Related Wild Species Research Articles

Molecular evolution of the rbcS multiple gene family in Oryza punctata

AbstractRubisco is assembled from large subunits (encoded by chloroplast gene rbcL) and small subunits (encoded by the nuclear rbcS multigene family), which are involved in the processes of carbon dioxide fixation in the Calvin cycle of photosynthesis. Although Rubisco has been studied in many plants, the evolutionary divergences among the different rbcS genes are still largely unknown. Here, using a rice closely related wild species, Oryza punctata Kotschy ex Steud, we investigated the differential properties of the rbcS genes in the species. We identified five rbcS genes (OprbcS1 through OprbcS5), OprbcS1 showed a different evolutionary pattern from the remaining four genes in terms of chromosome location, gene structure, and sequence homology. Phylogenetic analysis revealed that plant rbcS1 and other non‐rbcS1 genes originated from a common ancient duplication event that occurred at least in seed plants ancestor. RbcS1 was then retained in a few plant lineages, including Oryza, whereas non‐rbcS1 was mainly amplified in angiosperms. OprbcS1, OprbcS2–OprbcS4, and OprbcS5 were prominently expressed in stems and seeds, young leaves, and mature leaves, respectively. The yeast two‐hybrid assay detected a significant decrease in the interaction between OprbcS1 and OprbcL compared to the other four pairs of proteins (OprbcS2–OprbcS5 and OprbcL). We propose that OprbcS1 might be assigned a divergent function that was predominantly specific to nonphotosynthetic organs, whereas OprbcS2–OprbcS5, having different affinity in the assembly process of Rubisco, might be subfunctionalized in photosynthetic organs. This study not only deepens our understanding of the fine assembly of Rubisco, but also sheds some light on future de novo domestication of wild rice.

Comparative Characterization of Pseudoroegneria libanotica and Pseudoroegneria tauri Based on Their Repeatome Peculiarities.

Pseudoroegneria species play an important role among Triticeae grasses, as they are the putative donors of the St genome in many polyploid species. Satellite repeats are widely used as a reliable tool for tracking evolutionary changes because they are distributed throughout the genomes of plants. The aim of our work is to perform a comparative characterization of the repeatomes of the closely related species Ps. libanotica and Ps. tauri, and Ps. spicata was also included in the analysis. The overall repeatome structures of Ps. libanotica, Ps. tauri, and Ps. spicata were similar, with some individual peculiarities observed in the abundance of the SIRE (Ty1/Copia) retrotransposons, Mutator and Harbinger transposons, and satellites. Nine new satellite repeats that have been identified from the whole-genome sequences of Ps. spicata and Ps. tauri, as well as the CL244 repeat that was previously found in Aegilops crassa, were localized to the chromosomes of Ps. libanotica and Ps. tauri. Four satellite repeats (CL69, CL101, CL119, CL244) demonstrated terminal and/or distal localization, while six repeats (CL82, CL89, CL168, CL185, CL192, CL207) were pericentromeric. Based on the obtained results, it can be assumed that Ps. libanotica and Ps. tauri are closely related species, although they have individual peculiarities in their repeatome structures and patterns of satellite repeat localization on chromosomes. The evolutionary fate of the identified satellite repeats and their related sequences, as well as their distribution on the chromosomes of Triticeae species, are discussed. The newly developed St genome chromosome markers developed in the present research can be useful in population studies of Ps. libanotica and Ps. tauri; auto- and allopolyploids that contain the St genome, such as Thinopyrum, Elymus, Kengyilia, and Roegneria; and wide hybrids between wheat and related wild species.

Genome-wide identification of the C2H2 zinc finger gene family and expression analysis under salt stress in sweetpotato.

