Phenotypic Selection on Plant Height in a Segregating Hybrid Population of Crepis tectorum (Asteraceae)

1996 ◽  
Vol 157 (4) ◽  
pp. 488-492 ◽  
Author(s):  
Stefan Andersson
Keyword(s):  
Plant Height ◽  
Phenotypic Selection ◽  
Hybrid Population ◽  
Crepis Tectorum

Phenotypic selection in a population of Crepis tectorum ssp. pumila (Asteraceae)

1992 ◽  
Vol 70 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Stefan Andersson
Keyword(s):  
Life History ◽  
Multiple Regression ◽  
Large Scale ◽  
Demographic Data ◽  
Phenotypic Selection ◽  
Direct Selection ◽  
Surprising Result ◽  
Regression Analyses ◽  
Ecotypic Differentiation ◽  
Crepis Tectorum

A 3-year demographic study was conducted to reveal targets of selection on morphology and life history in a population of Crepis tectorum ssp. pumila, a winter annual plant confined to calcareous grasslands (alvars) on the Baltic island of Öland (south Sweden). I calculated the selection differential to describe the change in the mean value of a character due to selection and used multiple regression analyses to partition the direct effect of selection on the trait from indirect responses of selection on other traits. Rosette leaf number, a convenient measure of plant size, was strongly correlated with both viability and fertility (fitness). There was also a strong relationship between fitness and the extent to which the plants expressed traits characterizing this particular taxon. Multiple regression analyses indicated direct selection favouring plants with deeply lobed leaves and a densely branched stem, two distinctive traits of ssp. pumila believed to be adaptive in the alvar habitat. Only stem height was subject to both direct and indirect selection in the wrong direction; taller individuals were more successful than those with a shorter stem, a surprising result considering the inferred advantage of a short stature in the exposed alvar habitat. Selection on other traits assumed to be ecologically important (germination time, flowering time, and seed size) was found to be either absent or variable in direction when other traits were held constant. The failure of plants to survive to the flowering stage in the last two summers indicates strong selection for plants that produce a high percentage of dormant seeds. Overall, the contemporary selection regime as revealed by demographic data was only partly congruent with predictions regarding historical selection pressures based on large-scale patterns of variation (ecotypic differentiation). Key words: Crepis tectorum, ecotypic differentiation, life history, morphology, phenotypic selection.

scholarly journals Repeatability estimates and minimum number of evaluations for selection of elephant-grass genotypes for herbage production

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Erina Vitório Rodrigues ◽  
Rogério Figueiredo Daher ◽  
Geraldo de Amaral Gravina ◽  
Alexandre Pio Viana ◽  
Maria do Socorro Bezerra de Araújo ◽  
...  
Keyword(s):  
Plant Height ◽  
Principal Components ◽  
Dry Matter ◽  
Block Design ◽  
Phenotypic Selection ◽  
Stem Diameter ◽  
Dry Matter Yield ◽  
Elephant Grass ◽  
Minimum Number ◽  
Selection Of

In forage-plants breeding, the selection of superior genotypes has been undertaken through successive harvests in previously established intervals. However, this process involves many steps, the evaluation of many traits, and a great spending with costs and labor. Thus the estimate of the repeatability is essential in improvement of perennials, it allows predicting genotypic value of the individual, the minimum number of evaluations in the selection of genotypes and minimizes resources and time in the selection of promising individuals. The objective of this study was to estimate the repeatability coefficient for morphological traits in elephant grass and determine the number of evaluations needed for phenotypic selection more efficient. The experimental randomized block design with 53 genotypes and two replications. The repeatability coefficients were estimated for variables plant height, number of tillers, stem diameter and dry matter yield, using the methods of Anova, Principal Components and Structural Analysis. We observed significant differences between genotypes (P <0.01) for all variables. The main components provide larger estimates of repeatability when compared to other methods. Estimates of the repeatability coefficients are of high magnitude average for the variables plant height (0.44) number of tillers (0.44) and stem diameter (0.63) and low magnitude for dry matter production (0.27). The Principal Components method requires five, five, two and eleven measurements for plant height, number of tillers, stem diameter and dry matter yield, respectively, with 80% reliability.  

scholarly journals Dynamic QTL mapping for plant height in the hybrid population of Agropyron Gaertn.

