Search Results (469)

‘Jinyan’ is an interspecific hybrid kiwifruit (Actinidia eriantha × A. chinensis). It is a large, yellow-fleshed fruit with good taste and long storage potential. It is commonly referenced that storage potential is linked to the harvest maturity of the fruit and the subsequent temperature management. Hence, the findings from research covering the maturation, storage temperatures, ripening, and quality of ‘Jinyan’ fruit from the same orchard across three seasons have been evaluated with an overall objective of defining harvest and storage criteria for ‘Jinyan’ fruit. Good postharvest performance includes fruit not becoming too soft too soon in storage and retaining firmness at shelf temperatures. It was confirmed that harvest maturity is critical to the good storage performance of ‘Jinyan’ kiwifruit. Harvest time significantly affected fruit softening during cold storage, and treatment with the ethylene action inhibitor 1-methylcyclopropene slightly delayed fruit softening. Harvesting much before 180 days after full bloom, or at <9% soluble solids content (SSC), resulted in high incidences of chilling injury (41.8–52.0% after 24 weeks of cold storage at 1 °C + 7 d at 20 °C). These chill-damaged, early-harvested fruits also had a high incidence of rot. Leaving the fruit on the vine much after this threshold reduced chilling injury, but increased the risk of rot on otherwise sound fruit (total rot incidence ranging from 25.9% to 89.0% depending on maturity at harvest). As well as chilling risk, early-harvested fruit may reduce the consumer’s liking of the fruit because of a reduced ripe fruit SSC (rSSC). Consumer liking may also be reduced for long-stored fruit in years of low fruit dry matter content. The impact of low rSSC on consumer liking and the presence of any threshold values requires confirmation. These findings define a clear indication of when fruit should be harvested for long storage, whilst minimizing the risk of disorders. Full article

Contemporary iterations of avian phylogenies based on multiple genome sequence assemblies assign three major clades: Palaeognathae (mostly ratite birds), Galloanseres (land and waterfowl) and the largest group—Neoaves. The latter two are sister clades representing subdivisions of Neognathae, while Neoaves further subdivide into Columbaves (pigeons/doves/cuckoos/bustards, etc.), Mirandornithes (flamingos/grebes), Telluraves (“higher land birds”, including finches) and the newly recognized Elementaves (e.g., penguins/pelicans/hummingbirds/swifts/cranes/shorebirds). Molecular studies provide clade information, likely divergence timings and a framework from which gross genomic (chromosomal) changes may be mapped. In this review, we consider the patterns of chromosome change that have occurred throughout all avian clades thus far examined, citing studies from standard karyotyping through molecular cytogenetics to whole genome assemblies. Standard karyotyping led to the realization that most chromosomes (particularly the microchromosomes and dot chromosomes) could not be distinguished by classical means. Indeed, cross-species comparisons were difficult, even among the macrochromosomes, because of indistinct banding patterns. Based on fluorescence (or fluorescent) in situ hybridization (FISH), comparative genomics was thence progressed considerably by cross-species chromosome painting (Zoo-FISH) for the macrochromosomes and interspecific mapping of bacterial artificial chromosome (BAC) probes for the microchromosomes. A key finding was that the most studied species, the chicken, fortuitously, has a genomic organization somewhat akin to that of the ancestral karyotype and tends to be the standard from which all others are measured. A notable exception is the fusion of basal chromosome 4 with a smaller chromosome that convergently appears in some other Galliformes, at least one goose and one dove species. While some groups such as Falconiformes (falcons, etc.) and Psittaciformes (parrots, etc.) underwent extensive interchromosomal change, most, broadly speaking, retain a basic karyotype that differs little from bird to bird. Many, e.g., Passeriformes (finches, songbirds, etc.) and Columbiformes (pigeons, doves), do this despite multiple intrachromosomal rearrangements. The complete karyotype and fully established chromosome-level genome assembly of the chicken allow full integration of DNA sequence assembly with karyotype. They further permit cytogenetic studies to be performed using genome assemblies alone alongside cutting-edge long-read sequencing and optical mapping without the need for chromosome preparation. The classic ZW sex-determination system of birds is easily visible in most Neognathae species, but intrachromosomal change in the sex chromosomes is faster than in the autosomes; indeed, there are numerous examples of autosomal fusions and new sex chromosomes formed. Sex chromosomes aside, the classic avian karyotype represents a very successful mode of genome organization established before the emergence of the dinosaurs and perpetuated to this day in their only living descendants. Full article

