Genotypic Values Research Articles

Unraveling the interactive effect of opaque2 and waxy1 genes on kernel nutritional qualities and physical properties in maize (Zea mays L.)

The mutant waxy allele (wx1) is responsible for increased amylopectin in maize starch, with a wide range of food and industrial applications. The amino acid profile of waxy maize resembles normal maize, making it particularly deficient in lysine and tryptophan. Therefore, the present study explored the combined effects of genes governing carbohydrate and protein composition on nutritional profile and kernel physical properties by crossing Quality Protein Maize (QPM) (o2o2/wx1+wx1+) and waxy (o2+o2+/wx1wx1) parents. Selected homozygous genotypic classes from F2 populations showed that double mutants (o2o2/wx1wx1) had the highest amount of lysine (mean: 0.396%), tryptophan (mean: 0.099%), and amylopectin (mean: 98.56%) than respective single mutants (o2o2/wx1+wx1+: lysine: 0.338%, tryptophan: 0.083%, amylopectin: 74.66%; o2+o2+/wx1wx1: lysine: 0.223%, tryptophan: 0.040%, amylopectin: 95.21%). The wx1 was found to impart an enhanced effect on the lysine and tryptophan, while o2 complemented enhanced amylopectin content in the population in the o2+o2+ and wx1+wx1+ genotypic background, respectively, besides o2o2wx1wx1 genotypes. The pattern of kernel hardness observed based on average genotypic values was o2+o2+/wx1+wx1+ (401.28 N) < o2+o2+/wx1wx1 (330.99 N) < o2o2/wx1wx1 (304.28 N) < o2o2/wx1+wx1+ (210.96 N). Therefore, with the distinctive effects of wx1 and o2, improving lysine, tryptophan, and amylopectin while maintaining kernel hardness is feasible while breeding for o2o2/wx1wx1 germplasm and enhancing the utilization spectrum of waxy maize.

Nitsa is a new spring common wheat variety of ural breeding

The purpose of the current study was to characterize the spring common wheat variety ‘Nitsa’ of Ural breeding by its economically useful traits and properties in comparison with the standard variety and varieties of domestic and foreign breeding. The study was conducted at the Ural Federal Agrarian Research Center of the Ural Branch of the RAS in a specialized breeding crop rotation, the fields of which present the main range of soils in the Middle Urals region in 2020–2023. The variety ‘Nitsa’, developed by the method of intraspecific hybridization between the parents ‘Ekaterina’ (mother) and ‘Krasnoufimskaya 100’ (father), has been included in the State List of Breeding Achievements in the Volga-Vyatka and East Siberian regions of the Russian Federation since 2024. The mean productivity of the variety over the years of competitive variety testing was 3.82 t/ha, which is higher than that of the standard variety (‘Ekaterina’) by 0.36 t/ha or 10.4 %. In the environmental testing at the Krasnoufimsk Breeding Center (2021–2023), the mean productivity of ‘Nitsa’ was 3.40 t/ha, or 0.42 t/ha (14.1 %) higher than that of ‘Ekaterina’, there was identified an excess over the early-maturing varieties ‘Ekstra’ and ‘Iren’ (5.0–32.8 %), the middle-early varieties ‘Tyumenskaya rannyaya’, ‘Svecha’ and ‘Novosibirskaya 31’ (13.7–17.6 %). It was determined that the new variety formed the same productivity as the middle- maturing varieties ‘Ekada 70’, ‘Dariya’, ‘Omskaya 36’. It was established that stress resistance of ‘Nitsa’ was equal to ‘Iren’ and ‘Ekaterina’ and surpassed all the studied middle-early and middle-maturing varieties. The trait ‘breeding value of a variety genotype’ has shown that ‘Nitsa’ forms a high productivity combined with stability. There has been proven a variety’s advantage according to all energy efficiency indicators. There was established weak susceptibility of the variety ‘Nitsa’ against infectious background to loose and kernel smut, root rots. There was identified that baking properties of the new variety belonged to valuable wheat, and to the third class according to the standards for harvested grain. The research results have shown that wheat can be used in breeding as a source of high productivity, stability, disease resistance and improvement of the baking properties of grain.

