Quantitative Trait Variation Research Articles

Variability of quantitative traits in winter triticale in the central region of Belarus

Introduction: The article presents the results of a long-term study of quantitative traits in winter triticale varieties and accessions grown in the soil/climatic conditions of the central region of Belarus using conventional and intensive cultivation technologies. The effects of the intensification level on the yield, performance constituents and triticale grain quality are described.
 Purpose: to assess the variability of quantitative traits in winter triticale grown by conventional and intensive cultivation technologies in Belarus.
 Material and methods: Winter hexaploid triticale varieties and promising accessions grown by traditional and intensive technologies in a competitive variety trial nursery were studied. The plot area was 10 m2; the replication number was three; the design was randomized; the seeding rate was 4.5 million viable seeds per hectare; the observation period was in 2011-2020. Upon intensive cultivation, additional doses of nitrogen fertilizers, trace elements (Cu, Mn), growth regulators and fungicides were applied. The contents of crude protein, gluten and starch in grain were determined by near-infrared spectroscopy
 Results and discussion: During the observation period, the average yield from the winter triticale accessions in the competitive variety trial nursery was on 69.3 dt/ha and 77.8 dt/ha upon the application of traditional and intensive cultivation technologies, respectively. The additional factors of intensification increased the yield by 8.5 dt/ha or by 12.3 %. The constituents of the main spike performance as well as contents of crude protein and gluten in winter triticale grain also grew. Strengthening of intensification of the cultivation technology didn’t significantly affect the test weight, 1000-grain weight or crude protein content.
 Conclusions. The use of additional methods of intensification was demonstrated to change the absolute values of the winter triticale indicators, to have no key impact on the level of their environmental of genotypic variability. The test weight and crude protein content were the most stable traits, while the gluten content and yield – the least stable ones, as their values were determined by both varietal specificity and environmental factors

Autism-associated biomarkers: test\u2013retest reliability and relationship to quantitative social trait variation in rhesus monkeys

BackgroundRhesus monkeys (Macaca mulatta) exhibit pronounced individual differences in social traits as measured by the macaque Social Responsiveness Scale-Revised. The macaque Social Responsiveness Scale was previously adapted from the Social Responsiveness Scale, an instrument designed to assess social and autistic trait variation in humans. To better understand potential biological underpinnings of this behavioral variation, we evaluated the trait-like consistency of several biological measures previously implicated in autism (e.g., arginine vasopressin, oxytocin, and their receptors, as well as ERK1/2, PTEN, and AKT(1–3) from the RAS-MAPK and PI3K-AKT pathways). We also tested which biological measures predicted macaque Social Responsiveness Scale-Revised scores.MethodsCerebrospinal fluid and blood samples were collected from N = 76 male monkeys, which, as a sample, showed a continuous distribution on the macaque Social Responsiveness Scale-Revised. In a subset of these subjects (n = 43), samples were collected thrice over a 10-month period. The following statistical tests were used: “Case 2A” intra-class correlation coefficients of consistency, principal component analysis, and general linear modeling.ResultsAll biological measures (except AKT) showed significant test–retest reliability within individuals across time points. We next performed principal component analysis on data from monkeys with complete biological measurement sets at the first time point (n = 57), to explore potential correlations between the reliable biological measures and their relationship to macaque Social Responsiveness Scale-Revised score; a three-component solution was found. Follow-up analyses revealed that cerebrospinal fluid arginine vasopressin concentration, but no other biological measure, robustly predicted individual differences in macaque Social Responsiveness Scale-Revised scores, such that monkeys with the lowest cerebrospinal fluid arginine vasopressin concentration exhibited the greatest social impairment. Finally, we confirmed that this result held in the larger study sample (in which cerebrospinal fluid arginine vasopressin values were available from n = 75 of the subjects).ConclusionsThese findings indicate that cerebrospinal fluid arginine vasopressin concentration is a stable trait-like measure and that it is linked to quantitative social trait variation in male rhesus monkeys.

Phenotypic characterization and principal component analyses of indigenous chicken breeds in Indonesia.