Duckweeds are minute, fast-growing monocot aquatic plants that propagate clonally and combine high biomass productivity with a valuable biochemical composition (high-quality proteins, a favorable polyunsaturated fatty acid profile, and starch-rich tissues) and efficient nutrient uptake, making them attractive for feed/food, bioenergy, and wastewater-based phyto-bioremediation. Temperature is a key factor shaping duckweed growth, and selecting clones that perform well within specific thermal ranges can improve cultivation across different applications. Here, we screened 97 clones from the genera Spirodela, Landoltia, and Lemna, including the hybrids Lemna × japonica and Lemna × mediterranea, under warm (WC; 30/25 °C) and relative cool (CC; 20/16 °C) conditions. Relative growth rate (RGR) ranged from 0.150 to 0.338 day⁻¹ under WC and from 0.113 to 0.318 day⁻¹ under CC, revealing strong interspecific and intraspecific variation. While WC generally promoted higher growth than CC, notable exceptions occurred at both interspecific and intraspecific levels. Tests under more extreme regimes (EWC; 35/30 °C; ECC; 16/12 °C) confirmed strong clone-specific responses, with some clones maintaining or improving growth under EWC relative to WC, whereas ECC generally reduced growth relative to CC. Climatic provenance was a weak predictor of performance, showing limited correspondence between RGR and mean annual temperature at the site of origin. Overall, these results highlight the value of within-species phenotyping across relevant temperature regimes to identify high-performing duckweed material for applied use. Full article

Plant genetic resources are vital for crop improvement, ecological resilience, and agrobiodiversity conservation, making their characterization through morphological and cytogenetic methods essential for breeding and germplasm management. This study comparatively analyzed two herbaceous cultivars Hibiscus moscheutos cv. ‘Carousel Jolly Heart’ and cv. ‘Carousel Pink Passion’ and two woody cultivars, Hibiscus syriacus cv. ‘Sukim’ and cv. ‘Freedom’, to assess interspecific diversity and hybridization potential. Morphological assessments revealed notable differences in flower size and leaf shape between species, with ‘Carousel Pink Passion’ exhibiting the largest flower diameter (16.70 cm) and ‘Freedom’ exhibiting the smallest (10.20 cm). Chromosome analysis confirmed diploidy (2n = 38) in H. moscheutos and polyploidy (2n = 84) in H. syriacus, highlighting a fundamental genomic distinction between the two species. Fluorescence in situ hybridization (FISH) consistently identified two 5S rDNA loci across all cultivars; however, species-specific variation in 18S rDNA loci was detected with four loci in H. syriacus and six in H. moscheutos, suggesting divergent rDNA evolution and distinct genomic organization in the two species. Flow cytometry confirmed significant differences in nuclear DNA content corresponding to ploidy levels: ‘Carousel Jolly Heart’ and ‘Carousel Pink Passion’ measured 2.06 pg and 2.05 pg, respectively, while ‘Sukim’ and ‘Freedom’ measured 4.18 pg and 4.27 pg, respectively. Full article

Sex control technology has become a key technique in aquatic animal breeding, as many aquatic species exhibit distinct sexual dimorphism in growth, reproduction, immunity, and other economically important traits. Therefore, methods such as regulating sex ratios and establishing unisexual populations can significantly enhance aquaculture productivity and breeding efficiency. Recent years have seen a rapid advancement in the field of research on the mechanisms of sex determination and differentiation in aquatic animals, as well as sex control technologies. This review summarizes the latest advances in research on the mechanisms of sex formation in aquatic animals, including genetic sex determination, environmental sex determination, and genotype-environment interactions. Furthermore, this review outlines the major sex-linked genes and molecular markers used for genetic sex identification, introduces key male and female regulatory factors involved in gonadal differentiation, and explores the application of major sex control methods in aquaculture breeding, including techniques such as interspecific hybridization, environmental regulation, hormone induction, parthenogenesis, and gene editing. Full article

