Breeding Programs Research Articles

Parental Effect on Agronomic and Olive Oil Traits in Olive Progenies from Reciprocal Crosses

Olive growing is undergoing a transition from traditional cultivation systems to a more technological model characterized by increased mechanization and a higher density of plants per hectare. This shift implies the use of less vigorous varieties that can adapt to the new system. Most traditional varieties are highly vigorous, and breeding programs can provide solutions to this challenge. This study investigates the parental effect on different agronomic and olive oil characteristics and its role in breeding programs. The objectives were to evaluate and characterize different agronomic and olive oil traits in the progenies from ‘Arbosana’ × ‘Sikitita’ cross and its reciprocal cross ‘Sikitita’ × ‘Arbosana’. The results showed a high variability of the characters evaluated in the progenitors of the reciprocal crosses. The highest coefficients of variation were observed in traits related to ripening index, phenolic compounds, polyunsaturated fatty acids, and Δ5-avenasterol, with phenolic content exhibiting the greatest variability. No statistically significant maternal effect was detected for any of the evaluated traits, although a slight positive maternal effect was systematically observed in the mean values of the evaluated traits. These results suggest that the maternal effect on olive is quite subtle, although due to a slight tendency of the maternal effect in the descriptive analyses, future studies are suggested to understand in depth the possible maternal effect on olive breeding.

The Use of Genomic Screening for the Detection of Chromosomal Abnormalities in the Domestic Horse: Five New Cases of 65,XXY Syndrome in the Pura Raza Español Breed

Sex chromosomal abnormalities are a well-established cause of reproductive failure in domestic horses. Because of its difficult diagnosis, the Pura Raza Español breeding program established a routine screening for chromosomal abnormalities in all the horses prior to enrolling in the studbook. This genomic procedure combines an initial assessment based on the results from Short Tandem Repeat (STR) parentage testing followed by a Single-Nucleotide Polymorphism (SNP) based copy number aberration (CNA) confirmative analysis in positive cases. Using this methodology, we identified five new individuals carrying a 65,XXY chromosomal number aberration (CNA) among 27,330 foals enrolled over the past two reproductive seasons. The animals were initially flagged as CNA candidates due to abnormal results in STR testing. Subsequent analysis genotyping using an STR sex-linked dedicated panel and a medium-density SNP array in ECAX and ECAY confirmed the diagnosis as 65,XXY carriers. Four cases (upon sample availability) underwent further analysis using in situ fluorescent hybridization with ECAX and ECAY probes, showing identical results. Phenotypic analysis revealed abnormal gonad development in one of the cases, showing that the remaining four had a normal reproductive morphology. To our knowledge, this represents the largest number of horses exhibiting the equine form of Klinefelter syndrome (65,XXY) reported to date. Our study highlights the importance of genomic screening in the accurate detection of chromosomal abnormalities in horses.

Coral Disease: Direct and Indirect Agents, Mechanisms of Disease, and Innovations for Increasing Resistance and Resilience.

As climate change drives health declines of tropical reef species, diseases are further eroding ecosystem function and habitat resilience. Coral disease impacts many areas around the world, removing some foundation species to recorded low levels and thwarting worldwide efforts to restore reefs. What we know about coral disease processes remains insufficient to overcome many current challenges in reef conservation, yet cumulative research and management practices are revealing new disease agents (including bacteria, viruses, and eukaryotes), genetic host disease resistance factors, and innovative methods to prevent and mitigate epizootic events (probiotics, antibiotics, and disease resistance breeding programs). The recent outbreak of stony coral tissue loss disease across the Caribbean has reenergized and mobilized the research community to think bigger and do more. This review therefore focuses largely on novel emerging insights into the causes and mechanisms of coral disease and their applications to coral restoration and conservation.

