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Background. An ascertained possibility of culling segregating populations on the basis on their yield or grain weight per spike as a character closely correlated with yield can increase the efficiency of breeding practice with spring bread wheat. Materials and methods. Sixteen F2 –F4 segregating populations of spring bread wheat were assessed for their grain weight per spike, average grain weight per spike among the top 10%, coefficient of variation for grain weight per spike, and yield. The pedigree method was applied to select 2 to 3 F7 lines from each population. The obtained lines were tested for their yield in F8 and F9 . The data of grain weight per main spike in the parents that had been crossed to produce the studied segregating populations were retrospectively taken into account while the results were processed. Results Segregating populations persistently differed in their average grain weight per spike and the coefficient of its variation in different years of research. None of the 36 late-generation lines significantly surpassed the reference cultivar in yield. All the considered indicators of segregating populations had no significant correlations with the yield of late-generation lines. Average values of grain weight per main spike in the parent genotypes and the best parent as well as the differences between the parents in the average grain weight per main spike tended to have a negative correlation with the yield of late-generation lines (r up to –0.58). Conclusion. The culling of segregating populations based solely on the yield or grain weight per spike is associated with a risk of losing high-yielding genotypes. Late-generation lines with high yields occur in combinations where the grain weight per main spike in one parent or on average among the parents is not expressed to its highest level or when both parents differ only slightly from each other in the expression of this character.

Wheat is a crop of great food importance for food production in Brazil. However, the improvement of this crop is still concentrated in isolated areas, which hinders advances in new cultivation regions due to the extensive demand for existing information. In this investigation, four wheat genotypes analysed to study associations and interrelationships between wheat traits across nine environments during the agricultural years of 2016, 2017 and 2018. The experiment was conducted using a randomised block design with four repetitions, and the analysis was divided into two groups: morphological and productive traits of wheat, comprising three and eleven characteristics, respectively. Canonical correlations between the morphological and productive groups were found to be dependent in most environments. Taller plants with longer main spikes and longer tiller spikes can be indirectly selected to increase grain yield under different sowing conditions. The information generated in this study indicate that some care must be taken when using the interrelations between trait groups to select or recommend genotypes for broader regions, as these relationships are influenced by the specific conditions of each region and sub-region. [ABSTRACT FROM AUTHOR]

The evolution of suppressed recombination between sex chromosomes is widely hypothesized to be driven by sexually antagonistic selection (SA), where tighter linkage between the sex-determining gene(s) and nearby SA loci is favored when it couples male-beneficial alleles to the proto-Y chromosome, and female-beneficial alleles to the proto-X. Although difficult to test empirically, the SA selection hypothesis overshadows several alternatives, including an incomplete but often-repeated "sheltering" hypothesis which suggests that expansion of the sex-linked region (SLR) reduces the homozygous expression of deleterious mutations at selected loci. Here, we use population genetic models to evaluate the consequences of partially recessive deleterious mutational variation for the evolution of otherwise neutral chromosomal inversions expanding the SLR on proto-Y chromosomes. Both autosomal and SLR-expanding inversions face a race against time: lightly-loaded inversions are initially beneficial, but eventually become deleterious as they accumulate new mutations, after which their chances of fixing become negligible. In contrast, initially unloaded inversions eventually become neutral as their deleterious load reaches the same equilibrium as non-inverted haplotypes. Despite the differences in inheritance and indirect selection, SLR-expanding inversions exhibit similar evolutionary dynamics to autosomal inversions over many biologically plausible parameter conditions. Differences emerge when the population average mutation load is quite high; in this case large autosomal inversions that are lucky enough to be mutation-free can rise to intermediate to high frequencies where selection in homozygotes becomes important (Y-linked inversions never appear as homozygous karyotypes); conditions requiring either high mutation rates, highly recessive deleterious mutations, weak selection, or a combination thereof. [ABSTRACT FROM AUTHOR]

Drought escape is an important wheat mechanism that triggers rapid growth development to complete the life cycle before drought occurrence. Earliness could reduce the risk of dehydration during heading date to physiological maturity. Three gene groups including vernalization (Vrn), photoperiod (Ppd), and earliness per se (Eps) control heading time in bread wheat. In the present research, isogenic lines for Vrn-B1 and Vrn-D1 were developed to assess the precise effect of Vrn genes on days to heading, grain yield, and important agronomic traits under well-watered and rain-fed conditions. It was assumed that spring habit alleles improve earliness in bread wheat. Here we showed for the first time that a winter growth habit allele on the B genome, vrn-B1, reduced days to heading by 5.47 days. The mentioned allele, significantly increased grain yield under well-watered conditions by 0.36 t/ha. Spring growth habit allele of the D genome, Vrn-D1a, decreased days to heading by 4.89 days and significantly improved grain yield under both well-watered and rain-fed conditions. This allele improved grain yield by 0.88 t/ha and 0.14 t/ha under well-watered and rain-fed conditions, respectively. The combination of vrn-B1 and Vrn-D1a decreased days to heading by 9.87 days and significantly increased grain yield by 1.24 and 0.15 t/ha under well-watered and rain-fed conditions, respectively. [ABSTRACT FROM AUTHOR]

Understanding the influence of social interactions on individual fitness is key to improving our predictions of phenotypic evolution. However, we often overlook the different components of selection regimes arising from interactions among organisms, including social, correlational, and indirect selection. This is due to the challenging sampling efforts required in natural populations to measure phenotypes expressed during interactions and individual fitness. Furthermore, behaviours are crucial in mediating social interactions, yet few studies have explicitly quantified these selection components on behavioural traits. In this study, we capitalize on an online multiplayer video game as a source of extensive data recording direct social interactions among prey, where prey collaborate to escape a predator in realistic ecological settings. We estimate natural and social selection and their contribution to total selection on behavioural traits mediating competition, cooperation, and predator–prey interactions. Behaviours of other prey in a group impact an individual's survival, and thus are under social selection. Depending on whether selection pressures on behaviours are synergistic or conflicting, social interactions enhance or mitigate the strength of natural selection, although natural selection remains the main driving force. Indirect selection through correlations among traits also contributed to the total selection. Thus, failing to account for the effects of social interactions and indirect selection would lead to a misestimation of the total selection acting on traits. Dissecting the contribution of each component to the total selection differential allowed us to investigate the causal mechanisms relating behaviour to fitness and quantify the importance of the behaviours of conspecifics as agents of selection. Our study emphasizes that social interactions generate complex selective regimes even in a relatively simple ecological environment. Graphical Abstract [ABSTRACT FROM AUTHOR]