Genotypic and Phenotypic Correlation and Path Coefficient Analysis of Rhodes Grass (&amp;lt;i&amp;gt;Chloris gayana&amp;lt;/i&amp;gt;) Genotypes

Evidence on the collective association of traits is important for effective selection in forage-breeding program. Twenty four genotypes of Rhodes grass and one check were evaluated at Mechara Agricultural Research Center (Onstation) with lattice design in 2023/24 main rainy season to evaluate the Genotypic and phenotypic correlation and determine the direct and indirect effects of yield-related traits on dry matter yield. The mean sum of squares of genotypes showed significant differences (p &amp;lt; 0.05) for stand vigor, days to 50% emergence, date to 50% flowering and Plant height and highly significant (p &amp;lt; 0.001) for biomass yield, dry matter and number of leaf per plant. Maximum phenotypic variance and genotypic variance value was recorded for days to maturity. The range observed for heritability (H&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;bs) was from (0.0%) to (55%). Stand vigor exhibited highest value of genetic advance as percentage of mean followed by number of leaf per plant. Highest genotypic coefficient variation were recorded from days to maturity (89.8%) flowed by Plant height (62.3%) and Highest phenotypic coefficient variation were recorded from plot cover (184.9%) followed by days to maturity (225.4%). Phenotypically and Genotypically dry matter yield was highly positive significant associated with of Plot cover (0.546**), stand vigor (0.566**), leaf per plant (0.439**) and showed highly negative significant with days to 50% emergence. The results of phenotypic path coefficient analysis showed that stand vigor (0.378) and leaf per plant had exerted moderate positive direct effect on dry matter. stand vigor followed by plant height, plot cover and leaf per plant had exerted high and positive direct effect on dry matter yield and genotypic path analysis showed stand vigor followed by plant height, plot cover and leaf per plant had exerted high and positive direct effect on dry matter yield. This indicates that selection based on these traits could be more effective to maximize dry yield.

HLA-G gene polymorphisms as predictors of survival in colorectal cancer: A unified machine learning approach

ObjectivesHuman leukocyte antigen (HLA-G) is a potent molecule involved in immune-tolerance. Here, we investigated the contribution of HLA-G gene polymorphisms (14 bp Ins/Del and +3142C/G) for accurate prediction of colorectal cancer (CRC) overall survival (OS) status. Our study presents a comprehensive investigation of the prognostic value of HLA-G genotypes and haplotypes in predicting OS status in 266 Tunisian patients with CRC. MethodsWe used a machine learning (ML)-based framework described below: (1) A dimensionality reduction approach was used to examine evidence of an association between HLA-G genotypes and OS status. (2) Decision-tree ML models were used to explore the performance of the HLA-G genotype as a relevant contributing feature to accurately predict OS status. ResultsHLA-G polymorphisms were highly predictive of OS status when a random forest classifier was used. The HLA-G 14 bp Ins/Del polymorphism outperformed the HLA-G + 3142C/G polymorphism as a predictor of OS. The Del/Del genotype was associated with worse OS and the G/G genotype was associated with favorable OS. The InsC haplotype predicted a favorable prognosis, and the DelG haplotype predicted a worse OS. The combined prediction demonstrated, with 100 % precision and high accuracy, that Del/Del genotype associated with key clinical features, can efficiently predict poor OS. The results were evaluated through an external validation process to ensure their reliability. ConclusionsWe demonstrated the potential of HLA-G gene polymorphisms as robust candidate biomarkers to predict OS in CRC patients. Research on the HLA-G gene present a promising avenue for developing an innovative decision-making tool to identify candidates for personalized therapeutic interventions.

Human papillomavirus genotype and cycle threshold value from self-samples and risk of high-grade cervical lesions: A post hoc analysis of a modified stepped-wedge implementation feasibility trial.

