Search Results (39)

Passiflora germplasm represents an important genetic resource for improving fruit yield and quality in breeding programs targeting semi-arid environments. This study aimed to assess the phenotypic diversity, genetic parameters, and breeding potential of Passiflora accessions conserved in the Passion Fruit Active Germplasm Bank of Embrapa Semiárido. A total of 55 accessions, predominantly Passiflora cincinnata Mast., were evaluated using morphoagronomic descriptors related to plant, flower, and fruit traits. Quantitative data were analyzed using mixed linear models (REML/BLUP) to estimate genetic parameters, and multivariate analyses were applied to characterize phenotypic divergence. Substantial phenotypic variability was observed, particularly for fruit-related traits. Fruit weight ranged from 43.25 to 142.88 g, pulp weight ranged from 7.86 to 51.37 g, and pulp yield ranged from 17.06% to 40.27% among accessions. Broad-sense heritability estimates for key fruit traits were moderate to high, reaching 0.50 for fruit weight, 0.49 for pulp weight, and 0.36 for pulp yield, indicating favorable prospects for selection. Principal Component Analysis explained 66.0% of the total variation in the first two components, with fruit size, pulp-related traits, and seed number contributing most strongly to accession differentiation. Multivariate analyses consistently identified accessions 1 and 16 as superior for fruit weight and pulp yield, whereas accession 55 combined high fruit weight with elevated soluble solid content (up to 14.24 °Brix) but lower pulp yield. Overall, the observed variability highlights the relevance of Passiflora germplasm conserved under semi-arid conditions as a valuable resource for breeding programs focused on fruit yield, quality, and adaptation to water-limited environments. Full article

For the development of effective and secure methods for plant genetic resources preservation, different storage treatments of fiber flax seeds were compared. Seeds of the flax variety Orshanskiy-2 in aluminum foil bags were stored at different low temperatures, including in liquid nitrogen. Agronomic characters of plants grown from them and next-generation seeds were compared. Plants grown from frozen seeds changed 14 out of 31 evaluated characters in comparison with the non-frozen control. The biggest changes were detected after gradual freezing in liquid nitrogen, due to mechanical damage of the seed coat, and storage at −10 °C for 24 years. Freezing had a negative effect on production characters (straw, fiber and seed) because of the reduction of the germinated plant number. Seeds stored for 24 years at −10 °C, compared to control plants, ripened earlier, grew higher, produced a greater yield of straw and fiber, but had reduced fiber quality and increased seed size. Plants of the next generation showed a tendency toward attenuation of the storage time influence on flax characters. However, it is unknown how many years this process will take. For seed preservation in GeneBanks, it is recommended to use several variants of storage conditions and use rapid cooling and/or cryoprotectors. The latter two methods, which have been successfully used for other crops, should be implemented only after preliminary experiments. Full article

Background: Rhodiola quadrifida (Pall.) Fisch. & C.A. Mey. (Crassulaceae) is a rare medicinal species in the Kazakh Altai, yet information on its population structure and genetic diversity remains limited. This study presents findings from an investigation of natural R. quadrifida populations. Methods: The morphometric characteristics, population age structure, and genetic diversity of the plants were analysed using PCR-based genome profiling. Genetic diversity within R. quadrifida populations was assessed using PCR primers for binding sites complementary to a specific region at the 3′ terminus of a particular tRNA. Results: The populations exhibited variations in morphological traits, age structures, and reproductive strategies. The IVA-1, IVA-2 and KOK populations represent the most mature stages, characterized by a dominance of vegetative reproduction and a disturbed age structure, with a predominance of senile and virgin individuals. In contrast, the LIN-1 and LIN-2 population is characterized by a balanced age structure, encompassing all ontogenetic groups, and a mixed reproductive system that includes both sexual and vegetative propagation. Genetic diversity, as measured by Shannon’s information index, ranged from 0.194 to 0.247, indicating low genetic diversity in R. quadrifida. Analysis of molecular variance (AMOVA) revealed significantly greater variation within populations (62%) than among populations (38%). Genetic diversity was higher in the LIN-1 and LIN-2 populations, which employs a mixed reproductive system (clonal and seeds), than in populations dominated by vegetative reproduction. Both LIN populations, characterized by a mixed reproductive system, exhibited higher genetic diversity than the KOK, IVA-1 and IVA-2 populations, where vegetative reproduction predominated. Conclusions: These results underscore the necessity for priority conservation measures, including monitoring population size and age structure in populations with low levels of seed reproduction and disturbed age structure. Additional measures include supporting in situ and ex situ conservation, such as clonal collection, seed banks, and tissue cultures, as well as restricting the harvesting of medicinal raw materials. Full article