Background and Aim:Understanding the phenotypic characteristics of indigenous livestock breeds is essential for their utilization and conservation. This study aimed to characterize indigenous chicken breeds in Indonesia based on phenotypic traits.Materials and Methods:Data on eight qualitative and 12 quantitative traits were recorded for 250 chickens from six breeds: Black Kedu, Gaga, Merawang, Nunukan, Pelung, and Sentul. Data were analyzed using descriptive statistics and one-way analysis of variance to test the effect of breed on observed traits. Moreover, principal component analysis (PCA) was conducted separately for each chicken breed. Data on quantitative traits were subjected to Kaiser-Meyer-Olkin, which was computed to test the sampling adequacy and the pattern of correlation among the traits, and Bathlett’s tests were used to assess the validity of the factor analysis of each of the datasets and determine whether the partial correlations among traits were small.Results:We found considerable phenotypic variation in both qualitative and quantitative traits among indigenous chicken breeds. Multicolored plumage (96.40%), wild plumage (39.20%), gold feather flick (51.20%), yellow shank (36.80%), single comb (80.80%), red comb (94.80%), red earlobe (77.60%), and orange eyes (61.60%) were the most common features in the indigenous chickens. In addition, breed had a significant effect on all the quantitative traits that were analyzed (p<0.05). There were higher mean values for all quantitative traits for Pelung chickens than other chickens. In addition, the overall mean values for all quantitative traits in Merawang chicken were intermediate between Pelung chickens and Black Kedu, Gaga, and Nunukan chickens. The PCA showed two principal factors extracted that accounted for 77.80% and 78.38% of the total variance in the original variables for males and females, respectively.Conclusion:In general, body weight and body measurements, except wattle length, were loaded in PC1 as the primary factors responsible for the variation. The phenotypic variation observed in indigenous chickens in Indonesia could provide valuable basic information for the design of selection and genetic improvement programs.

Absence of genetic differentiation in performance traits of Sinapis arvensis populations from crop and non‐crop habitats across Northern Algeria: Implications for management

AbstractWeeds can originate from adjacent habitats, dispersing naturally from non‐crop habitats as well as brought in from other crop fields by machinery or as contaminants of crop seeds. This constant dispersal may homogenise populations and transmit resistance genes. In this study, we examined (a) the genetic variation in quantitative traits and (b) the level of resistance to two widely used herbicides, amidosulfuron + iodosulfuron‐methyl‐sodium and florasulam + 2,4‐D, in eight population pairs of Sinapis arvensis from crop and adjacent non‐crop habitats across eight regions in Northern Algeria. Our quantitative genetic approach on phenotypic and phenological data of plants grown under controlled conditions from seeds of these populations showed similar levels of within‐population genetic variation and no genetic differentiation in quantitative traits between the two habitat types. This points to an important exchange of S. arvensis seeds and/or pollen between the two habitat types, but not among crop fields at the regional scale, as we found a strong regional effect for most of the plant traits for both habitat types that correlated with longitudinal temperature and precipitation gradients. We also found an absence of resistance against the two herbicides at a detection level of 10%. Florasulam + 2,4‐D showed a higher level and speed of phytotoxicity compared to amidosulfuron + iodosulfuron‐methyl‐sodium. Given our findings, we propose measures for more efficient management of S. arvensis, including minimisation of seed dispersal during transport of straw balls, crop rotation to avoid the build‐up of herbicide resistance, and management of populations in the close vicinity of crop fields.

Variance Components of Some Quantitative Characters in 16 Varieties of Rice (Oryza sativa L.) influenced by Different Nitrogen Fertilizer Levels

