Negative Genotypic Correlations Research Articles

Multiple, Single Trait GWAS and Supervised Machine Learning Reveal the Genetic Architecture of Fraxinus excelsior Tolerance to Ash Dieback in Europe.

Common ash (Fraxinus excelsior) is under intensive attack from the invasive alien pathogenic fungus Hymenoscyphus fraxineus, causing ash dieback at epidemic levels throughout Europe. Previous studies have found significant genetic variation among genotypes in ash dieback susceptibility and that host phenology, such as autumn yellowing, is correlated with susceptibility of ash trees to H. fraxineus; however, the genomic basis of ash dieback tolerance in F. excelsior requires further investigation. Here, we integrate quantitative genetics based on multiple replicates and genome-wide association analyses with machine learning to reveal the genetic architecture of ash dieback tolerance and of phenological traits in F. excelsior populations in six European countries (Austria, Denmark, Germany, Ireland, Lithuania, Sweden). Based on phenotypic data of 486 F. excelsior replicated genotypes we observed negative genotypic correlations between crown damage caused by ash dieback and intensity of autumn leaf yellowing within multiple sampling sites. Our results suggest that the examined traits are polygenic and using genomic prediction models, with ranked single nucleotide polymorphisms (SNPs) based on GWAS associations as input, a large proportion of the variation was predicted by unlinked SNPs. Based on 100 unlinked SNPs, we can predict 55% of the variation in disease tolerance among genotypes (as phenotyped in genetic trials), increasing to a maximum of 63% when predicted from 9155 SNPs. In autumn leaf yellowing, 52% of variation is predicted by 100 unlinked SNPs, reaching a peak of 72% using 3740 SNPs. Based on feature permutations within genomic prediction models, a total of eight nonsynonymous SNPs linked to ash dieback crown damage and autumn leaf yellowing (three and five SNPs, respectively) were identified, these were located within genes related to plant defence (pattern triggered immunity, pathogen detection) and phenology (regulation of flowering and seed maturation, auxin transport). We did not find an overlap between genes associated with crown damage level and autumn leaf yellowing. Hence, our results shed light on the difference in the genomic basis of ADB tolerance and autumn leaf yellowing despite these two traits being correlated in quantitative genetic analysis. Overall, our methods show the applicability of genomic prediction models when combined with GWAS to reveal the genomic architecture of polygenic disease tolerance enabling the identification of ash dieback tolerant trees for breeding or conservation purposes.

Genome-Wide Association Study and Genomic Predictions for Hydroxycinnamate Concentrations in Maize Stover.

Hydroxycinnamates, like ferulate (FA) and p-coumarate (pCA), are important components of maize cell walls, which influence pest resistance, ruminal digestibility, and biofuel production. Increasing their concentration has been linked to increased pest resistance, but also may lead to a decrease in nutritional value or bioethanol production efficiency. Therefore, improving forage quality or biofuel production without compromising plant resistance and a thorough understanding of the biosynthesis and deposition of these compounds is necessary, especially in stover, which is the feedstock for second-generation biofuel production and determines animal forage quality. This study aimed to identify genomic regions associated with hydroxycinnamates and to develop genomic prediction models to determine the best selection approach to modify hydroxycinnamate content. Although heritability estimates for hydroxycinnamates were moderate, direct phenotypic selection is discouraged because hydroxycinnamate quantification is laborious and time-consuming. Negative genotypic correlations were observed between animal digestibility and pCA content and positive with diferulates content, suggesting differing effects compared to previous studies on maize pith. However, no colocalizations with digestibility QTLs were found, highlighting the need for further research. Given the moderate predictive capacity of GBLUP prediction models, genotypic selection is proposed as the most promising alternative for modifying hydroxycinnamate content.