A lack of reliable winter hardiness has impeded the adoption of winter barley (Hordeum vulgare L.) in much of the northern United States. Direct selection for winter survival is time consuming and often unreliable. In addition, because survival is a binary trait, selection towards small quantitative gains can be difficult. One solution to these challenges is to identify indirect selection traits: anatomical or physiological characteristics which can be measured in the absence of winter stress, but which contribute to improved winter survival. Here, we survey a range of winter and spring barley, as well as winter wheat, winter rye, and perennial species of the genus Hordeum, all of which are more winter hardy than barley, to identify traits associated with winter survival. We identified several traits as promising candidates for selection. These included crown depth and leaf metaxylem diameter, which previous studies have identified as indirect selection traits. New candidates identified by our study include crown diameter and leaf midvein and blade thickness, as well as a suite of traits which suggest a pattern of reduced and efficient investment in above-ground structures. The effect of these traits on winter survival need to be validated and quantified by further experiments, but they represent a promising early step in a potentially valuable breeding strategy. [ABSTRACT FROM AUTHOR]

Cacao is a tropical tree species, is highly sensitive to soil water limitations, and its production is strongly affected by global climatic fluctuations. The study of variability in cacao germplasms offers insights into identifying morphological traits associated with drought tolerance. Assessing the genetic parameters of these traits is essential to optimize selection strategies in breeding programs. This study estimated genetic parameters for eighteen cacao progenies and seven parental clones in the field and in greenhouse conditions. The family heritability (h2fam) and individual heritability (h2ind) of pod production during the dry season were calculated as h2fam = 0.30 and h2ind = 0.27. Regarding relative water content (RWC), the highest h2fam value was observed after 180 min of dehydration (0.26). High genetic values were observed for the parental clones CEPEC-2002 and SJ-02, as well as their progenies, in terms of production and RWC in the field. The survival and RWC of greenhouse seedlings were correlated with the evaluations carried out in adult plants in the field (a maximum r of 0.49*** between RWC in the field and survival in the greenhouse and a maximum r of 0.66*** between RWC in both conditions). These findings provide valuable insights to enhance breeding strategies to improve cacao drought tolerance. [ABSTRACT FROM AUTHOR]

Because the universe of possible DNA sequences is inconceivably vast, organisms have evolved mechanisms for exploring DNA sequence space while substantially reducing the hazard that would otherwise accrue to any process of random, accidental mutation. One such mechanism is meiotic recombination. Although sexual reproduction imposes a seemingly paradoxical 50% cost to fitness, sex evidently prevails because this cost is outweighed by the advantage of equipping offspring with genetic variation to accommodate environmental vicissitudes. The potential adaptive utility of additional mechanisms for producing genetic variation has long been obscured by a presumption that the vast majority of mutations are deleterious. Perhaps surprisingly, the probability for adaptive variation can be increased by several mechanisms that generate mutations abundantly. Such mechanisms, here called 'mutation protocols', implement implicit 'constraints that deconstrain'. Like meiotic recombination, they produce genetic variation in forms that minimize potential for harm while providing a reasonably high probability for benefit. One example is replication slippage of simple sequence repeats (SSRs); this process yields abundant, reversible mutations, typically with small quantitative effect on phenotype. This enables SSRs to function as adjustable 'tuning knobs'. There exists a clear pathway for SSRs to be shaped through indirect selection favouring their implicit tuning‐knob protocol. Several other molecular mechanisms comprise probable components of additional mutation protocols. Biologists might plausibly regard such mechanisms of mutation not primarily as sources of deleterious genetic mistakes but also as potentially adaptive processes for 'exploring' DNA sequence space. [ABSTRACT FROM AUTHOR]

Tandem-repeat DNA sequences appear to be singularly capable of yielding abundant repeat-number mutations with a potentially advantageous distribution of fitness effects. Although knowing the rates and relative proportions of deleterious, neutral and beneficial mutations is fundamental for understanding evolvability, analysis of adaptation routinely overlooks small-effect mutations arising in tandem repeats. Tandem-repeat DNA sequences appear to be singularly capable of yielding abundant repeat-number mutations with a potentially advantageous distribution of fitness effects. Although knowing the rates and relative proportions of deleterious, neutral and beneficial mutations are fundamental for understanding evolvability, analysis of adaptation routinely overlooks small-effect mutations arising in tandem repeats. [ABSTRACT FROM AUTHOR]

Bambara groundnut is vital for food security due to its high nutritional content and resilience to environmental stresses. The objectives of the study were to determine associations among agronomic traits and nutrients in Bambara groundnut and identify traits influencing grain production in Bambara groundnut. Field experiments were conducted at the University of KwaZulu-Natal's Ukulinga Farm and Controlled Environment Facility (CEF) to assess agronomic performance and nutritional content. Nutritional content was evaluated using standard combustion procedures and electron microscopy. Correlation, regression, and path coefficient analyses revealed varying relationships among agronomic traits, nutrient content, and grain yield. The number of seeds (NS), healthy seeds (NHS), and plant height (PH) exhibited significant associations with grain yield. Neutral detergent fiber (NDF), starch, magnesium (Mg), nitrogen (N), oxygen (O), and phosphorus (P), were the key predictors of grain yield productivity. Path coefficient analysis showed that NS, PH and magnesium, oxygen, and carbon contents positively affected grain yield. In conclusion, grain yield was influenced by multiple traits through different pathways that are complicated by the growing environment. Selecting taller genotypes with good agronomic traits and high nutrient content is recommended to develop high yielding Bambara groundnut cultivars.

ABSTRACTInner Mongolia Cashmere goats are excellent genetic resources in China. Cashmere yield/body weight (g/kg), staple diameter (It is the cross-sectional diameter of coarse wool)/staple length (μm/cm), and fiber diameter (It is the cross-sectional diameter of fluff)/fiber length(μm/cm) were studied as secondary traits. Using the CORR and REG programs of SAS9.2, it was found that there is a significant phenotypic correlation and regression between the three secondary traits. The variance components analysis and genetic parameters estimation using the AIREML of the WOMBAT software. The results showed that all secondary traits have moderate heritability (0.17–0.30), and the heritability of each secondary trait of the long staple type is higher than other types. The genetic correlation of each secondary trait is between −0.39 and 0.27, and the genetic correlation of each secondary trait increases with the increase of staple length. Therefore, selection staple length can be to indirect selection of secondary traits.