Heritability and phenotypic estimates of some quantitative traits and its influence on different nitrogen fertilizer levels give the room for recombinants which become a prerequisite for any breeding study. Genetic variation in quantitative traits for the development of a new variety of crop plant with different nitrogen fertilizer levels. Based on this background, the study was conducted in order to evaluate the quantitative traits from advanced blast-resistant rice varieties in order to establish relationship between yield and yield components using genetic variances. To achieve this objective, two field studies were carried out in Malaysia during the cropping season 2017/2018. Sixteen advanced blast-resistant rice genotypes were studied in order to find out phenotypic correlation and heritability in some quantitative characters to determine the effect of various levels of Nitrogen fertilizer. The field experiment was conducted in a split-plot design replicated three times in a plot of 35 × 28.5 m2. The planting distance was 25 × 25 cm and the plot size was 2 × 1.5 m2 unit for genotype in each replication. There was a highly significant variation among the genotypes in response to nitrogen levels, high PCV, GCV, heritability, relative distance and genetic advance which indicated that different quantitative traits especially tonnes per hectare (Tha), grain weight per plot (GWTPP) and kilogram per plot (kgplot) significantly influence the yield trait. Similarly, high heritability (&gt;60%) was observed indicating the substantial effect of additive genes more than the environmental effect. Yield per plant showed strong to low positive correlations (𝑟 = 0.99 - 0.09) at phenotypic level for grain weight per plot (GWTPP), number of tillers per hill (NTH), number of panicle per hill (NPH) and kilogram per plot (kg/plot).

Exploration of wheat wild relative diversity from Lahaul valley: a cold arid desert of Indian Himalayas

Climate change is causing a huge loss in biodiversity throughout the globe and the rate has accelerated in recent years. Plant diversity of temperate regions has continuously suffered due to this. The importance of conservation of wild relatives/species of staple crop such as Elymus, Leymus, Thinopyrum, Lolium either in situ or ex situ is essential to sustain these resources for future use due to their ability to withstand in a stressful environment. Thus plant researchers are always in a quest to explore novel species to enhance the genetic diversity of wild crop relatives to improve the resilience of staple crops to a wide range of stress conditions. Keeping these viewpoints in mind, in 2016–2018, we have explored the Lahaul valley, a cold arid region of District Lahaul and Spiti, Himachal Pradesh. A total of 230 accessions of four different species belonging to genus Elymus viz-E. semicostatus (Nees ex steud.) Meld., E. repens Gould, E. dahuricus Turrcz Ex Griseb. and E. longiaristatus (Boiss.) Tzvelev subsp. Canaliculatus (Nevski) Tzvelev belonging to the family Poaceae, tribe Triticeae were taken into consideration. Wide-range of variability was observed at an inter-and intraspecific level among these species. The variations in morphological characters at different ecological amplitudes were recorded. The presence of variation in abiotic stress tolerance traits such as spike pigmentation, low seed shattering, dense pubescence, waxiness was observed. Forty traits were recorded during field evaluation to ease wheat breeders and researchers to identify germplasm during the collection at an in situ level. The population of these four species had a variation for qualitative and quantitative traits at different ecological regimes at their native habitat suggesting their adaptability to a particular niche. Pre-breeding on these germplasm resources could be initiated for introgression novel alleles in wheat to mitigate environmental constraints posed by changing climate.

Induction of genetic variability for quantitative traits in horsegram (Macrotyloma uniflorum) through irradiation mutagenesis

Aim: The study was conducted to explore the magnitude of variability induced by gamma rays, electron beam and its combinations for quantitative traits in horsegram (Macrotyloma uniflorum (Lam) Verdc.). Methodology: The horsegram cultivar PAIYUR 2 was irradiated with twelve combinations involving G, EB and G+EB. Desirable mutagenic doses were identified in M1 based on plant injuries and forwarded to M2. Data on 11 yield component traits were recorded on normal looking M2 plants for identification of micro-mutants. Promising mutants were forwarded to M3 and the induced variability was ascertained using multivariate statistics. Results: Significant transgressive variants were observed in M2. The G+EB combination induced superior variants for yield. A positive shift in mean for yield and its attributing traits was observed in M3. Most of the polygenic traits were governed by additive gene effects. Interpretation: The increased mean for most of the polygenic traits in M3 population proved that selection made on early generation was highly effective. The isolated high yielding mutant progenies of selected families will contribute towards yield improvement in horsegram.