2020 ◽  
Vol 139 (5) ◽  
pp. 1016-1028 ◽  
Author(s):  
Yonghe Che ◽  
Nan Song ◽  
Yanping Yang ◽  
Xinming Yang ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Qtl Mapping ◽  
Plant Height ◽  
Hybrid Population ◽  
Dynamic Qtl

scholarly journals Genetic analysis of the hybrid rice population ‘Mavr × Kontakt’

2021 ◽  
pp. 39-44
Author(s):  
P. I. Kostylev ◽  
E. V. Krasnova ◽  
G. A. Sirapionov
Keyword(s):  
Plant Height ◽  
Kernel Weight ◽  
Hybrid Population ◽  
Rostov Region ◽  
Study Results ◽  
Spikelets Per Panicle ◽  
Rice Samples ◽  
Negative Dominance ◽  
Positive Effect ◽  
Black Color

Rice can form not only white-color kernels, but also of red, brown and black colors. In black-color rice kernels, the pericarp contains anthocyanin, which has antioxidant activity and therefore has a positive effect on human health. The purpose of the current study was to develop rice samples with black pericarp. The paper has presented the study results of the hybrid population ‘Mavr × Kontakt’ of the second generation. The variety ‘Mavr’ has a black pericarp, the variety ‘Kontakt’ has a white one. In the process of hybridological analysis there have been identified the patterns of inheritance of the main quantitative traits affecting productivity; there have been identified the best samples, in which formed compact erect panicles and black kernels; there has been selected the initial material for breeding work. The study was carried out in 2020 on the plots of the ES “Proletarskoye” in the Rostov region. There was established that the color of pericarp was inherited according to the type of complementary interaction of two genes. There was found an overdominance and interaction of two pairs of genes of different strengths according to ‘plant height’. There was also seen partial positive dominance, transgressions, and digenic differences of the initial varieties according to ‘panicle length’. According to the traits ‘number of spikelets per panicle’, there was identified overdominance of large values and positive transgression. There were found the forms with well-kerneled panicles. The trait ‘1000 kernel weight’ was characterized by negative dominance and dihybrid cleavage of 9:6:1. There have been selected the best morphotype F2 forms with black pericarp, which possessed optimal plant height, long panicles, larger kernel size, and an average 1000 kernel weight.

Genetic variability studies for yield, yield contributing and quality traitsin okra [Abelmoschus esculentus (L.) Moench.]

2016 ◽  
Vol 50 (6) ◽  
Author(s):  
R. A. Jadhav ◽  
S. B. Bagwale ◽  
L. N. Jawale ◽  
D. B. Deosarkar
Keyword(s):  
Vitamin C ◽  
Plant Height ◽  
Iron Content ◽  
Block Design ◽  
Calcium Content ◽  
Phenotypic Selection ◽  
Randomized Block Design ◽  
Additive Gene ◽  
High Heritability ◽  
Number Of Branches

The present investigation was carried out during Kharif 2014. The experimental material consists of 40 different genotypes of okra with three checks Arka Anamika, Parbhani Kranti and Pusa Sawani. The materials were grown in randomized block design with three replications during Kharif 2014 on the field of Department of Agricultural Botany, College of Agriculture, VNMKV, Parbhani. The investigation carried out in the present study revealed that the genotypes 136 Thin, 003163, Kashi Pragati, Kashi Vibhuti and BO 13 showed better performance for traits namely plant height, length of fruit, calcium content, iron content, vitamin C content and fruit yield per hectare. Among the genotypes 136 Thin and 003163 had given highest yield. The high genotypic and phenotypic coefficient of variation was observed for characters namely number of branches, yield per hectare, yield per plot and yield per plant. All these traits indicate additive effect showed response for selection. High heritability estimates were found for characters like number of branches, yield per plot, iron content, yield per plant, plant height, vitamin C content, number of seeds per fruit (dry fruit), fruit bearing node and calcium content indicated good inheritance of these characters. High heritability coupled with high expected genetic advance was observed for characters like plant height, calcium content, yield per plant and yield per hectare, indicated presence of additive gene action and phenotypic selection may become more effective for desired genetic improvement.