Human papillomavirus (HPV) testing of self-collected vaginal samples has potential to improve coverage of cervical screening programmes, but current guidelines mostly require those HPV positive on a self-sample to attend for routine screening. A pragmatic modified stepped-wedge implementation feasibility trial was conducted at primary care practices in England. Individuals aged 25 to 64 years who were at least 6 months overdue for cervical screening could provide a self-collected sample. The primary outcomes included the monthly proportion of non-attenders screened, changes in coverage, and uptake within 90 days. Self-samples from 7,739 individuals were analysed using Roche Cobas 4800. Individuals with a positive self-sample were encouraged to attend clinical screening. In this post hoc study of the trial, we related the HPV type (HPV16, HPV18, or other high-risk type) and cycle threshold (Ct) value on the self-sample to the results of clinician-collected sample and cervical intraepithelial neoplasia grade 2 or worse (CIN2+). We wished to triage HPV-positive individuals to immediate colposcopy, clinician sampling, or 12-month recall depending on risk. A total of 1,001 women tested positive through self-samples, and 855 women who had both an HPV-positive self-sample and a subsequent clinician-sample were included in this study. Of these, 71 (8.3%) had CIN2+. Self-sample Ct values were highly predictive of HPV in the clinician sample. Combining HPV type and Ct value allowed stratification into 3 risk groups; 44/855 (5%) were high-risk of whom 43% (19/44, 95% confidence interval [29.7%, 57.8%]) had CIN2+. The majority (52.9%, 452/855) were low-risk, of whom 4% (18/452, 95% CI [2.5%, 6.2%]) had CIN2+. The main limitation of our study was the colposcopy assessment was restricted to individuals who had abnormal cytology after positive results of both self-sample and clinician-collected sample. HPV type and Ct value on HPV-positive self-samples may be used for triage. The difference in the risk of CIN2+ in these groups appears sufficient to justify differential clinical management. A prospective study employing such triage to evaluate laboratory workflow, acceptability, and follow-up procedure and to optimise clinical performance seems warranted. ISRCTN12759467.

Adaptive capacity and ecological stability of some bean varieties in the conditions of the western forest-steppe of the Priobie region

Relevance. Crop productivity is determined by genotype, environmental effects and their interactions. Comprehensive evaluation of crop varieties based on their adaptability, plasticity and stability makes it possible to select the most promising varieties, high-yielding and adapted to many environmental conditions to improve productivity.Materials and Methods. Fourteen common bean varieties were tested in a randomized complete block design with three replications during two years (2022 and 2023) in the experimental field “Michurintsev Garden” of Novosibirsk State Agrarian University. Productivity traits were taken into account: number and weight of beans per plant, weight of 1000 seeds, yield. The purpose of the work was to evaluate bean samples for adaptive capacity and ecological stability in the conditions of the forest-steppe Priobie.Results. The article provides an assessment of the adaptability and stability of bean varieties in order to identify varieties with high productivity and adapted to climatic and farming conditions in the Siberian region. The results of the tests showed that the highest average net yields of Rubin, Krasnopestraya, Zolotistaya and Muhranula varieties were in the range of 0.41-0.64 kg/m2. Analysis of genotype-environment interaction (GxE) according to the mathematical model of Eberhart and Russel shows that varieties Rubin, Krasnopestraya, Zolotistaya and Muhranula have high indices of general adaptability and breeding value of genotype, Among them, varieties Rubin and Zolotistaya have stable productivity and high adaptability to environmental conditions.