English

Lablab purpureus is a multipurpose legume mainly grown by subsistence farmers for pulse, forage and vegetable. Despite these diverse uses that can be combined successfully under various agronomic conditions, the bean has not been extensively exploited. Dolichos production in Kenya is constrained by low yielding varieties, pests, poor growing techniques and varieties with non-preferred taste and flavor. A study to characterize six newly bred Lablab genotypes (G2, B1, M5, LG1, W7 and G2), was initiated at the University of Eldoret using morphological and molecular markers. Morphological traits (qualitative and quantitative) were characterized using the descriptors of genus Lablab. Molecular characterization was done at the KEPHIS- Muguga laboratory, using ten SSR markers that are specific for Dolichos. Results from morphological characterization demonstrated a high variation for both qualitative and quantitative traits evaluated. Most of the quantitative traits were highly significant at 99.999% or (P&le; 0.001), except for number of racemes per plant and number of seeds per pod which were significant at 99.99% or (P&le; 0.01) and 99.95% or (P&le; 0.05), respectively. Microsatellite analysis produced six polymorphic primers mapping an average of 3.17 alleles per locus. The combination of morphological and DNA-based markers takes advantage of the best features of both marker types which can be beneficial in selection of best Lablab genotypes and in the process integrates the application of molecular markers to legume breeding. Key words: Lablab (Lablab purpureus), microsatellites (SSR), genetic diversity.

Genetic association with boldness and maternal performance in a free-ranging population of grey seals (Halichoerus grypus).

Individual variation in quantitative traits clearly influence many ecological and evolutionary processes. Moderate to high heritability estimates of personality and life-history traits suggest some level of genetic control over these traits. Yet, we know very little of the underlying genetic architecture of phenotypic variation in the wild. In this study, we used a candidate gene approach to investigate the association of genetic variants with repeated measures of boldness and maternal performance traits (weaning mass and lactation duration) collected over an 11- and 28-year period, respectively, in a free-ranging population of grey seals on Sable Island National Park Reserve, Canada. We isolated and re-sequenced five genes: dopamine receptor D4 (DRD4), serotonin transporter (SERT), oxytocin receptor (OXTR), and melanocortin receptors 1 (MC1R) and 5 (MC5R). We discovered single nucleotide polymorphisms (SNPs) in each gene; and, after accounting for loci in linkage disequilibrium and filtering due to missing data, we were able to test for genotype-phenotype relationships at seven loci in three genes (DRD4, SERT, and MC1R). We tested for association between these loci and traits of 180 females having extreme shy-bold phenotypes using mixed-effects models. One locus within SERT was significantly associated with boldness (effect size = 0.189) and a second locus within DRD4 with weaning mass (effect size = 0.232). Altogether, genotypes explained 6.52-13.66% of total trait variation. Our study substantiates SERT and DRD4 as important determinants of behaviour, and provides unique insight into the molecular mechanisms underlying maternal performance variation in a marine predator.

Heritability of Productivity Elements of Chickpeas and its Importance for Practical Breeding

This study examined the genetics of the variability in quantitative traits and showed the possibility of selecting hybrids with a new, more favorable combination of traits, which is of practical interest for breeding. The main goal of our research was to determine the coefficients of heritability by the mass of seeds and the number of beans per plant in hybrid combinations of chickpeas, which allowed establishing the potential of parental varieties in the transfer of valuable genes responsible for plant productivity to offspring and expanding the spectrum of plant genetic diversity. The experiments were conducted in the fields of the educational and experimental farm of the Omsk State Agrarian University in the southern forest-steppe of the Omsk region in 2016-2018. The research included 6 chickpea samples with a complex of valuable traits from the Federal Research Center of the All-Russian Institute of Plant Genetic Resources named after N.I. Vavilov (VIR, St. Petersburg) and 8 hybrid combinations obtained on their basis. It was found that the mass of seeds per plant was characterized by low heritability (H2 = 22.8%) and the number of beans per plant was high (H2 = 54.0%). The variability of the mass of seeds per plant was largely paratypical and was influenced by environmental conditions; the variability in the number of beans per plant was due to genetic factors and indicated a high genetic diversity in the studied splitting chickpea populations. Selection based on the number of beans per plant was highly effective even in early generations of the hybrids. Selection by the mass of seeds from the plant was ineffective; it should be carried out in later hybrid generations under favorable growing conditions. The selection of valuable genotypes was most successful in hybrid chickpea populations by seed weight per plant: C-35 x ILC-2394, C-80 x ILC-2394, C-27 x ILC-2394, and by the number of beans per plant: C-27 x ILC-2394, C-27 x ILC-2402&#x0D; Keywords: chickpeas, heritability, selection, genetics, productivity