Assessing grain yield of quality protein maize under low soil nitrogen through associated agronomic traits

The study was conducted to improve a quality protein maize (QPM) population, ART/98/ILE 1-OB, for tolerance to low soil nitrogen, and to investigate the agronomic characters that are linked to grain yield of QPM in low soil nitrogen environments. S1 lines were selected in the maize population at cycle one (C1) in a recurrent selection programme, for evaluation to move to cycle 2 (C2). Data were collected on agronomic traits, stay-green ability (SGR) and grain yield (GY) and analysed using SAS. SGR rating at 8 weeks after planting (8WAP) was moderate under low nitrogen (3.09). GY was slightly higher under low nitrogen (LN) (2.19 tons/ha) than under high nitrogen (HN) condition (1.98 tons/ha). There were notable negative phenotypic and genotypic correlations between grain yield (GY) and traits such as days to 50% anthesis and silking, stay green rating (SGR), ear aspect (EA), and plant aspect (PA). In contrast, positive correlations were observed with plant height (PH) and number of ears per plant (EPP). In stepwise regression, EPP emerged as the most significant character under LN (R2 = 45%), with EA, SGR at 8WAP (SGR8), and PH following closely. EPP showed the highest positive direct effect on grain yield, followed by SGR8. EA had the highest negative direct effect. PC1 alone, which was mostly linked to PH, accounted for 96.5% of the overall variation. These findings underscore the importance of EPP, EA, SGR8 and PH as selection criteria in enhancing QPM productivity under LN conditions.

Study of Genetic Variability and Path Analysis for Yield in Greengram (Vigna radiata L. Wilczek)

The current study was conducted in order to estimate the genetic variability, Correlation and path analysis for yield and yield contributing traits assessed 31 genotypes of green gram during Zaid season 2023. The experiment followed a Randomized Block Design (RBD) with 3 replications. Data were collected from 5 randomly selected plants from each genotype in each replication, among 13 different traits seed index had highest genotypic and phenotypic coefficient of variance followed by number of pod per plant, while least GCV and PCV was recorded for days to maturity. High heritability was shown by plant height followed by number of seeds per pod. Seed index and harvest index had highly significant positive genotypic correlation with seed yields per plant. While days to maturity and days to 50% pod setting was recorded as highly significant negative genotypic correlation with seed yields per plant. Plant height followed by primary branches per plant, biological yield seed index and harvest index was recorded as positive direct effect on seed yield per plant at both genotypic and phenotypic levels while days to maturity followed by clusters per plant, pods per plant and pod length was recorded as negative direct effect on seed yield per plant at both genotypic and phenotypic levels. All the traits showed a strong and positive association with seed yield, proving that these traits actually correlate with one another. Therefore, identifying high yielding genotypes from highly segregating populations would be made easier with the use of direct selection for these traits.

Stability analysis of promising winter maize (Zea mays L.) hybrids tested across Bihar using GGE biplot and AMMI model approach

Multilocation evaluation facilitates the quantification of genotype-environment interaction (GEI) and the identification of high-yielding, stable hybrids along with partitioning the evaluating location into mega environments. Testing of 24 single cross hybrids and four checks across three environments revealed the significant GEI for all the studied traits. The environment contributed 12.90, 57.10, and 17.59% of the total variation for grain yield, anthesis silking interval, and days to maturity. The study indicated a negative genotypic correlation among grain yield and anthesis silking interval (-0.2244); days to maturity and anthesis silking interval (-0.019), whereas the positive correlation between grain yield and days to maturity (0.067). Location Sabour was found as the most representative environment for testing commonly adapted hybrids. Location Begusarai and Dholi are discriminatory and non-representative environments suitable for selecting location-specific genotypes. Both GGE biplot and AMMI analysis revealed that three hybrids, viz., IMHSB1, IMHSB20, and IMHSB13 were high-yielding with average stability. The identification of superior and stable maize hybrids may contribute to farmers’ income in Bihar.

Exploring genetic diversity and trait associations with foliar blast disease among parental lines in pearl millet [Pennisetum glaucum (L.) R Br