Prediction of genotypic values via REML/BLUP and path analysis in maize half-sib families

Maize has significant relevance to food and economic security. The study aimed to evaluate the genetic gain between maize half-sib families, in the first cycle of recurrent selection, using the REML/BLUP methodology. Path analysis was also performed in order to understand the relationship between the agronomic traits. The experiment was conducted at the Federal Institute of Education, Science and Technology of Triangulo Mineiro – Campus Uberlandia. The agronomic traits evaluated, were: plant height (PH), ear height (EH), stem diameter (SD), ear length (EL), ear diameter (ED) and grain weight (GW). The results indicated significant differences only for the traits EL, GW and ED. A high coefficient of genetic variation (CVg) was observed for the traits EL, GW and ED, with only ED presenting a coefficient of relative variation (CVr) above one. The REML/BLUP methodology demonstrated high accuracy values and the estimates of gains were promising, with values of 24.07%, 21.88% e 18.23% for EL, GW and ED, respectively. Path analysis revealed the possibility of indirect gains in GW through EL.

Differential expression of steviol glycoside pathway genes in NaCl-treated stevia genotypes with varied SG contents

The rebaudioside-A/stevioside (R/S) ratio influences the breeding and commercial values of stevia genotypes. Three stevia genotypes, “High Sugar,” “Levan,” and “ShouA3-2,” with respectively high, medium, and low steviol glycoside (SG) contents were investigated to answer the following questions: how do SG contents change when NaCl induces gene expression? Is SG-content positively correlated with NaCl tolerance? Does the genotype, with a high R/S ratio, exhibit higher expression of SG genes; compared to the genotype, with a low R/S ratio? Growth parameters, through our results, were decreased in “High Sugar” and “ShouA3-2” relative to “Levan” who showed better performance under the severe 200 mM NaCl treatment. Extendedly, “High Sugar” decreased the expression of SG-genes (cpps, ks, kh, and ugt74) under the low 50 NaCl treatments, while the “ShouA3-2” has upregulated all the genes (except ks) under the moderate (100 mM) NaCl treatments. Overall, the antioxidant sod1 gene was upregulated, similarly, the “Levan” has upregulated the cpps, while differentially expressed ks and kh across the NaCl treatments. In conclusion, high R/S ratio does not necessarily mean enhancement in responses to abiotic stresses in stevia. The R/S ratio in stevia does not solely rely on the expression of SG-pathway genes thus; other ancestral genetic elements may independently regulate them. Under salinity, the rooting characteristics improved when R/S ratio was low, while when moderate the shooting characteristics were superior. We recommend breeding for moderate R/S ratios to assure probable resilience to challenging climates (such as salinity) and potent higher agronomic traits.

A dual typing system establishment and global diversity analysis for sapoviruses

BackgroundThe genus Sapovirus in the family Caliciviridae comprises of a genetically diverse group of viruses that are responsible for causing acute gastroenteritis in both human and animals globally. As the number of sequences continues to grow and more recombinant sequences are identified, the classification criteria of genogroups and genotypes of sapovirus need to be further refined. In this study, we aimed to optimize the classification of sapoviruses.ResultsThrough evolutionary clustering and genetic distance analysis, we have updated the classification criteria for VP1 genogroup and genotypes. We adjusted the original mean values ± 3 standard deviations (SD) of genetic distances to mean values ± 2.5SD, resulting the corresponding cutoff values for the same genotype and genogroup set at <0.161 and <0.503, respectively. Additionally, we established classification criteria for RdRp types and groups, referred to as P-types and P-groups,, with mean values ± 2SD and cutoff values of <0.266 and <0.531 for the same type and group, respectively. This refinement has expanded the VP1 genogroups to thirty-four and identified twenty-four P-groups. For human sapoviruses, the new criteria have resulted in the addition of one genotype, GV.PNA1. Moreover, the new criteria defined three P-groups and 21 P-types for human sapoviruses. Spatial-temporal analysis revealed no specific distribution pattern for human sapoviruses.ConclusionsWe established a dual typing system on classification based on VP1 and RdRp nucleotide sequences for sapoviruses.

