Search Results (61)

The biosynthesis and accumulation of plant secondary metabolites are tightly regulated by environmental fluctuations, serving as a crucial interface mediating plant–environment interactions. Nevertheless, the phenotypic instability of secondary metabolism-related traits induced by environmental variability has hampered the precise breeding of stress-resistant cultivars. Pinus taeda is an key timber tree species in southern China, and its foliar catechins exhibit substantial stress-resistant potential. However, phenotypic variation driven by seasonal changes has limited the germplasm innovation and genetic selection of this species. In this study, 54 half-sib families of P. taeda were used as experimental materials. Combined with near-infrared spectroscopy (NIRS) and the BLUP model, we systematically analyzed the seasonal variation characteristics, genetic parameters of catechin content (CC), and genetic gains under different breeding strategies across four seasons. Our results demonstrated that family and season had extremely significant effects on CC (p < 0.001), whereas the season × family interaction effect was not significant, indicating that the genetic expression of CC is stable across seasons. CC was higher in spring and winter but lower in summer and autumn; specifically, the mean CC in summer was 47% lower than the peak value in spring (26.95 ± 0.46 μg·g⁻¹), reflecting a resource trade-off between growth and defense metabolism. Genetic parameter analysis revealed that family-mean heritability (0.373–0.714) was higher than individual heritability and within-family heritability, with August identified as the optimal selection season. The maximum genetic gain across the three breeding strategies (individual selection, family selection, and combined selection) reached 7.86%, among which individual selection exhibited the smallest fluctuation in genetic gain. Finally, three superior families and 14 superior individuals were screened out. This study elucidates the seasonal genetic pattern of foliar CC in P. taeda, clarifies the optimal selection stage and efficient breeding strategies, and provides theoretical guidance and material support for the genetic improvement, germplasm innovation, and resource utilization of secondary metabolic traits in this ecologically and economically important tree species. Full article

The genetic parameters at 6, 9 and 12 years were studied in two progeny trials (one half-sib and one full-sib) of silver fir (Abies alba Mill.) in Romania, in order to establish an appropriate breeding strategy for advancing second-generation seed orchards. The half-sib trial (HS) consists of 60 open-pollinated families of plus trees from four first-generation seed orchards, while the full-sib trial (FS) consists of 51 half-diallel crosses of 11 plus trees from one seed orchard. Tree height and diameter were found to be under moderate to strong genetic control at both the family and individual levels. Total height showed a higher percentage of additive genetic variance than diameter in both types of progenies. Additive genetic variances increased with age for the diameter (from 12% to 36%), while for the total height, it decreased (from 76% to 35%). In the HS trial, family heritability was higher than individual heritability for both traits. The highest values of heritability were obtained for total height, both at the individual (0.76–0.35) and family levels (0.88–0.63). In FS progenies, the estimates of the narrow-sense individual heritability were lower than those at the family level and remained almost constant over time. The additive age-age genetic correlations and genetic correlations among growth traits were more stable and stronger in FS progeny than in HS progenies. Expected genetic gains were calculated at individual and family levels for different breeding strategies. The highest genetic gain will be obtained through selection of the best parents. Genetic gain slightly varied over age and for progeny tests. The level of genetic diversity, calculated for selected parents based on the breeding values, was high, while the inbreeding coefficient reduced. Combining the backward selection strategy with SSR analyses allows optimization for seed orchard design in order to mitigate inbreeding depression risks and enhance genetic diversity in the next breeding generation. Full article