Reproductive barriers severely limit interspecific hybridization success among Hydrangea macrophylla, H. paniculata, and H. arborescens, thereby restricting the combination of ornamental traits and cold hardiness. We evaluated cross-compatibility, pollen tube growth, and embryo development in both direct and reciprocal crosses involving H. macrophylla with H. paniculata and H. arborescens. Both species pairs exhibited pronounced unilateral incompatibilities. When H. macrophylla served as the maternal parent, the percentages of seedling emergence were higher, whereas reciprocal crosses produced >84% ovary swelling but resulted in almost no seedlings. Fluorescence microscopy revealed mild prezygotic barriers in direct crosses but strong inhibition of pollen germination and pollen tube growth in reciprocal crosses. Paraffin section observations showed that postzygotic barriers were the primary cause of hybrid failure, with endosperm-type abortion predominating in direct crosses and embryo-type or complete abortion in reciprocal crosses. Consistent with these abortion patterns, direct crosses maintained higher proportions of normal embryos, whereas reciprocal crosses dropped below 10% at the globular stage and approached 0% at later stages. These findings support the use of timely embryo rescue for direct crosses and targeted mitigation of prezygotic barriers in reciprocal crosses to improve Hydrangea interspecific hybridization efficiency. Full article

The evolution of herbicide resistance can increase, decrease, or have no effect on the growth rate, competitive ability, and fitness of field-selected populations. The growth response of an ACCase-resistant (R) johnsongrass [Sorghum halepense (L.) Pers.] population harboring an Ile1781Leu mutation, and a susceptible (S) population was studied in pot experiments under intraspecific and interspecific competition with corn or sunflower, using a target-neighborhood design. The R population in the intraspecific competition indicated greater fitness-related traits such as height (H), tiller number (TN), aboveground fresh weight (AFW), and rhizome fresh weight (RFW) than the S population. Aggressiveness, competitive ratio, competition intensity index, and relative competition intensity indices confirmed also the superiority of the R population. Similarly, the R population grown in interspecific competition with corn or sunflower produced greater H, TN, and AFW than the S population. In addition, both R and S populations growing in competition with corn produced more H, TN, and AFW than those growing in competition with sunflower. Furthermore, the R population in competition with corn hybrids resulted in a greater reduction in H and AFW in corn plants. These findings strongly support the evidence of fitness advantage in the R population harboring the 1781Leu mutant allele as compared to the S counterpart. Full article

Cotton, as a globally significant economic crop, is intricately regulated in its growth and development by the key genes for SA (Salicylic acid) biosynthesis. In the present study, a systematic analysis of genes related to SA biosynthesis was conducted across four cotton species, leading to the identification of 70 genes. Specifically, the tetraploid species Gossypium hirsutum and G. barbadense were found to harbor 22 and 23 genes, respectively, representing a substantial expansion compared to the 12 and 13 genes identified in the diploid progenitors G. arboreum and G. raimondii. Comprehensive characterization of chromosomal localization, phylogeny, domain architecture, and promoter cis-elements revealed a uniform distribution of key genes involved in SA biosynthesis across A/D sub-genomes of tetraploids with extensive interspecific collinearity; whole-genome and segmental duplication act as the dominant drivers for the expansion of this gene family, while partial gene loss following polyploidization results in non-doubled gene copy numbers in tetraploids relative to diploids, which reflects the evolutionary selection for genomic dosage balance. The key genes for SA biosynthesis demonstrate a high degree of conservation in protein sequences, protein structures, and conserved motifs, which constitute the structural basis for the stable maintenance of their core functions in the SA biosynthesis pathway during plant evolution. This is closely related to their core function in the salicylic acid (SA) synthesis pathway and serves as the structural basis for the stable maintenance of gene functions during evolution. Analysis of cis-elements revealed that the expression of key genes involved in SA biosynthesis is governed by a complex interplay of phytohormones, stress signals, and transcription factors. Yeast one-hybrid (Y1H) assays confirmed the interaction between the GhPAL and GhICS gene and predicted candidate transcription factors, specifically the binding of GhWRKY21 to GhICS2-1 promoter and GhMYB12 to GhPAL1-2 promoter, thus elucidating their stage-specific regulatory mechanisms in cotton fiber development and reflecting their evolution. This study provides a fundamental basis for investigating the role of the SA signaling pathway in cotton development and offers support for cotton molecular breeding. Full article