scholarly journals SELEÇÃO FENOTÍPICA DE HÍBRIDOS DE MILHO PARA AMBIENTES DE BAIXA ALTITUDE E DÉFICIT HÍDRICO

Nativa ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 172
Author(s):  
Cristiani Santos Bernini ◽  
Fernando André Silva Santos ◽  
Douglas Santos Silva ◽  
Zulema Netto Figueiredo
Keyword(s):  
Zea Mays ◽  
Plant Height ◽  
Water Deficit ◽  
Zea Mays L ◽  
Block Design ◽  
Phenotypic Selection ◽  
Stay Green ◽  
Study Region ◽  
Mato Grosso ◽  
Secondary Characters

O emprego de cultivares tolerantes à seca apresenta como uma estratégia eficiente para aumentar a produtividade das culturas em áreas sujeitas a períodos de déficit hídrico frequente. Para construir um “padrão de cultivares” o desafio é adequar aos caracteres secundários do germoplasma de milho para os ambientes de estresse hídrico. O trabalho teve por objetivo: identificar híbridos comerciais de milho quanto aos caracteres secundários para o cultivo nos ambientes de baixa altitude e déficit hídrico. O experimento foi implantado em Cáceres (MT) na 2° safra de 2017/18, sob delineamento experimental de blocos ao acaso com 3 repetições. Foram avaliados os seguintes caracteres: alturas da planta e de espiga, florescimentos masculino e feminino, intervalo entre florescimentos, stay-green, peso de grãos e componentes de produção. Os dados foram submetidos à análise de variância, e posteriormente agrupados pelo teste Scott-Knott a 5% de probabilidade. Os híbridos comerciais AG8088 PRO2, DKB177 PRO3, MG600 PW e 30F53 VYH se mostraram favoráveis para região de estudo, por possuírem produtividade média alta, sendo recomendados para cultivo no Sudoeste do Mato Grosso. Pode-se selecionar florescimento masculino, altura de plantas e stay-green como caracteres de seleção fenotípica para discriminação de híbridos para programas de melhoramento visando tolerância à seca.Palavras-chave: Zea mays L.; caracteres secundários; safrinha. PHENOTYPIC SELECTION OF MAIZE HYBRIDS FOR ENVIRONMENTS OF  LOW LATITUDE AND WATER DEFICIT ABSTRACT: The use drought-tolerant cultivars presents itself as an efficient strategy to increase productivity of crops in areas subject to frequent periods of water deficit. To build a "pattern of cultivars" the challenge is to adapt to secondary characters of the germoplasm of maize for the environments of drought stress. The study aimed to: identify commercial hybrids of maize on the secondary characters for cultivation in environments of low altitude and water deficit. The experiment was deployed in Cáceres (MT) in second crop 2017/18, in a randomized block design with 3 replications. The following characters were evaluated: plant height and ear, flowering male and female, the interval between flowering, stay-green, grain weight and yield components. The data were subjected to analysis of variance, and subsequently grouped by Scott-Knott test at 5% probability. The commercial hybrids AG8088 PRO2, DKB177 PRO3, MG600 PW and 30F53 VYH proved favorable to the study region, because they have average productivity high, being recommended for cultivation in the southwest of Mato Grosso. You can select flowering male, plant height and stay-green as characters of phenotypic selection for discrimination of hybrids for breeding programs aiming to drought tolerance.Keywords: Zea mays L.; secondary character; off-season.

Combining abilities of certain characters and estimation of hybrid vigour in sunflower (Helianthus annuus L.)