This study assessed phenotypic variation among open-pollinated half-sib families from a single relict population. Autochthonous silver fir (Abies alba Mill.) preserved in the Tisovik Reserve of Białowieża Forest represents the northeasternmost isolated relict population of the species in Europe. To secure its genetic resources and evaluate its breeding potential, a conservation plantation of open-pollinated half-sib families was established in the Hajnówka Forest District outside the natural species range. This study assessed the effects of half-sib family affiliation on the growth and phenotypic performance of almost two thousand 28–31-year-old trees representing 20 half-sib families and compared them with age-matched managed stands in the State Forests of Poland. Significant within- and among-family variation was observed for diameter at breast height (DBH) and height (H), while environmental factors had only marginal influence under the uniform site conditions of the plantation. Several half-sib families produced disproportionately high numbers of individuals with exceptional phenotypic performance, including DBH values exceeding 25 cm and height values surpassing those of managed stands. Based on a combined assessment of qualitative traits, selection differential, and 95th percentile values, 30 prototype plus trees were selected as sources of scions for establishing a future seed orchard. The outstanding growth parameters of these individuals correspond to stand ages of 40–65 years according to yield tables, despite their biological age of only 28–31 years. The results confirm the high breeding value and substantial genetic variability of the Tisovik population and demonstrate its potential for producing genetically diverse planting material adapted to lowland sites under changing climatic conditions. Full article

Sitka spruce (Picea sitchensis (Bong.) Carr.) is among the most commercially important tree species in European and North American forestry, and genetic improvement programmes are therefore essential for promoting its productivity and sustainability. This research emphasises the significance of the breeding programmes. The primary objective of this study was to provide more reliable information on family selection for the improvement programme of Sitka spruce by accounting for competition and environmental heterogeneity effects. Analyses in the present study were carried out on historical inventory data of height (HT) and diameter at breast height (DBH) from a half-sib progeny trial of Sitka spruce in Ireland. Tree measurement data were collected at ages 6, 12, 15 and 20 years. A mixed linear model incorporating spatial and competition terms was applied to estimate genetic parameters of the Sitka spruce population. The direct genetic effects of each family on its own phenotypes and the competition effect on its neighbour’s phenotype were examined over time. The study demonstrated an analytical approach for assessing both genetic as well as environmental aspects of competition in a Sitka spruce progeny trial. The combined model integrating competition and spatial terms (model CS) improved model fit compared with the basic model, which only included the random effects of genetic and experimental design factors (model B), with an AIC difference of up to 3609 between them. Residual error obtained from model CS was usually smaller than from model B, with the greatest reduction of 85%. Furthermore, model CS generally improved the estimation of heritability for growth traits, by up to 241, when compared with model B. In addition, genetic differences in competitive ability among families were also observed. Families with favourable combinations of direct genetic and competitive breeding values were suggested for selection in subsequent cycles of the breeding programme, i.e., families with relatively high direct genetic breeding value but low and consistent competitive breeding value over time. This work develops a practical framework to inform future family selection for Sitka spruce improvement programmes. Full article

To overcome the seasonal constraints of explant availability and facilitate genetic improvement in Catalpa ovata, this study established a dual-pathway in vitro regeneration system (encompassing adventitious shoot organogenesis and somatic embryogenesis) using mature zygotic embryos. We systematically evaluated the synergistic effects of maternal genotypes, plant growth regulators (PGRs), basal media, and the histone deacetylase inhibitor Trichostatin A (TSA). Genotype screening revealed significant divergence in regenerative potential, with the half-sib family 32F17 exhibiting superior responsiveness (84.7% callus induction). A high cytokinin-to-auxin ratio (ZA3 medium) optimally drove direct shoot organogenesis. For adventitious shoot proliferation, the addition of TDZ significantly improved the multiplication coefficient (up to 2.99 on ZB4 medium), although a physiological trade-off with shoot elongation was observed. In parallel, the application of 10 µM TSA significantly enhanced somatic embryogenesis from embryogenic calli, effectively alleviating the inhibitory constraints of exogenous PGRs. For rhizogenesis, the DKW basal medium proved superior to half-strength MS, with the ZE3 treatment (0.1 mg·L⁻¹ NAA + 0.1 mg·L⁻¹ IBA) yielding the highest rooting frequency (69.6%) and robust root architecture. Notably, while somatic embryo conversion remained recalcitrant, plantlets derived exclusively from the adventitious shoot organogenesis pathway were successfully acclimatized ex vitro. These transplanted plantlets exhibited consistently high survival rates (83.1–84.4%) across all tested genotypes, effectively overcoming the initial genotype-dependent recalcitrance. Collectively, this optimized protocol provides a reliable technical platform for the large-scale clonal propagation and biotechnological breeding of C. ovata. Full article

