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ABSTRACT The leguminous chickpea is a good source of protein, but its yield potential is frequently constrained by biotic stresses, primarily Helicoverpa armigera, a major havoc for cultivation of the crop. To develop host plant resistance for minimizing the losses due to the pod borer, five kabuli parents with desired traits for pod borer tolerance were crossed in diallel mating design to produce 10 crosses which were analysed for traits related to pod borer and nutrition. Based on correlation studies, trichome density was found positively correlated with phenol content, but both the traits were negatively associated with number of damaged seeds. Therefore, the tolerant genotypes were identified on the basis of phenol content, trichome density, number of damaged seeds and field rating. Among parents ICC 12197 was found superior in terms of yield and borer tolerance features with an intermediate pest resistance susceptible rating in addition to higher Fe content. However, significant sca effects for higher phenol content and seed yield in ICC 11764 × ICC 14190 were recorded with reduced number of damaged seeds in addition to higher Fe and Zn content. It was observed that the specific combination involved good and poor combiners for each trait. The same cross also showed significant standard heterosis in desirable direction for phenol content, trichome density, number of damaged seeds and seed yield. Additionally, the ratio of σ2 GCA to σ2 SCA revealed nonadditive gene action in controlling the expression of phenol content, trichome density, number of damaged seeds and Fe and Zn content. Thus, breeder may focus efforts on desirable cross utilizing selection in further segregating generations for higher phenol content, trichome density and Fe and Zn content in addition to yield‐related traits while lesser number of damaged seeds per plant to concentrate for development of pod borer resilient high yielding kabuli genotypes to combat micronutrient deficiency. [ABSTRACT FROM AUTHOR]

The preservation of genetic variation is fundamental in biodiversity conservation, yet its importance for population viability remains contentious. Mixed‐source reintroductions, where individuals are translocated into a single vacant habitat from multiple genetically divergent and often depauperate populations, provide an opportunity to evaluate how genetic variation and hybridization influence individual and relative population fitness. Population genetic theory predicts that individuals with higher genetic variation and hybrids among populations should have higher fitness. We tested these two hypotheses by analyzing individual and population‐scale data for westslope cutthroat trout (Oncorhynchus clarkii lewisi) in four mixed‐source reintroductions. We observed more hybrid and fewer nonhybrid offspring than expected across four independent mixed‐source reintroductions. We also found clear evidence that heterozygosity influenced individual reproductive and relative population fitness. Overall, we found a strong, positive relationship between genetic variation, hybridization, and transplant fitness, emphasizing the importance of genetic variation and population mixing in conservation. [ABSTRACT FROM AUTHOR]

In this study, distant hybridisation was successfully conducted between Brassica rapa var. rosularis Tsen et Lee ‘Huangxinwu’ (2n = 20, AA) and B. oleracea var. alboglabra Bailey ‘Big Yellow Flower Kale’ (2n = 18, CC). A total of three hybrids were obtained through artificial hybridisation and ovary culture. Forty asexual seedlings were obtained by propagation, and thirty were doubled. The identifications of morphological analysis, cytological observation, and SSR molecular analysis showed that one strain was a true hybrid. Allotetraploid hybrids exhibited generally an intermediate phenotype between their parents. The wrinkled leaf surface and leaf colour were more inclined toward the maternal parent, while its leaf thickness and size were more inclined toward the paternal parent. Furthermore, the allotetraploid hybrids showed obvious over-parent heterosis in biomass and nutritional quality characteristics, including plant weight, soluble sugar, VC, and cellulose, with corresponding contents of 882.76 g, 2.84%, 107.91 mg/100 g and 1.27%. Moreover, the soluble solids and soluble protein contents of these hybrids were 5.62% and 2.56 g/100 g, respectively, which were similar to those of the high-value parent. In general, the newly synthesised allotetraploid is an innovative germplasm of Brassica vegetables that can be used for future heterosis utilisation and nutritional quality improvement. [ABSTRACT FROM AUTHOR]

SUMMARY: The utilization of rice heterosis is essential for ensuring global food security; however, its molecular mechanism remains unclear. In this study, comprehensive analyses of accessible chromatin regions (ACRs), DNA methylation, and gene expression in inter‐subspecific hybrid and its parents were performed to determine the potential role of chromatin accessibility in rice heterosis. The hybrid exhibited abundant ACRs, in which the gene ACRs and proximal ACRs were directly related to transcriptional activation rather than the distal ACRs. Regarding the dynamic accessibility contribution of the parents, paternal ZHF1015 transmitted a greater number of ACRs to the hybrid. Accessible genotype‐specific target genes were enriched with overrepresented transcription factors, indicating a unique regulatory network of genes in the hybrid. Compared with its parents, the differentially accessible chromatin regions with upregulated chromatin accessibility were much greater than those with downregulated chromatin accessibility, reflecting a stronger regulation in the hybrid. Furthermore, DNA methylation levels were negatively correlated with ACR intensity, and genes were strongly affected by CHH methylation in the hybrid. Chromatin accessibility positively regulated the overall expression level of each genotype. ACR‐related genes with maternal Z04A‐bias allele‐specific expression tended to be enriched during carotenoid biosynthesis, whereas paternal ZHF1015‐bias genes were more active in carbohydrate metabolism. Our findings provide a new perspective on the mechanism of heterosis based on chromatin accessibility in inter‐subspecific hybrid rice. Significance Statement: The utilization of rice heterosis is an essential avenue to overcome the yield bottleneck; however, the underlying molecular mechanism remains unclear. We characterized the more actively accessible chromatin state in the inter‐subspecific hybrid compared to that in its parents, revealing the regulation of chromatin accessibility and DNA methylation. This study offers a novel perspective on ACR as an embodiment of the regulation of hybrid rice. [ABSTRACT FROM AUTHOR]

Chili (Capsicum annuum L.) is an important functional food due to its main bioactive compound, capsaicin, and other nutritional phytochemicals. However, very few studies have been conducted to develop hybrids with a high content of nutritional phytochemicals. The present study involving six parents was conducted to identify superior hybrids with higher nutritional quality based on combining ability and heterosis following Griffing's diallel Method II Model I. A broad spectrum of genetic variation among the six parents and fifteen F1 hybrids was confirmed by analysis of variance. (H1/D)0.5 value indicated that partial dominance gene action controlled all the traits except capsaicin and total phenolic content. Based on general combining ability (GCA) results, parent P3 (PLP-2s) was the best general combiner for all the traits except K and Na, followed by the parents P6 (BU Capsicum 1), P5 (Morich-8), P4 (Chili Japan) and P1 (Red Chili). Specific combining ability (SCA), along with heterotic response, revealed that the F1 hybrid P3xP6 (PLP-2s x BU Capsicum 1) was the best hybrid, followed by the hybrids P4xP6 (Chili Japan x BU Capsicum 1) and P3xP4 (PLP-2s x Chili Japan), as they exhibited superiority for major nutritional components, such as capsaicin and ascorbic acid. Ultimately, the subsequent selection of the F1 hybrids would help develop better nutritional-quality hybrids. [ABSTRACT FROM AUTHOR]

