scholarly journals Selection Criteria and Selection Environment for Drought Tolerance of Egyptian Wheat (Triticum aestivum L.) Landraces

2020 ◽  
pp. 25-40
Author(s):  
Ahmed Medhat Mohamed Al-Naggar ◽  
Mohamed Abd El-Maboud Abd El-Shafi ◽  
Mohamed Helmy El-Shal ◽  
Ali Hassan Anany
Keyword(s):  
Drought Tolerance ◽  
Grain Yield ◽  
Selection Criteria ◽  
Selection Criterion ◽  
Correlation Coefficients ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Genetic Advance ◽  
Selection Environment ◽  
Selection For

Strong correlations between wheat traits and drought tolerance (DT) associated with high heritability and high genetic advance from selection would allow plant breeder to use such traits as selection criteria. The objective of the present investigation was to determine the optimum selection criteria and selection environment for drought tolerance via estimation of correlation coefficients (r) among 13 agronomic, grain yield and quality traits and DT of 20 wheat landraces, broad-sense heritability (h2b) and genetic advance (GA) from selection for such traits under well-watered (WW) and water stressed (WS) environments. A two-year experiment was carried out using a split-plot design with four replications. Results concluded that the best selection criterion for drought tolerance in our study was grain yield/plant (GYPP), followed by a number of grains/spike (GPS), grain filling period (GFP), grain starch (GSC) and protein (GPC) content, plant height (PH) and days to maturity (DTM), since they showed high (r), high h2b and high GA estimates. The best selection environment was WW for days to anthesis, PH, spikes/plant, GPS, spikelets/spike, GYPP, GPC and WS for DTM, GFP, GSC and thousand-grain weight traits. This information could help future breeding programs in selection for improving drought tolerance of wheat.

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 Evaluation of reciprocal cross populations for spike-related traits in early consecutive generations of bread wheat (Triticum aestivum L.)

Genetika ◽  
2017 ◽  
Vol 49 (2) ◽  
pp. 511-528
Author(s):  
Imren Kutlu ◽  
Alpay Balkan ◽  
Kayıhan Korkut ◽  
Oguz Bilgin ◽  
Ismet Baser
Keyword(s):  
Grain Yield ◽  
Maternal Effects ◽  
Genotypic Variation ◽  
Selection Criterion ◽  
Triticum Aestivum L ◽  
High Yield ◽  
Group Method ◽  
Genetic Advance ◽  
Spike Density ◽  
Successive Generations

Breeding effort on increasing grain yield of wheat will incessantly continue because it is indispensable product. Obtaining the genetic information such as genotypic variation, heritability, genetic advance is the fundamental components of these studies. It is important that the maternal effects are put forward throughout successive generations because of genotypic and/or environmental effects as far as variation. This research was conducted to investigate changes of reciprocal crosses throughout successive generations and determine selection criteria for high yield in early generations. For this purpose, the populations were analyzed with regard to genotypic and phenotypic variation coefficient, heritability, genetic advance and Unweighted Pair Group Method (UPGMA) cluster analysis for real crosses, reciprocals and all genotypes separately. According to the results, heritability and genetic advance values of traits investigated were highly varied throughout successive generations among real crosses, reciprocals and all genotypes. This finding indicated that non-additive gen effects or epitasis played a role in inheritance of all traits. Dissimilarity of crosses than their reciprocals indicated variation of successive generation. Dissimilarity value of each parent differed as generation progresses according to combination created. This condition suggested that there were maternal effects in this population throughout successive generations. Grain weight per spike, spike harvest index and spike density had high direct and indirect effects on the grain yield at all of three generations, it proved that these traits can be a selection criterion for early generations. Sana was the best parent and ?Bezostaja x Krasunia? and ?Krasunia x Pehlivan? were best performance in most of traits at all generations.

