Breeding white clover for increased ability to compete with associated grasses

2003 ◽  
Vol 140 (3) ◽  
pp. 255-266 ◽  
Author(s):  
P. ANNICCHIARICO
Keyword(s):  
Relative Efficiency ◽  
Competitive Ability ◽  
Clonal Selection ◽  
Selection Index ◽  
Size Variation ◽  
Leaf Size ◽  
Indirect Selection ◽  
Italian Ryegrass ◽  
Direct Selection ◽  
Selection Procedures

Greater white clover (Trifolium repens L.) competitive ability can increase the forage quantity and quality of clover-grass mixed stand (MS) cropping. The present work assessed the relationship of clover competitive ability with morphophysiological traits, and the efficiency of direct and indirect selection procedures for increasing clover dry matter (DM) yield in MS. Some 165 large-leaved clover genotypes representative of Italian Ladino germplasm and 13 clover genotypes from an elite small-leaved population were clonally evaluated for one year in pure stand (PS) and in MS environment with Italian ryegrass (Lolium multiflorum Lam.) and tall fescue (Festuca arundinacea Schreb.) that reproduced the level of interspecific interference met by the clover over a multi-year crop cycle. Results for all genotypes and their subsets indicated that the level of leaf size variation among tested genotypes can affect the results. Wider variation decreased the relative importance of clover genotype×evaluation environment interaction, because competitive ability was mainly correlated with traits (longer petiole; larger leaflet) contributing to scale foraging in MS and yielding ability in PS. Competitive ability tended to be more closely associated with other traits (high stolon density; plasticity of petiole elongation) contributing to foraging ability, i.e. the ability to make fine-scale exploitation of light and nutrients in MS, within germplasm of similar leaf size. Leaf size variation also affected the relative efficiency of selection procedures estimated from expected responses to clonal selection. Results for all entries indicated direct selection in MS as 23% more efficient than selection in PS based on a selection index including three traits associated with competitive ability (petiole length; stolon density; leaflet size) which, in turn, was predicted to be 16% more effective than selection in PS based on DM yield. The advantage in relative efficiency of direct selection was almost doubled when considering only large-leaved germplasm. In a second experiment, evaluating 16 clover half-sib progenies of elite large-leaved parents for 2 years in PS and in MS with Italian ryegrass, tall fescue and cocksfoot (Dactylis glomerata L.), direct selection was estimated to be over three-fold and 68% more effective than indirect selection in PS based on DM yield and the selection index, respectively, based on expected responses to genotypic selection. The selection index may improve the efficiency of preliminary, PS-based clonal selection. Further evaluation of elite genotypes and/or their polycross progenies in MS is recommended for final selection.

Estimates of selection parameters associated with protein and oil content of soybean seeds (Glycine max (L.) Merr.)

1977 ◽  
Vol 28 (2) ◽  
pp. 211 ◽  
Author(s):  
R Shorter ◽  
DE Byth ◽  
VE Mungomery
Keyword(s):  
Seed Yield ◽  
Variance Component ◽  
Selection Index ◽  
Chemical Yield ◽  
Indirect Selection ◽  
Direct Selection ◽  
Yield Traits ◽  
Oil Percentage ◽  
Selection For ◽  
Location Interaction

Three crosses of soybean involving United States and other germplasm were examined in the F3 and F4 generations at two locations, one near the coast, the other on the Darling Downs. Line and line x location interaction variances within crosses for most traits were almost all significant, except for protein, oil, and protein plus oil yield where line variances were non-significant when data were combined over locations. Line variances were considerably smaller for all traits when estimated across, rather than within, locations. For protein, oil, and protein plus oil percentage, the line x location interaction variance component generally was smaller than the line variance component in two crosses, but larger in a third even though the latter cross had the largest line variance for these traits. The line x location interactions may have been related in some cases to lower protein and oil percentages of late-maturing lines in that location where cold conditions prevailed late in the season. Heritability percentages computed from F4 variance components ranged from 49 to 89% and were largest for the chemical pexentage traits within locations. Standard unit heritability percentages estimated from F3–F4 generations were lower than those computed via the variance component method, and approached zero for oil percentage, protein plus oil percentage, and the chemical yield traits in some crosses if the generations were grown in different locations. Genotypic correlations between protein percentage and seed yield ranged from –0.50 to 0.16 across crosses and were opposite in sign to those between oil percentage and seed yield. Genotypic and phenotypic correlations between protein and oil percentage were highly negative in two crosses (–0.62 to –0.96) but much less negative in the third cross (–0.24 to –0.35). Predicted genetic advance (percentage of population mean) ranged from 5.9 to 26.1% for the chemical yield traits and from 1.5 to 6.3% for protein or oil percentage. Indirect selection for chemical yield through seed yield was 90–109% as efficient as direct selection, and a selection index that combined seed yield and either protein, oil, or protein plus oil percentage generally was no more efficient than direct selection for the corresponding chemical yield trait. Indirect selection for chemical yield through chemical percentage was much less efficient than direct selection for chemical yield.

scholarly journals Genotypic potentiality and selection index of ridge gourd (Luffa acutangula L.)