Trials were carried out to investigate the effects of light and temperature on C. rotundus seeds and tubers under two conditions: (i) in vitro and (ii) after sowing in soil. In the latter, seedling emergence was evaluated after sowing at increasing depths in different soil textures. While dormancy was evident in over 50% of the seeds, which also required light for germination, in contrast, tubers showed a significantly shorter period of dormancy that was independent of light. Seed burial strongly hindered seedling emergence, showing an “active” seed bank only in the shallowest soil layer (few mm). In contrast, tubers showed a marked ability to emerge from a depth exceeding 40 cm. Emergence capacity was found to be proportional to the size of the tubers, attributable to the greater energy reserves needed during autotrophic pre-emergence growth. Seedling emergence from both seeds and tubers, sown at increasing depths, was inhibited to a greater extent in a clay soil texture. A lower inhibitory effect was reported for sandy soils. Tuber vitality was significantly reduced or eliminated within a few days from progressive drying following exposure to solar rays during summer periods. Finally, the data were discussed within the context of planning the agronomic management of C. rotundus, in terms of soil tillage modalities, to ensure sustainable control of this strongly invasive and persistent weed. Full article

The effects of different storage conditions on seed germination and mortality may exhibit species-specific patterns. Burial serves as a natural seed storage mechanism, and its impact on seed germination and mortality holds critical implications for understanding the formation mechanisms of soil seed banks and the restoration of vegetation. Seed size is closely related to storage conditions, as it affects the ease with which seeds penetrate the soil, thereby potentially influencing their germination and mortality responses to those storage conditions. This study used 12 common plant species from a subalpine wet meadow. Employing in situ unheated storage as the control and in situ burial at a 15 cm depth (for seven months) as the experimental treatment, we aimed to explore the effects of burial on seed germination and survival, as well as the underlying mechanisms, in relation to seed size. The results showed the following: (1) Compared with the control, the burial treatment significantly increased the germination rates of four species (burial-promoted germination type), while no significant effect was observed on the germination of the remaining eight species (burial-insensitive germination type); it significantly increased the mortality rate of two species (survival-inhibited type), significantly decreased the mortality rate of four species (survival-promoted type), and had no significant impact on the mortality rate of the remaining six species (survival-insensitive type). (2) Seed size exhibited significant negative correlations with both post-burial germination rates and mortality rates under control conditions, while showing a significant positive correlation with the magnitude of mortality change. The species-specific responses of seed germination and mortality to storage conditions, and their close association with seed size, represent products of long-term plant evolution. This study provides important insights for understanding the mechanisms of soil seed bank formation and offers valuable guidance for vegetation restoration practices. Full article

The loss of plant species, especially endangered and endemic ones, poses a significant threat to global biodiversity. These species cannot easily be replaced when their populations decline or become extinct, which makes their loss particularly devastating. This study focuses on the geobotanical study of nine Rosaceae species (Cotoneaster karatavicus, Crataegus ambigua, Malus niedzwetzkyana, Malus sieversii, Prunus tenella, Prunus ulmifolia, Sibiraea laevigata, Sorbus persica, and Spiraeanthus schrenkianus) and the development of ex situ approaches for the conservation of Rosaceae species listed in the Red Book of Kazakhstan. The geobotanical study revealed an alarming trend of biodiversity loss in five regions of Kazakhstan. This loss is driven by threats from diseases and pests, as well as the aging of plants, small population sizes, weak in situ fruiting, and other factors, such as climate change. We have established an in vitro collection for the short- and medium-term conservation of seeds, embryos and shoots taken either directly from field-grown plants or from budwood cuttings forced indoors. We also use long-term sexual conservation methods, such as the cryopreservation of seed and embryonic axes, alongside conventional seed banking at −20 °C. Ex situ conservation efforts that use multiple propagules and storage methods for the same species are well-suited to a diverse genebank facility. These efforts enable future generations to use this valuable reservoir of genetic diversity for crop improvement and may also serve as a basis for propagating planting material to restore degraded populations. Full article

