scholarly journals Budbreak Number in Apple Seedlings as Selection Criterion for Improved Adaptability to Mild Winter Climates

HortScience ◽  
2003 ◽  
Vol 38 (6) ◽  
pp. 1186-1190 ◽  
Author(s):  
Iwan F. Labuschagné ◽  
J.H. Louw ◽  
Karin Schmidt ◽  
Annalene Sadie
Keyword(s):  
Environmental Conditions ◽  
Selection Criterion ◽  
Shoot Length ◽  
Natural Conditions ◽  
Mild Winter ◽  
Winter Conditions ◽  
Important Symptom ◽  
Selection For ◽  
Prolonged Dormancy

Absence or long delay of budbreak, also known as prolonged dormancy, is the most important symptom during incomplete dormancy. Budbreak number was evaluated to quantify seedling response to chilling and selection on excised and intact 1-year-old apple (Malus ×domestica Borkh.) seedlings under controlled and natural environmental conditions. Indices based on: 1) the number and distribution of budbreak (prolonged dormancy grade = PDG); 2) the number of buds breaking, including shoot length with increased budbreak as part of the calculation (prolonged dormancy index = PDI); and 3) budbreak number per 100-cm shoot (NB) were tested in association with budbreak time (TB). The indices expressed the effects of cold treatments that induce earlier and higher numbers of budbreak. PDI and NB, but not PDG, identified families with increased budbreak. Seedlings with high PDG and NB were also associated with families in which high chill requiring parents were used, indicating that TB as pre-selection criterion may fail to identify seedlings with increased budbreak. Response to pre-selection for increased budbreak using PDG could be verified with the PDS and NB indices in seedlings and seedling clones. The NB of intact 1-year-old shoots under natural conditions is recommended as a pre-selection criterion against prolonged dormancy in suboptimal winter conditions.

scholarly journals Hotel Selection Criteria of Solo Traveling Females

2020 ◽  
Vol 18 (2) ◽  
pp. 58-73
Author(s):  
Halimin Herjanto ◽  
◽  
Alexandra Chilicki ◽  
Chidchanok Anantamongkolkul ◽  
Erin McGuinness ◽  
...  
Keyword(s):  
Cell Phone ◽  
Selection Criteria ◽  
Academic Research ◽  
Selection Criterion ◽  
Product Evaluations ◽  
Purchasing Decisions ◽  
Study Results ◽  
Automated Teller Machine ◽  
Selection For ◽  
Cost Efficient

Consumers use online e-reviews as a popular tool for information and obtaining guidance. E-reviews have therefore become an important barometer in conducting product evaluations, and more importantly, to make purchasing decisions. This includes decisions about hotel selection. For hospitality industry marketers, the information in e-reviews is particularly important in translating and understanding consumer-specific needs. The current study brings valuable awareness to the limited academic research into hotel selection criteria among solo-traveling females. TripAdvisor’s top 25 list of cost-efficient hotels worldwide received 345 total consumer reviews. Noteworthy findings of the current study show unique selection criteria considered important to the solo traveling female including a hotel-provided cell phone programmed with emergency local contact information, and a nearby or on-premise automated teller machine. Study results also indicate that stewardship service, such as intimate and personalized hotel staff who “go the extra mile” is an important selection criterion. Also discussed are research limitations and implications.

scholarly journals Variability, Heritability, Genetic Advance and Interrelationships for Agronomic and Yield Traits of Sorghum B-Lines under Different Environments

2018 ◽  
pp. 1-13
Author(s):  
A. M. M. Al-Naggar ◽  
R. M. Abd El-Salam ◽  
M. R. A. Hovny ◽  
Walaa Y. S. Yaseen
Keyword(s):  
Grain Yield ◽  
Coefficient Of Variation ◽  
Block Design ◽  
Selection Criterion ◽  
Genetic Advance ◽  
Planting Dates ◽  
High Heritability ◽  
Selection For ◽  
Strength Of Association ◽  
B Lines