Proper waste management will reduce several pollutions arising out of burning of different agri-wastes such as stubble burning of rice. The lignocellulose in the dry matter, can be converted into various essential products including biofuel through gasification and pyrolysis. This will help to reduce the cost by minimizing the import of petroleum products. A productive sustainable strategy is the development of energy-efficient rice varieties possessing desirable biomass traits without undermining the yield potential. For this sufficient genetic variability should be available to develop suitable dual-purpose varieties. Considering these points, initially, the molecular diversity in popular varieties for biomass traits was explored using cellulose synthase specific markers. An archeopteryx tree constructed thereof indicated the presence of sufficient diversity among the varieties. Eight potential varieties, having sufficient diversity among each other, were selected as parents for developing dual- purpose hybrids. Some of the superior crosses identified concerning both grain and straw yield per plant were Kanchan/Meher, Kanchan/Pratikshya, Pratikshya/Ankit, Hiranmayee/Chandrama and Kanchan/Meher. The crosses including Kanchan/Pratikshya, Meher/Pratikshya, Meher/Ankit, Pratikshya/Hiranmayee, Hiranmayee/Gobinda, Hiranmayee/Pradeep and Gobinda/Pradeep exhibited both positive significant relative heterosis and heterobeltiosis for the biochemical traits. Non-additive gene action was reported to involve in the inheritance of traits viz., plant height, biochemical traits and grain yield, whereas additive gene action played a crucial role in the inheritance of traits viz., leaf area, seed weight and straw yield. [ABSTRACT FROM AUTHOR]

ABSTRACT Hybrid wheat could deliver the grain yield (GY) and stability levels to confront climate change while crossing genetically divergent pools should maximize heterosis. We crossed 22 breeding lines from Nebraska (USA) with two German cultivars to produce 44 hybrids. Hybrids, parents and 12 checks were reciprocally tested across their contrasting target environments for GY, plant height and flowering biology during 2 consecutive years at multiple locations. Trait variation within target environments had the greatest impact on performance. Therefore, mega‐environments could not be derived from target environments despite a clear clustering using weather variables. Short plants and locally optimized flowering biology were main drivers for crop performance and adaptation. Modified Rogers' distances derived from genotyping‐by‐sequencing revealed the genetic divergence between German and ‘Great Plains’ pools. However, variation on GY heterosis could not be explained by this divergence. In general, GY of hybrids was more stable across target environments than for locally adapted material, whereas GY heterosis was higher under harsh climate conditions of the Nebraska's ‘Great Plains’. [ABSTRACT FROM AUTHOR]

Purpose: Although the application of heterosis has significantly increased crop yield over the past century, the mechanisms underlying this phenomenon still remain obscure. Here, we applied transcriptome sequencing to unravel the impacts of parental expression differences and transcriptomic reprogramming in cotton heterosis. Methods: A high-quality transcriptomic atlas covering 15 developmental stages and tissues was constructed for XZM2, an elite hybrid of upland cotton (Gossypium hirsutum L.), and its parental lines, CRI12 and J8891. This atlas allowed us to identify gene expression differences between the parents and to characterize the transcriptomic reprogramming that occurs in the hybrid. Results: Our analysis revealed abundant gene expression differences between the parents, with pronounced tissue specificity; a total of 1,112 genes exhibited single-parent expression in at least one tissue. It also illuminated transcriptomic reprogramming in the hybrid XZM2, which included both additive and nonadditive expression patterns. Coexpression networks between parents and hybrid constructed via weighted gene coexpression network analysis identified modules closely associated with fiber development. In particular, key regulatory hub genes involved in fiber development showed high-parent dominant or over dominant patterns in the hybrid, potentially driving the emergence of heterosis. Finally, high-depth resequencing data was generated and allele-specific expression patterns examined in the hybrid, enabling the dissection of cis- and transregulation contributions to the observed expression differences. Conclusion: Parental transcriptional differences and transcriptomic reprogramming in the hybrid, especially the non-additive upregulation of key genes, play an important role in shaping heterosis. Collectively, these findings provide new insights into the molecular basis of heterosis in cotton. [ABSTRACT FROM AUTHOR]

Polyploid rice and its reverted diploid show rich phenotypic variation and strong heterosis, showing great breeding value. However, the genomic differences among tetraploids, counterpart common diploids, tetraploid-revertant diploids, and hybrid descendants are unclear. In this work, we bred a new excellent two-line hybrid rice variety, Y Liang You Duo Hui 14 (HTRM12), using Haitian tetraploid self-reverted diploid (HTRM2). Furthermore, we comparatively analyzed the important agronomic traits and genome-wide variations of those closest relatives, Haitian diploid (HT2), Haitian tetraploid (HT4), HTRM2, and HTRM12 in detail, based on multiple phenotypic investigations, genome resequencing, and bioinformatics analysis. The results of agronomic traits analysis and genome-wide variation analysis of single nucleotide polymorphism (SNP), insertion–deletion (InDel), and copy number variation (CNV) show that HT4 and HTRM2 had abundant phenotypic and genomic variations compared to HT2. HTRM2 can inherit important traits and variations from HT4. This implies that tetraploid self-reverted diploid has high potential in creating excellent breeding materials and in breeding breakthrough hybrid rice varieties. Our study verifies the feasibility that polyploid rice could be used as a mutation carrier for creating variations and provides genomic information, new breeding materials, and a new way of application for tetraploid rice breeding. [ABSTRACT FROM AUTHOR]

Background: Inter-subspecific hybrid rice represents a significant breakthrough in agricultural genetics, offering higher yields and better resilience to various environmental stresses. While the utilization of these hybrids has shed light on the genetic processes underlying hybridization, understanding the molecular mechanisms driving heterosis remains a complex and ongoing challenge. Here, chromatin immunoprecipitation-sequencing (ChIP-seq) was used to analyze genome-wide profiles of H3K4me3 and H3K27me3 modifications in the inter-subspecific hybrid rice ZY19 and its parents, Z04A and ZHF1015, then combined them with the transcriptome and DNA methylation data to uncover the effects of histone modifications on gene expression and the contribution of epigenetic modifications to heterosis. Results: In the hybrid, there were 8,126 and 1,610 different peaks for H3K4me3 and H3K27me3 modifications when compared to its parents, respectively, with the majority of them originating from the parental lines. The different modifications between the hybrid and its parents were more frequently observed as higher levels in the hybrid than in the parents. In ZY19, there were 476 and 84 allele-specific genes with H3K4me3 and H3K27me3 modifications identified, representing 7.9% and 12% of the total analyzed genes, respectively. Only a small portion of genes that showed differences in parental H3K4me3 and H3K27me3 modifications which demonstrated allele-specific histone modifications (ASHM) in the hybrid. The H3K4me3 modification level in the hybrid was significantly lower compared to the parents. In the hybrid, DNA methylation occurs more frequently among histone modification target genes. Additionally, over 62.58% of differentially expressed genes (DEGs) were affected by epigenetic variations. Notably, there was a strong correlation observed between variations in H3K4me3 modifications and gene expression levels in the hybrid and its parents. Conclusion: These findings highlight the substantial impact of histone modifications and DNA methylation on gene expression during hybridization. Epigenetic variations play a crucial role in controlling the differential expression of genes, with potential implications for heterosis. [ABSTRACT FROM AUTHOR]

Parental selection is important for heterosis formation during crossbreeding of Populus. However, in poplar hybrids, the effect of parents on vegetative growth heterosis is not well understood. In this study, one female parent (P. simonii XY4) and two male parents (P. nigra OH and P. deltoides × P. nigra BJLY3#) were used to produce two progenies (Hyb1 and Hyb2). Vegetative growth investigation showed that both Hyb1 and Hyb2 performed heterosis in plant growth and ground diameter. The vegetative growth of hybrids was strongly correlated with the male parents but not with the female parents. The gene expression levels in the hybrids were more biased toward the male parents. In Hyb1 and Hyb2, 51.93% and 45.03% of the expressed genes showed the non-additive effect, respectively, and over 65% of the non-additively expressed genes showed the dominant effect. It is noteworthy that genes of paternal expression dominant effect (ELD_♂) account for the majority of dominantly expressed genes, suggesting the paternal contribution to heterosis. KEGG enrichment analysis indicated that a large number of non-additively expressed genes were enriched in the plant hormone signal transduction pathway. WGCNA analysis showed that MEcyan was significantly correlated with the traits of hybrids, and 12 plant hormone signal transduction pathway genes were enriched in this module. Transcription factors (TFs) MYB88, LHY, and TCP4 may be involved in the regulation of these pathway genes. This finding supported that the male parents play an important role in the formation of vegetative growth heterosis of Populus. In addition, the non-additively expressed genes of the signal transduction pathway and the regulation of TFs related to these pathway genes may be one of the reasons for the generation of heterosis. [ABSTRACT FROM AUTHOR]