Assessing Heat Stress Tolerance of Wheat Genotypes through Integrated Molecular and Physio-Biochemical Analyses

Heat as an abiotic stress significantly impairs the sustainable productivity of wheat (Triticum aestivum L.). To determine the tolerance of genotypes to heat stress, a comprehensive approach should be used that integrates simultaneous phenotyping and genotyping analyses. The aim of this study is to identify local heat-tolerant genotypes using simple sequence repeat (SSR) markers and evaluate the selected genotypes under field conditions for their tolerance to heat stress. Of the 12 SSR markers that showed polymorphism, eight were associated with six important traits. The use of hierarchical cluster analysis (HC) based on SSR markers led to the identification of 13 genotypes that showed varying results and were grouped into three distinct heat tolerance classes: tolerant (T), moderately tolerant (MT), and sensitive (S). The results showed that heat stress had a significant effect on 19 traits under this study, with significant variation in tolerance to heat stress between genotypes. The tolerant genotypes exhibited a range of average thousand-kernel weight (TKW) values between 40.56 and 44.85, while the sensitive genotype (Yecora Rojo) had an average TKW of 35.45. Furthermore, the tolerant genotypes showed two to three times higher levels of antioxidants compared to the sensitive genotypes when exposed to heat stress. Among the traits analyzed, six showed a favorable combination of high heritability (>60%) and genetic gain (>20%). Through the integration of principal component analysis and stepwise multiple linear regression, it was determined that six traits (grain yield, 1000-kernel weight, plant height, intercellular carbon dioxide, flag leaf area, and grain filling duration) revealed differences between the 13 genotypes. HC analysis of the six traits resulted in the same division of genotypes into three main categories as observed in an HC analysis based on SSR markers. It is worth noting that Saudi wheat, including KSU106, KSU105, and KSU115 as local genotypes, in addition to the 16HTWYT-22 genotype, showed higher heat tolerance compared to the other genotypes tested, indicating its potential suitability for agriculture in Saudi Arabia. These results contribute to breeding programs focused on developing heat-tolerant wheat varieties and accelerate progress in wheat productivity improvement programs.

A study of the influence of the T2DL.2DS-2SS translocation and the 5S(5D) substitution from Aegilops speltoides on breeding-valuable traits of common wheat

The use of the gene pool of wild relatives for expanding the genetic diversity of common wheat is an important task of breeding programs. However, the practical application of common wheat lines with alien genetic material is constrained by the lack of information on chromosomal rearrangements and the negative impact of the transferred material on agronomically important traits. This research is aimed at studying 14 introgression lines with the T2DL.2DS-2SS translocation and the 5S(5D) substitution from Aegilops speltoides obtained from crossing common wheat varieties (Aurora, Krasnodarskaya 99, Nika Kubani) with the genome-substituted form Avrodes (BBAASS). Hybrid lines with different combinations of T2DL.2DS-2SS and T1BL.1RS translocations and 5S(5D) substitution were characterized by resistance to leaf and yellow rusts, productivity components and technological qualities of grain. The assessment of the varieties’ resistance to rust diseases showed that Krasnodarskaya 99, Nika Kubani and the Aurora variety, which is a carrier of the T1BL.1RS translocation, are highly susceptible to diseases, while the presence of the T2DL.2DS-2SS translocation and the 5S(5D) substitution, both together and separately, provides resistance to fungal pathogens. The analysis of the lines using markers designed for known resistance genes of Ae. speltoides did not reveal the presence of the Lr28, Lr35 and Lr51 genes in the lines. The results suggest that the genetic material of Ae. speltoides transferred to chromosomes 2D and 5D contains new resistance genes. To determine the effect of the T2DL.2DS-2SS translocation and the 5S(5D) substitution on the productivity and technological qualities of grain, the lines were assessed by weight of 1000 grains, grain weight and number of ears per 1 m2, by protein and gluten content, gluten quality and general baking evaluation. A positive effect was determined upon the weight of 1000 grains, protein and gluten content. There were no significant differences in other characteristics. The T2DL.2DS-2SS trans-location and the 5S(5D) substitution did not have a negative effect on the productivity and technological quality of grain, and are of interest for breeding practice.