Validation of functional polymorphisms affecting maize plant height by unoccupied aerial systems discovers novel temporal phenotypes.

Plant height (PHT) in maize (Zea mays L.) has been scrutinized genetically and phenotypically due to relationship with other agronomically valuable traits (e.g., yield). Heritable variation of PHT is determined by many discovered quantitative trait loci; however, phenotypic effects of such loci often lack validation across environments and genetic backgrounds, especially in the hybrid state grown by farmers rather than the inbred state more often used by geneticists. A previous genome-wide association study using a topcrossed hybrid diversity panel identified two novel quantitative trait variants controlling both PHT and grain yield. Here, heterogeneous inbred families demonstrated that these two loci, characterized by two single nucleotide polymorphisms (SNPs), cause phenotypic variation in inbred lines, but that size of these effects were variable across four different genetic backgrounds, ranging from 1 to 10 cm. Weekly unoccupied aerial system flights demonstrated the two SNPs had larger effects, varying from 10 to 25 cm, in early growth while effects decreased toward the end of the season. These results show that allelic effect sizes of economically valuable loci are both dynamic in temporal growth and dynamic across genetic backgrounds, resulting in informative phenotypic variability overlooked following traditional phenotyping methods. Public genotyping data show recent favorable allele selection in elite temperate germplasm with little change across tropical backgrounds. As these loci remain rarer in tropical germplasm, with effects most visible early in growth, they are useful for breeding and selection to expand the genetic basis of maize.

Dissecting cis-regulatory control of quantitative trait variation in a plant stem cell circuit.

Cis-regulatory mutations underlie important crop domestication and improvement traits1,2. However, limited allelic diversity has hindered functional dissection of the large number of cis-regulatory elements and their potential interactions, thereby precluding a deeper understanding of how cis-regulatory variation impacts traits quantitatively. Here, we engineered over 60 promoter alleles in two tomato fruit size genes3,4 to characterize cis-regulatory sequences and study their functional relationships. We found that targeted mutations in conserved promoter sequences of SlCLV3, a repressor of stem cell proliferation5,6, have a weak impact on fruit locule number. Pairwise combinations of these mutations mildly enhance this phenotype, revealing additive and synergistic relationships between conserved regions and further suggesting even higher-order cis-regulatory interactions within the SlCLV3 promoter. In contrast, SlWUS, a positive regulator of stem cell proliferation repressed by SlCLV3 (refs. 5,6), is more tolerant to promoter perturbations. Our results show that complex interplay among cis-regulatory variants can shape quantitative variation, and suggest that empirical dissections of this hidden complexity can guide promoter engineering to predictably modify crop traits.

High Quantitative Trait Variability in Faba Bean Mutagenized Population for High-yielding Breeding Program in Saudi Arabia

Background: The narrow genetic base and environmental stresses are behind the low rate of faba bean yield in the past two decades. Drought stress is one of the most destructive abiotic stresses. Using induced mutagenesis on locally adapted landrace cultivar is proposed to cope with this problem. Methods: This study was conducted on faba bean landrace cultivar of Saudi Arabia, namely Hassawi 2, treated by 25 and 50 Gray gamma radiation. The genetic diversity assessment of M2 mutant populations was based on seven quantitative traits and nine Amplified Fragment Length Polymorphism (AFLP) primer combinations. Result: A total of 3419 M2 seeds were planted, of which 2782 (81.4%) seeds germinated and 2658 plants survived. A 5 to a 10-fold range of quantitative traits studied among mutant plants compared to control plants showed high variability. The number of pods per plant and seeds per plant was a valid selection criterion for a high-yielding faba bean breeding program. Nine AFLP primer combinations generated 1079 polymorphic alleles from 88 samples that comprised mutant and control plants. Shannon index (I) and expected heterozygosity (He) were 0.337 and 0.206, respectively. The AFLP results validated high variability in M2 populations. These findings will assist faba bean breeders in developing high-yielding cultivars with drought stress tolerance.