Wheat hybrids have been widely demonstrated to have remarkable heterosis or hybrid vigor in increasing yield potential and stability since the 1960s. Two-line hybrid wheat can achieve higher yields than local varieties, especially in marginal environments. However, the commercial application of hybrid wheat is hindered by higher seed costs, primarily due to lower yields in hybrid seed production. Stigma exsertion has been verified as a decisive factor in increasing rice's hybrid seed yield, but more investigation is needed in hybrid wheat breeding and production. In this study, four thermo-photo-sensitive genic male sterile lines, including K41S, K64S, K66S, and K68S, with different stigma exsertion rates (SERs) were used to compare the differences in floral architecture relative to stigma exsertion over two growing seasons. The results revealed that the K41S and K64S exhibited a relatively higher SER at 21.87% and 22.81%, respectively. No exserted stigma was observed in K66S, and K68S had an SER of only 0.82%. This study found that the stigma length, glume width and the length–width ratio of the glume were significantly correlated with the SER, with correlation coefficients of 0.46, −0.46 and 0.60, respectively. Other stigma features such as the branch angle, stretch width and hairbrush length, as well as the glume length, also had a weakly positive correlation with SER (r = 0.09–0.27). For K41S and K64S, the SER was significantly affected by the differences in the stigma branch angle and stigma stretch width among florets. A cross-pollination survey showed that the out-crossing ability of florets with an exserted stigma was about three times as high as that of florets with a non-exserted stigma. As a result, the stigma-exserted florets that accounted for 21.87% and 22.81% of the total florets in K41S and K64S produced 46.80% and 48.53% of the total cross-pollinated seeds in both sterile lines. These findings suggest that a longer stigma combined with a slender glume appears to be the essential floral feature of stigma exsertion in sterile wheat lines. It is expected that breeding and utilizing sterile lines with a higher SER would be a promising solution to cost-effective hybrid wheat seed production. [ABSTRACT FROM AUTHOR]

Cotton is a valuable industrial fiber crop grown in many regions worldwide. Four cotton (Gossypium hirsutum L.) cultivars, i.e., Ishonch, Navbakhor-2, C-6524, and Tashkent-6, and their F1-2 diallel hybrids’ cultivation comprised a randomized complete block design with a factorial arrangement and four replications during 2019–2021 in the Tashkent Region, Uzbekistan. Significant (P ≤ 0.01) differences were notable among the parental genotypes and their F1 hybrids for boll weight and seed cotton yield. The parental cultivars Ishonch and Navbakhor-2 and their F1 diallel hybrids showed more stability and performed better than other genotypes. Broad-sense heritability estimates were the highest for boll weight and seed cotton yield while lowest for bolls per plant. Based on this trait’s yield, heritability, and variability, the inbreeding depression was positive in the F2 populations Ishonch × Navbakhor-2 and Navbakhor-2 × Tashkent-6. According to yield, the cultivars Ishonch, Navbakhor-2, and Tashkent-6 were outstanding as positive donors. [ABSTRACT FROM AUTHOR]

Spodoptera frugiperda, also known as fall armyworm (FAW), is an invasive crop pest that can feed on a variety of host plants, posing a serious threat to food security. There are two sympatric strains of FAW that are morphologically identical but described with different food preferences: the "rice strain" (SfR) and the "corn strain" (SfC). A few genetic loci exist to identify these two strains. Mitochondrial and Z‐chromosome‐linked haplotypes are the most used, but the biggest part of the genome displays little polymorphism between strains that could explain their adaptation to different plants. We have previously observed consistent transcription differences between the strains in both laboratory and natural populations. Therefore, we wonder if there are effects from host‐strain‐associated loci, maternally or paternally inherited, on FAW performance that could explain the divergence between the two FAW strains. To test this hypothesis, we first produced two F1 hybrid generations (SfR ♀ × SfC ♂, SfC ♀ × SfR ♂). These reciprocal hybrids should be heterozygous for all chromosomes except for the maternally inherited mitochondrial and sexual W chromosomes. To evaluate whether plant preference is determined by these genetic loci, we cultivated the two hybrids and the two parental strains in triplicate on an artificial diet and recorded several phenotypic traits such as weight over time, survival rate, emerging rate, developmental time, and sex ratio. Then, the same performance experiment was carried out on corn plants. Surprisingly, on the artificial diet, the two hybrid genotypes were both more performant than the two parental strains in terms of survival rate, pupal emerging rate, and developmental time, whereas they were intermediate to the inbred parental strains in pupal weight. On the corn plant diet, both hybrid genotypes outperformed the two parental strains in larval weight. Although these asymmetrical results revealed that mitochondrial or sex‐linked haplotypes alone cannot explain the performance differences, they suggested a heterosis effect in FAW. A reduction of the female number for the CR genotype and the decreased F1 offspring reproduction in both hybrids suggested the possibility of Haldane's rule, which might be explained by the dominance model. [ABSTRACT FROM AUTHOR]

Blue honeysuckle (Lonicera caerulea) is a circumpolar species complex with representatives in Europe, Asia, and North America. Although honeysuckles (Lonicera spp.) from Eurasia have a history of invasiveness in North America, farmers and homeowners are interested in growing nonnative blue honeysuckle hybrids because of their edible blue fruits. To assess whether these cultivars and closely related native blue honeysuckles (Lonicera caerulea subsp. villosa) might have similar growth and fecundity, we planted five nonnative cultivars of blue honeysuckle and five native genotypes in a common garden in Orono, ME, USA, along with invasive red-fruited honeysuckles [Tatarian honeysuckle (Lonicera tatarica) and European fly honeysuckle (Lonicera xylosteum)] for comparison. Rooted cuttings were planted into a field plot in Jun 2016 and fully maintained during the first season; thereafter, maintenance consisted of weeding once annually. Seventy-three percent of native blue honeysuckle plants survived to the end of the study, whereas survival and growth of nonnative cultivars were more robust. In 2021, nonnative cultivars had an average height of 81 cm and width of 86 cm, which were 2.8 times the height and 2.9 times the width of surviving native plants. The estimated canopy volumes of nonnative blue honeysuckles were an average of 20 times those of their native counterparts. The bloom periods of native and nonnative blue honeysuckles overlapped considerably. However, only seven of the 22 living native plants produced fruits in 2021, with an average of three fruits per plant among them. In contrast, nearly all plants of the nonnative cultivars produced fruits, with an average of 616 fruits per plant. In comparison, the red-fruited invasives had an average of 9739 fruits per plant. Native blue honeysuckles produced very few seeds, whereas nonnative cultivars had an average of 13,918 seeds per plant, which was approximately one-fourth the number produced by invasive red-fruited honeysuckles. We concluded that native and nonnative genotypes of blue honeysuckle differ strikingly in survival, growth, and production of fruits and seeds. However, invasive red-fruited honeysuckles grew faster with higher fecundity than nonnative blue honeysuckles in our full-sun landscape. Because bloom times overlapped substantially between native and nonnative blue honeysuckles, the potential for gene flow to occur from planted cultivars into native populations merits consideration. Several possible explanations of differences in performance among blue honeysuckles include hybrid vigor of cultivars or shallow rooting or poor adaptability of native genotypes to the environment of the common-garden trial. Our results, which demonstrated that nonnative blue honeysuckles are likely to be distinct from their native relatives in terms of competitiveness and fecundity, suggest that caution is warranted during the introduction and cultivation of agricultural genotypes. [ABSTRACT FROM AUTHOR]