Determination of pre-harvest sprouting tolerance and quality traits of the bread wheat landraces

In this study, pre-harvest sprouting tolerance and some quality characteristics of some wheat landraces and modern varieties in Turkey were determined. In Eskişehir, Karaman and Samsun locations of Turkey, 126 genotypes were tested in the 2014-2015 growing seasons, and 48 genotypes were tested in the 2015-2016 and 2016-2017 growing seasons in two-replication experiments. Data regarding germination index, protein content, sedimentation volume and falling number of genotypes were observed. Physical properties of grain, the number of days to spike, and plant height were also investigated. The difference between genotypes was found to be statistically significant for all traits. We found the germination index of the genotypes varied between 0.19 and 0.70 for the 2015-2016 and 2016-2017 growing seasons, respectively. The average germination index value of red kernel genotypes is lower than white kernel genotypes. The landraces from Turkiye included in the research were taller and harvested lately. In comparison, modern genotypes are in the first place regarding sedimentation volume. The landraces had higher protein content but lower protein qualities than modern cultivars. The grain hardness of landraces was lower than that of modern cultivars in the three years. We found positive relationships between the germination index, grain filling time, thousand-grain weight, and grain color. Protein content, sedimentation volume, falling number, and grain hardness are negatively and significantly related to the germination index. The results showed that white kernel Clark's Cream and red kernel Karakılçık (1) genotypes could be used as gene sources for pre-harvest sprouting tolerance breeding in bread wheat.

Evaluation of silage quality characteristics and nutritive value of oat genotypes

Evaluation of silage quality characteristics and nutritive value of oat genotypes

Studies on Path Coefficient Analysis and Correlation to Evaluate the Relationships between Yield and Its Components in Fenugreek (Trigonella foenum-graecum L.)

The present investigation was carried out for correlation and path coefficient analysis in Fenugreek (Trigonella foenum-graecum L.) The correlation of different traits with seed yield was examined both at phenotypic and genotypic levels and the study showed that genotypic correlation coefficient values were higher than the phenotypic values. This indicated that how much of phenotypic correlation coefficient are influenced by environment. The seed yield per plant was positive and significant with biological yield per plant, test weight and number of branches per plant at genotypic and phenotypic levels. The maximum direct positive effect on seed yield per plant was observed in biological yield per plant, harvest index, days to 50 per cent flowering, number of seed per pod, number of branches per plant and number of pods per plant. In the present investigation, genotypes viz., AFG-4 and RMT-303 were superior for seed yield per plant along with other traits like biological yield, test weight and number of pods per plant. These diverse genotypes can be used in future breeding programme of fenugreek.

Genetic diversity, relationships among traits and selection of tropical maize inbred lines for low-P tolerance based on root and shoot traits at seedling stage.

The tropical maize breeding for low-P tolerance and good performance under low-P stress environments can be achieved through selection based on root morphology traits at seedling stage. Here, we assessed the genotypic variation and genetic diversity of a panel of 151 tropical maize inbred lines for root and shoot seedling traits, investigated the relationship among traits and selected a set of promising inbred lines for low-P tolerance and performance. We evaluated the inbred lines at seedling stage in a greenhouse experiment under two conditions: applied P (AP) and non-applied P (NAP). A mixed model approach was used to estimate variance components and predict the genotypic values of each inbred line. The genetic diversity among inbred lines based on root and shoot traits was assessed, and correlations were estimated between tested traits under AP and NAP. Our panel of inbred lines showed huge genetic variability for all traits and presented large genetic diversity under both P conditions. Variance components due to the inbred line × P condition interaction were also highly significant (P < 0.01) for all traits. Root dry weight (RDW) was positively associated with stalk dimeter (SD), shoot dry weight (SDW) and root length, volume, and area under both P conditions. Also, the SD and SDW were associated with most root traits under AP. Based on low-P tolerance and performance indices, we selected a set of top 20 inbred lines to be used in our maize breeding program. We therefore concluded that there is a significant genetic diversity in the tropical maize inbred lines which have the genetic potential to be use in association mapping studies and also to develop improved low-P tolerant and P-efficient hybrids and maize breeding populations for low-P stress environments.