Thirty-seven pearl millet genotypes were evaluated for morphometric traits and disease incidence and severity during summer and kharif, 2022. Pooled ANOVA revealed significant variation were present in all genotypes across different season. Association studies identified high positive correlations between grain yield and traits such as single earhead weight, single ear head threshed weight, and test weight, with direct and indirect effects on grain yield through key characters. E2 (kharif – 2022) showed favourable conducive weather parameters for disease infection throughout the growing season compared to E1. The higher PCV relative to GCV for disease incidence underscores the environmental influence in disease resistance programs. Negative correlations between disease metrics and yield traits highlight blast disease’s detrimental effect on grain yield. Disease severity indirectly suggests environmental factors may enhance its impact. Disease incidence exhibited a direct negative impact on yield, supported by negative genotypic correlations. The line, PT 6679, exhibit both high yield and highly resistant to blast. Restorer lines (PT 6029, PT 6067, PT 6300, PT 6707, PT 7068) and B lines (ICMB 01666, ICMB 02777) showed promising yield attributes with high to moderate disease resistant for future breeding programs. In D2 analysis, five clusters revealed distinct genetic diversity with Clusters II and V indicating strong hybrid vigor, while Clusters IV (PT 6946, ICMB 06111) and V (ICMB 93111, ICMB 95444) excelled in disease resistance. Clusters I (PT 6029, PT 7068) and II (GMR 58) exhibited superior grain yield, particularly Cluster I, had potential restorer lines for future breeding. Clear differentiation between B and R lines underscored genetic distinctions in trait expression, validating the use of morphological data for assessing genetic diversity.

Variability and Correlation Coefficient Analysis Studies in Promising Germplasm of Sorghum [Sorghum bicolor (L.) Moench

The present investigation was carried out at Crop Research Centre-1, ITM University, Sithouli campus, Gwalior during kharif, 2022-23 in a Randomized Block Design with three replications. Eleven quantitative traits were used to evaluate the performance of 15 genotypes. The results of character association analysis showed a substantial positive correlation between stem diameter and plant-level grain yield. As a result, developing these characters also enhances the yield of each plot. On the other hand, days to 50% blooming showed a substantial negative genotypic correlation with yield per plot, which is desirable to increase the selection of early genotypes.

Association Between Dominant Wheat Stem Rust Races Found in Ethiopia and Grain Yield in Advance Bread Wheat Genotypes

The study was conducted in 2019 and in 2020 across two locations: Dhera and Asasa in Ethiopia to study the correlation between dominant stem rust races found in Ethiopia and grain yield on bread wheat genotypes found in the national wheat research program pipelines. Twenty three bread wheat genotypes and two released bread wheat varieties set as a Bread Wheat National Variety Trial by the national wheat research program for low altitude and planted at Dhera and Asasa. A square lattice design with two replications used for experiment conducted on the field. A plot of six rows, size of 2.5 m by 1.2 m, and a total area of 3 m2 used. The same genotypes planted using complete randomized design in three replications at Kulumsa Agricultural Research Center green house. Seven-day old seedlings were inoculated with spores of selected races: TTTTF, TKTTF, TKKTF, TTRTF and BULK. Data on infection types (IT) were recorded 14 days after inoculation using 0–4 scale. Result in the study revealed that Grain yield had positive genotypic association with all four races but bulk at Dhera. A very high negative significant genotypic correlation r=-0.708*** obtained between Grain yield and field Stem rust diseases score at Asasa. Those genotypes carrying race-specific effective gens for the races used in the green house were resistance at the seedling stage. But, on the field, at the adult stage, they lost the resistance and become susceptible.

Path coefficient analysis of seed yield in Indian mustard [Brassica juncea (L.) Czern. & Coss.] under drought

The present investigation was carried out to assessthe components ofseed yield under droughtstress using pathcoefficient analysis. Twenty two genotypes ofIndian mustard were grown in a Randomized Complete Block Design with three replications during rabi, 2007-08. Analysis of variance indicated presence of variability in theexperimental genotypesforseed yield and other morpho-physiological characters except main shoot length, harvest index, protein content, SLW at 35 days aftersowing (DAS) and seed: husk ratio. Seed yield/plant was positively and significantly correlated at both phenotypic and genotypic levels with days to maturity, plant height, primary branches/plant, secondary branches/plant, siliquae on main shoot, LAI, CGR and biological yield/plant. Seed yield/plant had negative genotypic correlations of moderate strength with transpiration quotient at 35 and 75 DAS indicating its positive relationship with water use efficiency. TheRGRduring 35-75 DAS followed byRGRbetween 75 and 95 DAS exerted the highest direct positive effects on seed yield. Biological yield/plant, SLW at 75 DAS, TDM at 75 and 95 DAS, SCMR at 35 DAS, siliquae on main shoot, days to maturity and siliqua length also had substantial positive direct effects. The characters under study explained about 96.5% and 100% variability in the seed yield at phenotypic and genotypic level, respectively. Dry matter production, early growth and development of the crop are important under drought due to continuous decline in available soil moisture. Since LAI, LGR, CGR, RGR and NAR are the functions of dry matter production and/or leaf area, therefore, selection on the basis of high biological yield and large LAI at 50% flowering should be quite effective in improving seed yield under drought. An increase in LAI might increase radiation load resulting in to high transpiration. Therefore, genotypes having high LAI with erect leaves and low TQ should be accorded priority in the selection programme.