2020 ◽  
Vol 49 (4) ◽  
pp. 1169-1175
Author(s):  
Ayasha Ahmed ◽  
Jahangir Alam Tarafder ◽  
Mohammad Kamal Hoassain ◽  
Nazmul Alam
Keyword(s):  
Genetic Gain ◽  
Relative Efficiency ◽  
Significant Variation ◽  
Selection Index ◽  
Male Flower ◽  
Direct Selection ◽  
Flower Plant ◽  
Superior Genotypes ◽  
Selection For ◽  
Luffa Acutangula

Fifteen ridge gourd genotypes were investigated to select the superior genotypes. The overall analysis reveals that PCV was higher than GCV for all the traits. Significant variation was found among genotypes for the qualitative traits under divergence analysis. The selection index reveals that maximum genetic gain and relative efficiency over selection for yield was obtained for the index I123 based on yield/plant (g), No. of secondary branch, No. of male flower/plant characters. In the presented functions, selection index I1234 and I12345 showed highest relative efficiency over direct selection and genetic gain when all the characters were included to construct the selection index. On the basis of performance, the genotype-3023 was found to be most promising parent in order to develop a commercial ridge gourd variety.

scholarly journals Protogyny in Autumn Migration: Do Male Birds ”Play Chicken”?

The Auk ◽  
2005 ◽  
Vol 122 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Alexander M. Mills
Keyword(s):  
Migratory Birds ◽  
Indirect Selection ◽  
Male Competition ◽  
Autumn Migration ◽  
Direct Selection ◽  
Differential Migration ◽  
The North ◽  
Parsimonious Explanation ◽  
Ground Conditions ◽  
Wintering Ground

AbstractProtandry, the earlier arrival of males than of females on breeding areas, occurs in many taxa, including many migratory birds. Numerous hypotheses have been generated to explain protandry. Using bird-banding records, I show that protogyny, the earlier migration of females, frequently occurs in the autumn, though it is less universal and less dramatic than spring protandry. In one species, it occurs in both hatch-year and adult birds. When (1) spring and autumn, (2) departures and arrivals, and (3) breeding and wintering ground conditions are considered, hypotheses generated only to explain spring protandry can be more thoroughly evaluated. Using that approach, the most parsimonious explanation of differential migration between the sexes explains earlier male arrival in spring and later male departure in autumn through either (1) indirect selection operating on intrasexual male competition for territories or (2) direct selection operating on intersexual relations requiring males to be present on breeding territories when females are present. In autumn-protogynous species, males may ”play chicken,” balancing the benefits of remaining longer than females and protecting territories for subsequent years against the costs of remaining in the north under deteriorating conditions and delaying the acquisition of a good winter territory.Protogynie et migration automnale: Est-ce que les mâles ”jouent les dégonflés”?

scholarly journals Forage Potential of Cereal/Legume Intercrops: Agronomic Performances, Yield, Quality Forage and LER in Two Harvesting Times in a Mediterranean Environment

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 121
Author(s):  
Monica Bacchi ◽  
Michele Monti ◽  
Antonio Calvi ◽  
Emilio Lo Presti ◽  
Antonio Pellicanò ◽  
...  
Keyword(s):  
Crop Yield ◽  
Competitive Ability ◽  
Agronomic Traits ◽  
Italian Ryegrass ◽  
Forage Yield ◽  
Biological Efficiency ◽  
Common Vetch ◽  
Sole Crop ◽  
Cereal Grain ◽  
Green Fodder

The crop yield and quality of seven annual forages (four grasses and three legumes) in sole crop and in mixtures (ratio 50:50) for oat (Avena sativa L.), Italian ryegrass (Lolium multiflorum Lam.), triticale (x Triticosecale Wittmack), barley (Hordeum vulgare L.), pea (Pisum sativum L.), berseem (Trifolium alexandrinum L.) and common vetch (Vicia sativa L.) were evaluated in a two-year field experiment adopting two harvesting times, green fodder and silage. The main bio-agronomic traits, dry matter forage yield (DMY) and quantity of crude protein (CP) were determined in both sole crop and intercrop. The land equivalent ratio (LER) was used for evaluating biological efficiency and competitive ability of the intercrops. Our results showed that the total calculated LER for fodder and protein yields was always greater than one and corresponded to crop yield advantages of 16.0% and 11.5%, respectively. Our data also highlighted the low competitive ability of the ryegrass in intercrop, which achieved the lowest yield among all the mixtures. Conversely, the same grass showed the best green fodder quality, due to the high incidence of the legume, equal (on average) to 46%. Triticale and barley, harvested for silage (hard dough stage), provided the best quantitative and qualitative results both in sole crop and intercropped with common vetch and pea, determined mainly by the cereal grain.