Reproductive inefficiency remains a major constraint in Penaeus vannamei hatcheries due to high rates of non-spawning females. This study presents the first two-generational quantitative genetic analysis of female reproductive performance under standardized SPF (Specific Pathogen-Free) conditions. A total of 986 females across two generations (2021–2022) from 198 full-sib and 68 half-sib families were evaluated. Traits analyzed included spawning frequency (SF), mean spawning interval (MSI), number of eggs laid for the first time (NE1), average spawning (AS), total spawning (TS), and spawning success (SS). Heritability estimates for SF, SS, and TS were moderate (0.30 ± 0.06, 0.23 ± 0.06 and 0.28 ± 0.07, respectively), while MSI, NE1, and AS showed low heritability (0.10–0.16). When analyzed separately by year, heritability estimates declined substantially for most traits in the second generation. Strong positive genetic correlations were observed between SF, MSI, NE1, AS, and TS, with pairwise estimates ranging from 0.82 to 0.99, indicating that these traits are under shared genetic control. Despite not being direct selection objects, all reproductive traits exhibited relative genetic progress (246–488% per generation), which is attributable to the high selection intensity applied to the parental generation. Our findings provide a robust foundation for integrating reproductive performance into breeding programs for P. vannamei, particularly under biosecurity and commercial feed-dominated conditions. Full article

(1) Background: In the Sudano-Sahelian zone of Cameroon, which is affected by drought and forest decline, Vachellia nilotica leaves and seeds are fodder for livestock. (2) Methods: A provenance and progeny study on growth performance and heritability of V. nilotica was carried out to provide a reliable database for tree selection, improvement programs, and the creation of future forested areas in this region. Open-pollinated seeds from 120 mother trees (10 half-sib families per provenance) representing twelve provenances, 50–100 km apart, were used for a progeny trial near Maroua, the Far North region of Cameroon. The experimental design was a Fisher block. (3) Results: The results reveal significant differences among provenances only for the number of leaves, and the variability was marked by coefficients of variation ranging from 0.24−0.63. Narrow-sense heritability was measured, varying from 0.01 ± 0.009 to 0.74 ± 0.02, and genetic gain reached 21.83 at the selection intensity of 5% for the number of leaves per plant. The phenotypic coefficient of variation varied between 14% and 90%. Half-sib families were classified into three subgroups using hierarchical ascending classification, and provenances were grouped into five groups using principal component analysis. (4) Conclusions: These results could contribute to initiating tree selection, but more provenances, longer-term experiments, and molecular genetic testing are needed to complement these nursery-level observations. Full article

Integrating perennial grain crops into agricultural systems can become a key milestone for increasing the provision of ecosystem services of food production systems. Intermediate wheatgrass is a novel perennial grain and forage crop that is undergoing domestication. Potential trade-offs between resource allocation and reproductive and vegetative plant structures can challenge the response to selection for both grain and forage production under dual-purpose use. Our goal was to understand the genetic relationship between grain and forage yield components, quantify potential trade-offs between vegetative and reproductive allocation, and optimize the response to selection under dual-purpose management. Phenological, grain, and forage traits were evaluated in 30 half-sib families across two field experiments conducted over three years. No trade-offs were detected between grain and forage yield traits, indicating that the simultaneous improvement of both traits is feasible. Grain yield per spike and spikes per plant are promising secondary traits for indirect selection, given their moderate-to-high heritability (h² = 0.58 and 0.41) and strong Pearson correlation coefficients with grain yield per plant (0.68 and 0.82). These traits could be assessed in the first year, increasing genetic gain per unit time. Intermediate wheatgrass germplasm could therefore be efficiently developed by shortening the time to first evaluation, using secondary traits, and performing selection under dual-purpose management. Full article