Genetic changes that enabled the evolution of eusociality have long captivated biologists. More recently, attention has focussed on the consequences of eusociality on genome evolution. Studies have reported higher molecular evolutionary rates in eusocial hymenopteran insects compared with their solitary relatives. To investigate the genomic consequences of eusociality in termites, we analysed nine genomes, including newly sequenced genomes from three non-eusocial cockroaches. Using a phylogenomic approach, we found that termite genomes have experienced lower rates of synonymous substitutions than those of cockroaches, possibly as a result of longer generation times. We identified higher rates of non-synonymous substitutions in termite genomes than in cockroach genomes, and identified pervasive relaxed selection in the former (24–31% of the genes analysed) compared with the latter (2–4%). We infer that this is due to reductions in effective population size, rather than gene-specific effects (e.g. indirect selection of caste-biased genes). We found no obvious signature of increased genetic load in termites, and postulate efficient purging of deleterious alleles at the colony level. Additionally, we identified genomic adaptations that may underpin caste differentiation, such as genes involved in post-translational modifications. Our results provide insights into the evolution of termites and the genomic consequences of eusociality more broadly. [ABSTRACT FROM AUTHOR]

The growth of Nelore cattle was analysed considering the following performance parameters; the effect of the calving order of cows on the phenotypic expression of birth weight (BW), average daily gain from birth to weaning (BWG), and weaning weight (WW), the estimated genetic parameters for the traits, including the covariance components between direct and maternal genetic effects. Genetic trends and correlated responses were also obtained for the studied traits. The calving order of cows, as well as other fixed effects used to obtain the adjusted phenotypic means, were statistically significant (p < 0.001) for studied traits. Direct heritability was estimated at 0.24 ± 0.01 (BW), 0.15 ± 0.01 (BWG), and 0.18 ± 0.01 (WW), while maternal heritability was 0.06 ± 0.01 (BW), 0.12 ± 0.01 (BWG), and 0.11 ± 0.01 (WW). The correlations between direct and maternal effects within the same trait were negligible. Moderate to higher direct genetic correlations (ranging from 0.54 ± 0.04 to 0.98 ± 0.01) and maternal genetic correlations (ranging from 0.34 ± 0.09 to 0.99 ± 0.002) were estimated between the studied traits. Unlike direct genetic effects, there was no significant change in maternal genetic effects over time (p > 0.05). These results indicated the need for revising selection indexes for enhancing maternal ability. Correlated responses were generally lower compared to direct responses, except for BWG. The selection for BWG, considering the maternal genetic effect, would be more efficient to improve maternal ability of the cows for pre-weaning growth in relation to selection for WW. Our results found that direct genetic merit improves pre-weaning weight and this trait can be incorporated into the breeding goal as reflected in the WW. [ABSTRACT FROM AUTHOR]

As selection acts on multivariate phenotypes, the evolution of traits within populations not only depends on the genetic basis of each trait, but also on the genetic relationships among traits. As metabolic rate is often related to vital traits such as growth, physiology and behaviour, its variation and evolution is expected to have important repercussions on individual fitness. However, the majority of the correlations between metabolic rate and other traits has been based on phenotypic correlations, while genetic correlations, basis for indirect selection and evolution, have been overlooked. Using a case study, we explore the importance of properly estimating genetic correlations to understand and predict evolution of multivariate phenotypes. We show that selection on metabolic traits could result in indirect selection mainly on growth-related traits, owing to strong genetic correlations, but not on swimming or risk-taking and sociability behaviour even if they covary phenotypically. While phenotypic correlation can inform about genetic correlation direction, caution is needed in predicting the magnitude of genetic correlation. Therefore, even though phenotypic correlations among physiological and behavioural traits could be useful, deriving evolutionary conclusions based purely on them is not robust. In short, proper estimation of genetic correlations is needed when predicting evolutionary consequences. This article is part of the theme issue 'The evolutionary significance of variation in metabolic rates'. [ABSTRACT FROM AUTHOR]

Fisher proposed that female preference for mates with extreme traits could evolve as an essentially arbitrary outcome of a self-reinforcing process. Although Fisher's runaway has been shown to be a theoretical possibility, it is not clear whether it occurs in real populations, in part because existing models express the necessary conditions in terms of parameters that would be nearly impossible to estimate in the wild. Here, I reformulate models of the runaway in terms of two estimable parameters, the heritability and phenotypic variance of realized mate choices. Higher values of both quantities make the runaway more likely. In the most realistic model considered, in which mate choices are based on a mixture of absolute and relative criteria, a runaway cannot occur unless mate choice increases the variance of the male trait, which seems incompatible with the strong directional mating preferences typically observed in polygynous species. Even in the most favourable case for the runaway, purely relative preference without direct selection on preference, a substantial heritability of realized mate choices would be required if there is moderately strong stabilizing selection on the male trait. These results cast some doubt on whether the runaway is a plausible outcome in natural populations. [ABSTRACT FROM AUTHOR]

Wheat, as one of the most important crop on earth, is the main supplier of human food. This research was conducted to investigate the wheat recombinant inbred lines based on the germination components and compare them with the control varieties of the region to select the best lines using the selection index of the multi-trait genotype-ideotype distance (MGIDI). For this purpose, 40 wheat inbred lines (F8) were evaluated along with six control varieties (Arman, Araz, Ehsan, Tirgan, Meraj and Kalateh). According to the results of the analysis of variance, a significant difference between the studied lines was observed for all traits (P<.01). The results of factor analysis for the studied traits identified three factors that explained 86.93% of the total variation. Based on the MGIDI index, seven lines L3-4, L7- 5, L7-4, L8-5, L4-4, L5-3, and L3-3 were selected as the superior genotypes with the lowest distance to the ideal genotype. Based on the cluster analysis, the genotypes were divided into five groups, and the genotypes of the fifth group were identified as the best genotypes in terms of all germination components and seedling traits, and were consistent with the genotypes identified based on the MGIDI index. The highest percentage of differential selection and genetic gain was assigned to the fresh weight vigour index (49.16% and 29.14%, respectively), which shows that the superiority of the selected genotypes is more prominent in terms of this trait. Based on the results, the recombinant inbred lines were significantly superior to the control cultivars in terms of the studied traits. Also, the results of this study showed that the use of the MGIDI index can efficiently identify superior genotypes. [ABSTRACT FROM AUTHOR]