scholarly journals A New Approach to Select Doubled Haploid Rice Lines under Salinity Stress Using Indirect Selection Index

Rice Science ◽  
2021 ◽  
Vol 28 (4) ◽  
pp. 368-378
Author(s):  
Muhammad Fuad Anshori ◽  
Bambang Sapta Purwoko ◽  
Iswari Saraswati Dewi ◽  
Sintho Wahyuning Ardie ◽  
Willy Bayuardi Suwarno
Keyword(s):  
Salinity Stress ◽  
Doubled Haploid ◽  
Selection Index ◽  
Indirect Selection ◽  
New Approach

scholarly journals The limits of sexual conflict in the narrow sense: new insights from waterfowl biology

2012 ◽  
Vol 367 (1600) ◽  
pp. 2324-2338 ◽  
Author(s):  
Patricia L. R. Brennan ◽  
Richard O. Prum
Keyword(s):  
Sexual Conflict ◽  
Female Preference ◽  
Indirect Selection ◽  
Direct Selection ◽  
Sensory Bias ◽  
Indirect Benefits ◽  
Female Preferences ◽  
Male Display ◽  
Male Displays ◽  
Coercive Mating

Sexual conflict occurs when the evolutionary interests of the sexes differ and it broadly applies to decisions over mating, fertilization and parental investment. Recently, a narrower view of sexual conflict has emerged in which direct selection on females to avoid male-imposed costs during mating is considered the distinguishing feature of conflict, while indirect selection is considered negligible. In this view, intersexual selection via sensory bias is seen as the most relevant mechanism by which male traits that harm females evolve, with antagonistic coevolution between female preferences and male manipulation following. Under this narrower framework, female preference and resistance have been synonymized because both result in a mating bias, and similarly male display and coercion are not distinguished. Our recent work on genital evolution in waterfowl has highlighted problems with this approach. In waterfowl, preference and resistance are distinct components of female phenotype, and display and coercion are independent male strategies. Female preference for male displays result in mate choice, while forced copulations by unpreferred males result in resistance to prevent these males from achieving matings and fertilizations. Genital elaborations in female waterfowl appear to function in reinforcing female preference to maintain the indirect benefits of choice rather than to reduce the direct costs of coercive mating. We propose a return to a broader view of conflict where indirect selection and intrasexual selection are considered important in the evolution of conflict.

scholarly journals Early generation selection strategy for yield and yield components in white oat

2005 ◽  
Vol 62 (4) ◽  
pp. 357-365 ◽  
Author(s):  
Giovani Benin ◽  
Fernando Irajá Félix de Carvalho ◽  
Antônio Costa de Oliveira ◽  
Claudir Lorencetti ◽  
Igor Pires Valério ◽  
...  
Keyword(s):  
Grain Yield ◽  
Indirect Selection ◽  
Grain Weight ◽  
Yield Potential ◽  
High Yield ◽  
Direct Selection ◽  
Selection Strategy ◽  
Breeding Method ◽  
Growing Seasons ◽  
Selection For

Several studies have searched for higher efficiency on plant selection in generations bearing high frequency of heterozygotes. This work aims to compare the response of direct selection for grain yield, indirect selection through average grain weight and combined selection for higher yield potential and average grain weight of oat plants (Avena sativa L.), using the honeycomb breeding method. These strategies were applied in the growing seasons of 2001 and 2002 in F3 and F4 populations, respectively, in the crosses UPF 18 CTC 5, OR 2 <FONT FACE=Symbol>´</FONT> UPF 7 and OR 2 <FONT FACE=Symbol>´</FONT> UPF 18. The ten best genetic combinations obtained for each cross and selection strategy were evaluated in greenhouse yield trials. Selection of plants with higher yield and average grain weight might be performed on early generations with high levels of heterozygosis. The direct selection for grain yield and indirect selection for average grain weight enabled to increase the average of characters under selection. However, genotypes obtained through direct selection presented lower average grain weight and those obtained through the indirect selection presented lower yield potential. Selection strategies must be run simultaneously to combine in only one genotype high yield potential and large grain weight, enabling maximum genetic gain for both characters.