Pedigree selection in two Egyptian cotton crosses for some traits

One cycle of direct Pedigree selection was performed with selection intensity 5 % to improve productivity with accepTable fiber quality of the two Egyptian cotton ( G. barbadense L.) cross combinations. Comparing mean performance of F2 with those of F3 generation revealed increased mean values for all traits with advanced generations from F2 to F3, indicating accumulation of increasing alleles. The phenotypic variance for all traits was highly significant through F2 and F3 generations. Heritability estimates in broad sense improved considerably for all traits from F2 to advanced F3 generations. The genotypic correlation between three earliness characters was highly significant negative with most yield traits in F2 pop. I. While genotypic correlation between the previous earliness traits with yield traits in F3 generation was positively non-significant except for lint percentage that was highly significant positive. Genotypic correlation was highly significant positive among most yield and yield component traits in both generations, which helps pedigree selection to achieve high fast genetic advance. The data of the genotypic correlation among studied characters in F2 and F3 generations in population II showed highly significant negative genotypic correlation between earliness traits in F2 generation, changed to highly significant positive in F3 generation after applying pedigree selection. The genotypic correlation between most yield characters and fiber properties showed highly significant positive correlation in population II in both generations. The superior ten families in F3 generation in both populations ranked on high yield, yield components and fiber quality showed higher means than that of F2, F3, better parent and check in most yield characters

VARIATION AND CORRELATION OF SEED PHYSICO-CHEMICAL PROPERTIES OF SUDANESE OKRA LINES (ABELMOSCHUS ESCULENTUS (L.) MOENCH.)

Fifteen collections of okra accession were examined for seed physico-chemical properties. Basic seed physical parameters such as seed length, seed width, seed thickness and hundred-seed weight were examined. Chemical parameters such as crude oil%, protein %, fibre, Moisture content%, ash %, calcium mg/100g and carbohydrates were measured and analysed as per recommended methods of the Association of Official Analytical Chemists. Line HSD4899 was identified for best performance for Hundred-seed weight (g) and ash %; Line HSD5021 was identifies as the best performer for carbohydrate %; Line HSD5017 was identified for seed thickness (mm), seed width (mm) and fibre %; HSD6655 were identified for seed thickness (mm), crude oil content % and calcium mg/100g; and line HSD5024 was identified for high protein content. Seed length( mm), seed thickness (mm), seed width (mm), hundred-seed weight (g), sphericity ratio, moisture %, and ash % recorded high heritability estimates and coupled with a high genotypic coefficient of variation suggesting that these traits are under the influence of genetic control and less affected by the environment. Considerable progress can be achieved using phenotypic selection on these traits. Crude protein content has a significant but weak negative correlation with seed width and a moderate negative genotypic correlation with hundred-seed weight. Protein content recorded a significantly moderate negative genotypic

Genetic Variability and Interrelationships of Some Traits in Six Sesame (Sesamum indicum L.) Genotypes under Rainfed Conditions

The objectives of this study was to estimate the genetic variability and association between yield and its components in six sesame genotypes widely grown in North Kordofan under rainfed conditions. The genotypes showed highly significant variation in agronomic performance for all of the studied traits except of plant height. The phenotypic coefficient of variation (PCV) was higher than the genotypic coefficient of variation (GCV) for all studied traits. High PCV and GCV were recorded for biological yield and seed yield. High heritability (in a broad sense) was obtained for 1000 seed weight and the number of seeds per capsule. The highest genetic advanced (GA) was exhibited by biological yield and seed yield. High genetic advance as a percentage of the mean (GAM %) was recorded for a thousand seed weight and number of branches per plant. High heritability coupled with genetic advance as a percentage of the means was registered by thousand seed weight, number of branches per plant and harvest index. Number of capsules per plant showed significant negative genotypic and phenotypic correlations with a thousand seed weight indicating selection of one trait will be accompanied by low performance of the other. Highly significant positive genotypic and phenotypic correlations were revealed by the association of plant populations with a thousand seed weight, number of seed per capsule with harvest index, and thousand seeds weight with biological yield. Therefore, selection based on these traits would be effective in future sesame yield under rain fed conditions.