Information on heritability and trait association in crops assist breeders to allocate resources necessary to effectively select for desired traits and to achieve maximum genetic gain with little time and resources. The objectives of this investigation were to determine the amount of genetic variability, heritability, genetic advance and strength of association of yield related traits among sorghum lines under different environments in Egypt. Six environments with 25 sorghum B-lines were at two locations in Egypt (Giza and Shandaweel) in two years and two planting dates in one location (Giza). A randomized complete block design was used in each environment with three replications. Significant variation was observed among sorghum lines for all studied traits in all environments. Across environments, grain yield/plant (GYPP) showed positive and significant correlations with number of grains/plant (r = 0.71), days to flowering (r = 0.47), 1000-grain weight (r = 0.16) and plant height (PH) (r = 0.19). In general, the estimates of phenotypic coefficient of variation (PCV) were higher than genotypic coefficient of variation (GCV). Combined across the six environments, the highest PCV and GCV was shown by PH trait (95.14 and 43.57%) followed by GYPP (36.42 and 30.78%), respectively, indicating that selection for high values of these traits of sorghum would be effective. GYPP and PH traits showed high heritability associated with high genetic advance from selection, indicating that there are good opportunities to get success in improvement of these traits via selection procedures. Results concluded that PH is good selection criterion for GYPP and therefore selection for tall sorghum plants would increase grain yield.

scholarly journals Sympatric Atlantic puffins and razorbills show contrasting responses to adverse marine conditions during winter foraging within the North Sea

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Katie St. John Glew ◽  
Sarah Wanless ◽  
Michael P. Harris ◽  
Francis Daunt ◽  
Kjell Einar Erikstad ◽  
...  
Keyword(s):  
North Sea ◽  
Environmental Conditions ◽  
Trophic Position ◽  
Survival Rates ◽  
Sympatric Species ◽  
Ecological Niches ◽  
Overwinter Survival ◽  
The North ◽  
Winter Conditions ◽  
The North Sea

Abstract Background Natural environments are dynamic systems with conditions varying across years. Higher trophic level consumers may respond to changes in the distribution and quality of available prey by moving to locate new resources or by switching diets. In order to persist, sympatric species with similar ecological niches may show contrasting foraging responses to changes in environmental conditions. However, in marine environments this assertion remains largely untested for highly mobile predators outside the breeding season because of the challenges of quantifying foraging location and trophic position under contrasting conditions. Method Differences in overwinter survival rates of two populations of North Sea seabirds (Atlantic puffins (Fratercula arctica) and razorbills (Alca torda)) indicated that environmental conditions differed between 2007/08 (low survival and thus poor conditions) and 2014/15 (higher survival, favourable conditions). We used a combination of bird-borne data loggers and stable isotope analyses to test 1) whether these sympatric species showed consistent responses with respect to foraging location and trophic position to these contrasting winter conditions during periods when body and cheek feathers were being grown (moult) and 2) whether any observed changes in moult locations and diet could be related to the abundance and distribution of potential prey species of differing energetic quality. Results Puffins and razorbills showed divergent foraging responses to contrasting winter conditions. Puffins foraging in the North Sea used broadly similar foraging locations during moult in both winters. However, puffin diet significantly differed, with a lower average trophic position in the winter characterised by lower survival rates. By contrast, razorbills’ trophic position increased in the poor survival winter and the population foraged in more distant southerly waters of the North Sea. Conclusions Populations of North Sea puffins and razorbills showed contrasting foraging responses when environmental conditions, as indicated by overwinter survival differed. Conservation of mobile predators, many of which are in sharp decline, may benefit from dynamic spatial based management approaches focusing on behavioural changes in response to changing environmental conditions, particularly during life history stages associated with increased mortality.

Environmental Conditions in TT 209, Luxor. The Case of a Theban Tomb Subject to Periodic Flooding

2019 ◽  
Vol 105 (1) ◽  
pp. 115-125
Author(s):  
Miguel Ángel Molinero Polo ◽  
Vicente Soler Javaloyes
Keyword(s):  
Relative Humidity ◽  
Data Collection ◽  
Environmental Conditions ◽  
Flash Floods ◽  
Environmental Data ◽  
Natural Conditions ◽  
Archaeological Work ◽  
Ancient Times ◽  
Collection Temperature ◽  
Periodic Flooding

TT 209 was built in a wadi, a location that means it has been affected by flash floods since ancient times. The team in charge of its study and conservation has initiated a systematic programme of environmental data collection (temperature and relative humidity) in order to understand the natural conditions of the tomb and any transformations caused by archaeological work in its underground chambers, as well as to inform future conservation. These statistics can also be useful for excavation and conservation programmes in nearby tombs whose architectonic structure is similar and have also suffered from exposure to water damage.

