Genetic Resources and Crop Evolution最新文献

Heirloom Danish apple cultivars are historically and pomologically important, part of the cultural heritage, and have valuable adaptation to regional climate conditions. However, lack of information about their genetic identity and pedigree relatedness with other cultivars hampers proper cultivar identification, germplasm curation, genebank management, and future regional breeding efforts. Many Danish apple cultivars are maintained in the national collection “The Pometum”, maintaining around 850 apple accessions. Additional material is maintained in public or private Danish collections. However, no information exists regarding genotypic duplicates between these collections and germplasm collections in other countries, pedigree inferences across collections, and genotypically unique accessions at the genebank level.

To provide such information, 976 accessions from Denmark were genotyped with simple sequence repeat (SSR) markers and the Illumina Infinium 20K single nucleotide polymorphism (SNP) array. The resulting genotypic data were compared to large databases of genotypic data from germplasm collections in multiple countries to identify genotypic duplicates and conduct pedigree reconstruction. The germplasm maintains 305 unique genotypic profiles which were not found in other germplasm collections. The study exposed previously unknown synonyms, accessions not true-to-type, and novel pedigree relationships involving accessions from multiple collection sites. The most frequent parents of Danish germplasm were ‘Hvid Vinter Pigeon’ and ‘Cox’s Orange Pippin’ whereas ‘Reinette Franche’ was the most common grandparent. The accession-level information will benefit germplasm curation, cultivar identification, genebank management, and future breeding efforts, and shed new light on cultivar history and origin.

Rice is recognized worldwide as a primary staple food crop which provides calories approximately half of growing world population and the maintenance of its high productivity is of utmost importance in the context of global food security. The objective of this research was to examine the variability and correlation between yield-related characteristics in rice. A total of 15 F₁ crossings, in addition to five lines and three testers were subjected to evaluate in a Randomized Complete Block Design with three replications at the experimental site of the Department of Plant Breeding and Genetics, Faculty of Agriculture and Environment, Islamia University of Bahawalpur, Pakistan, during the year 2022–2023. Analysis of variance (ANOVA) showed that genotype revealed significant differences for most variables except grain length, days to maturity, panicle weight and grain yield per plant. The study found adequate spontaneous genetic diversity for rice yield parameters such as plant height, panicle length, grain per panicle, grain width, days to heading and spikelets per panicle. ANOVA also revealed significant differences among the studied traits in parents, crosses, lines, testers and their combinations. Combing ability revealed potential parents and hybrids for different studied parameters. Line 37651 had positive general combining ability (GCA) (8.888) effect for grain yield per plant and line 37481 reveled highest negative GCA among the lines (− 4.984). Tester 37500 showed significant positive GCA (4.072) effect for grain yield per plant while among the negative GCA (− 3.598) was exhibited by tester 37644. Cross 37651 × 7968 exhibited significant positive specific combining ability (SCA) (18.362) effect and among cross 37651 × 37500 showed significant negative SCA (− 13.18) effect for grain yield per plant. Grain yield per plant exhibited significant genotypic positive and negative correlation with various studied parameters. From the results it was found that diversified parents and best combiners (hybrids) may be useful in breeding high-yielding rice cultivars.

Sorghum (Sorghum bicolor (L.) Moench) is one of the most important cereal crops occupying the fifth position based on the cultivated extent among the cereal crops in the world. Characterization of genetic resources is a pre-requisite for utilization of conserved genetic resources in breeding programmes and cultivation. The present study was carried out to reveal the genetic variation and population structure of local and exotic sorghum germplasm collection conserved in ex-situ seed genebank at the Plant Genetic Resources Centre, Sri Lanka. Total genomic DNA was extracted from 60 germplasm accessions using CTAB miniprep DNA extraction protocol. A two-step PCR amplification was performed at 16 Simple Sequence Repeat (SSR) loci. Four differentially labeled PCR products were multiplexed and size-fractioned using capillary electrophoresis. Data analyses were performed using GeneMapper 4.0, OSIRIS, PowerMarker 3.25, Structure 2.2 and STRUCTURE HARVESTER. The 16 SSR loci recorded polymorphism and the dendrogram revealed four distinct clusters. The optimum number of subpopulations was three in addition to two admixture subpopulations. The revealed population structure did not depict the geographical origin of the germplasm accessions. The present study confirmed that the majority of local sorghum germplasm accessions tested were genetically distinct. Varying degrees of outcrossing selfing in subsequent generations may have led to the creation of novel sorghum genotypes at global level.