Pigeonpea [Cajanus cajan (L.) Mill.] may have cross- or self-pollination that allows the use of hybrids or improved genotypes by conventional breeding approaches in pigeonpea production. The objectives of this research were to: 1) compare the agronomic performance of a hybrid vs. breeding lines (BLs) developed by pedigree and bulk methods, and 2) determine if there were average and useful heterosis and heterobeltiosis for quantitative traits. The hybrid 13KLAF1 and UPE-1, UPE-2, UPE-3, UPE-4, UPE-5 BLs, their parents (13KPP-264-05 and 'Lázaro'), and one early maturity check 'ICPL 86012' were evaluated in field trials in Isabela and Lajas, PR. Data of plant height, days to flowering and harvest, seed yield, and weight of 100 dry-seeds were noted for all genotypes. There were no significant differences between 13KLAF1 and UPE BLs for plant height in both locations. 'Lázaro' was late maturity in Isabela (157 days) and Lajas (124 days), as expected. The weight of 100 seeds for all genotypes did not reach values more than 18.5 and 16.3 g such as those observed for 13KPP-264-05 in Isabela and Lajas, respectively. The higher seed yields were observed for 13KLAF1 (3112 kg·ha-1), UPE-4 (2970 kg·ha-1), and 'ICPL 86012' (2739 kg·ha-1) in Isabela, whereas 13KLAF1 (1599 kg·ha-1) and 'ICPL 86012' (1450 kg·ha-1) produced the higher yields in Lajas. The 13KLAF1 showed an average heterosis and heterobeltiosis of 87% and 60%, and 78% and 30% for seed yield in Isabela and Lajas, respectively. The useful heterosis was >125% in both locations. [ABSTRACT FROM AUTHOR]

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Despite hybrid dominance contributing to the genetic improvement of crops, little is known about heterosis and inheritance patterns of endogenous substances in sorghum (Sorghum bicolor (L.) Moench) root bleeding sap. In this study, six sterile and six restorer lines of sorghum and 36 hybrid sorghum combinations formulated as incomplete double-row crosses were selected as test materials, and heterosis, combining ability, heritability, and their interrelationships of root bleeding sap endogenous substances in different hybrid sorghum combinations and their parents were investigated. The results showed that the root bleeding sap of the F1 generation of hybrid sorghum had a high heterosis in both soluble sugar content and amino acid content at the flowering stage, and the average high-parent heterosis was 129.34% and 74.57%, respectively. Indole-3-acetic acid (IAA), cytokinins (CTK), gibberellic acid (GA3), abscisic acid (ABA), soluble sugar, amino acid, and root bleeding intensity were mainly affected by non-additive genetic effects of the genes. Soluble protein was affected by additive genetic effects of the genes and had a high narrow heritability (75.50%), which could be selected at low generations in breeding. The combining ability analyses showed that the sterile lines 521A and 170A, and the restorer lines Ji318R and 0–30 were promising parents with high general combining ability. Correlation analysis showed that all endogenous substances of root bleeding sap were positively correlated with the sum of parental general combining ability (GCA) at highly significant levels, and IAA, CTK, GA3, ABA, soluble sugar, amino acid, and root bleeding intensity were positively correlated with male GCA at significant or highly significant levels. Therefore, the GCA of the restorer lines root bleeding sap endogenous material or the sum of both parents' GCA can be used to predict the performance of wounding endogenous material in the F1 generation of hybrid sorghum. Overall, this study results can help elucidate heterosis mechanisms of root bleeding sap endogenous material and improve sorghum quality. [ABSTRACT FROM AUTHOR]

The present studied carried out at Sakha Agricultural Research Station, Cotton Research Institute, Agricultural Research Center, Egypt, during 2022 and 2023 growing summer, during 2022 growing season, six cotton varieties of cotton belong to (Gossypium barbadense L.) were sowing and crossed in a half diallel mating design produce 15 F1 hybrids. The F1 hybrids and parents growing in 2023 season at randomized complete blocks design with three replications. The results showed that the squares of the genotypes, parents as well as crosses were highly significant for all traits studied with boll weight trait parents. The parental genotypes Giza 88 and Giza 92 gave significant (desirable) GCA effects for most fiber properties. Karshenky and Australy 13 showed GCA positive significant effects of most yield traits, this direction is desirable. Both of Giza 88 x Giza 86 and Australy 13 x Karshenky crosses recorded significant (desirable) SCA effects for most yield and fiber properties. Desirable relative to midand better-parent for some yield traits were found for the crosses, Giza 88 x Giza 86 and Australy 13 x Karshenky while, the crosses Giza 92 x Pima S7 and Giza 92 x Karshenky indicated desirable for some studied fiber properties. Non-additive genetic variances were larger than the additive genetic variance with respect to all traits studied. The broad sense heritability of seed cotton yield per plant was the highest value (93.91%) while the lowest value was recorded to boll weight (50.51%). Generally, Karshenky and Australy 13 could be used in breeding programs for improving high yielding varieties, while Giza 88 and Giza 92 could be considered as excellent parents for breeding programs to produce new varieties characterized with best fiber properties. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) is one of the most demanded grain crops in the world. Currently, production has exceeded one billion tons and is increasing by 3–5% annually. Such growth is due to the genetic potential of the crop and the use of heterosis F1 hybrids in production. However, the need to produce first-generation seed annually poses significant challenges and is an economically costly technology. A solution to this problem may be the transfer of the asexual (apomictic) mode of reproduction to maize from its wild relative, eastern gamagrass (Tripsacum dactyloides L.). In this work, we report the production of 56-chromosome apomictic hybrids of maize (Zea mays L.) with eastern gamagrass (T. dactyloides L.) with restored anther fertility. The mode of reproduction of the plant was confirmed by counting chromosomes and sequencing the nuclear gene (Pox3) and chloroplast tRNA-Leu (trnL) gene. These apomictic hybrids had karyotypes of 2n = 56 = [(10Zm(573MB) + 36Td) + 10Zm(611CB)] and 2n = 56 = [(10Zm(611CB) + 36Td) + 10Zm(611CB)]. The resulting hybrids can be widely used as a fodder crop. [ABSTRACT FROM AUTHOR]

The presence of variability in phenotypic traits is of less significance in vegetable breeding including okra. Meanwhile, the development of hybrids offers an opportunity to enhance productivity and introduce desired characteristics through variation. A diallel analysis was conducted on five advanced breeding lines (Parents—F8) during Rabi [monsoon] 2020, to assess the combining ability and ascertain the magnitude of heterosis for yield and its attributes. The seeds of parents (P1, P2, P3, P4 and P5), 20 hybrids and a commercial check were sown in Kharif [winter] 2021 for evaluation. Statistical analysis was performed to determine the extent of heterosis, general combining ability (GCA) and specific combining ability (SCA). The results illustrated that parent 1 (P1) and parent 3 (P3) were better combiners for key yield characters, while crosses P1 × P2, P2 × P3, P4 × P3, P3 × P1, P3 × P2, P4 × P1, P1 × P4 and P5 × P2 exhibited as desirable specific combiners for yield attributes. The combining ability outcomes disclosed that GCA variances remained lesser than SCA, indicating non-additive gene action. The cross combinations with better heterosis over standard cultivars can be tested for superior and stable performance across different environments. In addition, the study highlights the importance of considering diverse parents and their gene effects in hybrid development. [ABSTRACT FROM AUTHOR]