Characterization of Oilseed Crop Noug (Guizotia abyssinica) Using Agro-Morphological Traits

Noug (Guizotia abyssinica) is an outcrossing oilseed crop that serves as a source of edible oil and other nutrients although its seed yield is generally low. The analysis of agro-morphological traits in relation to seed and oil yields is important for improving the productivity of this crop. The present study aimed at assessing the variation and heritability of quantitative (10) and qualitative (6) traits in noug based on 60 landrace accessions collected from wide geographic area in Ethiopia. The field trial was conducted at two sites in Ethiopia using a square lattice design. The analysis of variance revealed significant variation (p < 0.05) among these accessions. The highest broad-sense heritability (H2) was recorded for days to 10% flowering (DTF10; 85.4%), whereas number of capitula per plant (NCPP) and number of seeds per capitulum (NSPC) showed medium heritability (H2 = 38.5% and 31.6%, respectively). NCPP and NSPC showed a highly significant (p < 0.01) positive and negative genotypic correlation with days to flowering, respectively. These three traits showed very low genotypic coefficient of variation (<1%). In the case of qualitative traits, small capitulum, large flower, green leaf, green stem and course leaf margin showed significant association with higher number of seeds per plant (NSPP). Euclidean distance-based cluster analysis revealed that the clustering pattern of the accessions poorly correlates with the geographic distance between sample collecting sites. Similarly, no clear clustering pattern of accessions was revealed by principal component analysis (PCA) that explained 66.3% and 53.6% of the total variation of quantitative traits and qualitative traits, respectively. The oil content of these accessions was previously investigated and accessions with high oil content show large differences in terms of days to flowering, NSPP and thousand seed weight (TSW). Among the accessions included in this research, Hr_B21; Gj_C17, Sh_I4 and Gr_F15 Gj_G18 and Tg-R13 are top ranking, as they have at least one the following highly desirable traits: early maturity, high oil content, NSPP and TSW. Hence, crossbreeding of their selected genotypes would lead to the development of new cultivars that combine early maturity and both high seed and oil yields.

Correlation and Path Coefficient Analysis of Fruit Yield Attributes in Forty Genotypes of Okra (Abelmoschus esculentus)

Farmers and plant breeders are often faced with the problem of selecting the best genotypes of okra as a result of lack of adequate knowledge of association among yield and its component characters which has led to the inefficiency of crop improvement. Efficient selection in any breeding programme will not only depend on yield alone but on yield together with other yield components. Based on this fact, this research was carried out on forty genotypes of okra to determine the association of different agronomic characters with pod yield and their direct and indirect effects on pod yield so as to select the best genotype for further breeding work. The seed of each genotype was sown in a plot laid out in randomised complete block design with three replications, and data were collected on fourteen agronomic characters and analysed. Pod yield per plant had highly significant and positive genotypic and phenotypic correlations with plant height, number of leaves, petiole length, internode length, plant height at flowering, peduncle length, fruit length, fruit diameter, number of seeds and number of pods, indicating that pod yield in okra could be a function of these traits. Highly significant, negative genotypic and phenotypic correlations were observed for pod yield per plant with days to 50% flowering and days to maturity, suggesting that early flowering and maturity are desirable traits for improved productivity in okra. Path coefficient analysis revealed that number of pod per plant had the highest positive direct effect on pod yield per plant with its largest indirect effect with days to 50% flowering and reduction in days to maturity. Due to close associations among these traits, they could be used as basis of selection when high yield is the breeding objective.