The objective of this study was to identify the linear relationships between the morphological variables of corn hybrids, associated with grain yield and fungicide use in subtropical environments. Seven experiments were conducted in three locations: Santa Maria - RS, São Vicente do Sul - RS, and Frederico Westphalen - RS, Brazil. The design used was a randomized block design with subdivided plots and three replications, where the main factor was the use or not of fungicide and the subplots corresponded to six corn hybrids. The following traits were evaluated: leaf angle, stem diameter, ear insertion height, ear length, ear diameter, number of rows, grain length, thousand-grain mass, percentage of damaged grains, and grain yield. The characters were subjected to Pearson correlation analysis and path analysis using R software. It can be concluded that there is a difference in the magnitudes of the linear relationships depending on whether or not fungicides are used on corn hybrids in subtropical environments, with cultural management influencing the results of the linear relationships. The characters ear diameter, grain length, ear length, and thousand-grain mass are positively related, while leaf angle and the percentage of damaged grains are negatively related to grain yield in corn hybrids. [ABSTRACT FROM AUTHOR]

Early vigor, stress resistance, uniformity, high yield, and breeder right protection have turned hybrid cultivar development into the most successful breeding strategy in rapeseed (Brassica napus L.). The goals of this research were to develop the first CMS based rapeseed hybrids in Iran and to evaluate their performance and fertility. The effect of different traits on yield increasing of hybrids was also studied. Seven CMS lines were crossed with R2000 (a restorer-line) and the seed yield of hybrids was tested using a randomized complete block design with three replications in 2019-2020 and 2020-2021. Three of hybrids with 4.64, 4.40, and 4.38 tons per hectare, showed considerable yield and were significantly different than Nilufar, Neptune, and Nima (3.44, 3.37, and 3.30 tons per hectare, respectively), as check cultivars. R2000×A8 demonstrated the highest heterosis (34.71%) to high-check cultivar. All hybrids obtained were normal in terms of fertility, having no male-sterile flowers. Based on the results of principal component analysis and cluster analysis, the simultaneous increase in the number of pods per plant and the thousand seed weight, together with crossing the more distant parents will lead to more high yielding hybrids. The promising hybrids with high yield and remarkable fertility could be released as new cultivars after passing adaptability and stability experiments. [ABSTRACT FROM AUTHOR]

As one of the most important stages of plant development, germination significantly impacts plant establishment and grain yield. The exploration of relationships between germination stages and plant agronomic traits can be of utmost importance in identifying the principal germination components to predict superior genotypes concerning yield-related traits in the field. This study examined this relationship through canonical correlation analysis (CCA). To this end, two field experiments were conducted using 100 barley lines and five check cultivars. A germination experiment was also conducted to investigate germination components. The CCA results based on both germination field experimental analyses revealed highly significant associations between agronomical traits and germination components. The first pair of canonical variables had significant correlation coefficients of 0.74 and 0.69 in both experiments (P < 01). The interpretation of the relationships between canonical variables and their own canonical variables, as well as the associations between the first variables and their opposite canonical variables, indicated that the germination key variables were: dry weight of radicles and plumule. These variables were highly correlated with the most important agronomical and morphological traits, such as grain yield, thousand-grain weight, and the number of spikes per square meter in the field (P <.01). Consequently, they can be used to predict superior and ideal barley genotypes regarding agronomic traits and yield in the field. This study's findings demonstrate that the CCA effectively identifies the relationship between the two groups of traits. [ABSTRACT FROM AUTHOR]

Abstract The objective of this work was to determine the genetic correlations and the direct and indirect associations of agronomic traits and grain quality attributes with the percentage of whole grains in flood irrigated rice. The experiment was carried out in two environments, in a randomized complete block design with three replicates, using 23 irrigated rice genotypes. The evaluated traits were: percentage of whole grains, caryopsis length, caryopsis width, panicle length, panicle weight, 1,000 grain weight, days to flowering, percentage of chalky grains with white belly, total chalky area, total whiteness, vitreous whiteness, and defects in coloring. The percentage of grains with white belly and total chalky area were positively correlated, whereas the percentage of grains with white belly and vitreous whiteness were negatively correlated. The traits caryopsis width, percentage of chalky grains with white belly, panicle weight, and 1,000 grain weight showed indirect effects on whole-grain yield response according to total chalky area and total whiteness. Total chalky area and total whiteness are the factors that most negatively influence the percentage of whole grains according to the genotypic correlations and direct effects.

Introduction Maize as a tropical cereal is a main source of food for humans and livestock, as well as biofuels and fiber in some regions of the world. Increasing maize production is one of the main priorities of the country, Iran. One of the elements of increasing production is development of new high-yielding cultivars. To improve a complex trait such as grain yield that has low heritability, indirect selection by other traits or developing a suitable index based on several traits can be used. The objective of the present study was to prepare appropriate selection indices in maize to improve grain yield. In this regad, linear phenotypic selection index (LPSI) and linear molecular selection index (LMSI) were calculated using the combination of morphological traits and informative ISSR molecular markers. Materials and methods The plant materials of this research were 97 maize genotypes that were cultivated in a randomized complete block design with six replications in the research field of the Faculty of Agriculture, Urmia University, Urmia, Iran. Morphological traits were measured from the tasseling stage to the physiological maturity. Sixty ISSR primer combinations were used to prepare the molecular profile of the studied maize genotypes. To select the suitable genotypes, two indices including linear phenotypic selection index and linear molecular selection index were used, and the efficiency of the indices was compared with the estimation of different ceriteria such as the rate of genetic gain and response to selection. Research findings The results of the linear phenotypic selection index showed that the highest rate of genetic gain based on the index (∆G) was observed for chlorophyll content (99.15) and the lowest one for number of ears per plant (0.01). The expected genetic gain for all studied traits (∆H) and response to selection was estimated at 163.2234 and 0.774, respectively. Based on the linear molecular selection index, the highest rate of genetic gain (∆G) was observed for leaf area (99.31) and the lowest one was observed for number of ears per plant (0.02). The expected genetic gain for all studied traits (∆H) and response to selection was also estimated at 50.972 and 0.774, respectively. The results showed that the correlation between index and breeding value (rHI) in the LPSI index was relatively favorable (less than one), and in the LMSI index was optimal (one), but both correlations were significant at 0.05 probability level according to the t-test. However, the efficiency of selection based on the index (ΔH) was 163.22 for the LPSI index and 50.97 for the LMSI index. On the other hand, the degree of genetic gain of trait (∆G) was different depending on the type of index. For example, the ratio of genetic gain (∆G) derived from molecular to phenotypic index for the number of ears per plant and grain yield (2.00 and 1.28, respectively) was higher than the other traits. Also, the best genotype based on both indices was genotype number of 61. Conclusion According to the results obtained from the present study and the review of sources in this field, it seems that it is possible to benefit from the advantages of development of the LMSI index in the breeding programs in early generations, but in advanced generations, it is better to select genotypes using the LPSI index, in which case the cost of molecular evaluations will be reduced. [ABSTRACT FROM AUTHOR]