The coconut (Cocos nucifera L.), a valuable tropical crop, is rapidly declining in genetic diversity due to natural disasters, pest and disease attack, and land clearing for other crops. Seed banking is impractical for coconut conservation due to its large, recalcitrant seed, and maintaining field gene bank collections is costly and vulnerable to environmental pressures. Cryopreservation offers a promising alternative method for conserving coconut genetic diversity, but the success in recovering cryopreserved materials remains limited, with few studies consistently reporting high rates of recovery. This highlights the need for improved cryopreservation protocols, particularly in tissue dehydration, which is one of the critical steps in the process of cryopreservation and plant recovery. A desiccator was developed that enabled rapid embryo dehydration with ultra-dry airflow. The desiccator reduced embryo moisture content to 20% (the predetermined viability threshold) within 6 h representing a 2-h improvement when compared to a previous dehydration approach, while maintaining a high germination rate (71%). Smaller embryos (500 to 550 mg fresh weight) desiccated faster than larger embryos (800 to 900 mg fresh weight) but germination was reduced (30%), making small embryos unsuitable for cryopreservation. A 5-day sucrose (0.4 M) pre-treatment further reduced the dehydration time to 4 h, while maintaining a high germination rate (70%). These advances in the use of a sucrose pre-treatment, the rapid embryo dehydration, and selection of large embryos size will help to enhance the success of coconut embryo cryopreservation and recovery. Full article

The world’s grasslands are under increasing threat of degradation. Given the potential for multiple drivers of decline, precise diagnosis of degradation is best achieved by comparison with a local, sustainable grassland community. Comparisons of this kind are becoming increasingly common for regional grassland plant communities, but these studies largely overlook interactions between soil responses to system degradation and the effective functioning of the soil seed bank. Surveys of grassland degradation studies have revealed that only around 5% include information on soil seed bank composition and no one aspect of community structure features across all studies. Furthermore, the majority of studies provide information only on ground coverage, sward biomass or species diversity in the plant subcommunity, with very few including information on the health of the soil seed bank or how changes in the soil environment could drive further deterioration in the plant community size, structure or effective functioning of the soil seed bank. We consider that soil responses to sward degradation are likely to exacerbate rather than mitigate impacts on soil seed bank function, leading to a spiral of system degradation in the absence of timely and targeted intervention. We propose improvements for future studies seeking to diagnose and quantify grassland degradation. Full article

Naked barley (Hordeum vulgare var. nudum) is a staple food crop, contributing significantly to global food security. Understanding genetic diversity will facilitate its effective conservation and utilization. To determine genetic diversity and its distribution within and among varieties, we characterized 30 naked barley varieties from Tibet, representing the traditional, modern, and germplasm-resources-bank gene pools, by analyzing SSR molecular fingerprints. The results demonstrate abundant genetic diversity in Tibetan naked barley varieties, particularly those in the traditional gene pool that holds much more private (unique) alleles. Principal coordinates and STRUCTURE analyses indicate substantial deviation of the modern varieties from the traditional and germplasm-resources-bank varieties. A considerable amount of seed mixture is detected in the modern varieties, suggesting the practices of using mixed seeds in modern-variety cultivation. Cluster analyses further indicate the narrow genetic background of the modern varieties, likely due to the limited number of traditional/germplasm-resources-bank varieties applied in breeding. Relationships between increases in genetic diversity and sample sizes within naked barley varieties highlight the importance of effective sampling strategies for field collections. The findings from this study have important implications for the sustainable utilization and effective conservation of different types of naked barley germplasm, both in Tibet and in other regions around the world. Full article