Cross potential selection: a proposal for optimizing crossing combinations in recurrent selection using the usefulness criterion of future inbred lines.

In plant breeding programs, rapid production of novel varieties is highly desirable. Genomic selection allows the selection of superior individuals based on genomic estimated breeding values. However, it is worth noting that superior individuals may not always be superior parents. The choice of the crossing pair significantly influences the genotypic value of the resulting progeny. This study has introduced a new crossing strategy, termed cross potential selection, designed to expedite the production of novel varieties of inbred crops. Cross potential selection integrates fast recurrent selection and usefulness criterion to generate novel varieties. It considers the segregation of each crossing pair and computes the expected genotypic values of the top-performing individuals, assuming that the progeny distribution of genotypic values follows a normal distribution. It does not consider genetic diversity and focuses only on producing a novel variety as soon as possible. We simulated a 30-year breeding program in 2 scenarios, low heritability (h2=0.3) and high heritability (h2=0.6), to compare cross potential selection with 2 other selection strategies. Cross potential selection consistently demonstrated the highest genetic gains among the 3 strategies in early cycles. In the 3rd year of the breeding program with a high heritability (h2=0.6), cross potential selection exhibited the highest genetic gains, 138 times that of 300 independent breeding simulations. Regarding long-term improvement, the other selection strategies outperformed cross potential selection. Nevertheless, compared with the other 2 strategies, cross potential selection achieved significant short-term genetic improvements. Cross potential selection is a suitable breeding strategy for the rapid production of varieties within limited time and cost.

Prognostic Significance of Human Papillomavirus Genotypes in Oropharyngeal Squamous Cell Carcinoma.

The prognostic significance of human papillomavirus (HPV) genotypes in oropharyngeal squamous cell carcinoma (OPSCC) has garnered considerable attention due to the increasing reliance on HPV status for clinical decision-making. This study aimed to compare the survival outcomes associated with different HPV genotypes in patients with OPSCC relative to HPV-negative tumors, providing insights into the potential implications for treatment de-intensification strategies. Patients diagnosed with invasive OPSCC were included from the National Cancer Database (NCDB). Patients were stratified based on HPV status and genotype, with HPV-negative tumors serving as the reference group. Multivariable Cox regression analysis was performed to assess the independent prognostic value of different HPV genotypes. Th majority of patient were classified as HPV-positive (N = 17,358, 70.0%), with HPV 16 being the most common genotype (N = 15410/17358, 88.8%) compared with other high-risk (N = 1217/17,358, 7.0%) and low-risk (N = 731/17,358, 4.2%) HPV genotypes. A significantly lower risk of death was measured for all HPV-positive compared with HPV-negative tumors (HPV 16: adjusted HR 0.51; 95% CI: 0.49-0.54; other high-risk HPV: adjusted HR 0.56; 95% CI: 0.49-0.63; low-risk HPV: adjusted HR 0.59; 95% CI: 0.50-0.68; p < 0.001). This study highlights the significant prognostic value of HPV genotypes in OPSCC, underscoring the superior survival outcomes of HPV-positive tumors across all genotypes compared with HPV-negative tumors. Detailed HPV subtype analysis can inform better treatment decisions and support de-intensification strategies for patients with low-risk genotypes. 3 Laryngoscope, 2024.

Hemoglobin polymorphism and its association with morphometric and egg production traits in Ethiopian indigenous and Sasso chicken breeds.