The utilization of cytoplasmic male sterility (CMS) is essential in hybrid seed production; however, its operational value in eggplant is insufficiently documented under practical conditions. This study compared CMS-based and conventional (non-CMS) hybridization systems with respect to flower production, flower functionality, and hybrid seed production efficiency, quantified as seed and viable seedling output per unit time, in three eggplant cultivars (‘Emi’, ‘Langada’, and ‘Tsakoniki’) in intra- and interspecific crosses. CMS did not affect total flower production or inflorescence architecture, which were primarily genotype-dependent. However, it altered flower opening, resulting in genotype- and position-dependent proportions of semi-opened and closed flowers at anthesis. Despite this effect, sufficient flowers suitable for hybridization remained available across all genotypes. CMS substantially simplified the hybridization process by eliminating emasculation, reducing flower manipulation time by approximately 55%, and increasing crossing rate by nearly twofold. Importantly, CMS did not negatively affect female fertility, as indicated by comparable percentages of successful crosses and high seed germination rates across cytoplasmic backgrounds. Seed production per fruit was moderately but significantly increased in intraspecific crosses, while it remained comparable between CMS and non-CMS systems for the interspecific crosses. As a result, CMS significantly increased hybrid seed output and effective seedling production per unit time in intraspecific crosses, while similar trends were observed in interspecific crosses, with gains ranging from 86% to 184% depending on genotype and pollen parent. Overall, this study demonstrates, from an operational perspective, that CMS enhances the efficiency of eggplant hybrid seed production by reducing labor requirements and increasing output per unit time without compromising reproductive performance. These findings highlight the practical value of CMS as a tool for improving hybrid seed production systems, including applications in both commercial hybrid development and rootstock breeding. Full article

Almond (Prunus dulcis (Mill.) D.A. Webb) is one of the most economically important nut crops worldwide, valued for its nutritional properties and adaptability to diverse agroecological environments. This review summarizes current knowledge on almond domestication, genetic diversity, production trends, and improvement strategies, with a focus on drought tolerance under climate change. Archaeobotanical and molecular evidence indicate central Asia and the eastern Mediterranean as key centers of origin, where recurrent introgression from wild Prunus species contributed to the high genetic variability of cultivated almond. Global production trends reveal increasing challenges due to prolonged drought, climate variability, and rising water and energy costs, particularly affecting major producers such as the United States. Mediterranean regions are transitioning from traditional low-density orchards to intensive systems, where cultivar and rootstock choice are crucial for sustainability. Self-fertile and late-blooming cultivars improve yield stability, while interspecific hybrid rootstocks enhance water use efficiency and tolerance to drought and poor soils. Drought stress impacts almond physiology and yield, although moderate deficit irrigation can maintain productivity and improve kernel quality. Future improvement relies on germplasm conservation, marker-assisted selection, and genomic tools to develop climate-resilient cultivars integrated with sustainable water management strategies. Full article

Understanding the genetic diversity and population structure of Cucurbita species is essential for effective germplasm conservation and the development of improved cultivars. This study aimed to evaluate the genetic diversity, population structure, and genetic relationships among accessions of C. pepo, C. moschata and C. maxima and their interspecific hybrids (Tetsukabuto hybrid C. maxima × C. moschata). A total of 92 accessions were analyzed using 22 polymorphic simple sequence repeat (SSR) markers selected from previous studies due to their high polymorphic information content (PIC). Genetic diversity parameters were estimated, and population structure was inferred using Bayesian clustering, complemented by dendrogram and principal component analysis (PCA). All markers were successfully amplified in C. pepo, C. moschata, C. maxima, and the hybrids, with polymorphic information content (PIC) values ranging from 0.191 (CMTm232) to 0.448 (CMTm48) and average of 0.274. The AMOVA analysis showed that 50% of the total variation was attributed to differences both within and among groups. PCA revealed clear genetic differentiation among the analyzed species, with C. maxima and hybrid accessions clustering closely and exhibiting lower genetic dissimilarity. In contrast, C. pepo displayed greater genetic divergence, supporting its distinct evolutionary trajectory. According STRUCTURE analysis the accessions can be divided into four subpopulations, which are closely related to the species. PCA and dendrogram showed similar results for genetic structure of Cucurbita germplasm; C. maxima and hybrid accessions clustering closely and C. pepo as a distinct group. These findings provide valuable insights for breeding programs, germplasm management, and conservation strategies aimed at preserving genetic diversity and exploiting interspecific variation. Full article

In this study, 101 F₁ hybrid lines were constructed using Medicago sativa L. ‘Xinjiang Daye’ and Medicago falcata L. ‘Hulunbeier’ as parents, and their agronomic and quality traits were systematically evaluated over two consecutive years. The results showed that the hybrid progeny exhibited more pronounced phenotypic variation in the second year. Specifically, the X4H4 combination demonstrated superior biomass accumulation, while the H4X4 combination showed notable advantages in quality indices. In the second year, the correlations among agronomic traits were clearly strengthened, with morphological traits closely associated with biomass; coordinated variation was also observed among quality traits, as crude protein content was negatively correlated with fiber-related indices. Based on principal component and heterosis analysis, the hybrid lines were classified into distinct advantage groups: Group 1 exhibited clear agronomic heterosis, while Groups 2 and 3 displayed distinct advantages in quality traits. Finally, 12 elite individuals were selected based on integrated KASP molecular marker profiling and comprehensive phenotypic evaluation. This study establishes a strategy for marker-assisted phenotypic evaluation in alfalfa breeding, providing a theoretical basis and germplasm resources for the development of high-yield and high-quality cultivars. Full article