Summary: Hybridization, the process of crossing individuals from diverse genetic backgrounds, plays a pivotal role in evolution, biological invasiveness, and crop breeding.At the transcriptional level, hybridization often leads to complex nonadditive effects, presenting challenges for understanding its consequences. Although standard transcriptomic analyses exist to compare hybrids to their progenitors, such analyses have not been implemented in a software package, hindering reproducibility.We introduce hybridexpress, an R/Bioconductor package designed to facilitate the analysis, visualization, and comparison of gene expression patterns in hybrid triplets (hybrids and their progenitors). hybridexpress provides users with a user‐friendly and comprehensive workflow that includes all standard comparative analyses steps, including data normalization, calculation of midparent expression values, sample clustering, expression‐based gene classification into categories and classes, and overrepresentation analysis for functional terms.We illustrate the utility of hybridexpress through comparative transcriptomic analyses of cotton allopolyploidization and rice root trait heterosis. hybridexpress is designed to streamline comparative transcriptomic studies of hybrid triplets, advancing our understanding of evolutionary dynamics in allopolyploids, and enhancing plant breeding strategies. hybridexpress is freely accessible from Bioconductor (https://bioconductor.org/packages/HybridExpress) and its source code is available on GitHub (https://github.com/almeidasilvaf/HybridExpress). [ABSTRACT FROM AUTHOR]

Simple Summary: The application of advantages can not only effectively improve the disease resistance and meat quality of livestock, but also significantly promote the reproduction and growth of livestock and poultry. A total of 78,579 SNPs and 42,018 ROHs were detected from autosomal samples of 380 meat rabbits after quality control for whole-gene association analysis using a mixed linear model. The homozygosity of the population genome was evaluated, and the number, length, frequency, and distribution of ROHs in the population were analyzed. Notably, candidate genes associated with growth and development were found in the high-frequency ROH region. In this study, the identified candidate genes can be used as molecular markers for assisted selection in meat rabbits. At the same time, the inbreeding situation based on ROH evaluation can provide reference for breeding and breeding preservation of meat rabbits. The application of heterosis can not only effectively improve the disease resistance and meat quality of livestock, but also significantly enhance the reproduction and growth of livestock and poultry. We conducted genome-wide association studies using data from F2 crossbred meat rabbits to screen out candidate genes with significant dominant effects associated with economic trait variation. High-throughput sequencing technology was used to obtain SNPs covering the whole genome to evaluate the homozygosity of the population genome, and analyze the number, length, frequency, and distribution of ROHs in the population. Candidate genes related to economic traits of meat rabbits were searched based on high-frequency ROH regions. After quality control filtering of genotype data, 380 F2 crossbred rabbits were identified with 78,579 SNPs and 42,018 ROHs on the autosomes. The fitting of the Logistic growth curve model showed that 49-day-old rabbits were a growth inflection point. Then, through genome-wide association studies, 10 SNP loci and seven growth trait candidate genes were found to be significantly related to body weight in meat rabbits at 84 days of age. In addition, we revealed the functional roles and locations of 20 candidate genes in the high-frequency ROH region associated with economic traits in meat rabbits. This study identified potential genes associated with growth and development in the high-frequency ROH region of meat rabbits. In this study, the identified candidate genes can be used as molecular markers for assisted selection in meat rabbits. At the same time, the inbreeding situation based on ROH assessment can provide reference for breeding and breeding preservation of meat rabbits. [ABSTRACT FROM AUTHOR]

How organisms respond to environmental stress is a key topic in evolutionary biology. This study focused on the genomic evolution of Laburnicola rhizohalophila, a dark-septate endophytic fungus from roots of a halophyte. Chromosome-level assemblies were generated from five representative isolates from structured subpopulations. The data revealed significant genomic plasticity resulting from chromosomal polymorphisms created by fusion and fission events, known as dysploidy. Analyses of genomic features, phylogenomics, and macrosynteny have provided clear evidence for the origin of intraspecific diploid-like hybrids. Notably, one diploid phenotype stood out as an outlier and exhibited a conditional fitness advantage when exposed to a range of abiotic stresses compared with its parents. By comparing the gene expression patterns in each hybrid parent triad under the four growth conditions, the mechanisms underlying growth vigor were corroborated through an analysis of transgressively upregulated genes enriched in membrane glycerolipid biosynthesis and transmembrane transporter activity. In vitro assays suggested increased membrane integrity and lipid accumulation, as well as decreased malondialdehyde production under optimal salt conditions (0.3 M NaCl) in the hybrid. These attributes have been implicated in salinity tolerance. This study supports the notion that hybridization-induced genome doubling leads to the emergence of phenotypic innovations in an extremophilic endophyte. The dark septate endophytes prefer extreme conditions. Here, Li et al. show that diploidization-driven heterosis confers a fitness advantage to Laburnicola rhizohalophila under abiotic stresses. [ABSTRACT FROM AUTHOR]

When two species hybridize, the two parental genomes are brought together and some alleles might interact for the first time. To date, the extent of the transcriptomic changes in first hybrid generations, along with their functional outcome constitute an important knowledge gap, especially in parasite species. Here we explored the molecular and functional outcomes of hybridization in first-generation hybrids between the blood fluke parasites Schistosoma haematobium and S. bovis. Through a transcriptomic approach, we measured gene expression in both parental species and hybrids. We described and quantified expression profiles encountered in hybrids along with the main biological processes impacted. Up to 7,100 genes fell into a particular hybrid expression profile (intermediate between the parental expression levels, over-expressed, under-expressed, or expressed like one of the parental lines). Most of these genes were different depending on the direction of the parental cross (S. bovis mother and S. haematobium father or the reverse) and depending on the sex. For a given sex and cross direction, the vast majority of genes were hence unassigned to a hybrid expression profile: either they were differentially expressed genes but not typical of any hybrid expression profiles or they were not differentially expressed neither between hybrids and parental lines nor between parental lines. The most prevalent profile of gene expression in hybrids was the intermediate one (24% of genes assigned to a hybrid expression profile). These results suggest that transcriptomic compatibility between S. haematobium and S. bovis remains quite high. We also found support for an over-dominance model (over- and under-expressed genes in hybrids compared to parental lines) potentially associated with heterosis. In females in particular, processes such as reproductive processes, metabolism and cell interactions as well as signaling pathways were indeed affected. Our study hence provides new insight on the biology of Schistosoma hybrids with evidences supporting compatibility and heterosis. Author summary: When two species, composed of different parental genetic material, manage to produce a viable offspring, new allelic interactions might arise. We do not know much about how genes are expressed in such hybrids compared to their parental species, especially for parasite species. Here we investigated gene expressions in first generation hybrids of two blood fluke parasites: Schistosoma haematobium and S. bovis. We quantified and assigned in five typical profiles genes expressed in first generation hybrids (i.e., intermediate between the parental expression levels, over-expressed, under-expressed, or expressed like one of the parental lines) and investigated their associated biological processes. Gene expressions in hybrids revealed a substantial fraction of genes being unassigned (once the sex and the direction of the cross from which a hybrid resulted were controlled) which were differentially expressed genes but not typical of any expression profiles or were not differentially expressed neither between hybrids and parental lines nor between parental lines. Among assigned genes, we recorded a predominance of genes being expressed at an intermediate level in hybrids compared to both parental species, hence highlighting the compatibility between the two species. Interestingly, we found, in particular in female hybrids, genes over- and under-expressed compared to parental lines. Those synergetic expression profiles are usually associated with heterosis in a model called over-dominance. At the functional level, our results provide evidence for compatibility between parental lines and potential heterosis in hybrids with biological processes expressed in hybrids involved in signaling pathways, energy intake, and reproduction. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) Fusarium ear rot (FER), which is caused by the fungal pathogen Fusarium verticillioides, is a major ear disease affecting maize production in China. Developing resistant maize hybrids is a cost‐effective and environmentally friendly method of reducing yield losses due to FER. Using the nail punch inoculation method, 17 highly resistant and 16 highly susceptible inbred lines were identified in this study, and a large‐scale maize hybrid consisting of 528 F1's was produced using a half‐diallel cross model. The hybrids were inoculated with F. verticillioides in 6 year–location environment combinations during 2020–2022. Our results showed that estimates of genotypic, environmental, and genotype × environment interaction variance components were very significant (p < 0.001). All the crosses generated from highly resistant inbred lines exhibited high kernel resistance, whereas those generated from highly susceptible inbred lines mostly exhibited high susceptibility to FER. Crosses between resistant and susceptible inbred lines showed intermediate resistance to FER. The general combining ability (GCA) effect was greater than the specific combining ability effect across multiple environments, indicating that the inheritance of FER resistance was mainly influenced by additive genetic effects. The correlation coefficient between the expected GCA value and hybrid resistance was 0.789, whereas that between the mid‐parent value and hybrid resistance was only 0.644. Inbred performance per se and their corresponding hybrids across multiple environments were significantly correlated (r = 0.823). However, no relationship was observed between the FER resistance of F1's and that of their parental heterotic groups. Core Ideas: In breeding, selecting parents with Fusarium ear rot (FER) resistance is more crucial than selecting the hybrids themselves.The additive effect is the main genetic component of ear rot in maize, whereas the non‐additive effect is minor.Additional inoculation tests for FER resistance are required for specific hybrid combinations.Hybrid resistance can be inferred based on the general combining ability of parental inbred lines.The additive effects of resistance genes in highly inbred lines are minor. [ABSTRACT FROM AUTHOR]