Evaluation of confectionary sunflower germplasm accessions and their derived hybrids

AbstractConfectionary sunflower (Helianthus annuus L.) has gained popularity due to its utilization in roasting as snacks, poultry, bird food, and bakery products. However, seed quality of confectionary sunflower differs from non-oil seed types. In the present study, 71 sunflower accessions were selected for the evaluation of seed quality traits. Significant genetic variability was observed for traits such as 100-seed mass and seed length, as indicated by high genotypic coefficients of variability. Genotypic correlation analysis revealed a positive association between 100-seed mass and seed size, protein content, and oleic acid content. Path coefficient analysis based on genotypic and phenotypic correlations suggested that accessions with high sugar content may be selected to develop superior germplasm for confectionary products. Biplot analysis was conducted to identify suitable accessions with favorable confectionary traits. Accessions ‘Hybrid 100’, ‘GOR101’, and ‘Odesskijj112’ exhibited high sugar content, while ‘Yawn’ demonstrated comparatively higher oleic acid content. Accessions ‘Vinimik 6931’ and ‘HA 305’ displayed high 100-seed mass, while seed length was greater in accessions ‘Comet’ and H. × multiflorous. Combining ability analysis were performed to assess the breeding value of accessions. ‘Comet’ exhibited the highest general combining ability (GCA) effects for seed yield per plant, head diameter and 100-achene mass; while ‘G.OR.104’ had positive GCA for achene yield per plant but negative combining ability for other traits. ‘Tenissiei’ displayed positive GCA for all traits. Among the testers, accession ‘Universal’ showed positive GCA for seed yield per plant, while ‘HA-292’ exhibited positive GCA for head diameter. The accessions with higher values for confectionary traits and positive general combining ability effects for yield related traits may be further exploited in confectionary sunflower breeding programs as parents.

Current Advances in the Black Tiger Shrimp Penaeus monodon Culture: A Review

ABSTRACTThe increasing high‐end market demand for the black tiger shrimp Penaeus monodon has brought tremendous industry opportunities. Although the industry has tried its best to increase production, according to the report data from the Food and Agriculture Organization (FAO), annual global production has shown no significant upward trend over the past decade. Besides that, newly implemented policies such as seafood safety and food security negatively impacted the industry and reduced production. However, P. monodon cultivation is still promising due to its larger body size and higher market acceptance as a premium product. Over the years, numerous studies have been conducted to increase the production of P. monodon by optimizing its culture conditions, implementing new culture system, increasing disease resistance to disease such as WSSV, AHPND, WFD, implementation of pre‐ and probiotics in feed, and selective breeding programs to increase genetic diversity and population of P. monodon broodstock. This review provides an overview of the current advances in P. monodon broodstock cultivation, thereby providing an essential baseline for P. monodon aquaculture. Areas needing urgent research focus are also highlighted. Future research should take great strides and take into account the impact of future climate change scenario during P. monodon culture and optimization, and increase biosecurity measures to prevent its introduction as an alien species in wild settings.

Assessment of physio-morphological traits, genetic variability, and growth performance among amaranth (Amaranthus species) genotypes from Ethiopia