Influence of agronomic and kernel‐related properties on popping expansion in popcorn

AbstractKnowledge about relationships between traits can contribute to raising the efficiency of selection of superior genotypes. The objective of this study was to estimate the correlations, direct and indirect effects of agronomic, chemical and physical traits of kernels on popping expansion (PE) in popcorn (Zea mays L.). The trial was carried out in the 2017/2018 growing season, in Maringá ‐ PR, with 49 treatments, which consisted of 43 popcorn, four flint, and two sweet corn. The trial was arranged in a randomized complete block design with three replications. Multiple agronomic, chemical, physical, and popcorn quality traits were evaluated. Analysis of variance was performed to estimate the coefficients of phenotypic and genotypic correlations and the direct and indirect effects of path analysis. The genotypes were partitioned into genotype within each kernel type (popcorn, flint, and sweet corn) and two more contrasts (popcorn vs. [flint + sweet corn]) and flint vs. sweet corn. Positive phenotypic (.76) and genotypic correlations (.81) between popping expansion and pericarp thickness were detected. Kernel length had negative phenotypic (−.75) and genotypic correlations (−.78) with PE. Path analysis indicated that pericarp thickness has a direct and positive effect on PE and that the observed positive correlation with thermal diffusivity of the kernel pericarp and kernel length can be explained by indirect effects of the pericarp thickness. Evaluating kernel length may be most prudent considering economical and practical constraints to popcorn breeding programs.

Map overlapping of QTL for resistance to Fusarium ear rot and associated traits in maize

Mapping QTL for disease resistance and associated traits is important to develop maize (Zea mays L.) hybrids less susceptible to ear rots. A biparental mapping population of 298 F5 recombinant inbreds (RIs), obtained from the cross between LP4637 (moderately resistant) and L4674 (susceptible), was genotyped with 250 single nucleotide polymorphism (SNP) markers. A set of 120 of those RIs, selected by uniRec procedure, and parental inbreds were phenotyped in two environments for pericarp thickness, pericarp content of trans-ferulic acid (tFA) and resistance to Fusarium ear rot. The set of parental inbreds exhibited an average density of one marker every 5 cM, 6% of a residual heterozygosity, and 5% of lost data. Moderate negative genotypic correlations were observed between disease severity and pericarp thickness (rG = − 0.31) and between disease severity and pericarp content of tFA (rG = − 0.32). Quantitative trait loci were mapped for disease severity in bins 1.06, 2.03, 3.06, 5.04, 5.07 and 6.05, for pericarp thickness in bins 1.06, 2.03, 4.02 and 4.05, and for pericarp content of tFA in bins 2.03, 3.06, 4.05 and 6.05. The joint models, including some additive-by-additive epistasis gene effects, explained 56.0–58.2%, 46.6–45.5%, 41.4–47.1% of the phenotypic variability for disease severity, pericarp thickness and pericarp content of tFA, respectively, depending on the environment. The most important QTL for the three traits overlapped in bin 2.03 indicating that genes from this genomic region might contribute to the expression of disease resistance by increasing thickness and tFA content of the pericarp.

Correlation and Path Coefficient Analysis in Coffee (<i>Coffea arabica </i>L.) Germplasm Accessions in Ethiopia

Sufficient information on the nature and magnitude of traits association will facilitate effective selection and hybridization to develop high yielding coffee progenies. The study was conducted at Metu Agricultural Research Sub Center to determine the extent of association among yield and yield related traits of coffee. Sixty four Coffee (Coffea arabica L.) germplasm including two standard check varieties (74110 and 74112) were used for this study. The field experiment was superimposed during 2018 cropping seasons on six years old coffee trees, which was laid down in 8x8 simple lattice design. The orchard was managed as per the coffee agronomic production practices. Data on 19 quantitative traits were recorded from four representative trees per row for each accession. Yield per tree exhibited significant (P<0.05) and positive phenotypic and genotypic association with fruit width (r_ph=0.19; r_g=0.19) and fruit thickness (r_ph=0.18; r_g=0.15). On the other hand, number of primary branches showed positive and significant (P<0.05) phenotypic and genotypic correlations with fruit width (r_ph=0.23; r_g=0.12) and fruit thickness (r_ph=0.21; r_g=0.07). Hence, indirect selection in favor of this trait can improve yield in coffee. Coffee berry disease mainly attacks fruits and beans, however, the disease showed negative phenotypic and genotypic correlation with fruit and bean quantitative traits. Average inter-node length of main stem, number of nodes on primary branches, Number of primary branches, fruit width and thickness, bean width and thickness and hundred beans weight exerted positive direct effect and also had positive genotypic association with yield per tree, while the other traits affected yield indirectly, mainly through average inter-node length of primary branches production. Therefore, these traits could be used as a reliable indicator in indirect selection for higher tree yield.