The present study investigated the biochemical polymorphism of hemoglobin (Hb) and its relationship with performance traits of Ethiopian indigenous and Sasso chicken breeds. A total of 284 chickens reared in three agro-ecologies were examined for genetic diversity and associations with productive traits at Hb locus using agarose gel electrophoresis. The results showed that the HbA allele was dominant in both breeds, and a higher proportion of male chickens were HbAA genotypes, while females were predominantly HbBB types. In the highland agro-ecology, chickens with the HbAA genotype were the most dominant, whereas in mid- and low-land agro-ecologies, chickens with HbBB and HbAB genotypes were found to be more frequent. A moderate level of expected heterozygosity was obtained with 0.47 and 0.445 for indigenous and Sasso chickens, respectively, with an average effective number of alleles per locus of 1.89 and 1.80. Moreover, chickens with HbAA genotypes showed significantly (p ≤ 0.05) higher body weight and linear body measurements than those of HbAB and HbBB genotypes. However, for appendage body structures (comb and wattle dimensions), chickens with the HbAB and HbBB genotypes had higher mean values. Additionally, clutch size (14.2 ± 0.4), clutch length (21.8 ± 0.7), and eight-month egg production (84.1 ± 1.2) were significantly (p ≤ 0.05) higher for hens with HbBB genotypes, followed by those with HbAB-types. Therefore, the considerable hemoglobin variability and significant associations of Hb variants with the performance traits can be sought as guiding information for further genetic improvement interventions in the chicken breeds under investigation. Further microsatellite marker-based genotyping is recommended to validate the higher morphometric values for HbAA genotypes and the better egg production for HbBB and HbAB genotypes.

Genetic divergence and truncation and simultaneous selection in inbred families (S1) of elephant grass for bioenergetic purposes via mixed models

The State University of North Fluminense Darcy Ribeiro (UENF) has been developing for fifteen years a breeding program that aims at the development of new cultivars of elephant grass due to its high potential and the low availability of cultivars developed by genetic breeding programs that meet the needs of producers in the State of Rio de Janeiro. In this sense, inbred families were also obtained as a way of fixing potential alleles for traits related to production, as the inbreeding process apparently does not strongly affect elephant grass in aspects related to inbreeding depression. This study aimed to estimate genetic diversity, variance components and prediction of genotypic values in 11 (S1) elephant grass families, and perform the truncation and simultaneous selection of traits using the selection index, by mixed models. The experimental design consisted of randomized blocks with 11 (S1) families, three replications, and six plants per plot. For variables dry matter production, percentage of dry matter, plant height, stem diameter, number of tillers and leaf blade width, was performed the estimation of genetic parameters and selection of the best genotypes based selection index using mixed model. The descriptors were subjected to correlation analysis, distance matrices were generated by the Mahalanobis method, and individuals were grouped by the UPGMA method. In the selection via mixed models (REML/BLUP), families 6, 11, 8, 1, 3, 7, and 9 contributed most of the genotypes selected for the evaluated traits, indicating their high potential to generate superior genotype. The selection indices via mixed models indicated that the multiplicative index presented a greater selection gain.The phenotypic correlations showed the possibility of performing an indirect selection from six evaluated traits.The genotypes were separated into 18 groups by the Mahalanobis distance, allowing the observation of a wide genetic diversity. The most divergent and productive genotypes were self-fertilized to obtain the second generation (S2), continuing the development program.

Combining Ability and Hybrid Breeding in Tunisian Melon (Cucumis melo L.) for Fruit Traits

A half-diallel cross study of seven melon inbred lines was carried out. The seven parents and their 21 F1 hybrids were evaluated for precocity of maturity, average weight per fruit, and fruit quality (fruit size, rind thickness, and soluble solids). The Diallel analysis was investigated for breeding values of these melon genotypes via general and specific combining ability, relationships between general and specific combining ability, and heterosis for the evaluated traits. The analysis of variance of the traits evaluated indicated highly significant differences among genotypes, suggesting the presence of adequate genetic variation for breeding. Additive genetic effects were most important with respect to fruit weight, while genetic dominance and epistasis effects mainly controlled fruit quality traits (fruit size, rind thickness, and TSS). Parent 1 (P1) and parent 3 (P3) had significant positive general combining ability effects for fruit weight. Also, P3 had positive general combining ability effects for fruit length and diameter, and cavity diameter. P3 was found to show maximum significant GCA in the desirable direction for all the traits except for TSS. Evaluation of heterosis (%) revealed that hybrid P1 × P3 can be considered as the best-performing hybrid for average fruit weight, TSS, and precocity, which also exhibited the highest positive and significant SCA effect for these traits. These results suggested that, among the melon genotypes studied, there is the potential to generate superior new varieties in hybrid production.