The taxonomic classification of the Nepeta genus (Lamiaceae) and its intrageneric species has long been a subject of debate. This study aims to comprehensively examine the palynological characteristics of selected Nepeta species and compare these findings with their phylogenetic relationships and taxonomic classifications. Using scanning electron microscopy, the pollen morphology of 10 species within Nepeta genus was meticulously investigated. Measurements, observations, and statistical analyses were conducted on eight quantitative features and five qualitative ones of the pollen grains. The study showed several key characteristics of Nepeta pollen. These included their monad, hexacolpate, hexacolporate, and Stephanocolpate nature, ranging a size range from small to large (14.39–58.42 μm) and exhibiting elongated prolate to oblate shapes. Furthermore, the examination of exine ornamentation under SEM revealed three distinct sexine sculpture types: type I-reticulate with micro-perforations, type II-micro-reticulate with macro-perforations, and type III-bi-reticulate. The principal component analysis (PCA) was validating the distinct separation of Nepeta species based on quantitative pollen grain variables. Concerning exine patterns and aperture numbers, the Nepeta genus stands out from other Lamiaceae genera due to its pollen being 6-colporate with a bi-reticulate perforated exine. The findings developed the taxonomic dichotomous key based on Nepeta species pollen signify the qualitative traits explained the micromorphology of palyno-morphs identification of Nepeta genus as Stenopalynous. However, this study holds implications for Lamiaceous species comparative morphological, taxonomic, and phylogenetic interpretations.

This article provides an overview over taxonomy, distribution, cultivation and use of the Fiji Dragonplum, Dracontomelon vitiense Engl. The species belongs to the Anacardiaceae family with about 860 species in 83 genera. The majority of its species are distributed in warm subtropical and tropical areas. Among them, there are economically important timber, fruit and nut trees. Species in the genus Dracontomelon are distributed from tropical Asia to the south–western parts of the Pacific. Dracontomelon vitiense is endemic to the western Pacific region, from Santa Cruz Islands (Solomon Islands), Vanuatu, Fiji (including Rotuma), Tonga, Futuna, to Upolu (Samoa). It is a tall canopy tree and occurs predominantly at altitudes from sea level to 200–300 m asl. Dracontomelon vitiense is valued as a locally important, native fruit and timber tree. Although being a wild species, it is often planted in gardens and villages. Its fruits are widely consumed and sold in local markets. Dracontomelon vitiense produces commercially valuable timber, which is used for light constructions, furniture, canoes, wood carving, and as firewood. Dracontomelon vitiense can be considered a neglected tree for the Pacific region, with no active breeding going on. The species retains a large potential for improvement, commercialisation and income generation and as a component in sustainable agroforestry production systems however no figures about its commercial use are available. Ex-situ gene bank accessions of Dracontomelon vitiense are not available. No information exists about the genetic variation of the species. Several lines of future research are suggested.

Pointed gourd (Trichosanthes dioica Roxb.) is a vegetatively propagated and an underutilised cucurbitaceous vegetable crop of India and Bangladesh. The crop has not yet been characterized based on distinctiveness, uniformity, and stability (DUS) characters. Clonal diversity has also not been properly assessed utilizing multivariate analysis and molecular marker. The present investigation was carried out to analyse genetic diversity of 34 female clones employing 29 qualitative and 27 quantitative characters for multivariate analysis and inter simple sequence repeat (ISSR) markers. Shannon–Wiener Diversity Index (H’) suggested that plant and fruit morphological characters viz., fruit shape, fruit apex shape at blossom end, number of secondary branches up to 20th node, leaf colour, petiole length, leaf blade length, vine length, fruit skin primary colour, and depth of leaf lobing should be considered when evaluating pointed gourd genotypes for DUS testing. The clones grouped in six clusters which do not correspond to origin locations. Principal components of variable traits for number of secondary branches up to 20th node, leaf blade length, leaf blade width, leaf blade size, petiole length, number of leaf lobes, vine length, node at which 1st female flower appeared, days to 50% flowering and fruit weight had eigen values > 1 and accounting for 81.06% of total variation. Based on average values, multivariate, and molecular analysis of economic traits, the female clones, ‘BCPG-4’ and ‘Swarna Alaukik’ emerged as potential and diverse genetic stocks for future breeding programme. Classification of the female clones and their diversity could conveniently be analysed using ISSR markers. We could frame the possible ways of future improvement strategies of pointed gourd.