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The ability to connect genetic information between traits over time allow Bayesian networks to offer a powerful probabilistic framework to construct genomic prediction models. In this study, we phenotyped a diversity panel of 869 biomass sorghum (Sorghum bicolor (L.) Moench) lines, which had been genotyped with 100,435 SNP markers, for plant height (PH) with biweekly measurements from 30 to 120 days after planting (DAP) and for end-of-season dry biomass yield (DBY) in four environments. We evaluated five genomic prediction models: Bayesian network (BN), Pleiotropic Bayesian network (PBN), Dynamic Bayesian network (DBN), multi-trait GBLUP (MTr-GBLUP), and multi-time GBLUP (MTi-GBLUP) models. In fivefold cross-validation, prediction accuracies ranged from 0.46 (PBN) to 0.49 (MTr-GBLUP) for DBY and from 0.47 (DBN, DAP120) to 0.75 (MTi-GBLUP, DAP60) for PH. Forward-chaining cross-validation further improved prediction accuracies of the DBN, MTi-GBLUP and MTr-GBLUP models for PH (training slice: 30-45 DAP) by 36.4-52.4% relative to the BN and PBN models. Coincidence indices (target: biomass, secondary: PH) and a coincidence index based on lines (PH time series) showed that the ranking of lines by PH changed minimally after 45 DAP. These results suggest a two-level indirect selection method for PH at harvest (first-level target trait) and DBY (second-level target trait) could be conducted earlier in the season based on ranking of lines by PH at 45 DAP (secondary trait). With the advance of high-throughput phenotyping technologies, our proposed two-level indirect selection framework could be valuable for enhancing genetic gain per unit of time when selecting on developmental traits.

Caesalpinia ebano is a tropical tree from Colombia; its conservation status is in the endangered category since the remaining populations are suffering genetic erosion. The objective of this study was to estimate the phenotypic (rF) and genetic (rG) correlations among biometric fruit and seeds traits, and the path analysis for the fruit weight. Ten trees (treatments) were evaluated under the random effects model, with 10 fruits/tree as replications. There was significant variability between trees for seven quantitative traits. The fruit weight showed genetic correlations with six traits (0.56* > rG < 1.00**). The number and weight of the seeds per fruit showed high genetic correlations with five traits (rG ≥ 0.85**). The weight of the seeds per fruit exerted direct and indirect effects of greater importance in determining the fruit weight. It is possible to improve the production and physiological quality of the seed by directly selecting trees with fruits of greater seed weight.

Sexual selection has a rich history of mathematical models that consider why preferences favor one trait phenotype over another (for population genetic models) or what specific trait value is preferred (for quantitative genetic models). Less common is exploration of the evolution of choosiness or preference strength: i.e. by how much a trait is preferred. We examine both population and quantitative genetic models of the evolution of preferences, specifically developing "baseline models" of the evolution of preference strength during the Fisher process. Using a population genetic approach, we find selection for stronger and stronger preferences when trait variation is maintained by mutation. However, this force is quite weak and likely to be swamped by drift in moderately-sized populations. In a quantitative genetic model, unimodal preferences will generally not evolve to be increasingly strong without bounds when male traits are under stabilizing viability selection, but evolve to extreme values when viability selection is directional. Our results highlight that different shapes of fitness and preference functions lead to qualitatively different trajectories for preference strength evolution ranging from no evolution to extreme evolution of preference strength. [ABSTRACT FROM AUTHOR]

The correlation between physical and chemical attributes of fruits can serve as indicators for the ideal harvest time and function as selection criteria to enhance the management and productivity of crops. This study aimed to investigate the correlations among physical and chemical properties of Cortibel guava fruits grown in the Brazilian Cerrado. Parameters assessed included skin and pulp color, weight, diameter, length, total soluble solids, titratable acidity, and the ratio of these characteristics. Data were analyzed using Pearson's linear correlation with a significance level of P < 0.05. Several physical and chemical properties of the fruits exhibited significant correlations. The highest correlation coefficients were observed between weight and fruit diameter, as well as between hue angle of the skin and skin lightness. The properties of Cortibel guava fruits cultivated in the Brazilian Cerrado exhibit significant correlations. These findings enable the utilization of straightforward parameters in the selection processes of Cortibel guava for breeding objectives. Highlights: • Guava is a significant crop with high economic value. • The characterization of fruits assists in selecting genotypes with desirable commercial properties. • Cortibel guava fruits exhibited significant correlations between some physical and chemical characteristics. • The correlations between the physical and chemical characteristics of the fruits allow the selection of materials of interest for breeding.

The knowledge of correlation and path coefficient analysis allow crop breeders to practice indirect selection to improve traits like grain yield which are complex in nature. The objectives of the present study were to measure association among yield and yield related traits and to identify important traits for indirect selection to improve faba bean grain yield. Eighty-one faba bean accessions were evaluated following 9 × 9 simple lattice design at one of the Bahir Dar University research sites at Mecha district in 2019 rainy cropping season. The result of correlation analysis revealed that grain yield had highly significant (p < 0.01) and positive phenotypic and genotypic correlations with plant height, pod length, number of pods per plant, number of branches per plant, biomass yield, 100-seed mass and harvest index indicating the possibility of simultaneous improvement of grain yield with these traits through selection. Path coefficient analysis demonstrated that higher positive direct effects were exerted by biomass yield and harvest index on grain yield both at phenotypic and genotypic levels, as a result, these traits could be used as indirect selection criteria to improve faba bean grain yield.