Pedunculate oak (Quercus robur L.) face increasing threats from drought and nutrient limitation under climate change, yet their genetic variation may have adaptive potential. We examined the responses of pedunculate oak (Quercus robur L.) half-sib progeny from five maternal trees (1, 12, 32, 57, and 60) to water stress (WS), nitrogen limitation (NL), and combined WS+NL. WS reduced leaf relative water content (RWC) by 18–32% in all families and decreased proline only in two families (233.57 and 209.1), while four families (63.12, 149.1, 303.32, and 339.57) showed 1.7–2.0-fold proline accumulation. Exposure to WS+NL inhibited height and diameter growth in family 339.57 and diameter growth in families 23.12, 303.32 and 405.60, relative to the control. NL decreased chlorophyll (Chl) in two families (23.12 and 405.60) 1.5-fold and increased carotenoids in one of them (405.60) and RWC by 29% and 12% in 23.12 and 303.32 families, respectively. ROS-scavenging activities of catalase (CAT), guaiacol-dependent peroxidase (POD), and superoxide dismutase (SOD) enzymes increased 1.4- to 26.7-fold across all families except 151.1. Overall, families 303.32 and 339.57 were the most resilient to WS, NL, and WS+NL, whereas 233.57 and 151.1 were the most sensitive to WS, 23.12 to NL, and 405.60 to both stresses. These results highlight the family-level variation in stress responses and provide a basis for selecting resilient oak genotypes for forestry and conservation. Full article

Gamba grass (Andropogon gayanus Kunth) is a promising forage alternative for Brazil’s Cerrado regions, attracting increasing research interest due to its potential to complement or replace widely planted species such as Urochloa and Megathyrsus. Despite the release of three cultivars, significant improvements in dry matter (DM) yield and forage quality are needed to fully realize its agronomic potential. This study aimed to evaluate genetic variability, estimate narrow sense heritability, and predict expected genetic gains for DM yield and key forage quality traits in two gamba grass populations derived from the cultivars BRS Sarandi and Planaltina. Trials were established in spring 2017 in Planaltina, DF, and evaluated during February–March 2018 and January–March 2019. Crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose (CEL), and hemicellulose (HEMIC) were quantified alongside DM yield. BRS Sarandi exhibited higher CP (12.3% vs. 9.8%) and lower NDF (57.1% vs. 63.4%), ADF (36.2% vs. 41.5%), CEL (20.8% vs. 23.7%), and HEMIC (20.9% vs. 21.9%) compared to Planaltina, while DM yield did not differ significantly between populations (4.57 t·ha⁻¹ vs. 4.50 t·ha⁻¹ per harvest, p > 0.05). Heritability estimates for individual harvests ranged from 0.31 to 0.68 for DM yield and 0.28 to 0.62 for quality traits, whereas multi-harvest models across years yielded lower estimates (0.07–0.27). Expected annual genetic gains were modest, with the highest predicted increase for CP (0.45% per year) and the largest decrease for NDF (−0.78% per year), reflecting the quantitative nature of trait inheritance and strong environmental influence. This study provides novel insights by simultaneously comparing two populations for multiple harvests and quantifying both yield and detailed forage quality traits, offering practical guidance for gamba grass breeding strategies. Results indicate that breeding programs should prioritize multiple selection cycles, precise phenotyping, genotypic and potentially genomic selection to accelerate improvement in both DM yield and forage quality, overcoming the constraints of low heritability and multi-trait selection. Full article