PERFORMANCE UNDER STRESS OF ADVANCED CYCLES OF FOUR POPULATIONS OF CORN (Zea mays L.) IN AN S1 PER SE RECURRENT SELECTION PROGRAM

1981 ◽  
Vol 61 (1) ◽  
pp. 29-36
Author(s):  
O. A. ADARA ◽  
L. W. KANNENBERG
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Recurrent Selection ◽  
Zea Mays L ◽  
Selection Criterion ◽  
Grain Filling ◽  
Primary Selection ◽  
Per Se ◽  
Selection For ◽  
Advanced Cycles

Two cycles of S1 per se recurrent selection were conducted in four populations of corn (Zea mays L.). The primary selection criterion was a performance index: grain yield divided by percent moisture at harvest. The original (C0) source material and first cycle (C1) of selection for each population were evaluated in a favorable (1977) and an unfavorable (1978) growing season. Second cycle (C2) materials were also included in the 1978 comparisons. In 1977, C1 yielded significantly more grain than C0 in three of the four populations. In contrast, performance of C1 and C2 materials in 1978 was inferior to C0 in all populations but one. The advanced cycles of only one population showed improvement over C0 in both years. Comparisons of the 1977 data for days to silking, grain yield, and percent ear moisture at harvest suggest that rate of grain filling in C1 was higher than in C0 for all populations. The higher rates of grain filling in the advanced cycles may have caused a carbohydrate deficiency under stress (1978) so that the leaves no longer functioned normally and kernel filling was terminated prematurely. In general, the four populations showed inherent differences in their respective responses to selection, to environmental stress, and to inbreeding.

scholarly journals Heritability and Correlations for Agronomic and Physiologic Traits of Maize under Deficit Irrigation at Two Growth Stages

2019 ◽  
pp. 1-17
Author(s):  
A. M. M. Al-Naggar ◽  
M. M. Shafik ◽  
M. O. A. Elsheikh
Keyword(s):  
Drought Tolerance ◽  
Selection Criteria ◽  
Chlorophyll Concentration ◽  
Grain Filling ◽  
Kernel Weight ◽  
Stem Diameter ◽  
Growth Stages ◽  
Tolerance Index ◽  
Genetic Advance ◽  
Maize Genotypes

Strong associations between agronomic and physiologic traits and drought tolerance, high heritability and high genetic advance for such traits would allow plant breeder to use such traits as selection criteria for selecting drought tolerant genotypes. The objectives of the present investigation were: (i) to explain the relationships between the drought tolerance index (DTI) and 14 agronomic and physiologic traits of 22 maize genotypes and (ii) to estimate the broad-sense heritability (h2b) and genetic advance (GA) from selection for such traits, in order to determine the selection criteria for DTI. A two-year experiment was carried out using a split plot experiment with three replications. The main plots were devoted to irrigation regimes, i.e. well watering (WW), water stress at flowering (WSF) and at grain filling (WSG), and sub plots to maize genotypes. It is evident from results that the best selection criteria for drought tolerance in our study were: 100-kernel weight (100KW) and chlorophyll concentration index (CCI) under WSF and WSG, anthesis-silking interval (ASI), upper stem diameter (SDU) and lower stem diameter (SDL) under WSF and kernels/row (KPR) and ear leaf area (ELA) under WSG, since they show high correlation (r) values with grain yield/plant (GYPP), high h2b and high GA estimates under the respective environments. Under well watering conditions, KPR, 100KW, CCI, and SDL traits showed high (r) values, high h2b and high GA estimates and therefore could be considered selection criteria for GYPP under non-stressed environment. The results concluded that predicted selection gain would be higher if selection was practiced under WW for lower values of days to silking and higher values of ears/plant, rows/ear, KPR, 100KW, SDU and SDL, under WSF for lower values of ASI and higher values of GYPP and under WSG for lower values of plant height, ear height, and barren stalks, and higher values of CCI and ELA.

scholarly journals Increasing Grain Yield in Bread Wheat (Triticum aestivum L.) by Selection for High Spike Fertility Index

2020 ◽  
Author(s):  
Ana Clara Pontaroli ◽  
María Pía Alonso ◽  
Nadia Estefania Mirabella ◽  
Juan Sebastián Panelo ◽  
María Fiorella Franco ◽  
...  
Keyword(s):  
Grain Yield ◽  
Bread Wheat ◽  
Selection Criterion ◽  
Triticum Aestivum L ◽  
Grain Protein Content ◽  
Wheat Breeding ◽  
Genetic Progress ◽  
Fertility Index ◽  
Ril Population ◽  
Selection For

