  
Author(s):  
N.J. Ledgard
Keyword(s):  
Risk Factors ◽  
Land Use ◽  
Growth Rate ◽  
Decision Support ◽  
Decision Support Systems ◽  
Seed Production ◽  
Vegetation Cover ◽  
Natural Regeneration ◽  
Seed Weight ◽  
Seedling Growth Rate

Two decision support systems (DSS) have been developed to assess (a) the threat of introduced conifer (wilding) spread from new plantings and (b) the risk of wildings establishing at any particular site Scores (04) are given for risk factors related to the species involved their spreading vigour (includes seedling growth rate age of coning seed production and seed weight) palatability siting of the parent seed trees and vegetation cover and land use particularly downwind of the seed source The maximum possible score is 20 and scores above 12 (DSSa) and 14 (DSSb) indicate high levels of risk The two DSSs can be used by land managers to quickly assess the likely risk of wilding spread and to test how they might lower the risk by changing input factors In this way spread risk can be mitigated or avoided by good decisionmaking prior to unwanted wilding spread occurring

scholarly journals A Quantitative Genetic Analysis of Nuclear-Cytoplasmic Male Sterility in Structured Populations of Silene vulgaris

Genetics ◽  
2001 ◽  
Vol 158 (2) ◽  
pp. 833-841 ◽  
Author(s):  
Douglas R Taylor ◽  
Matthew S Olson ◽  
David E McCauley
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Genetic Analysis ◽  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Sex Expression ◽  
Silene Vulgaris ◽  
Population Variance ◽  
Quantitative Genetic ◽  
Quantitative Genetic Analysis

Abstract Gynodioecy, the coexistence of functionally female and hermaphroditic morphs within plant populations, often has a complicated genetic basis involving several cytoplasmic male-sterility factors and nuclear restorers. This complexity has made it difficult to study the genetics and evolution of gynodioecy in natural populations. We use a quantitative genetic analysis of crosses within and among populations of Silene vulgaris to partition genetic variance for sex expression into nuclear and cytoplasmic components. We also use mitochondrial markers to determine whether cytoplasmic effects on sex expression can be traced to mitochondrial variance. Cytoplasmic variation and epistatic interactions between nuclear and cytoplasmic loci accounted for a significant portion of the variation in sex expression among the crosses. Source population also accounted for a significant portion of the sex ratio variation. Crosses among populations greatly enhanced the dam (cytoplasmic) effect, indicating that most among-population variance was at cytoplasmic loci. This is supported by the large among-population variance in the frequency of mitochondrial haplotypes, which also accounted for a significant portion of the sex ratio variance in our data. We discuss the similarities between the population structure we observed at loci that influence sex expression and previous work on putatively neutral loci, as well as the implications this has for what mechanisms may create and maintain population structure at loci that are influenced by natural selection.

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