Selection on ram 18-month weight to improve lamb growth rate

1983 ◽  
Vol 36 (2) ◽  
pp. 159-164
Author(s):  
D. Croston ◽  
J. L. Read ◽  
D. W. Jones ◽  
D. E. Steane ◽  
C. Smith
Keyword(s):  
Growth Rate ◽  
Live Weight ◽  
Indirect Selection ◽  
Direct Selection ◽  
Selection For ◽  
The Relationship ◽  
Lamb Growth

ABSTRACTThirteen pairs of Suffolk rams were selected on high and low 18-month adjusted live weight from six farms over 2 years, to establish the relationship between 18-month weight and early lamb growth. Progeny were first produced in recorded crossbred flocks (618 lambs) and then in an experimental flock of crossbred ewes (1083 lambs). Different results were obtained from the recorded and experimental flocks. The regressions of lamb 12- to 13-week weight on ram 18-month weight (within farm deviation) were 0·053 ± 0·022 kg and –0·004 ± 0·020 kg, respectively. These regressions for indirect selection correspond to ‘effective’ heritabilities for direct selection for lamb growth of 0·18 ± 0·07 and 0·02 ± 0·06 respectively. Improvement of early Iamb growth is discussed and it is concluded that selection for 18-month weight is unlikely to be a useful method.

scholarly journals Selection strategies in agronomic characters in progenies F3:4 of transgenic soy RR

2021 ◽  
Vol 45 ◽  
Author(s):  
Anna Regina Tiago Carneiro ◽  
Osvaldo Toshiyuki Hamawaki ◽  
Ana Paula Oliveira Nogueira ◽  
Arthur Felipe Eustáquio e Silva ◽  
Raphael Lemes Hamawaki ◽  
...  
Keyword(s):  
Agronomic Traits ◽  
Indirect Selection ◽  
Direct Selection ◽  
Selection Strategies ◽  
Aggregate Information ◽  
Genetic Potential ◽  
Superior Genotypes ◽  
Selection Indexes ◽  
Total Gain ◽  
Selection Of

ABSTRACT The selection indexes aggregate information to multiple characters and, with this, they are able to carry out the selection of a set of variables simultaneously. The objective was to verify the genetic potential of agronomic traits and to select soybean F3:4 progenies based on different selection strategies. 123 progenies and the parents were sown in randomized blocks with two replications. The gains of direct selection by the indexes, the sum of “ranks” and the genotype-ideotype were lower for all characters when compared to the gains of direct and indirect selection. The rank sum index stood out for achieving the highest total gain with 37.11%. The index of the genotype-ideotype obtained a lower gain (-0.48%) for the character number of days for flowering compared to the sum index of “ranks” (-0.54%) and reached a negative gain for the attribute insertion height of the first pod with -1.82%. The genetic potential of the F3:4 population is high and allows different selection strategies to be applied to reach superior genotypes. The progenies UFU 72, UFU 116, UFU 86, UFU 45, UFU 117, UFU 56, UFU 5, UFU 106, UFU 6, UFU 4, UFU 73, UFU 101, UFU 96, UFU 90, UFU 123, UFU 116, UFU 88, UFU 65, UFU 70, UFU 3, UFU 69 and UFU 37 were selected by both selection indexes. The UFU 72, UFU 90, UFU 88 and UFU 69 progenies are agronomically superior both in direct and indirect selection, as in Mulamba and Mock (1978) sum of “ranks” selections and genotype-ideotype.

scholarly journals Estimates of genetic variability in vegetable amaranth (A. tricolor) over different cuttings

2011 ◽  
Vol 32 (No. 2) ◽  
pp. 60-67 ◽  
Author(s):  
S. Shukla ◽  
A. Bhargava ◽  
A. Chatterjee ◽  
A. Srivastava ◽  
S. P Singh
Keyword(s):  
Genetic Variability ◽  
Protein Content ◽  
Plant Height ◽  
Leaf Size ◽  
Indirect Selection ◽  
Stem Diameter ◽  
Genetic Advance ◽  
Plant Leaves ◽  
General Protein ◽  
Selection Parameters

The present investigation was carried out to study different selection parameters for foliage yield and its important yield contributing traits in 29 strains of vegetable amaranth (A. tricolor). The data were recorded for plant height (cm), stem diameter (cm), branches/plant, leaves/plant, leaf size (cm<sup>2</sup>), and protein content (mg/100 mg) in each cutting separately. Foliage yield (kg) was recorded on plot basis comprising 4 cuttings. The highest foliage yield per plot was recorded for strain AV-38, followed by AV-23 and AV-31. In general, protein content was high in the 2<sup>nd</sup> cutting in all strains. The heritability estimates were in general high for all the characters in all the cuttings and ranged from 74.87% to 93.33%. Genetic advance was maximum for foliage yield (42.50%), followed by leaf size (31.02%) and stem diameter (21.13%). It was concluded that foliage yield could be increased substantially in vegetable amaranth through indirect selection based on the characters leaf size and stem diameter. &nbsp;

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