scholarly journals Factors Affecting Egg Deposition of the European Mantis

2020 ◽  
Vol 68 (2) ◽  
pp. 45-49
Author(s):  
Joanna Kajzer-Bonk
Keyword(s):  
Habitat Selection ◽  
Environmental Conditions ◽  
Plant Cover ◽  
Egg Laying ◽  
Natural Conditions ◽  
Factors Affecting ◽  
Egg Deposition ◽  
Predatory Insect ◽  
Egg Case ◽  
Potential Tool

In this paper, we studied the egg-case (oothecae) deposition of the European mantis, Mantis religiosa (Linnaeus 1758), a predatory insect. We hypothesized that the height of ootheca deposition on a plant reflects the insolation requirements of the species, and would increase when plant cover is denser. We found that the taller the plants nearby, the greater the height of egg deposition. Oothecae were also oviposited higher in denser vegetation. The observed behavior may ensure the proper insolation of developing offspring. To our knowledge, this is the first description of an egg laying strategy of this species under natural conditions. This finding allows for a better understanding of habitat selection and the overall ecology of the European mantis. It may be also useful in identifying the mechanisms of the range extension of this species and is a potential tool to effectively conserve xerothermic ootheca-laying animals. Further studies are required to assess the flexibility of this behavior under different environmental conditions.

Estimation of phenotypic selection differentials for predicting genetic responses to ratio-based selection

Genome ◽  
1988 ◽  
Vol 30 (6) ◽  
pp. 838-843 ◽  
Author(s):  
D. E. Mather ◽  
F. C. Gunsett ◽  
O. B. Allen ◽  
L. W. Kannenberg
Keyword(s):  
Selection Criteria ◽  
Crop Improvement ◽  
Selection Criterion ◽  
Phenotypic Selection ◽  
Worked Examples ◽  
Genetic Response ◽  
Analysis And Evaluation ◽  
Selection For ◽  
Genetic Responses ◽  
Selection Differentials

Ratios of the phenotypic values of two traits may be used as selection criteria in animal and plant breeding to improve the ratio traits themselves or to effect changes in their two component (numerator and denominator) traits. Prediction of genetic responses to ratio-based selection would facilitate quantitative analysis and evaluation of selection based on ratios. Methods for predicting such responses are derived and presented here. They employ expressions for the truncation value of a ratio and for the phenotypic selection differentials of the numerator and denominator traits. The derivation of these expressions is based upon the assumption that the phenotypic values of each of these traits are normally distributed. Worked examples relating to livestock and crop improvement are included to demonstrate how responses to selection for ratios may be predicted.Key words: ratio selection criterion, selection differential, genetic response.

Seed coat specific weight in Lupinus angustifolius: influence of genotype and environment and relationship with seed coat proportion

2004 ◽  
Vol 55 (11) ◽  
pp. 1189 ◽  
Author(s):  
M. Mera ◽  
R. Jerez ◽  
H. Miranda ◽  
J. L. Rouanet
Keyword(s):  
Seed Coat ◽  
Seed Weight ◽  
Mass Density ◽  
Selection Criterion ◽  
Specific Weight ◽  
Equal Mass ◽  
Lupinus Angustifolius ◽  
Broad Sense ◽  
Broad Sense Heritability ◽  
Selection For

Abstract. The relatively high seed coat proportion of the narrow-leafed lupin reduces its economic value. This character has been shown to be affected by seed weight, and this limits the use of seed coat proportion as a selection criterion. We examined the variation for seed coat specific weight, a potential alternative selection criterion, and tested its relationship with seed coat proportion and seed weight. Seeds were sampled from mainstem pods of 14 winter-sown genotypes of Lupinus angustifolius L. grown at 4 southern Chile sites over 2 years. Seed coat specific weight had an overall mean of 30.1 mg/cm2. Highly significant genotypic effects were found (range 28.9–32.1 mg/cm2). The ranges for sites and years were 29.1–31.1 and 28.9–31.2 mg/cm2, respectively. Genotypes interacted significantly with years, but not with sites. Broad-sense heritability was 0.59, a value that predicts a good response to selection for this character. Seed coat specific weight was weakly correlated (rph = 0.11*) with seed coat proportion, and was not associated with mean seed weight. Seed coat proportion was negatively correlated with mean seed weight (rph = –0.75***) and had high broad-sense heritability (0.95). The correlation between seed coat specific weight and a theoretical seed coat thickness, calculated under the assumptions of equal mass density of seed coat, cotyledons, and embryo, and a spherical-shaped seed, was r = 0.14*. Phenotypic and genotypic correlations between seed coat specific weight and number of seeds per pod were 0.41 and 0.84, respectively. Our results indicate that selection for low seed coat proportion will lead to larger seeded genotypes, but will not reduce seed coat specific weight. Selection for low seed coat proportion after crosses would presumably be effective in reducing seedcoat specific weight if all segregating materials were uniformly large seeded, but that scenario is unrealistic. The evidence presented here suggests that selection for low seed coat specific weight (or measures correlated with it) in segregating populations will be necessary in order to increase the proportion of higher value kernels in seeds and to improve the economic yield of lupins.