Wright fishhook cactus is a small globose cactus endemic to an area of 280,000 ha in south-central Utah and was listed as endangered in October of 1979 by the U.S. Fish and Wildlife Service (USFWS). There is a general paucity of information about this species, and no published data on the seed bank for any species in the genus. Our objective with this study was to provide insight into the established seed bank density for this species. We processed 500 soil samples from various locations near individual cacti and potential neighboring nurse plants. We found that the species had a detectable seed bank of a size similar to other members of the Cactaceae family. Seed bank densities were the highest immediately adjacent to, and downslope from, parent plants. Our data indicate that areas within 20 cm of seed-producing cacti contain by far the greatest density of seeds. These areas should be given special consideration in future management plans for this species. Full article

Taxus baccata L. is a tertiary relict, long-lived, wind-pollinated dioecious tree species found throughout Europe. In the rocky mountains of Thasos island, monumental old trees create a unique area of natural beauty. In recent times, the need to implement conservation measures for key endangered species such as Taxus baccata has intensified. Exploring the genetic diversity of the species is a prerequisite for successful forest management decisions aimed at conservation. In this study, 28 monumental trees from two natural populations of Thasos were investigated using eight Simple Sequence Repeat markers in order to assess the levels of genetic diversity and genetic differentiation within the individuals, to estimate the degree of inbreeding and the effective population size of each population, and to discuss the impact this study has on conservation efforts for the species. Although the population size was small (14 individuals per population), the results showed moderate to high genetic diversity parameters. The mean expected heterozygosity was He = 0.649 and the number of effective alleles was Ne = 3.270 for both populations. Moreover, allelic richness (A_R = 3.395) was high, indicating a variable genetic pool which is probably a result of a past established expansion of the species in the area. The results of the present study present a unique genetic pool harbored by specific trees, which is an important advantage for ensuring their conservation and resistance against biotic and abiotic threats. Our study paves the way towards conservation measures, which can be prioritized as follows: (a) in situ conservation, (b) seed bank establishment, and (c) in vitro propagation in order to secure future resilience and sustainability of the species. Full article

The extreme weather that humanity has been confronting in recent years is the result of climate change. All over the world, unknown plant species are disappearing daily, which humankind has not discovered and will never know. Since 1900, the angiosperms and gymnosperms have been disappearing at a frequency of three species per year, but it is worrying that this rate of disappearance is up to 500 times higher currently. These data, correlated with the information provided by the United Nations (the world population will reach 10 billion by the year 2050) and FAO (food insecurity and the decrease of feedstock) lead to a crucial need to conserve and study plant germplasm. Therefore, plant germplasm conserved, especially in gene banks, can represent an important source for the development of varieties with an increased resistance to abiotic stress factors. Considering the origin of the current species of Phaseolus vulgaris L. as being in two distinct centers with different gene pools (Andean and Mesoamerica), the aim of the article is to infer the ancestry of 27 landraces according to their sampling geographical origin and morphological and molecular traits based on DNA sequences of three genes associated with abiotic stress tolerance (drought and thermal stress): PvREB5A, PvDREB6B, and PvRPS4. Phaseolus vulgaris L. has two different centers of origin: the Mesoamerican and the Andean basins. In this research, 27 landraces were evaluated from different counties in Romania. Three genes, PvREB5A, PvDREB6B, and PvRPS4, were amplified by the PCR reaction, sequenced by the Sanger technique, and the data obtained were analyzed using MEGA XI software. For morphological data, the GraphPad Prism 9 software was used. According to PvDREB5A, 81.5% of all studied landraces belong to the Mesoamerican gene pool and 18.5% belong to the Andean. PvDREB6B revealed a high nucleotide and amino acid diversity between the Andean and Mesoamerican genotypes compared to the other evaluated genes. Also, the PvRPS4 gene from the chloroplast genome showed one SNP within its coding region, different for those two gene pools, which is directly involved in a nonsynonymous substitution. The morphological characteristics, such as weight for 100 seeds, length, height, width, weight, seed flatness, flatness index, seed elongation, and eccentricity index were determined. European landraces of Mesoamerican origin indicated a large seed size compared to Andean genotypes. This work can be a foundation for the identification of interesting traits that establish plant adaptation to abiotic stress and conserve landraces of common beans from genetic depletion. Full article