Canonical correlation analysis based on genotypic correlations allows determining the associations between groups of traits and carrying out the direct or indirect selection of superior genotypes. This study investigated the existence of linear and multivariate relationships between high and low heritability traits via canonical correlation analysis based on genotypic correlations. The experiment was conducted at the Professor Diogo Alves de Melo Experimental Field at the Universidade Federal de Viçosa, in Viçosa, MG. 90 wheat cultivars were evaluated under a 9 × 10 alpha-lattice design, with three replications and plots consisting of four rows of three meters spaced at 0.20 meters. Canonical groups were established between spike height and plant height, days for heading, number of spikelets per spike, and number of grains per spike (Group I) and, spike weight, spike grain mass, 100-grain mass, hectoliter weight, and grain yield (Group II). There was dependence between the established groups, which allowed the investigation of the relationships between traits based on their genotypic values. The traits cycle and plant height can be used for indirect selection of genotypes superior in hectoliter weight and grain yield, which are important factors for industries and farmers. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the application of shear strength and its correlations with leaf blade morphological and chemical variables as a tool capable of detecting differences between species and accessions of the genus Paspalum in the early stages of a forage plant breeding programme. A total of 13 Paspalum accessions from two species (Paspalum atratum and Paspalum regnellii) were subjected to analyses of shear strength, which also analysed the neutral detergent fibre, acid detergent fibre, lignin, and digestibility. Morphological measurements were also performed to standardize the shear strength per unit of leaf tissue. The experimental design consisted of complete randomized blocks, with four replications and eight cuts performed over 2 years. Shear strength was evaluated for its potential usefulness for detecting differences between accessions of the same species and the correlations of accessions. It was possible to use the shear strength measured with the texturometer to detect differences between species and accessions of the Paspalum genus. The results showed significant correlations of shear strength and neutral detergent fibre (r = 0.49), and negative correlations were found between digestibility and shear strength (r = -0.55). These correlations were maintained when the strength variables were standardized according to the morphological variables. Thus, shear strength can be used in the initial stages of the selection of species of the genus Paspalum. [ABSTRACT FROM AUTHOR]

The correlation between physical and chemical attributes of fruits can serve as indicators for the ideal harvest time and function as selection criteria to enhance the management and productivity of crops. This study aimed to investigate the correlations among physical and chemical properties of Cortibel guava fruits grown in the Brazilian Cerrado. Parameters assessed included skin and pulp color, weight, diameter, length, total soluble solids, titratable acidity, and the ratio of these characteristics. Data were analyzed using Pearson's linear correlation with a significance level of P < 0.05. Several physical and chemical properties of the fruits exhibited significant correlations. The highest correlation coefficients were observed between weight and fruit diameter, as well as between hue angle of the skin and skin lightness. The properties of Cortibel guava fruits cultivated in the Brazilian Cerrado exhibit significant correlations. These findings enable the utilization of straightforward parameters in the selection processes of Cortibel guava for breeding objectives. [ABSTRACT FROM AUTHOR]

High-throughput phenotyping (HTP) using vegetation indices (VIs) is an important data source for managing plant breeding programs and can be a promising tool in indirect selection. This study hypothesized that VIs are correlated with agronomic traits in corn, and therefore, HTP can be an auxiliary tool for selecting superior genotypes. The objectives were: i) to analyze the association between agronomic traits and VIs, and ii) to identify superior corn hybrids for the evaluated traits using multivariate techniques. Ten corn hybrids (AGRI 330, AGRI 340, FS575PWU, KTZ006VP3, MG545AW, MG580PW, MG711PW, MZ1780, MZ1952, and TROPI 102) were evaluated for plant height (PH), stem diameter (SD), and grain yield (GY). The VIs studied were NDVI, NDRE, EVI, GNDVI, SAVI, and MSAVI. Pearson’s correlation network was constructed to analyze the relationship between the variables, and a canonical analysis was performed to verify the inter-relationship between the variables and hybrids. The VIs evaluated are strongly positively correlated with each other and with PH. The most productive hybrids are MG545AW, FS575PWU and KTZ006VP3. Hybrid MZ1952 has higher correlations with VIs and PH. The findings reveal that VIs can be excellent auxiliary variables for selecting agronomically superior genotypes, being a promising alternative to increase corn breeding efficiency. [ABSTRACT FROM AUTHOR]

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Heritability and association between agronomic traits with sesamin and sesamolin are very important. The aims of this study were to estimate broad-sense heritability and to investigate association of agronomic traits with sesamin and sesamolin in sesame. Seven parental lines and twenty-one hybrid genotypes were evaluated in RCBD with three replications. Agronomic traits were recorded. Sesamin and sesamolin were determined using HPLC. Parent and hybrid populations had large genetic coefficient of variation for both sesamin and sesamolin. Broad-sense heritability of sesamin and sesamolin was high for both parent and hybrid populations. Therefore, selection for those traits based on phenotype in the early generation should be effective. Plant height had significant negative correlation and the largest negative direct effect on both target traits in parental population. Day to harvest was the most influential trait on the target traits in hybrids. These results may facilitate sesame breeding programs to improve lignan content in sesame.

Due to the increasing need of the country to imported edible oil and rapeseed importance among oilseeds, efforts to increase its grain yield and oil content are of high importance. Therefore, recognizing the traits that increase grain yield of rapeseed has an important role in the success of breeding programs. Thus, sixteen rapeseed genotypes were evaluated in a randomized complete block design with three replications in three regions with different climatic conditions in Iran, including Karaj, Isfahan, and Hamadan in 2016-2017. Traits such as number of pods per plant, number of seeds per pod, grain yield, 1000-grain weight, plant height, height of the first branch, stem diameter, oil percent, number of days to flowering, number of days to the end of flowering, duration of flowering, and number of days to maturity were measured. Stepwise regression analysis showed that number of grain/pod, number of days to maturity and number of pods/plant (R2 = 97.7), number of pods/plant and number of days to maturity (R2 =78.4) and number of days to maturity and number of grains/pod (R2 = 45.5) accounted for total variations of grain yield in Karaj, Isfahan and Hamadan, respectively. The results showed that the number of days to maturity, number of pods/plant, number of grain/pods, stem diameter and plant height had the greatest positive effect on grain yield and oil content. Therefore, these traits can be used as suitable selection tools for increasing grain and oil yield in winter rapeseed breeding programs

Red clover is an important perennial forage legume and a rich source of highly nutritional voluminous forage for livestock feed, which is continuously improved by plant breeding efforts that rely significantly on trait correlation studies. A two-year field trial was conducted at Rimski Šančevi, Novi Sad, Serbia. The aim of this research was to assess correlations of important morpho-agronomic traits and forage quality properties of 46 red clover accessions of diverse origins. The highest Spearman's correlation coefficient (0.97, p