South African cattle comprise diverse breeds with distinct evolutionary histories, potentially reflecting differences in recombination landscapes. This study assessed genome-wide recombination rates and hotspots in Bonsmara (n = 190) and Nguni (n = 119) cattle using three-generation half-sib pedigrees genotyped with the Illumina Bovine SNP50 BeadChip. Phasing across 29 autosomes was conducted using SHAPEIT v2, and crossover events were inferred using the DuoHMM algorithm. The total number of crossover events detected was higher in Nguni (n = 8982) than in Bonsmara (n = 7462); however, the average recombination rate per 1 Mb window was significantly higher in Bonsmara (0.31) compared to Nguni (0.18) (p < 0.01). This apparent discrepancy reflects differences in genomic distribution and crossover clustering across breeds, rather than overall recombination frequency. A critical limitation of the study is the reliance on half-sib families with small family sizes, which may underestimate recombination rates due to limited meiotic sampling and increased variance in crossover detection. We identified 407 recombination hotspots in Bonsmara and 179 in Nguni, defined as intervals exceeding 2.5 standard deviations above the mean recombination rate. Genes such as PDE1B and FP which are associated with productions traits were located within hotspot-enriched regions. However, functional causality between these genes and local recombination activity remains unverified. Our results provide statistically supported evidence for breed-specific recombination patterns and hotspot distributions, underscoring the importance of incorporating recombination architecture into genetic improvement strategies for South African cattle. Full article

Perennial ryegrass (Lolium perenne L.) is a cornerstone forage species in temperate dairy systems worldwide, valued for its high yield potential, nutritive quality, and grazing recovery. However, current regional evaluation systems face challenges in accurately assessing complex traits like seasonal dry matter yield due to polygenic nature, environmental variability, and lengthy evaluation cycles. This review examines the evolution of perennial ryegrass evaluation systems, from regional frameworks—like Australia’s Forage Value Index (AU-FVI), New Zealand’s Forage Value Index (NZ-FVI), and Ireland’s Pasture Profit Index (PPI)—to advanced genomic prediction (GP) approaches. We discuss prominent breeding frameworks—F2 family, Half-sib family, and Synthetic Population—and their integration with high-throughput genotyping technologies. Statistical models for GP are compared, including marker-based, kernel-based, and non-parametric approaches, highlighting their strengths in capturing genetic complexity. Key research efforts include representative genotyping approaches for heterozygous populations, disentangling endophyte–host interactions, extending prediction to additional economically important traits, and modeling genotype-by-environment (G × E) interactions. The integration of multi-omics data, advanced phenotyping technologies, and environmental modeling offers promising avenues for enhancing prediction accuracy under changing environmental conditions. By discussing the combination of regional evaluation systems with GP, this review provides comprehensive insights for enhancing perennial ryegrass breeding and evaluation programs, ultimately supporting sustainable productivity of the dairy industry in the face of climate challenges. Full article

Forests face increasing threats due to climate change and anthropogenic pressures, exacerbating plant stress and disease susceptibility. Norway spruce (Picea abies (L.) H. Karst.), a key conifer species in European forestry, is particularly vulnerable. Developing innovative seed treatments to enhance tree resilience is crucial for sustainable forest management. Despite the growing interest in cold plasma (CP) technology for seed treatment, research on its long-term effects on trees, particularly Norway spruce, remains scarce. This study aimed to investigate the effects of pre-sowing CP treatment on Norway spruce seeds from 10 half-sib families over two vegetation seasons. Results indicate that CP treatment influenced key physiological and biochemical parameters in a genotype-specific and treatment duration-dependent manner (1 or 2 min). In some cases, CP-treated seedlings exhibited increased chlorophyll levels (e.g., increased chlorophyll a by up to 49% in some genotypes treated with CP for 1 min, and by up to 35% in those treated with CP for 2 min), reduced malondialdehyde (MDA) content in second-year samples (by up to 52% in some genotypes), and enhanced production of phenolics (by up to 21% in some genotypes in both treatment groups), suggesting improved stress tolerance. The 541 half-sib family is particularly noteworthy, as first-year seedlings exhibited increased levels of chlorophylls, flavonoids, and total phenols following a 2 min treatment. In contrast, second-year seedlings of the same family showed an increase in flavonoids and a reduction in MDA levels compared to the control, indicating a sustained and possibly age-modulated physiological response to CP exposure (2 min). However, responses varied across genetic backgrounds, highlighting the importance of genotype in determining treatment efficacy. These findings underscore the potential of CP technology as a tool for improving Norway spruce resilience and inform future strategies for seed enhancement in forestry. Full article