Amaranths are a type of plant that belongs to the NAD-malic enzyme-type C4 metabolism category. They have a unique C4 anatomy, which is present in their bracts, cotyledons, and leaves. This allows them to produce food through the C4 photosynthetic pathway and rapidly adapt to unfavorable environmental conditions. In this study, 120 amaranth genotypes were evaluated for physio-morphological traits, genetic variability, and growth performance assessment from Ethiopia. The results of the analysis of variance showed that all examined physio-morphological parameters, except the rate of photosynthesis and stomata conductance, had mean squares that varied considerably (P < 0.001) owing to genotypes. The estimates of genetic variability, heritability, and expected genetic advance indicated an incredible extent of genetic diversity among amaranth genotypes, with a significant selection pressure for these traits in the population to produce better genotypes for improved amaranth. Selection based on desirable features such as leaf-to-air vapor pressure deficit, transpiration rate, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, leaf area, plant height, leaf number, and root weight can be useful in achieving the intended genetic gains for improvement since these traits appear to be more controlled by additive gene activity. Thus, selection in amaranth genotypes may consider these desired yield-related features. Moreover, the study showed that certain genotypes (ALE-073) exhibited better intercellular CO2 concentration (Ci), leaf-to-air vapor pressure deficit (VPD), transpiration rate (E), and leaf number (LN), resulting in better grain yield. Understanding the relationship between LA and E can help in selecting crops for high E and may provide an avenue to improve leaf yield. Furthermore, some of the selected genotypes in this study could be used as potential parents for improving the genetic gain in amaranth breeding programs. The study concluded that there was additive gene action present since the Ch a, Ch b, TCh, and Tca markers exhibited 100% heritability. This showed that the use of these characteristics for selection, which indicated a potentially exploitable variation, would be more effective and successful in the long run in breeding programs than the use of other traits for splitting generations.

Progress in genomic-driven breeding for improving the disease and insect pest resistance in black gram (Vigna mungo)

Urdbean or black gram (Vigna mungo) is a short-duration pulse crop with a high nutritional profile, and its main cultivation areas are in South and Southeast Asia, including India. The production of black gram is constrained by various biotic stresses, particularly diseases like yellow mosaic disease, leaf crinkle disease, and powdery mildew. Additionally, insect pests like bruchids and pod borers also affect black gram production. These biotic stresses cause significant losses in yield and reduce yield quality. Breeding for resistance is the most desirable and economical approach for the management of diseases and insect pests. In the past, conventional approaches used in black gram breeding contributed to improving resistance to biotic stress in black gram, but the success was not at the desired level. Therefore, to enhance biotic stress resistance, the black gram breeding programs shifted their focus toward genomics. Recently, several genomics resources, including genome and transcriptome sequences, DNA markers, and genetic linkage maps, have been developed exclusively for the black gram. However, the progress of improving black gram resistance to biotic stress using these genomic resources is still very slow. In this review, we discuss the black gram genomic resources and their use in breeding programs for developing biotic stress resistance. In addition, we discuss the existing research gaps and offer our view on future research on combating the biotic stress in black gram.

Exploration of stable host-plant resistant sources to sterility mosaic disease of pigeonpea (Cajanus cajan L. Huth)

Sterility mosaic disease (SMD) presents a major challenge in pigeonpea cultivation throughout the Indian subcontinent. Chemical control methods, such as acaricides, are neither economically viable nor sustainable, making host plant resistance the preferred approach for managing this disease. In this study, we evaluated 45 pigeonpea germplasm accessions and breeding lines for SMD resistance over two consecutive Kharif seasons (2021-22 and 2022-23). Of the 45 genotypes tested, 8 exhibited low disease incidence (0-10%) (LRG-471, ICPL 151, ICPB 2089, ICPB 2047, ICPB 2092, ICPB 2211, ICPL 85063, and ICPL 14003) and were classified as resistant. Additionally, 23 genotypes showed disease incidence between 10.1-20.0% and were categorized as moderately resistant. These resistant genotypes offer promising new sources of SMD resistance and should be considered for inclusion in future pigeonpea breeding programs aimed at improving resistance. This research provides valuable phenotypic insights and identifies stable resistant sources essential for advancing SMD resistance breeding efforts.