Current maize (Zea mays L.) breeding methods and the limited germplasm infusion and mixing may slow the rate of genetic gain in the future. Using inter‐heterotic group composites for maize inbred development has been questioned because of the issue of choosing appropriate testers. However, three observations can be revisited to facilitate the exploration of alternative methods. First, since the adoption of single‐cross hybrids and the establishment of heterotic groups, the amount of heterosis has only been increasing slightly. Second, genomic analysis indicated the frequencies of the favorable alleles had significantly increased after a century's breeding. Third, the divergence of maize heterotic groups was preceded by the merging of landraces and diverse inbreds, after which three major heterotic groups were established. The objective of this study was to design different scenarios to generate inter‐heterotic group composites and evaluate their usefulness in the commercial breeding program. We investigated two methods: the inter‐heterotic group composite method (termed as super population [SupPop]) and the modified SupPop method (ModiSP, that is, backcrossing SupPop lines with elite inbreds). The results showed that the best scenario for the SupPop method was to use the SupPop inbreds to cross with a tester from the B14 group. When all four heterotic groups were mixed, the favored tester was from stiff stalk. However, ModiSP showed a higher chance of producing the best yield performance. These empirical results suggest that solutions can be proposed to identify the testers so that using inter‐heterotic group composites for inbred development can be considered. Core Ideas: Alternative maize inbred development methods may be tested to enhance genetic gain.A large‐scale, empirical study was conducted to develop inbreds from the inter‐heterotic group composites.With appropriate testers, inter‐heterotic group composites can be considered for inbred development. [ABSTRACT FROM AUTHOR]

Background and Aim: There is a limited amount of research conducted on quail breeding domestically and internationally, particularly at the molecular level. This study aimed to detect single-nucleotide polymorphisms in the growth hormone (GH) and insulin-like growth factor-1 (IGF-1) genes across two quail varieties and their hybrids correlate these genetic factors with body weight (BW) and growth rate at 0 and 6 weeks, and assess crossing effects. Materials and Methods: White and Japanese quail were crossed. Simultaneously producing pure varieties and crosses (genotypes) was achieved through this breeding strategy. Fifty females from each genotype were randomly selected for blood sampling. Genomic DNA was extracted and amplified from the blood using the DNeasy blood kit (Qiagen, Germany). Nucleotide polymorphism between quail genotypes was determined through DNA sequencing. Results: Two types of alleles (A and B) for the GH gene in quails showed significant genotypic differences (AA, BB, and AB). The quail carried a mutated IGF-1 gene. For growth traits, substantial positive heterosis was detected. Conclusion: The genotype AA had the highest BW and weight gain. The white variety can act as a sire, and both white and Japanese varieties can function as dams to improve growth traits. The growth characteristics of the hybrids surpassed those of the original varieties. [ABSTRACT FROM AUTHOR]

Background: Carcass weight (HCW) and marbling (MARB) are critical for meat quality and market value in beef cattle. In composite breeds like Brangus, which meld the genetics of Angus and Brahman, SNP-based analyses have illuminated some genetic influences on these traits, but they fall short in fully capturing the nuanced effects of breed of origin alleles (BOA) on these traits. Focus on the impacts of BOA on phenotypic features within Brangus populations can result in a more profound understanding of the specific influences of Angus and Brahman genetics. Moreover, the consideration of BOA becomes particularly significant when evaluating dominance effects contributing to heterosis in crossbred populations. BOA provides a more comprehensive measure of heterosis due to its ability to differentiate the distinct genetic contributions originating from each parent breed. This detailed understanding of genetic effects is essential for making informed breeding decisions to optimize the benefits of heterosis in composite breeds like Brangus. Objective: This study aims to identify quantitative trait loci (QTL) influencing HCW and MARB by utilizing SNP and BOA information, incorporating additive, dominance, and overdominance effects within a multi-generational Brangus commercial herd. Methods: We analyzed phenotypic data from 1,066 genotyped Brangus steers. BOA inference was performed using LAMP-LD software using Angus and Brahman reference sets. SNP-based and BOA-based GWAS were then conducted considering additive, dominance, and overdominance models. Results: The study identified numerous QTLs for HCW and MARB. A notable QTL for HCW was associated to the SGCB gene, pivotal for muscle growth, and was identified solely in the BOA GWAS. Several BOA GWAS QTLs exhibited a dominance effect underscoring their importance in estimating heterosis. Conclusions: Our findings demonstrate that SNP-based methods may not detect all genetic variation affecting economically important traits in composite breeds. BOA inclusion in genomic evaluations is crucial for identifying genetic regions contributing to trait variation and for understanding the dominance value underpinning heterosis. By considering BOA, we gain a deeper understanding of genetic interactions and heterosis, which is integral to advancing breeding programs. The incorporation of BOA is recommended for comprehensive genomic evaluations to optimize trait improvements in crossbred cattle populations. [ABSTRACT FROM AUTHOR]

The wealth of sorghum genetic resources in Africa has not been fully exploited for cultivar development in the continent. Hybrid cultivars developed from locally evolved germplasm are more likely to possess a well-integrated assembly of genes for local adaptation, productivity, quality, as well as for defensive traits and broader stability. A subset of 560 sorghum accessions of known fertility reaction representing the major botanical races and agro-ecologies of Ethiopia were characterized for genetic, agronomic and utilization parameters to lay a foundation for cultivar improvement and parental selection for hybrid breeding. Accessions were genotyped using a genotyping by sequencing (GBS) generating 73,643 SNPs for genetic analysis. Significant genetic variability was observed among accessions with Admixture and Discriminant Analysis of Principal Components where 67% of the accessions fell into K=10 clusters with membership coefficient set to > 0.6. The pattern of aggregation of the accessions partially overlapped with racial category and agro-ecological adaptation. Majority of the non-restorer (B-line) accessions primarily of the bicolor race from the wet highland ecology clustered together away from two clusters of fertility restorer (R-line) accessions. Small members of the B accessions were grouped with the R clusters and in vice-versa while significant numbers of both B and R accessions were spread between the major clusters. Such pattern of diversity along with the complementary agronomic data based information indicate the potential for heterosis providing the foundation for initiating hybrid breeding program based on locally adapted germplasm. [ABSTRACT FROM AUTHOR]