scholarly journals Selection Criteria for Drought-Tolerant Bread Wheat Genotypes at Seedling Stage

2019 ◽  
Vol 11 (9) ◽  
pp. 2584 ◽  
Author(s):  
Hafiz Ahmed ◽  
Muhammad Sajjad ◽  
Mingju Li ◽  
Muhammad Azmat ◽  
Muhammad Rizwan ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Selection Criteria ◽  
Dry Weight ◽  
Shoot Length ◽  
Seedling Stage ◽  
Chlorophyll B ◽  
Fresh Weight ◽  
Drought Tolerant ◽  
Selection For ◽  
Thermo Stability

Diminishing water resources as a result of excessive use of water for irrigation and climate change posture a severe global threat to food security. Herein, an experiment was conducted to determine the selection criteria for drought-tolerant bread wheat genotypes at the seedling stage using morphological and photosynthetic pigmentation-related traits. A panel of 105 wheat landraces, historical Pakistani varieties, and advance breeding lines were evaluated under normal and drought stress using factorial completely randomized design. The root length, fresh weight, dry weight, cell membrane thermo-stability, and chlorophyll b were positively correlated among themselves under both normal and stress conditions. Hence, selection of any one of these traits enhances the performance of other traits. The shoot length was non-significant and negatively associated with all other studied characters except relative water content. The results suggested that selection for shoot length could not improve genetic gain for drought tolerance. Out of 10 principal components (PCs), the first three PCs were showed significant genetic variation under both conditions. The first three PCs showed 74.6% and 76% cumulative genetic variation under normal and drought conditions, respectively. Based on PCA, 10 drought-tolerant and five drought-susceptible genotypes were identified. Overall results suggested that selection for root length, fresh weight, dry weight, cell membrane thermo-stability, and chlorophyll b at the seedling stage would improve genetic gain for drought tolerance. The outperforming genotypes under drought stress conditions can be useful in future wheat breeding programs, and early selection for the traits recommended in this study will be effective for developing high-yielding and drought-tolerant wheat varieties.

scholarly journals Effects of lead on seedling growth of spesia populnea

2010 ◽  
Vol 56 (No. 4) ◽  
pp. 194-199 ◽  
Author(s):  
M. Kabir ◽  
M.Z. Iqbal ◽  
M. Shafiq ◽  
Z.R. Farooqi
Keyword(s):  
Leaf Area ◽  
Environmental Conditions ◽  
Root Length ◽  
Growth And Development ◽  
Strong Influence ◽  
Dry Weight ◽  
Shoot Length ◽  
Thespesia Populnea ◽  
Seedling Length ◽  
Number Of Leaves

The effects of lead on root, shoot and seedling length, leaf area, number of leaves, plant circumference, seedling dry weight, root/shoot and leaf area ratios of <I>Thespesia populnea</I> L. were determined in greenhouse under natural environmental conditions with and without phytotoxic metal ions at 5, 10, 15, 20, and 25 µmol/l. Lead treatments have a strong influence on the growth and development of <I>T</I>. <I>populnea</I> by reducing significantly (<I>P</I> &lt; 0.05) all the above parameters. Lead treatment at 5–25 µmol/l produced significant (<I>P</I> &lt; 0.05) effects on seedling and root length, plant circumference and seedling dry weight of <I>T</I>.<I> populnea,</I> while lead treatment at 10–25 µmol/l produced significant (<I>P</I> &lt; 0.05) effects on shoot length, number of leaves and leaf area as compared to control. Tolerance in <I>T</I>.<I> populnea</I> seedling at 25 µmol/l of lead treatment was lowest as compared to all other treatments.

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