Genome-wide association study of lignin trait in elite spring wheat against spot blotch disease

Spot blotch disease in wheat is one of major yield-limiting factor in warm humid conditions of South Asia. Developing the disease-resistant variety through molecular methods is an economically and environmentally eco-friendly approach. Diseased wheat leaves associated with lignin content increased by two or three times at 72 h compared with control. The genomic region associated with lignin content was investigated in a set of 289 diverse spring wheat genotypes. The genome - wide association studies panel employed a 90K Illumina SNP array and phenotyped in four environments. The GWAS analysis showed a total of 86 marker-trait associations on 1A, 1B, 2A, 2B, 2D, 3A, 3D, 4A, 5A, 5B, 6A, 6D, 7A, 7B, 7D were linked lignin trait. Insilco analysis revealed that significant SNPs were located on import putative candidate genes thirteen in the Transmembrane domain of the protein-kinase family and were involved in the host-pathogen interaction. The identified significant MTAs for further validation and useful for the wheat breeding programs to develop the spot blotch disease resistance.

Determination of Adoption Traits and Key Production Constraints of Improved Maize Varieties Using Participatory Research Appraisal

Introduction: Maize is a staple crop critical to the food security and livelihoods of millions of smallholder farmers in Sub-Saharan Africa. Despite the availability of improved maize varieties, adoption rates among farmers remain suboptimal. Understanding the traits that drive adoption and identifying key production constraints is essential for the development and dissemination of varieties that meet farmers' needs. Aims: This study aimed to identifying the most valued traits of improved maize varieties from the farmers' perspective, assessing the socio-economic and biophysical factors influencing the adoption of these varieties and identifying the main production constraints faced by farmers in different agro-ecological zones. Study Design: The study was conducted in three regions representing diverse agro-ecological zones. A multi-stage sampling technique was used to select a representative sample of maize farmers. Data collection involved focus group discussions (FGDs), key informant interviews (KIIs), and household surveys. PRA tools such as pairwise ranking and matrix scoring were employed to capture qualitative and quantitative data on adoption traits and production constraints. Place and Duration of Study: The study took place at Ejura Sekyeredumasi, Nkoranza South District and Wenchi Municipal district, between June 2017 and December 2017. Methodology: Descriptive statistics were used analyzed the demographic characteristics of maize farmers as well as socioeconomic factors influencing the adoption of improved maize farming technology using SPSS 16 version. Data collected included; socio-demographic characteristics, adoption of improved maize varieties and constraints to maize production. Results: The results showed that about 78 % and 18 % of farmer respondents perceived that both fertilizers and improved seed were too expensive. Other constraints to maize production were drought, high cost of other agro-inputs, lack of improved cultivars and poor soil fertility significantly influenced the adoption of improved maize farming technologies in the area Conclusion: The study underscores the importance of incorporating farmers' preferences and addressing context-specific production constraints in maize breeding programs. Enhanced extension services, improved seed distribution systems, and tailored agronomic practices are recommended to increase adoption rates and improve productivity. Participatory approaches in agricultural research are vital for aligning breeding objectives with the real-world needs of smallholder farmers, ensuring the relevance and impact of improved maize varieties in the Ghana.

Modeling Chickpea Productivity with Artificial Image Objects and Convolutional Neural Network

The chickpea plays a significant role in global agriculture and occupies an increasing share in the human diet. The main aim of the research was to develop a model for the prediction of two chickpea productivity traits in the available dataset. Genomic data for accessions were encoded in Artificial Image Objects, and a model for the thousand-seed weight (TSW) and number of seeds per plant (SNpP) prediction was constructed using a Convolutional Neural Network, dictionary learning and sparse coding for feature extraction, and extreme gradient boosting for regression. The model was capable of predicting both traits with an acceptable accuracy of 84–85%. The most important factors for model solution were identified using the dense regression attention maps method. The SNPs important for the SNpP and TSW traits were found in 34 and 49 genes, respectively. Genomic prediction with a constructed model can help breeding programs harness genotypic and phenotypic diversity to more effectively produce varieties with a desired phenotype.