TGF-β1/Smads is a classic signaling pathway, which plays important roles in the development process of organisms. Black porgy Acanthopagrus schlegelii and red porgy Pagrus major are valuable economic fishes, and their hybrid offspring show excellent heterosis traits. Yet the molecular regulation mechanism of the heterosis traits is less clear. Here, we explored the TGF-β1/Smads pathway's molecular genetic information for heterosis in A. schlegelii ♂ × P. major ♀ (AP) and A. schlegelii ♀ × P. major ♂ (PA) in terms of growth and development. The mRNA expression levels of TGF-β1, TβR-I, TβR-II, and Smad2 genes in different developmental stages of A. schlegelii were detected. Furthermore, the expression levels of TGF-β1, TβR-I, TβR-II, and Smad2 genes in different tissues of adult (mRNA level) and larva (mRNA and protein level) of A. schlegelii, P. major, and their hybrids were determined by both real-time quantitative PCR and Western blot techniques. The results indicated the ubiquitous expression of these genes in all developmental stages of A. schlegelii and in all tested tissues of A. schlegelii, P. major, and its hybrids. Among them, the mRNA of TGF-β1, TβR-I, and TβR-II genes is highly expressed in the liver, gill, kidney, and muscle of black porgy, red porgy, and their hybrid offspring. There are significant changes in gene and protein expression levels in hybrid offspring, which indirectly reflect hybrid advantage. In addition, there was no correlation between protein and mRNA expression levels of Smad2 protein. The results provide novel data for the differential expression of growth and development genes between the reciprocal hybridization generation of black porgy and red porgy and its parents, which is conducive to further explaining the molecular regulation mechanism of heterosis in the growth and development of hybrid porgy. [ABSTRACT FROM AUTHOR]

The present experiment was conducted in bhindi / okra to observe the extent of heterosis for eight characters of plant and fruit yield traits through diallel analysis. The characters consist of plant height (cm), number of primary branches per plant, node at which 1st flower appears, number of nodes on main stem, internodal length, days to 50% flowering, pod yield per plant (g) and pod yield per hectare (q/ha). The experimental material comprised of 66 F1 hybrids developed from crossing 12 okra genotypes in diallel crossing excluding reciprocals. Out of eight characters studied, plant height, number of branches per plant and number of nodes on main stem are growth determining features. They generally decide the fruit/pod bearing surface of the okra plant. Therefore, Positive heterosis is desirable for plant height, number of branches per plant, number of nodes on main stem including fruit yield per plant and fruit yield per hectare but negative heterosis is profitable for node at which 1st flower appears, intermodal length and days to 50% flowering. Out of 66 F1, 50, 32 and 38 hybrids showed significant heterosis positively over mid parent, better parent and standard check respectively for fruit yield per plant and fruit yield per hectare and the highest was reported in hybrids IC-45831 ×IC-43733 subsequently IC-45831 ×Pusa A-4. [ABSTRACT FROM AUTHOR]

Two important characteristics of metapopulations are extinction–(re)colonization dynamics and gene flow between subpopulations. These processes can cause strong shifts in genome-wide allele frequencies that are generally not observed in "classical" (large, stable, and panmictic) populations. Subpopulations founded by one or a few individuals, the so-called propagule model, are initially expected to show intermediate allele frequencies at polymorphic sites until natural selection and genetic drift drive allele frequencies toward a mutation–selection–drift equilibrium characterized by a negative exponential-like distribution of the site frequency spectrum. We followed changes in site frequency spectrum distribution in a natural metapopulation of the cyclically parthenogenetic pond-dwelling microcrustacean Daphnia magna using biannual pool-seq samples collected over a 5-yr period from 118 ponds occupied by subpopulations of known age. As expected under the propagule model, site frequency spectra in newly founded subpopulations trended toward intermediate allele frequencies and shifted toward right-skewed distributions as the populations aged. Immigration and subsequent hybrid vigor altered this dynamic. We show that the analysis of site frequency spectrum dynamics is a powerful approach to understand evolution in metapopulations. It allowed us to disentangle evolutionary processes occurring in a natural metapopulation, where many subpopulations evolve in parallel. Thereby, stochastic processes like founder and immigration events lead to a pattern of subpopulation divergence, while genetic drift leads to converging site frequency spectrum distributions in the persisting subpopulations. The observed processes are well explained by the propagule model and highlight that metapopulations evolve differently from classical populations. [ABSTRACT FROM AUTHOR]

The limited knowledge about the inheritance of traits in roses makes the efficient development of rose varieties challenging. In order to achieve breeding goals, the inheritance of traits needs to be explored. Additionally, for the inheritance of a trait like scent, which remains a mystery, it is crucial to know the success of parental traits in transmitting them to the next generation. Understanding this allows for accurate parental selection, ensuring sustainability in meeting market demand and providing convenience to breeders. The aim of this study was to assess the success of cross-combinations between scented old garden roses and hybrid tea roses used in cut roses in transferring their existing traits, with the objective of achieving scented cut roses. The evaluated traits included recurrent blooming, flower stem length, flower diameter, petal number, scent, and bud length of both parents and progenies. The inheritance of these traits was evaluated through theoretical evaluations, including calculating heterosis and heterobeltiosis and determining narrow-sense heritability. The combinations and examined traits were assessed using a hierarchical clustering heat map. The results of this study indicated that flower stem length, flower diameter, petal number, and bud length traits had a moderate degree of narrow-sense heritability, suggesting the influence of non-additive genes on these traits. This study observed a low success rate in obtaining progenies with scent in cross combinations between cut roses and old garden roses, indicating the challenges in obtaining scented genotypes. The discrepancy between the observed phenotypic rates and the expected phenotypic and genotypic rates, according to Punnett squares, suggests that the examined traits could be controlled by polygenic genes. The progenies were observed to exhibit a greater resemblance to old garden roses than hybrid tea roses and did not meet the commercial quality standards for cut flowers. The significant negative heterosis observed in 65.12% (petal number) and 99.61% (flower diameter) of the progenies provides strong evidence of resemblance to old garden roses. Considering these findings, it is recommended to consider old garden roses as parents, taking into account their suitability for other breeding objectives. [ABSTRACT FROM AUTHOR]