Microbial inoculation plays a crucial role in shaping plant physiological and biochemical responses, influencing growth, secondary metabolism, and stress-related markers. This study investigates the effects of PAH-degrading microorganisms (Pseudomonas putida, Sphingobium yanoikuyae, and Rhodotorula sphaerocarpa) on the growth, secondary metabolism, photosynthetic pigment, and stress-related biochemical markers of silver birch (Betula pendula Roth) seedlings from two half-sib families grown hydroponically. Results demonstrate family-dependent variations in the response to microbial treatments. In family 73, the growth of both shoots and roots was inhibited by certain microbial treatments, along with a decrease in key biochemical markers such as phenolic content and carotenoids. Conversely, family 86 showed no growth inhibition and exhibited improvements in some biochemical markers, including flavonoids and chlorophyll. Stress indicators, such as malondialdehyde (MDA) and soluble sugars, displayed contrasting patterns between families, with increased MDA observed in family 73 under certain microbial treatments. In contrast, family 86 did not exhibit an increase in MDA, suggesting differences in stress mitigation. Soluble sugars were generally reduced in family 73. Antioxidant enzyme activity further highlighted these family-specific responses, with variations in enzymes like ascorbate peroxidase (APX) and guaiacol peroxidase (POX) across treatments. Notably, significant interactions between family and microbial treatments were observed for several oxidative stress enzymes, underscoring the role of genotype in shaping the response to microbial stress. These findings highlight the genotype-dependent interactions between microbial inoculation and plant secondary metabolism, providing insights into the role of specifically selected microbial inoculation in stress mitigation and growth regulation. Full article

The dendrochronological parameters of 97 pedunculate oak (Quercus robur L.) trees including 20 plus trees (142-year-old on average) and four half-sib families for four of them were analyzed considering also specifically years of the most severe droughts that were identified using average monthly air temperature and precipitation data. The tree-ring width (TRW) was mostly affected by air temperature that had the largest cross-dating indices (CDI), up to 78% maximum. However, the 32-year Brückner–Egeson–Lockyer cycle (a climatic cycle of approximately 30–40 years that correlates with sunspot activity) was more reflected in the TRW dynamics in plus trees than precipitation and air temperature. A high-frequency of abnormal TRW was clearly observed during drought periods and in the following 2–3 years. Tree radial-growth reduction due to drought stress varied significantly between families. The resistance to drought based on TRW was higher in the maternal plus oak trees than in progeny. Drought resulted in reduced growth during the subsequent year(s); hence, the minimum growth occurred after the actual climate event. Autumn–winter precipitation and weather conditions were of the greatest importance at the onset of active vegetation in April and May. The influence of air temperature on oak growth was the largest in March (r = 0.39, p < 0.05). The strongest positive correlation between precipitation and growth (with r up to 0.38) was observed in May 2023. Plus trees had a high adaptive potential due to the stability of radial growth during drought with high resistance (Rt = 1.29) and resilience (Rs = 1.09) indexes. The offspring of families 1 (Rt = 0.89, Rs = 0.89) and 2 (Rt = 1.04, Rs = 0.87) had similar resistance and resilience, but the recovery indices (Rc) for offspring in families 1, 2 and 3 exceeded the recovery values for plus trees. For offspring in families 3 and 4, the index values were lower. The revealed responses of wood growth of plus trees to climatic parameters estimated as resistance (Rt), resilience (Rs) and recovery (Rc) indexes and similar responses in their progeny can be used in breeding pedunculate oak for wood growth productivity and drought resistance. Full article