Evaluation on Morphological and Quality Attributes of Mango Cultivars in Western Uttar Pradesh

The study aimed to assess the morpho-economic and biochemical attributes of twelve mango cultivars grown in western Uttar Pradesh, using pooled data from the years 2021-22 and 2022-23 and conducted at Horticulture Research Center of Sardar Vallabhbhai Patel University of Agriculture &amp; Technology, Meerut, the experiment utilized a Randomized Block Design (RBD) with four replications per treatment. The cultivars are regular bearers included Ambika, Pusa Arunima, Dashehari-51, Kesar, Pusa Surya, Amrapali, Mallika, Burma Surakha, Neelum Chausa, Mithua Malda, Rataul and Saurav, all planted in 10-year-old orchards with a spacing of 6x6 meters. The study aimed to evaluate the morpho-economic and biochemical attributes of twelve mango cultivars in western Uttar Pradesh, identify the most suitable cultivars for the region and determine the cultivars with the most marketable fruit traits. Additionally, it sought to assess the genetic diversity among the cultivars for future breeding programs. The results demonstrated significant differences in morpho-economic and quality attributes among the cultivars. Mallika, Pusa Arunima and Amrapali emerged as superior varieties, excelling in tree morpho-economic and quality attributes, while others were classified as moderate. Mallika and Pusa Arunima were identified as the highest-yielding varieties, based on the mean number of fruits per plant and fruit weight over the two-year period. Furthermore, the fruits of Mallika, Pusa Arunima, Amrapali, Rataul and Kesar exhibited the most marketable attributes. The findings underscore the significant genetic and environmental influences on mango attributes. Mallika and Pusa Arunima consistently demonstrated superior performance in yield, fruit quality and biochemical attributes, positioning it as a promising cultivar for the region. The diversity observed among the cultivars highlights the need for targeted selection and management practices to optimize mango production and quality. The study also emphasizes the importance of preserving and conserving these unique genetic resources for future breeding programs aimed at developing new, commercially viable cultivars.

Transcriptomic and Physiological Studies Unveil that Brassinolide Maintains the Balance of Maize’s Multiple Metabolisms under Low-Temperature Stress

Low-temperature (LT) is one of the major abiotic stresses that restrict the growth and development of maize seedlings. Brassinolides (BRs) have been shown to enhance LT tolerance in several plant species; the physiological and molecular mechanisms by which BRs enhance maize tolerance are still unclear. Here, we characterized changes in the physiology and transcriptome of N192 and Ji853 seedlings at the three-leaf stage with or without 2 μM 2,4-epibrassinolide (EBR) application at 25 and 15 °C environments via high-performance liquid chromatography and RNA-Sequencing. Physiological analyses revealed that EBR increased the antioxidant enzyme activities, enhanced the cell membrane stability, decreased the malondialdehyde formation, and inhibited the reactive oxygen species (ROS) accumulation in maize seedlings under 15 °C stress; meanwhile, EBR also maintained hormone balance by increasing indole-3-acetic acid and gibberellin 3 contents and decreasing the abscisic acid level under stress. Transcriptome analysis revealed 332 differentially expressed genes (DEGs) enriched in ROS homeostasis, plant hormone signal transduction, and the mitogen-activated protein kinase (MAPK) cascade. These DEGs exhibited synergistic and antagonistic interactions, forming a complex LT tolerance network in maize. Additionally, weighted gene co-expression network analysis (WGCNA) revealed that 109 hub genes involved in LT stress regulation pathways were discovered from the four modules with the highest correlation with target traits. In conclusion, our findings provide new insights into the molecular mechanisms of exogenous BRs in enhancing LT tolerance of maize at the seedling stage, thus opening up possibilities for a breeding program of maize tolerance to LT stress.