To mitigate supply risks associated with Hevea brasiliensis, Taraxacum kok-saghyz is being developed as a promising temperate source of natural rubber. For it to be successfully integrated into conventional cropping systems, optimized agronomic practices are required. The present study investigates the effects of sowing season (spring vs. autumn) and harvest timing (June–October) on rubber yield, determined by root dry weight and rubber content. Field trials were conducted at two contrasting locations in Germany using wild-type T. kok-saghyz and the interspecific hybrid ‘Hyb207’. Root dry weight accumulation was influenced by genotype, sowing season, harvest date and site conditions. Despite this variability, autumn sowing increased modeled root dry weight by approximately 81% and rubber content by 84% on average compared to spring sowing. In addition, autumn-sown plants reached peak root dry weight earlier in the season than their spring-sown counterparts. These results demonstrate that strategic selection of sowing and harvest windows is critical for optimizing yield formation. Site-specific management strategies can enhance biomass production and facilitate the integration of Tks into temperate cropping systems. Full article

(1) Reproductive isolation serves as a critical mechanism that prevents interspecific hybridization among closely related species, thereby preserving species integrity. In termites, hybridization between certain closely related species can overcome prezygotic isolation and produce offspring. However, whether these hybrids can overcome postzygotic barriers remains substantially underexplored. (2) This investigation conducted a comparative analysis of reproductive output (egg production and offspring count), physiological traits (body weight), functional characteristics (locomotor capacity), and hybrid fertility between the hybrid colony that was established by Reticulitermes flaviceps and R. chinensis and the conspecific pairing colonies of R. flaviceps and R. chinensis, respectively. (3) The results showed that hybrid colonies laid significantly more eggs and produced significantly more larvae than conspecific colonies. The hybrid offspring showed no decline in weight and locomotor capacity. Furthermore, the hybrid offspring maintained balanced sex ratios with unimpaired caste differentiation and fertility in both sexes. (4) These results demonstrate that the prezygotic reproductive isolation mechanism is incomplete between two closely related termite species, and there is a risk of forming hybrid populations. This work not only provides a theoretical basis for monitoring the risk of hybrid populations in termite management but also offers new insights into the evolution of reproductive isolation and speciation in social insects. Full article

Blackberry cultivars typically exhibit high fruit antioxidant levels but poor drought tolerance compared with their wild Rubus relatives. Few studies have employed wild Rubus species in hybridization programs aimed at improving drought tolerance and fruit quality in cultivated blackberries. In this study, we comprehensively assessed growth traits, fruit characteristics, and drought tolerance in 108 F₁ progenies derived from a cross between the cultivated blackberry ‘Prime-Ark^® Freedom’ and the wild species Rubus chingii. Correlation analysis of fruit morphological traits indicated significant positive associations among single fruit weight, fruit thickness, and fruit diameter, reflecting coordinated fruit development. Among the nutritional quality traits evaluated, both anthocyanin and total phenolic contents exhibited transgressive segregation. Specifically, 47.78% of the progeny demonstrated higher anthocyanin content, and 45.56% exhibited greater total phenolic content than the higher-performing parent. The corresponding genetic transmission ability (Ta) reached 139.23% and 101.24% for these traits, respectively, indicating pronounced additive genetic effects and high heritability. After a 7-day drought treatment, the hybrid progenies exhibited significant heterosis in catalase (CAT) activity, with 24.07% exceeding the higher-parent value. In contrast, proline content exhibited high broad-sense heritability (H² = 0.990) and considerable genetic variation. Under drought stress, all chlorophyll components were strongly positively correlated. Using principal component analysis (PCA), we established comprehensive evaluation models for fruit quality and drought tolerance. Based on these models, seven accessions—H3, H4, H8, H10, H11, H14, and H25—were identified as superior in both drought tolerance and fruit quality. This study provides an integrated evaluation framework for selecting drought-tolerant and high-quality genotypes from interspecific hybrid progenies in blackberry, offering a theoretical basis for utilizing wild Rubus resources in breeding improved cultivars. Full article