I investigated the size, composition and persistence of the seed-bank in primary forests, secondary forests and old-fields in southern Mexico. I also assessed the contribution of the seed-bank to regeneration relative to other propagule sources. In all habitats, I removed by hand all plants and litter and excluded the seed-rain. For one year, I counted the number of plant species (5–50 cm tall) emerged and grouped them into different growth-forms: trees, shrubs, palms, herbs, woody lianas, epiphytes and hemi-epiphytes. A total of 95 species emerged. The seed-bank size, composition and persistence showed strong variation among successional stages. Emergence was low for primary and secondary forests, but high for old-fields (19, 26, and 68 plants per m⁻², respectively). Herbs were the most abundant in the seed-bank and palms the less. Time had a negative effect on seed-bank size in primary forests and old-fields; whereas for secondary forests size remained constant throughout the year. The number of emerged plants in different growth-forms changed significantly across time for all successional stages. Overall, the seed-bank provided a greater number of plants in old-fields relative to other propagule sources combined. The results showed that forest modification alters the input of propagules throughout the seed-bank for different plant growth-forms. Full article

Climate change has a significant impact on species distribution, especially for the relict plants. Euptelea pleiosperma is a type of tertiary relict plant. This plant shows a decreasing trend in population size, and it is on the edge of extinction given the background of climate change. Understanding the change in suitable habitats of E. pleiosperma will provide significant academic value for investigating species conservation and sustainable development. According to the 236 distribution records of E. pleiosperma in China, and 11 environmental factors, the optimal model was selected from MaxEnt, BIOCLIM, and DOMAIN models, aiming to estimate the future potential suitable habitats and exploring the major environmental factors influencing the distribution of E. pleiosperma. By comparison, the BIOCLIM model was the optimal for estimation, since it achieved the highest precision and the lowest standard error. Our results demonstrated that temperature was the most important factor affecting the suitable habitats of E. pleiosperma, followed by precipitation and altitude. Under the medium- and high-emission scenarios, the future suitable habitats of E. pleiosperma will migrate northward to the high-latitude areas, whereas those under the low-emission scenario will migrate southward to the low-latitude areas. During 2041–2060, the suitable habitat areas will present a positive trend, while those during 2081–2100 will exhibit a negative trend to varying degrees. Consistent with the above results, it is advisable to establish natural reserves and seed resource banks of E. pleiosperma in the current high suitability areas, as well as to provide artificial assistance to guide its migration to the high suitability areas under the future climate scenarios. The findings in this research not only reveal the response of suitable habitats of E. pleiosperma to climate change but also lay a reliable foundation for its population resource conservation and sustainable development. Full article

In this study, the origin of Spanish durum wheat and olive tree landrace collections (preserved in seed banks and ex situ field collections, respectively) was traced throughout different studies on genetic structure analysis of different landrace collections and historical records of plant material circulation of these two crops in the south and east of Spain (the main cultivation areas). Although there were several groups of Spanish durum wheat landraces, they did not cluster geographically and likely came from intense grain circulation within the country and abroad (due to a high seeding rate of about 100 kg/ha and an unstable production) from the 15 to 19th centuries (especially the Maghreb and Sicily). However, Spanish olive tree landraces experienced lower genetic circulation over time and space due to the longevity of the species and the large size of the reproductive material. They can be clearly divided into two groups: those from the south, of Maghrebi origin, which most likely originated during the Islamic expansion of the 8–15th centuries, and those from the east, arriving most likely during Roman times from Italy. The genetic circularity levels of the plant material of these two crops are different. Full article