Human selection on wild populations mostly favored a common set of plant traits during domestication. This process of direct selection also altered other independent traits that were not directly perceived or desired during crop domestication and improvement. A deeper knowledge of the inadvertent and undesirable phenotypic effects and their underlying genetic causes can help design strategies to mitigate their effects and improve genetic gain in crop plants. We review different factors explaining the negative consequences of plant domestication at the phenotypic and genomic levels. We further describe the genetic causes of undesirable effects that originate from the selection of favorable alleles during plant domestication. In addition, we propose strategies that could be useful in attenuating such effects for crop improvement. With novel -omics and genome-editing tools, it is relatively approachable to understand and manipulate the genetic and biochemical mechanisms responsible for the undesirable phenotypes in domesticated plants. [ABSTRACT FROM AUTHOR]

Nitrogen fertilization enhances the tillering capacity of white oats and a greater number of fertile tillers is directly related to the increase in grains per area, which is related to grain yield. The objectives of this work were to evaluate the tillering capacity and the linear relationships between characters of white oat cultivars, associated with the use of nitrogen fertilization. The experiment was carried out in Santa Maria - RS, in a randomized block design, with the main plot comprising five white oat cultivars and the subplot comprising four doses of nitrogen applied as a top dressing when the crop had 3 developed leaves (0 kg ha-1, 50 kg ha-1, 100 kg ha-1, and 150 kg ha-1). Six hundred plants were sampled when the crop was at the full tillering stage and the characters were assessed: plant height (cm), height of first leaf insertion (cm), number of fully expanded leaves, number of tillers, stem diameter (cm), and dry matter phytomass (g). Nitrogen had a positive effect on the number of tillers, with the most effective doses being between 101.67 and 122.14 kg ha-1. The 122.14 kg ha-1 dose is recommended in order to achieve maximum technical efficiency for the production of tillers in the white oat crop, with emphasis on the URS Altiva cultivar, which had the highest number of tillers. The number of tillers and plant height have a positive linear relationship with dry matter phytomass and can be used for indirect selection. [ABSTRACT FROM AUTHOR]

Lima bean is an important crop in Northeastern Brazil and a source of food and income for farmers in the region. However, there have been few genetic studies on this species, which limits the knowledge available for use in breeding programs. The objective of this study was to estimate the relationship between cycle and production traits using canonical correlation analysis and to identify traits that can be used for the indirect selection of lima bean. The experiment was conducted at the Department of Plant Science of the Universidade Federal do Piauí, Teresina, in a randomized block design with five replications, in which 11 agronomic traits from six lima bean populations in the F3 generation originating from biparental crosses were evaluated in 2019. The data were subjected to canonical correlation analysis using the virtual environment R. The results showed that only the first coefficient of the canonical pair was significant (r = 0.5531) by the quisquare test, suggesting that the studied groups were not independent, as the cycle traits showed coefficients of large magnitudes in the relationship between groups. The canonical correlation results suggested that there is a linear association between cycle and production traits in lima beans, in which days to flowering, days to maturation, pod length, seed width, and seed thickness contribute the most to the association between groups. [ABSTRACT FROM AUTHOR]

We recently published a paper quantifying the genome‐wide consequences of natural selection, including the effects of indirect selection due to the correlation of genetic regions (neutral or selected) with directly selected regions (Gompert et al., 2022). In their critique of our paper, Charlesworth and Jensen (2022) make two main points: (i) indirect selection is equivalent to hitchhiking and thus well documented (i.e., our results are not novel) and (ii) that we do not demonstrate the source of linkage disequilibrium (LD) between SNPs and the Mel‐Stripe locus in the Timema cristinae experiment we analyse. As we discuss in detail below, neither of these are substantial criticisms of our work. This is a reply to the commentary by Charlesworth and Jensen (2022); [ABSTRACT FROM AUTHOR]

The interaction between the genotype and feeding regimen (G×FR) for slaughter traits was estimated from data corresponding to 2557 animals under full (FF) and 2424 with restricted feeding (RF). Expected responses to selection under different scenario regarding feeding regimen were also calculated. Body weight at slaughter (SW), carcass weight (CW) and dressing out percentage (DoP) were analysed by using linear animal models in which records obtained under different feeding regimes were treated as different traits. Animals belonged to Caldes line, selected for average daily gain (G) under ad libitum feeding. The selection process information was included in the analyses. Marginal posterior mean of heritabilities were 0.102 for G, and 0.364, 0.257 and 0.167 for SW, CW and DoP under FF feeding. The corresponding values for animals fed on RF were 0.243, 0.203 and 0.379 for SW, CW and DoP, respectively. Genetic correlations between G and CW were positive and moderate, and those between G and DoP were low. The estimated genetic correlation between SW, CW and DoP under different feeding regimens were: 0.73, 0.69 and 0.87, respectively. These correlations cannot be said to be far enough from one to generate relevant G×FR interaction variance, which were estimated to be only 11.1%, 8.6% and 5.3% of the mean of the phenotypic variance for SW, CW and DoP, respectively. This lack of G×FR interaction variance, jointly with the higher heritability of DoP under RF, explains that the genetic improvement of DoP can be done more efficiently recording traits on animals under RF, even if the interest is on the performances under FF, i.e. by indirect selection. [ABSTRACT FROM AUTHOR]

Abstract Fishing‐associated selection is one of the most important human‐induced evolutionary pressures for natural populations. However, it is unclear whether fishing leads to heritable phenotypic changes in the targeted populations, as the heritability and genetic correlations of traits potentially under selection have received little attention. In addition, phenotypic changes could arise from fishing‐associated environmental effects, such as reductions in population density. Using fish reared at baseline and reduced group density and repeatedly harvested by simulated trawling, we show that trawling can induce direct selection on fish social behaviour. As sociability has significant heritability and is also genetically correlated with activity and exploration, trawling has the potential to induce both direct selection and indirect selection on a variety of fish behaviours, potentially leading to evolution over time. However, while trawling selection was consistent between density conditions, the heritability and genetic correlations of behaviours changed according to the population density. Fishing‐associated environmental effects can thus modify the evolutionary potential of fish behaviour, revealing the need to use a more integrative approach to address the evolutionary consequences of fishing.

The present study aimed to evaluate the application of shear strength and its correlations with leaf blade morphological and chemical variables as a tool capable of detecting differences between species and accessions of the genus Paspalum in the early stages of a forage plant breeding programme. A total of 13 Paspalum accessions from two species (Paspalum atratum and Paspalum regnellii) were subjected to analyses of shear strength, which also analysed the neutral detergent fibre, acid detergent fibre, lignin, and digestibility. Morphological measurements were also performed to standardize the shear strength per unit of leaf tissue. The experimental design consisted of complete randomized blocks, with four replications and eight cuts performed over 2 years. Shear strength was evaluated for its potential usefulness for detecting differences between accessions of the same species and the correlations of accessions. It was possible to use the shear strength measured with the texturometer to detect differences between species and accessions of the Paspalum genus. The results showed significant correlations of shear strength and neutral detergent fibre (r = 0.49), and negative correlations were found between digestibility and shear strength (r = -0.55). These correlations were maintained when the strength variables were standardized according to the morphological variables. Thus, shear strength can be used in the initial stages of the selection of species of the genus Paspalum.