Effect of germplasm exchange strategies on genetic gain, homozygosity, and genetic diversity in dairy stud populations: A simulation study

While genomic selection has led to considerable improvements in genetic gain, it has also seemingly led to increased rates of inbreeding and homozygosity, which can negatively affect genetic diversity and the long-term sustainability of dairy populations. Using genotypes from US Holstein animals from 3 distinct stud populations, we performed a simulation study consisting of 10 rounds of selection, with each breeding population composed of 200 males and 2000 females. The investigated selection strategies consisted of selection using true breeding values (TBV), estimated breeding values (EBV), estimated breeding values penalized for the average future genomic inbreeding of progeny (PEN-EBV), or random selection (RAND). We also simulated several germplasm exchange strategies where the germplasm of males from other populations was used for breeding. These strategies included exchanging males based on EBV, PEN-EBV, low genomic future inbreeding of progeny (GFI), or randomly (RAND). Variations of several parameters, such as the correlation between the selection objectives of populations and the size of the exchange, were simulated. Penalizing genetic merit to minimize genomic inbreeding of progeny provided similar genetic gain and reduced the average homozygosity of populations compared with the EBV strategy. Germplasm exchange was found to generally provide long-term benefits to all stud populations. In both the short and long-term, germplasm exchange using the EBV or PEN-EBV strategies provided more cumulative genetic progress than the no-exchange strategy; the amount of long-term genetic progress achieved with germplasm exchange using these strategies was higher for scenarios with a higher genetic correlation between the traits selected by the studs and for a larger size of the exchange. Both the PEN-EBV and GFI exchange strategies allowed decreases in homozygosity and provided significant benefits to genetic diversity compared with other strategies, including larger average minor allele frequencies and smaller proportions of markers near fixation. Overall, this study showed the value of breeding strategies to balance genetic progress and genetic diversity and the benefits of cooperation between studs to ensure the sustainability of their respective breeding programs.

A genomic framework to assist conservation breeding and translocation success: A case study of a critically endangered turtle

AbstractConservation breeding programs are an effective approach to addressing biodiversity loss. Captive populations are managed to maintain genetic diversity, yet there remains an “implementation gap” in effectively translating molecular genetic data into management. Technological advancements are facilitating rapid generation of genetic data, increasing accessibility for breeding programs. In 2010, Frankham and colleagues proposed a six‐stage process for establishing successful conservation breeding and release programs. Here, we describe the conservation breeding program for the critically endangered Bellinger River turtle (Myuchelys georgesi) and characterize the value of genetic sampling for informing management actions. By generating a chromosome‐level genome and population genetic data, we investigated past and present diversity and assessed relatedness among captive founders. We present a framework modeled on Frankham and colleagues six stages to assist managers in implementing genetic data into actionable conservation strategies. This framework, and worked case study, for managers aims to better guide implementation of genetic approaches into conservation breeding programs.

Prediction of additive genetic variances of descendants for complex families based on Mendelian sampling variances.

The ability to predict the outcome of selection and mating decisions enables breeders to make strategically better selection decisions. To improve genetic progress, those individuals need to be selected whose offspring can be expected to show high genetic variance next to high breeding values. Previously published approaches enable to predict the variance of descendants of two future generations for up to 4 founding haplotypes, or 2 outbred individuals, based on phased genotypes, allele effects and recombination frequencies. The purpose of this study was to develop a general approach for the analytical calculation of the genetic variance in any future generation. The core development is an equation for the prediction of the variance of double haploid lines, under the assumption of no selection and negligible drift, stemming from an arbitrary number of founder haplotypes. This double haploid variance can be decomposed into gametic Mendelian sampling variances (MSV) of ancestors of the double haploid lines allowing usage for non-double haploid genotypes which enables application in animal breeding programs as well as in plant breeding programs. Together with the breeding values of the founders, the gametic MSV may be used in new selection criteria. We present our idea of such a criterion that describes the genetic level of selected individuals in four generations. Since breeding programs do select, the assumption made for predicting variances is clearly violated which decreases the accuracy of predicted gametic MSV caused by changes in allele frequency and linkage disequilibrium. Despite violating the assumption, we found high predictive correlations of our criterion to the true genetic level which was obtained by means of simulation for the "corn" and "cattle" genome models tested in this study (0.90 and 0.97). In practice, the genotype phases, genetic map and allele effects all need to be estimated meaning inaccuracies in their estimation will lead to inaccurate variance prediction. Investigation of variance prediction accuracy when input parameters are estimated was not part of this study.