Genetic diversity of Ethiopian cocoyam (Xanthosoma sagittifolium (L.) Schott) accessions as revealed by morphological traits and SSR markers.

Cocoyam (Xanthosoma sagittifolium (L.) Schott) is an exotic species from tropical America that is widely cultivated in Ethiopia for its edible cormels and leaves. There is a dearth of information on the genetic diversity of Ethiopian cocoyam. In order to evaluate and select cocoyam germplasm for breeding and conservation, genetic diversity of 100 Ethiopian cocoyam accessions (65 green- and 35 purple- cocoyam) were analyzed using 29 morphological traits (16 qualitative and 13 quantitative) and 12 SSR loci. Two classes of qualitative traits were observed. ANOVA revealed significant variation in 11 (84.6%) of the 13 studied quantitative traits. The SSR marker analysis showed high genetic diversity. A total of 36 alleles were detected with a range of 2 to 5 (average of 3.273) alleles per locus. The average observed heterozygosity (Ho) and expected heterozygosity (He) values across populations were 0.503 and 0.443, respectively. The analysis of molecular variance showed that the variation among populations, among individuals within populations, and within individuals explained 14%, 18%, and 68% of the total variation, respectively. Cluster analysis grouped the accessions irrespective of the collection sites. A dendrogram based on Nei's standard genetic distance grouped the green cocoyam accessions together while the purple cocoyam accessions occupied a separate position within the dendrogram. Significant variation in quantitative traits and the high level of genetic diversity revealed by the SSR markers suggest that diverse cocoyam accessions, probably with multiple lineage, were introduced multiple times, through multiple routes and probably by multiple agents, an hypothesis that needs futher testing and analyis. The crop, therefore, needs more research efforts commensurate with its economic and social values than it has been accorded thus far. Further study is recommended to clarify the taxonomic status of Ethiopian cocoyam accesions and to trace their evolutionary relationships with Xanthosoma species elsewhere.

Morphological variability of fruits of Cola millenii K. Schum. from seven phytogeographical districts in Benin: opportunity for domestication

Cola millenii K. Schum. is a wild edible fruit tree of high socio-economic importance in Sub-Sahara Africa. Its fruit pulp is used for food and nutritional purposes. Other parts of the tree are locally used against several diseases. Given the current threats to natural stands of this species, its domestication has been suggested as one of the methods for its sustainable management. The present study analyzed the domestication potential of this species through evaluation of morphological variability of its fruits across seven phytogeographical districts in Benin. Morphological data on fruits were collected on 1750 fruits from 175 trees distributed among the phytogeographical districts. Univariate and multivariate statistical methods were used for data analyses. The morphological traits of the fruits varied significantly among the phytogeographical districts. Among others, the weight of the pulp fluctuated between 4.18 and 15.55 g and the Bassila phytogeographical district presented the highest value. Variation in quantitative traits was greater between phytogeographical districts (55.44–89.13%) than among individuals within phytogeographical districts (9.52–34.32%). Qualitative descriptors such as shape and the color of the fruits and seeds also unfolded noticeable variation among phytodistricts (Shannon diversity: 0.14–1.46). However, there was no evidence of significant link between the morphological characteristics and the climatic variables considered (rainfall, relative humidity, minimum temperature and maximum temperature). Clustering suggested three fruit morphotypes. Fruits of morphotype 3, in majority from the Bassila and Zou phytogeographical districts had interesting characteristics (e.g. high fruit and pulp weight, and large fruit and seed size) for selection programs.

Signatures of natural selection in morphological quantitative traits in Argentinean populations of Senegalia gilliesii (Fabaceae).