2005 ◽  
Vol 52 (4) ◽  
pp. 361-368 ◽  
Author(s):  
A. T. Göksoy ◽  
Z. M. Turan
Keyword(s):  
Plant Height ◽  
Seed Yield ◽  
Combining Ability ◽  
Seed Weight ◽  
Specific Combining Ability ◽  
Hybrid Population ◽  
Hybrid Vigour ◽  
Head Diameter ◽  
Combining Abilities ◽  
Number Of Seeds

This research was carried out in 1997 and 1998 in order to study the genetic structure of a hybrid population established from three CMS (cytoplasmic male sterile) lines and four pollen tester (restorer) lines, to identify the parents and crosses showing superior general and specific combining abilities and finally to evaluate F1 hybrid vigour. According to the results, the variance due to specific combining ability (SCA) was highly significant for seed yield, number of seeds per head and plant height. These traits of sunflower were influenced, mostly, by dominant gene actions. Neither general (GCA) nor specific combining ability (SCA) variances were found to be significant for head diameter and 1000-seed weight. most of the total genetic variation in these characteristics was caused by epistatic gene actions due to SCA variances, which were higher than GCA variances. The parental lines CMS381, CMS461, RHA684 and RHA892 had the highest positive GCA effects for seed yield and in terms of the other traits studied, but these effects were not significant for all the traits observed. The crosses CMS191×RHA723, CMS191×RHA892, CMS381×RHA684 and CMS461×RHA684 might be considered as promising combinations in terms of seed yield and yield components. The amounts of heterosis and heterobeltiosis ranged from -8.4 to +16.3% to -21.3 to +3.4% for plant height, from 46.3-82.3% to 20.3-48.3% for head diameter, from -14.8 to +52.6% to.-16.5 +46.9% for number of seeds per head, from -3.3 to +42.7 to -19.0 to +21.0% for 1000-seed weight and from 19.8-98.1 to 4.6-89.8% for seed yield.

scholarly journals Comparison of Marker-Based Genomic Estimated Breeding Values and Phenotypic Evaluation for Selection of Bacterial Spot Resistance in Tomato

2018 ◽  
Vol 108 (3) ◽  
pp. 392-401 ◽  
Author(s):  
Debora Liabeuf ◽  
Sung-Chur Sim ◽  
David M. Francis
Keyword(s):  
Prediction Models ◽  
Phenotypic Selection ◽  
Hybrid Population ◽  
Bacterial Spot ◽  
Training Population ◽  
Prediction Ability ◽  
Breeding Values ◽  
Genomic Estimated Breeding Values ◽  
Estimated Breeding Values ◽  
Efficiency Of Selection

Bacterial spot affects tomato crops (Solanum lycopersicum) grown under humid conditions. Major genes and quantitative trait loci (QTL) for resistance have been described, and multiple loci from diverse sources need to be combined to improve disease control. We investigated genomic selection (GS) prediction models for resistance to Xanthomonas euvesicatoria and experimentally evaluated the accuracy of these models. The training population consisted of 109 families combining resistance from four sources and directionally selected from a population of 1,100 individuals. The families were evaluated on a plot basis in replicated inoculated trials and genotyped with single nucleotide polymorphisms (SNP). We compared the prediction ability of models developed with 14 to 387 SNP. Genomic estimated breeding values (GEBV) were derived using Bayesian least absolute shrinkage and selection operator regression (BL) and ridge regression (RR). Evaluations were based on leave-one-out cross validation and on empirical observations in replicated field trials using the next generation of inbred progeny and a hybrid population resulting from selections in the training population. Prediction ability was evaluated based on correlations between GEBV and phenotypes (rg), percentage of coselection between genomic and phenotypic selection, and relative efficiency of selection (rg/rp). Results were similar with BL and RR models. Models using only markers previously identified as significantly associated with resistance but weighted based on GEBV and mixed models with markers associated with resistance treated as fixed effects and markers distributed in the genome treated as random effects offered greater accuracy and a high percentage of coselection. The accuracy of these models to predict the performance of progeny and hybrids exceeded the accuracy of phenotypic selection.

scholarly journals Pea Breeding for Intercropping With Cereals: Variation for Competitive Ability and Associated Traits, and Assessment of Phenotypic and Genomic Selection Strategies