Crop Wild Relatives (CWR) are wild plants that are genetically related to cultivated crops. Conserving the genetic diversity of CWR is essential for maintaining the sustainability of agriculture and food production in the face of various anthropogenic and environmental pressures. In this study we aim to contribute to the conservation planning of CWR taxa in Lebanon, in particular, to document ecogeographic survey and collection missions, carried out in 2022 and 2023, to assess the presence and conservation status of CWR taxa populations belonging to Poaceae and Fabaceae families and eventually propose sites for in situ conservation based on collected data. Ecogeographic and botanical surveys were carried out using the transect method and targeting priority CWR taxa. Agrobiodiversity trends, based on distribution data available in public databases, were compared with the current occurrence of the priority CWR taxa. Preliminary observations of disturbances (e.g. grazing, urbanization) were also documented to serve as a baseline for future monitoring of agrobiodiversity. Additional survey and collection missions were specifically targeted on wild Triticum populations. Forty-seven sites were surveyed, in which 500 new records for target CWR taxa (Aegilops L., Triticum L., Avena L., Hordeum L., Cicer L., Lens Mill. and Pisum L. genera) were documented. A total of 17 new collections were performed and the material stored in ICARDA genebank. Two sites (Yanta/Kfarqouq and Ham) were recommended for the in situ conservation of wild Triticum as well as two other sites for conservation of wild Lens culinaris Medik. Several concerns were raised, mainly the declining distribution of Triticum boeoticum and Triticum urartu over the last 30 years, as well the absence of Cicer taxa in the two years of surveys. The collection of 500 CWR occurrence data points for the target taxa provides a solid ground for future analyses, including ecogeographic and predictive characterization approaches, to identify the best areas for establishing genetic reserves for active in situ protection of these crucial taxa in Lebanon, which is urgently needed.

Heat stress poses a significant threat to cotton, affecting crucial developmental stages from fertilization to boll development and thereby reducing both yield and quality. As global climate change advances, the likelihood of severe heat waves increases, presenting a serious challenge to agricultural production and our ability to feed a growing population. Cotton’s resilience to heat involves a suite of physiological and biochemical responses, including adjustments in water management and protective mechanisms at the cellular level, such as the synthesis of heat shock proteins (HSPs) and antioxidants. These adaptations are crucial for maintaining cellular integrity and overall plant health under thermal stress. Recent research highlighted specific proteins and enzymes within the plant that help combat stress-related damage. However, the exact molecular mechanisms facilitating these protective responses are not fully delineated. Further research is needed to identify and validate additional molecular mechanisms underlying the plant’s response to heat stress. Additionally, exploring new breeding strategies for the development of more resilient cultivars. In addition, field trials and testing under real-world conditions will be essential to assess the effectiveness of the proposed strategies for mitigating the negative effects of heat stress on crop yields.

Wild species of genus Corchorus are valuable resource for improving fibre quality, stress tolerance and nutritional attributes in cultivated species. In the present study a total of 120 accessions of 7 Corchorus species (6 wild species and one cultivated species i.e. Corchorus olitorius) naturalized in Southern India studied for habitat distribution, species richness, variability, genetic diversity and population structure. For these study, agro-morphological traits (leaf blade length, leaf blade width, petiole length, plant height, stem basal diameter, green weight, dry stem weight and dry fibre weight), Inter Simple Sequence Repeat (ISSR) and Sequence Related Amplified Polymorphism (SRAP) markers were employed. These species are found frequently but unevenly distributed along geographical boundaries in the region. C. aestuans was the most frequently distributed species followed by C. trilocularis, C. olitorius, C. tridens, C. urticifolius, C. fascicularis and C. pseudo-olitorius. Naturalized habitats represented arid to humid agro-climatic zones. Altitude emerged the key determinant influencing species differential spatial distribution in the region. The multispecies population revealed broad spectrum phenotypic coefficient of variation (PCV) for important agro-morphological traits including green weight (PCV = 50.40%) and dry fibre weight (PCV = 97.16%). The highest genetic diversity in the population was exhibited by ISSR having high Shannon’s Information index (SI = 0.384) and expected heterozygosity (He = 0.255). But, the highest intra-species variance was recorded by SRAP (86%) markers. Nevertheless, SRAP marker estimated higher gene flow in the population (3.702). Both the markers together positively correlated with the geographical distances of naturalized habitats. Based on genetic similarity among wild species C. urticifolius is suggested to be the closest extant relative of cultivated species of jute (C. olitorius).

Climate change has a detrimental impact on food security, agricultural productivity, production stability, and revenue. As a result, agriculture must adapt to changing scenarios in order to meet the demand for food security and to endure the impact of climate change. Hence, under these situations, more focus should be given to climate-smart crops that can resist climate change and provide food to the population with minimal inputs. In this context, the production of dragon fruit crops can be a viable option. Dragon fruit is an important fruit crop in the Cactaceae family and is known for its high nutraceutical properties, greater monetary returns, low maintenance, and stress resistance. Three of its species viz. Selenecereus undatus, Selenecereus megalanthus, and Selenecereus polyrhizus are extensively grown in the world. The present review will focus on the adaptation and applicability of the dragon fruit in all situations under the climate change scenarios. This paper reviews all available information related to taxonomy, botany, cytogenetics, genetic resources (species and cultivars), phenology, flowering biology, breeding methodologies, and genomic approaches that would be useful for students, researchers, and policymakers.