In order to elucidate the role of evolutionary forces in shaping the variation of quantitative traits in Senegalia gilliesii we evaluate seven phenotypic traits in three Argentinean populations, two of them sharing environmental and vegetation type conditions, and a third one ecologically differentiated from the former. The phenotypic traits were compared with molecular markers. Here, we search for signatures of selection by means of the comparison PST-FST . We assessed if the averages of the seven phenotypic traits were different among populations by means of ANOVA and we performed discriminant analysis of principal components (DAPC) for both morphological and molecular data. The ANOVA showed significant results only for two traits. For all foliar traits and two spine traits, the PST-FST comparison suggested the occurrence of stabilizing selection. The DAPC obtained from AFLP data showed three well defined groups of populations; when the same analysis was conducted with morphological data the scatterplot showed high overlapping among individuals and could not separate the populations. Overall, our findings suggest a prominent role of stabilizing selection in all foliar traits and stipular spine length. These results could be extrapolated to other tropical and subtropical acacias. Further studies are needed to analyse the mechanisms underlying genetic differentiation in natural populations of S. gilliesii, find its relationship with eco-geographical variables.

Selection of Hancornia speciosa germplasm accessions based on the FAI-BLUP index

ABSTRACT Hancornia speciosa Gomes is one of the native fruit species most frequent in the Brazilian Savanna. Studies on the genetic variability of quantitative traits for this species are scarce and the identification of accessions with the best agronomic traits may support strategies for conservation and breeding programs. This study aimed to estimate the genetic diversity of accessions from the H. speciosa germplasm collection of the Universidade Federal de Goiás (Goiânia, Goiás state, Brazil) and rank them based on a selection index combining eleven agronomic traits. A total of 192 individual accessions from 57 progenies, from 29 natural populations, were evaluated. The data were subjected to multivariate analysis and the individuals and progenies evaluated using the FAI-BLUP selection index. The Tocher cluster analysis allowed grouping the progenies into ten divergent clusters and the individuals into 18 divergent clusters. The simultaneous selection of traits based on the FAI-BLUP index may be recommended while maintaining the potential variability in the population resulting from the recombination. The individual selection proved to be more effective than the selection based on progenies means, because it exploits the genetic variation among and within progenies.

МОРФОЛОГІЧНИЙ ПОТЕНЦІАЛ ГЕНОФОНДУ РЕДИСКИ ПОСІВНОЇ

The article presents the research of samples of the collection material of radish sowing Raphanus sativus L. Ukrainian and foreign selection of different ecological and geographical origin. Weather conditions during the research period (2015–2017) were characterized by a high variability of hydrothermal conditions, which manifested itself in the lack of moisture at different stages of ontogenesis of the.radish. Subsequently, the uneven amount of precipitation during the growing season led to a decrease in yield and a change in the biometric indicators of the rosette of leaves and root crops. As you know, varieties of radish Raphanus sativus L. are complex populations with a variety of genetic material, especially in terms of quantitative characteristics. The quantitative traits of a plant organism are subject to strong modification variability, which is the main obstacle to increasing the efficiency of selection of the required selection genotypes. One of the criteria for the variability of quantitative traits is the coefficient of variation (V, %). This statistical indicator allows one to obtain information about the characteristics of the reaction rate of various quantitative traits of a plant, while ensuring the comparability of the results obtained. The conducted studies of biometric indicators of sowing radish made it possible to analyze the variation of its main quantitative characteristics. In the course of the research, a description of the variability of the morphological characteristics of the samples of sowing radish of various breeding and geographical origin was carried out. The revealed features make it possible to analyze the nature of variability of quantitative traits and contribute to the widespread involvement of the best varieties in the breeding process as donors of valuable traits. According to the research results, it was allocated for mechanized harvesting on the basis of the «smallest rosette of leaves» varieties of sowing radish: 18 days (Russia) a variety of pink-red with a white tip and a cylindrical root crop, Zarya (Russia) — a dark red variety with a rounded root crop, Duet (Italy) is a pink-red variety with an oval root crop. And also varieties White cylindrical and Ice icicle — a variety of white cylindrical Ukrainian selection. During the study, it was found that the size of the root crop is controlled by the genotype, but its formation is more dependent on external environmental factors. For selection according to the parameter «length of the root crop», the following samples were selected: 18 days (Russia) and White brekfast (Germany), according to the «width of the root crop» — Belaya (Czech Republic), Zhara (Netherlands)