2021 ◽  
Vol 12 ◽  
Author(s):  
Paolo Annicchiarico ◽  
Nelson Nazzicari ◽  
Tommaso Notario ◽  
Cristina Monterrubio Martin ◽  
Massimo Romani ◽  
...  
Keyword(s):  
Genomic Selection ◽  
Plant Height ◽  
Competitive Ability ◽  
Phenotypic Selection ◽  
Indirect Selection ◽  
Flowering Plant ◽  
Complete Suppression ◽  
Selection Strategies ◽  
A Genome ◽  
Selection For

Mixed stand (MS) cropping of pea with small-grain cereals can produce more productive and environment-friendly grain crops relative to pure stand (PS) crops but may require selection to alleviate the pea competitive disadvantage. This study aimed to assess the pea variation for competitive ability and its associated traits and the efficiency of four phenotypic or genomic selection strategies. A set of 138 semi-leafless, semi-dwarf pea lines belonging to six recombinant inbred line populations and six parent lines were genotyped using genotyping-by-sequencing and grown in PS and in MS simultaneously with one barley and one bread wheat cultivar in two autumn-sown trials in Northern Italy. Cereal companions were selected in a preliminary study that highlighted the paucity of cultivars with sufficient earliness for association. Pea was severely outcompeted in both years albeit with variation for pea proportion ranging from nearly complete suppression (&lt;3%) to values approaching a balanced mixture. Greater pea proportion in MS was associated with greater total yield of the mixture (r ≥ 0.46). The genetic correlation for pea yield across MS and PS conditions slightly exceeded 0.40 in both years. Later onset of flowering and taller plant height at flowering onset displayed a definite correlation with pea yield in MS (r ≥ 0.46) but not in PS, whereas tolerance to ascochyta blight exhibited the opposite pattern. Comparisons of phenotypic selection strategies within or across populations based on predicted or actual yield gains for independent years indicated an efficiency of 52–64% for indirect selection based on pea yield in PS relative to pea yield selection in MS. The efficiency of an indirect selection index including onset of flowering, plant height, and grain yield in PS was comparable to that of pea yield selection in MS. A genome-wide association study based on 5,909 SNP markers revealed the substantial diversity of genomic areas associated with pea yield in MS and PS. Genomic selection for pea yield in MS displayed an efficiency close to that of phenotypic selection for pea yield in MS, and nearly two-fold greater efficiency when also taking into account its shorter selection cycle and smaller evaluation cost.

scholarly journals Breeding Amaranth for Biomass: Evaluating Dry Matter Content and Biomass Potential in Early and Late Maturing Genotypes

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 970
Author(s):  
Ali Baturaygil ◽  
Markus G. Stetter ◽  
Karl Schmid
Keyword(s):  
Plant Height ◽  
Vegetative Growth ◽  
Dry Matter ◽  
Recurrent Selection ◽  
Biogas Production ◽  
Phenotypic Selection ◽  
Matter Content ◽  
Growth Patterns ◽  
Stem Diameter ◽  
Dry Matter Content

Amaranth (Amaranthus spp.) is a promising biomass crop for silage and biogas production. Under long-day conditions, it exhibits prolonged vegetative growth. To evaluate the breeding potential of amaranth for biomass production, we characterized phenotypic variation in biomass yield components, quantitative genetic parameters, and the relationships between traits. We conducted field trials of 10 biomass-type genotypes exhibiting a ‘giant’ growth habit derived from spontaneous hybridization between genetically diverse parents, and used the variety “Bärnkrafft” as check. We observed two contrasting growth patterns: Bärnkrafft is a variety for grain production and was characterized by a short vegetative growth followed by a long seed ripening. In contrast, the biomass genotypes displayed a long vegetative growth followed by a short seed ripening. We observed strong correlations between dry matter content and stem diameter (r =−0.78, p < 0.01) and between plant height and biomass score (r = 0.95, p < 0.001). High values for broad-sense heritability of stem diameter (H2 = 0.88) and plant height (H2 = 0.92) suggest that the dry matter content and yield can be improved by indirect phenotypic selection. We hypothesize that selection for dry matter content and yield implies a trade-off between earliness and photoperiod sensitivity. Hence, dry matter content should be improved first by recurrent selection, which can be then combined with short-day genes to improve dry matter yield. Overall, this work provides an avenue to the breeding of biomass amaranth.

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