Character association studies for morphological and quality characters in basmati rice (Oryza sativa L.)

The present study was undertaken to estimate correlation coefficients among 22 yield components and quality characters in thirty rice (Oriza sativa L.) genotypes. The genotypes were evaluated in RBD and ANOVA results revealed the highly significant mean sum of squares among the genotypes for all the characters. Highest significant positive genotypic as well as phenotypic correlation was found between traits 100 kernel weight and 100 grain weight whereas, highest significant negative genotypic correlation was found between characters water absorbed by 10gm kernel and 100 grain weight, whereas, highest significant negative phenotypic correlation was found between characters grain weight per plant and days to maturity. Highest significant positive phenotypic correlation was found between traits 100 kernel weight and 100 grain weight. Grain weight per plant showed highly significant positive correlation with hulling %, kernel breadth before cooking, kernel breadth after cooking, breadth increase ratio after cooking and water absorbed by 10 gm kernel; significant positive association with peduncle length and flag leaf length. These characters could be utilized as indices of selection for future breeding programme.

Характеристика продуктивно-хозяйственных показателей коров ярославской породы различных генотипов

Abstract. Aim. The study of the influence of crossbriding on the growth and development of heifers and subsequent productive and reproductive qualities of cows on the first lactation. Methods. Using statistical methods, correlation analysis and ANOVA for evaluated genetic indicators of economic-valuable traits of dairy cattle. In particular was studied live weight of heifers from birth to 18 months, first insemination age and first fecundation age, live weight at fecundation, frequency of insemination, first calving age, days open, live weight at first lactation, milk yield for 305 days (kg), fat (%, kg) and protein (%, kg) in milk. Results. Relationship between productive indicators and the genotype of the animal is established. When assessing the strength of the influence of the factor «blood on the Holstein breed» it was found that the greatest impact can be traced at the age of 6 and 18 months, and is respectively 12.7 % and 17.1 %.The reproductive qualities of the first-calf cows decreased with the increase percent of blood in the Holstein breed. Evaluation of the impact of crossbreeding on milk production at first lactation has revealed significant strong influence on milk yield for 305 days of first lactation, and related signs the amount of milk fat and protein. According to qualitative indicators, the low influence of the Holstein blood fraction was found, while to a greater extent on the fat content than on the protein content in milk. Evaluation of phenotypic and genotypic correlations of milk yield and quality components of milk revealed average negative phenotypic and low negative genotypic correlation in all groups. The exception was in heifers of Yaroslavl breed with percent of Holstein blood less than 50 %, in which the relationship of yield x protein was positive. The relationship between milk yield and fat and protein content in milk has the opposite moderate character and strength. Practical significance. Studies was established that breeding of animals of Holstein and Yaroslavl breeds in one herd allows to receive an optimum ratio of milk production with optimal percentage fat and protein. For this herd among animals of the improved genotypes of the Yaroslavl breed, the use of genotypes with a percent of blood in the Holstein breed from 75.1 % to 87.6 % is optimal, which should be taken into account when selecting bulls to the breeding program.

Estimates of genetic parameters, genetic variability, and selection in the S1 generation of peach

ABSTRACT: The growing of peach in mild winter regions is made viable through the use of genotypes that have low need for cold conditions, and this is one of the main aims of breeding for these regions. Thus, the aims of this study were to estimate genetic parameters, evaluate genetic variability, and select families adapted to mild winter regions in the S1 generation of peach through mixed model methodology (REML/BLUP). For that purpose, 22 populations, 84 families, and 2090 individuals were evaluated for the following traits: bud burst rate (BR), node density (ND), plant height (PH), and trunk diameter (TD). Genetic variability was found for all the traits. Individual heritability in the broad sense was of low and medium magnitudes. The PH trait had positive genotypic correlation of high magnitude with TD. The ND trait had moderate negative genotypic correlation with PH and TD. Clustering by the Tocher method resulted in the formation of six mutually exclusive groups. Considering selection intensity of 25%, simultaneous selection for BR, ND, and TD led to predicted gains of 11.3% for BR, 9.7% for ND, -14.2% for PH, and -14.3% for TD, showing the great potential of the germplasm evaluated.