Dissecting the Genotypic and Environmental Factors Underpinning the Quantitative Trait Variation in a Set of Wild Tomato (Solanum habrochaites LA1777) Introgression Lines

Exotic libraries have proven a powerful tool for the exploitation of wild relatives and quantitative trait loci (QTLs) detection in crop species. In early 2000, an introgression line (IL) population of the wild tomato Solanum habrochaites (SH) acc. LA1777 was developed and made publicly available. Despite the potentiality of the donor parent, so far, these lines have been poorly explored for their agronomic performance and for the identification of genomic regions underlying the variation of quantitative traits (QTLs). Here, we report the evaluation of 19 morpho-agronomic and chemical traits on a set of 39 ILs grown in three consecutive field seasons with the aim to: (a) Determine the overall phenotypic performances of the studied collection, (b) estimate the influence of the genotype (G) and the year of cultivation (Y) and their interaction on the traits analyzed, (c) investigate the plasticity of the traits, and (d) identify whole-genome QTLs in the wild SH background. The ILs showed lower productivity compared to the control genotype, while no major effects were found for the morphological fruit-related traits. Instead, a general increase in the soluble solids content was observed. The combined analysis of G × Y highlighted a major effect of the genotype on trait variation, although yield-related traits were more influenced by environmental factors. In total, 75 associations for 17 traits were detected. Major QTLs increasing soluble solids, pericarp thickness, and trichome density were respectively found on chromosomes 1, 5, and 11 with a percentage variation (PV) of 24.01%, 32.49%, and 200%. Furthermore, different QTLs increasing the color intensity and fruit shape were detected. These results suggest that SH could be a potential source of favorable alleles for qualitative traits despite its inferior phenotype compared to the cultivated parent. The evaluated set of SH LA1777 ILs is a potential for novel allele discovery in wild tomatoes and for breeding purposes towards the exploitation of the available introgressions and for the pyramiding of traits.

The influence of sows age on multiple pregnancy and nest weight during weaning

The results of the study of the indices of the own productivity of sows of Large White breed of different reproductive ages and the influence of this trait on the multiple pregnancy and the weight of the nest when weaning piglets are presented on the basis of using the documentation of the pedigree registration of pigs of the State Enterprise "Experimental farm" Elite "of the Institute of Agriculture of the Steppe NAAN" for the last three years. Based on the results of our research, it was found that the multiple births of sows of group I (18–24 months) is 10.4 heads, the weight of the nest at weaning at the age of 60 days is 181.8 kg, the safety of piglets at weaning is 91 %. Similar indicators in animals of the II and III groups (25–36 and 36 months and older) were 11.1–10.2 heads, 193.8 and 174.2 kg, 96 and 93 %, respectively. The variability of quantitative traits, which were the subject of our research, ranges from 9.3 to 17.5 %, that is, it corresponds to low and medium risk. When determining the influence of the age of mothers on their multiple births and the weight of the nest during weaning of piglets, it was found that the highest correlative relationship – r = 0.44 is observed between the age of the queens 18–24 months and multiple births and weak – r = 0.10 between the age of the uterus 25–36 months and multiple pregnancy. In queens older than 36 months, the correlation between age and productivity is weak and negative, which confirms that with an increase in their age, the reproductive and productive qualities of animals decrease. Improving selection work depending on age is an important and urgent issue in increasing the efficiency of pig breeding, since the volume of pork production depends on it. The age of sows is one of the key factors that affects the reproductive qualities of animals and determines the terms of the economic use of the broodstock, which, in turn, predetermines the need to study this aspect. Key words: pigs, age, sows, productivity, multiple pregnancy, influence, correlation, nest mass.