Characterization of Strubbelig-Receptor Family (SRF) Related to Drought and Heat Stress Tolerance in Upland Cotton (Gossypium hirsutum L.)

Cotton is one of the world’s leading fiber crops, but climate change, drought, heat, and salinity have significantly decreased its production, consequently affecting the textile industries globally. To acclimate to these environmental challenges, a number of gene families involved in various molecular, physiological, and hormonal mechanisms play crucial roles in improving plants response to various abiotic stresses. One such gene family is the GhSRF, a Strubbelig-Receptor family (SRF), and member of the leucine-rich repeat (LRR-V) group. This family encodes leucine-rich repeat transmembrane receptor-like kinases (LRR-RLKs) and have not yet been explored in cotton. Arabidopsis thaliana Strubbelig-Receptor gene sequences were used as queries to identify the homologs in cotton, with subsequent support from the literature and functional prediction through online data. In the current study, a comprehensive genome-wide analysis of cotton was conducted, identifying 22 SRF putative proteins encoded by 22 genes. We performed the detailed analysis of these proteins, including phylogeny, motif and gene structure characterization, promoter analysis, gene mapping on chromosomes, gene duplication events, and chromosomal sub-cellular localization. Expression analysis of putative genes was performed under drought and heat stress conditions using publicly available RNAseq data. The qRT-PCR results showed elevated expression of GhSRF2, GhSRF3, GhSRF4, GhSRF10, and GhSRF22 under drought and heat stress. So, it could be speculated that these genes may play a role in drought and heat tolerance in cotton. These findings could be helpful in cotton breeding programs for the development of climate-resilient cultivars.

Developing genomic tools to assist turnip rape [Brassica rapa (L.) subsp.oleifera (DC.) Metzg.] breeding

IntroductionTurnip rape is recognized as an oilseed crop contributing to environmentally sustainable agriculture via integration into crop rotation systems. Despite its various advantages, the crop’s cultivation has declined globally due to a relatively low productivity, giving way to other crops. The use of genomic tools could enhance the breeding process and accelerate genetic gains. Therefore, the present research investigated 170 turnip rape accessions representing its global gene pool to identify SNP markers associated nine phenological and agro-morphological traits and estimate the genomic breeding values (GEBVs) of the germplasm through GWAS and genomic prediction analyses, respectively.MethodsField trials were conducted at two sites in northern and southern Sweden to obtain the phenotypic data while genotyping was conducted via the genotyping-by-sequencing (GBS) method. The traits studied include days to flowering (DTF) and maturity (DTM), plant height (PH), seed yield (YLD), thousand seed weight (TSW), silique length (SL), number of siliques (NS), number of seeds per silique (SS), and pod shattering resistance (PSHR).Results and conclusionAnalysis of variance revealed substantial variation among accessions, with significant genotype-by-environment interaction for most traits. A total of 25, 17, 16, 14, 7, 5, 3, and 3 MTAs were identified for TSW, DTF, PH, PSHR, SL, YLD, SS and DTM, respectively. An 80%–20% training-test set genomic prediction analysis was conducted using the ridge regression – BLUP (RR-BLUP) model. The accuracy of genomic prediction for most traits was high, indicating that these tools may assist turnip rape breeders in accelerating genetic gains. The study highlights the potential of genomic tools to significantly advance breeding programs for turnip rape by identifying pivotal SNP markers and effectively estimating genomic breeding values. Future breeding perspectives should focus on leveraging these genomic insights to enhance agronomic traits and productivity, thereby reinstating turnip rape as a competitive and sustainable crop in Sweden and broader global agriculture.