The present research was conducted to determine the mean performance of parental variety and lines and heterotic effects in F1 hybrids of upland cotton. Six parental genotypes were included in the present study: Yulduz, Niso, Guliston, SS-BK, T-1336, and T-1391. All six parents were randomly crossed, and ten F1 hybrids were developed for evaluation. The experiment was laid out in a randomized complete block design with three replications. The mean squares from the analysis of variance revealed that parents and F1 hybrids differed significantly in their mean performance regarding all the traits studied, except those hybrids were non-significant for staple length. The importance of heterotic effects was evident from the significant mean squares of parents vs. hybrids. The mean performance revealed that F1 hybrids performed better over the parents for the traits due to the manifestation of heterotic effects. The crosses Niso x Yulduz among the hybrids formed more bolls per plant. Also, they gave yet Niso x Yulduz maximum lint %, and longer fiber was measured in Yulduz x Guliston and Guliston x Yulduz. Also, T-1391 x Niso va SSB K-1 x Niso o formed a higher boll weight. The parental performance was not reflected in hybrid combinations; therefore, the potentiality of parents per se may not be taken for granted for expecting similar performance in the F1 hybrids. The heterotic effects of the hybrids revealed that at least three hybrids viz. Niso x Yulduz va Niso x Guliston were identified, and they exhibited relative heterosis above 50% and heterobeltiosis over 45% for bolls per plant. The hybrids also expressed a fair amount of heterosis for boll weight, lint %, and fiber length. The high heterotic effects for bolls per plant, boll weight, lint %, and fiber length highlight the promising potential for heterosis breeding in upland cotton, offering a bright outlook for future research. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The basic mechanism of heterosis has not been systematically and completely characterized. In previous studies, we obtained three economically important fishes that exhibit rapid growth, WR (WCC ♀ × RCC ♂), WR-II (WR ♀ × WCC ♂), and WR-III (WR-II ♀ × 4nAU ♂), through distant hybridization. However, the mechanism underlying this rapid growth remains unclear. In this study, we found that WR, WR-II, and WR-III showed muscle hypertrophy and higher muscle protein and fat contents compared with their parent species (RCC and WCC). Candidate genes responsible for this rapid growth were then obtained through an analysis of 12 muscle transcriptomes. Notably, the mRNA level of mstnb (myostatin b), which is a negative regulator of myogenesis, was significantly reduced in WR, WR-II, and WR-III compared with the parent species. To verify the function of mstnb, a mstnb-deficient mutant RCC line was generated using the CRISPR-Cas9 technique. The average body weight of mstnb-deficient RCC at 12 months of age was significantly increased by 29.57% compared with that in wild-type siblings. Moreover, the area and number of muscle fibers were significantly increased in mstnb-deficient RCC, indicating hypertrophy and hyperplasia. Furthermore, the muscle protein and fat contents were significantly increased in mstnb-deficient RCC. The molecular regulatory mechanism of mstnb was then revealed by transcription profiling, which showed that genes related to myogenesis (myod, myog, and myf5), protein synthesis (PI3K-AKT-mTOR), and lipogenesis (pparγ and fabp3) were highly activated in hybrid fishes and mstnb-deficient RCC. This study revealed that low expression or deficiency of mstnb regulates somatic growth by promoting myogenesis, protein synthesis, and lipogenesis in hybrid fishes and mstnb-deficient RCC, which provides evidence for the molecular mechanism of heterosis via distant hybridization. [ABSTRACT FROM AUTHOR]

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Abstract Background Inter-subspecific hybrid rice represents a significant breakthrough in agricultural genetics, offering higher yields and better resilience to various environmental stresses. While the utilization of these hybrids has shed light on the genetic processes underlying hybridization, understanding the molecular mechanisms driving heterosis remains a complex and ongoing challenge. Here, chromatin immunoprecipitation-sequencing (ChIP-seq) was used to analyze genome-wide profiles of H3K4me3 and H3K27me3 modifications in the inter-subspecific hybrid rice ZY19 and its parents, Z04A and ZHF1015, then combined them with the transcriptome and DNA methylation data to uncover the effects of histone modifications on gene expression and the contribution of epigenetic modifications to heterosis. Results In the hybrid, there were 8,126 and 1,610 different peaks for H3K4me3 and H3K27me3 modifications when compared to its parents, respectively, with the majority of them originating from the parental lines. The different modifications between the hybrid and its parents were more frequently observed as higher levels in the hybrid than in the parents. In ZY19, there were 476 and 84 allele-specific genes with H3K4me3 and H3K27me3 modifications identified, representing 7.9% and 12% of the total analyzed genes, respectively. Only a small portion of genes that showed differences in parental H3K4me3 and H3K27me3 modifications which demonstrated allele-specific histone modifications (ASHM) in the hybrid. The H3K4me3 modification level in the hybrid was significantly lower compared to the parents. In the hybrid, DNA methylation occurs more frequently among histone modification target genes. Additionally, over 62.58% of differentially expressed genes (DEGs) were affected by epigenetic variations. Notably, there was a strong correlation observed between variations in H3K4me3 modifications and gene expression levels in the hybrid and its parents. Conclusion These findings highlight the substantial impact of histone modifications and DNA methylation on gene expression during hybridization. Epigenetic variations play a crucial role in controlling the differential expression of genes, with potential implications for heterosis.

Abstract Background Carcass weight (HCW) and marbling (MARB) are critical for meat quality and market value in beef cattle. In composite breeds like Brangus, which meld the genetics of Angus and Brahman, SNP-based analyses have illuminated some genetic influences on these traits, but they fall short in fully capturing the nuanced effects of breed of origin alleles (BOA) on these traits. Focus on the impacts of BOA on phenotypic features within Brangus populations can result in a more profound understanding of the specific influences of Angus and Brahman genetics. Moreover, the consideration of BOA becomes particularly significant when evaluating dominance effects contributing to heterosis in crossbred populations. BOA provides a more comprehensive measure of heterosis due to its ability to differentiate the distinct genetic contributions originating from each parent breed. This detailed understanding of genetic effects is essential for making informed breeding decisions to optimize the benefits of heterosis in composite breeds like Brangus. Objective This study aims to identify quantitative trait loci (QTL) influencing HCW and MARB by utilizing SNP and BOA information, incorporating additive, dominance, and overdominance effects within a multi-generational Brangus commercial herd. Methods We analyzed phenotypic data from 1,066 genotyped Brangus steers. BOA inference was performed using LAMP-LD software using Angus and Brahman reference sets. SNP-based and BOA-based GWAS were then conducted considering additive, dominance, and overdominance models. Results The study identified numerous QTLs for HCW and MARB. A notable QTL for HCW was associated to the SGCB gene, pivotal for muscle growth, and was identified solely in the BOA GWAS. Several BOA GWAS QTLs exhibited a dominance effect underscoring their importance in estimating heterosis. Conclusions Our findings demonstrate that SNP-based methods may not detect all genetic variation affecting economically important traits in composite breeds. BOA inclusion in genomic evaluations is crucial for identifying genetic regions contributing to trait variation and for understanding the dominance value underpinning heterosis. By considering BOA, we gain a deeper understanding of genetic interactions and heterosis, which is integral to advancing breeding programs. The incorporation of BOA is recommended for comprehensive genomic evaluations to optimize trait improvements in crossbred cattle populations.

Future breeding is likely to involve the detection and removal of deleterious alleles, which are mutations that negatively affect crop fitness. However, little is known about the prevalence of such mutations and their effects on phenotypic traits in the context of modern crop breeding. To address this, we examined the number and frequency of deleterious mutations in 350 elite maize inbred lines developed over the past few decades in China and the United States. Our findings reveal an accumulation of weakly deleterious mutations and a decrease in strongly deleterious mutations, indicating the dominant effects of genetic drift and purifying selection for the two types of mutations, respectively. We also discovered that slightly deleterious mutations, when at lower frequencies, were more likely to be heterozygous in the developed hybrids. This is consistent with complementation as a potential explanation for heterosis. Subsequently, we found that deleterious mutations accounted for more of the variation in phenotypic traits than nondeleterious mutations with matched minor allele frequencies, especially for traits related to leaf angle and flowering time. Moreover, we detected fewer deleterious mutations in the promoter and gene body regions of differentially expressed genes across breeding eras than in nondifferentially expressed genes. Overall, our results provide a comprehensive assessment of the prevalence and impact of deleterious mutations in modern maize breeding and establish a useful baseline for future maize improvement efforts.