Copyright of Revista de Ciencias Agricolas is the property of University of Narino, Faculty of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

On-farm genotype screening is at the core of every breeding scheme, but it comes with a high cost and often high degree of uncertainty. Phenomics is a new approach by plant breeders, who use optical sensors for accurate germplasm phenotyping, selection and enhancement of the genetic gain. The objectives of this study were to: (1) develop a high-throughput phenotyping workflow to estimate the Normalized Difference Vegetation Index (NDVI) and the Normalized Difference Red Edge index (NDRE) at the plot-level through an active crop canopy sensor; (2) test the ability of spectral reflectance indices (SRIs) to distinguish between sesame genotypes throughout the crop growth period; and (3) identify specific stages in the sesame growth cycle that contribute to phenotyping accuracy and functionality and evaluate the efficiency of SRIs as a selection tool. A diversity panel of 24 sesame genotypes was grown at normal and late planting dates in 2020 and 2021. To determine the SRIs the Crop Circle ACS-430 active crop canopy sensor was used from the beginning of the sesame reproductive stage to the end of the ripening stage. NDVI and NDRE reached about the same high accuracy in genotype phenotyping, even under dense biomass conditions where "saturation" problems were expected. NDVI produced higher broad-sense heritability (max 0.928) and NDRE higher phenotypic and genotypic correlation with the yield (max 0.593 and 0.748, respectively). NDRE had the highest relative efficiency (61%) as an indirect selection index to yield direct selection. Both SRIs had optimal results when the monitoring took place at the end of the reproductive stage and the beginning of the ripening stage. Thus, an active canopy sensor as this study demonstrated can assist breeders to differentiate and classify sesame genotypes. [ABSTRACT FROM AUTHOR]

The evolution of suppressed recombination between sex chromosomes is widely hypothesized to be driven by sexually antagonistic selection (SA), where tighter linkage between the sex‐determining gene(s) and nearby SA loci is favored when it couples male‐beneficial alleles to the proto‐Y chromosome, and female‐beneficial alleles to the proto‐X. Despite limited empirical evidence, the SA selection hypothesis overshadows several alternatives, including an incomplete but often‐repeated "sheltering hypothesis" that suggests that expansion of the sex‐linked region (SLR) reduces homozygous expression of partially recessive deleterious mutations at selected loci. Here, we use population genetic models to evaluate the consequences of deleterious mutational variation for the evolution of neutral chromosomal inversions expanding the SLR on proto‐Y chromosomes. We find that SLR‐expanding inversions face a race against time: lightly loaded inversions are initially beneficial, but eventually become deleterious as they accumulate new mutations, and must fix before this window of opportunity closes. The outcome of this race is strongly influenced by inversion size, the mutation rate, and the dominance coefficient of deleterious mutations. Yet, small inversions have elevated fixation probabilities relative to neutral expectations for biologically plausible parameter values. Our results demonstrate that deleterious genetic variation can plausibly drive recombination suppression in small steps and would be most consistent with empirical patterns of small evolutionary strata or gradual recombination arrest. [ABSTRACT FROM AUTHOR]

In shrimp production, product quality plays a crucial role and determines consumer acceptance. However, there are no studies on its genetic determination. The main purpose of this study was, for first time in Penaeus vannamei, to estimate the additive genetic variation of flesh quality traits in terms of composition and texture, and their genetic correlation with growth and morphological traits. To this end, 388 shrimps from the fourth generation of the PMG-BIOGEMAR© breeding program, belonging to 79 full-sib families, were reared under an extensive industrial culturing system (PRODUMAR, Durán, Ecuador). At the same day, they were harvested and measured for fresh weight. They were kept at −20 °C for later sampling for flesh quality traits, in terms of composition, by Near-Infrared spectroscopy (NIR), and texture by Texture analyzer technologies. Growth and morphological traits were manually measured with a vernier caliper. Low heritabilities were estimated for flesh composition traits (0.01 to 0.07), and low-medium for meat quality traits related to texture (0.01 to 0.37). Medium-high heritabilities were estimated for total length and weight (0.35 and 0.50, respectively), with a very high genetic correlation between both (0.99). Regarding morphological traits, heritabilities ranged from 0.05 to 0.52 for length-related traits, from 0.15 to 0.36 for height-related traits, and from 0.22 to 0.42 for width-related traits. Cephalothorax length showed the highest heritability among all analyzed traits (0.52), with high genetic correlations with growth, flesh composition, and texture traits. The high genetic correlations found between growth and morphometric traits, and both flesh composition and texture traits suggest indirect selection as a successful, undemanding, and cost-effective method to obtain high-quality shrimps under industrial conditions. • High heritability and positive correlations with growth and meat traits were observed for shrimp cephalothorax length • Meat quality showed low heritabilities but high and positive genetic correlations with growth and morphological traits. • High genetic correlations between growth, morphology, and meat quality traits suggest indirect selection in P. vannamei. • Shrimp body hardness showed a medium heritability, which was the highest of all the meat quality traits. [ABSTRACT FROM AUTHOR]

ABSTRACT: Canonical correlation analysis based on genotypic correlations allows determining the associations between groups of traits and carrying out the direct or indirect selection of superior genotypes. This study investigated the existence of linear and multivariate relationships between high and low heritability traits via canonical correlation analysis based on genotypic correlations. The experiment was conducted at the Professor Diogo Alves de Melo Experimental Field at the Universidade Federal de Viçosa, in Viçosa, MG. 90 wheat cultivars were evaluated under a 9 × 10 alpha-lattice design, with three replications and plots consisting of four rows of three meters spaced at 0.20 meters. Canonical groups were established between spike height and plant height, days for heading, number of spikelets per spike, and number of grains per spike (Group I) and, spike weight, spike grain mass, 100-grain mass, hectoliter weight, and grain yield (Group II). There was dependence between the established groups, which allowed the investigation of the relationships between traits based on their genotypic values. The traits cycle and plant height can be used for indirect selection of genotypes superior in hectoliter weight and grain yield, which are important factors for industries and farmers.

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)