Multi-model approach for optimizing cold-wave resilient maize selection: unveiling genotype-by-environment interaction and predicting yield stability

Cold waves both significantly reduce yield & damage crops as well; unforeseeable nature of cold waves makes it challenging for farmers to manage risk. Thus, we aim to select maize hybrids that thrive under cold stress (both escaping early cold-waves and tolerating cold snaps); pinpoint stable, high-yielding hybrids ideal for regions prone to cold stress. In this investigation 2 years winter trial in Nepal was appraised on diverse maize hybrids for cold wave tolerant, stable across four stations with a Randomized Complete Block Design & 3 replications at each station. Likewise, this research employed 4 statistical methods both fixed effect and linear mixed model: genotype-environment interactions (AMMI), visually analyzes genotype performance and stability across environments (GGE) breeding values of genotypes for selection (BLUP), multiple traits for selection (MTSI). This scholarship revealed significant (P < 0.001) impacts of genotype, environment, and their interaction (GEI) on yield. This GEI, accounting for 100% of yield variance, was mainly captured by 3 principal components, with the first explaining 49%. Notably, mixed-effects models and biplots identified superior hybrids exhibiting both high average yields and consistent performance. GGE biplot analysis unveiled high-yielding and adaptable: GK3157, NK6607, RMH1899 Super, GK3254, RMH666, Shan 111, DKC9149, and Sweety-1. Further, BLUP and WAASBYY analyses delineated the superior performers and stabilized hybrids for yield, with DKC9141, Uttam 121, NK6607, MM2929, RMH-666, GK 3254, and GK3157, and RMH-1899 super candidates for both high yield and stability. In Nepalgunj, Delta 3333, MM2122, and Shaan 111 excelled in both yield and stability, while Rampur favored Rampur Hybrid 6 and MM2424 for stability. Parwanipur and Tarahara shared similar winners for stability and yield, including MM2122, Shaan 111, and Delta 3333 in Parwanipur, and NK7884, MM2424, and Delta 2222 in Tarahara. Based on Multi genotype ideotype distance (MGDI), 9 hybrids were selected for yield and stability, including MM 2033, NK 6607, Sweety 1 so on; exhibited escape to cold waves whilst GK3254, TMMH-846, and MM-9442, were chosen for cold waves adapted hybrids. Moreover, by identifying cold-tolerant maize hybrids, this study has potential to mitigate risks for farmers (economic burden, crop failure) and bolster food security.

Selection of Saccharum spp. × Saccharum spontaneum progeny for sugar and biomass traits

ABSTRACT This study evaluated an interspecific hybrid (Saccharum spp. × S. spontaneum) population with the aim of developing germplasm for use in both sugar and bioenergy (biomass) production. Specific objectives were to determine the genetic variability and heritability among the interspecific hybrid progenies for traits of economic importance and to use the Best Linear Unbiased Predictions (BLUPs) to determine their genotypic values. The 46 interspecific hybrids used in this study originated from crossing commercial sugarcane cultivars (UT5, F152, and KK07–559) as female and S. spontaneum clones (THS98–41, THS98–91, THS98–95, THS98–94, and THS97–51) as male parents. There were significant residual variances, attributed to the small plot size, but the juice quality traits were measured with relatively higher precision than other traits. Selection recommendations varied for different traits, suggesting selection pressure could be moderate to high for juice quality traits and moderate for yield-related traits. No hybrid genotypes were found to outperform cultivar parents for traits such as commercial cane sugar and low fiber, necessitating further germplasm enhancement for improvement of varieties destined for sugar production. On the contrary, transgressive segregation was observed for cane yield and other traits influencing biomass yield. The production potential of these hybrids could be tested in larger plots across multiple locations.