ABSTRACTSpike fertility index (SF; a.k.a. fruiting efficiency at maturity) has been proposed as a promising selection criterion for increasing grain yield (GY) in bread wheat. In this study, changes in GY and related traits after simulated selection (10% intensity) for high SF or high GY were assessed in (i) a RIL population of 90 individuals (Avalon/Glupro) (ii) a RIL population of 146 individuals (Baguette 10/Klein Chajá); (iii) 28-36 advanced lines from a breeding program. Grain yield, SF, grain number per unit area (GN), grain weight, test weight and grain protein content were determined. Regardless of the environmental conditions, simulated selection for high SF alone always resulted in GN increases (between 1.6 and 27.4%). Average GY increase observed after simulated selection for high SF (5.6%; N=20; S2 =80.1) did not differ (p=0.2) from the average GY increase observed after simulated selection for GY per se (12.9%; N=12; S2 =308.1). Our findings validate the use of SF as a selection criterion for increasing genetic progress of grain yield in bread wheat breeding programs.

scholarly journals Effect of Heat Stress on Inter-relationship of Physiological and Biochemical Traits with Grain Yield in Wheat (Triticum aestivum L.)

2020 ◽  
pp. 19-29
Author(s):  
Amrita Kumari ◽  
R. D. Ranjan ◽  
Chandan Roy ◽  
Awadesh Kumar Pal ◽  
S. Kumar
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Flag Leaf ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Seedling Stage ◽  
Biochemical Traits ◽  
Highly Correlated ◽  
Complex Phenomena ◽  
Physiological And Biochemical

Heat stress, particularly the stress appears at the time of flowering to grain filling stages causing severe yield loss in wheat. Heat tolerance is complex phenomena that include adjustment in morphological, physiological and biochemical traits of the crop. Present investigation was carried out to understand the effect of terminal heat stress on different traits of wheat. The experiment was conducted in three dates of sowing as timely sown, late sown and very late sown to expose the crop to heat stress at later stages of the crop growth. Significant genetic variations for all the traits evaluated under three conditions indicated the presence of variability for the traits. Trait association analysis revealed that flag leaf chlorophyll content and MSI at seedling stage; MDA at reproductive stage had direct relationship with grain yield. While under very late sown condition MDA and RWC at seedling stages were found to be highly correlated with grain yield. It indicates that MDA, RWC at seedling stage and days to booting, days to milking plays important role in very late sown condition that can be used as selection criteria in breeding programme.

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.

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.

scholarly journals Changes in stem and spike related traits resulting from breeding in Iranian wheat cultivars: associations with grain yield

2017 ◽  
Vol 53 (No. 3) ◽  
pp. 107-113
Author(s):  
M. Joudi ◽  
A. Ahmadi ◽  
V. Mohammadi
Keyword(s):  
Grain Yield ◽  
Selection Criterion ◽  
Dry Weight ◽  
Grain Filling ◽  
Specific Weight ◽  
Indirect Selection ◽  
Wheat Cultivars ◽  
Terminal Drought ◽  
Positive Correlations ◽  
Terminal Drought Stress

This study investigated changes in stem and spike characteristics resulting from breeding in Iranian wheat cultivars, and their relationship with grain yield. Eighty-one wheat cultivars released between 1930 and 2006 were examined under well-watered (WW) and terminal drought stress (DS) conditions in Karaj during 2007–2008 and 2008–2009 and under WW condition at Parsabad in Moghan region during 2010–2011. A genetic improvement over time in stem specific weight (SSW) along with significant positive correlations between this trait and grain yield were found at Karaj under DS conditions and at Parsabad, suggesting that SSW could be used as an indirect selection criterion for yield in these environments. Time-dependent changes in spike dry weight showed that the magnitude of partitioned photoassimilates to the spike during the phase anthesis – 16 days after anthesis (16 DAA) was not changed by breeding. However, during the 16 DAA ‒ maturity phase, modern cultivars had more photoassimilates allocated to the spike than the old ones. This suggests that the sink is more limited during early grain growth than during the end of grain filling. 

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