The higher plant transcription factor C2H2 zinc finger protein (C2H2-ZFP) is essential for plant growth, development, and stress response. There are limited studies on C2H2-ZFP genes in sweetpotato, despite a substantial number of C2H2-ZFP genes having been systematically found in plants. In this work, 178 C2H2-ZFP genes were found in sweetpotato, distributed randomly on 15 chromosomes, and given new names according to where they were located. These members of the zinc finger gene family are separated into six branches, as shown by the phylogenetic tree. 24 tandem repeats of IbZFP genes and 46 fragment repeats were identified, and a homology study revealed that IbZFP genes linked more regions with wild relative species of sweetpotato as well as rhizome plants like potato and cassava. And we analyzed the expression patterns of IbZFP genes during the early development of sweetpotato storage roots (SRs) and salt stress using transcriptome data, and identified 44 IbZFP genes that exhibited differences in expression levels during the early expansion of sweetpotato SRs in different varieties, and 92 IbZFP genes that exhibited differences in expression levels under salt stress in salt tolerant and salt sensitive sweetpotato varieties. Additionally, we cloned six IbZFP genes in sweetpotato and analyzed their expression patterns in different tissues, their expression patterns under abiotic stress and hormone treatment, and subcellular localization. The results showed that the IbZFP genes had tissue specificity in sweetpotato and were induced to varying degrees by drought and salt stress. ABA and GA3 treatments also affected the expression of the IbZFP genes. We selected IbZFP105, which showed significant differences in expression levels under salt stress and ABA treatment, to be heterologously expressed in Arabidopsis thaliana. We found that IbZFP105 OE lines exhibited higher tolerance to salt stress and ABA stress. This indicates that IbZFP105 can enhance the salt tolerance of plants. These results systematically identified the evolution and expression patterns of members of the C2H2-ZFP gene family in sweetpotato, providing a theoretical basis for studying the role of IbZFP genes in the development of sweetpotato SRs and in resistance to stress.

Increasing diversity among Lens species for improving biological nitrogen fixation in lentil

AbstractExotic germplasm is a key resource for reintroducing genetic variability into cultivars. We evaluated 36 accessions from cultivated lentil (Lens culinaris Medik.) and six related wild species inoculated with a commercial strain of Rhizobium leguminosarum bv. viciae under greenhouse conditions. The objective was to explore Lens species and/or accessions that can contribute higher biological nitrogen fixation ability to the lentil crop. A split plot design was used with either Rhizobium inoculation, added nitrogen (+N), or neither as the main plots, and accessions in subplots randomized in blocks. Two repeats of the experiment were evaluated at flowering for N fixation and nodulation characters, and two subsequent experiments, with a subset of 14 accessions, were evaluated at maturity for seed production, seed quality, and harvest index. Differences in phenotypic expression corresponded to specific accessions but not to any particular Lens species. CDC Greenstar had the highest N fixation among lentil cultivars and also had superior yield results compared to the added N treatment. When inoculated, wild accessions, including IG 72643 (Lens orientalis), displayed unique and multiple desirable characteristics compared to cultivars, including indeterminate nodulation, higher N translocation, stable yield compared to added N treatment, and exceptionally high protein concentration in seeds.

The Population Divergence and Genetic Basis of Local Adaptation of Wild Soybean (Glycine soja) in China.

Glycine soja is the wild relative species of cultivated soybean. In this study, we investigated the population divergence and genetic basis of the local adaptation of wild soybean in China using genome-wide single-nucleotide polymorphisms (SNPs) of a population of 72 G. soja accessions. Using phylogenetic analysis, we observed that G. soja accessions clustered into three distinct groups, each corresponding to a specific geographic region, the northeastern region (NER), central region (CR), and southern region (SR), consistent with previous studies. Notably, we found a significant positive correlation between genetic and geographic distances. Further population structure analysis revealed each group was associated with an ancestral population and a specific geographic area. By utilizing the genome sequencing data of accessions from 16 different locations, we inferred the population history of these wild soybean groups. Our results indicate that the three groups diverged ~25,000 years ago, coinciding with the time of the last glacial maximum. The effective population size of the SR group expanded first, and subsequently, the NER and CR groups expanded approximately 5000 and 2500 years ago, respectively. Moreover, 83, 104, and 101 significant associated loci (SALs) were identified using genome-wide association analysis for annual mean temperature, annual precipitation, and latitude, respectively. Functional analysis of genes located in SALs highlighted candidate genes related to local adaptation. This study highlights the significant role of geographic isolation and environmental factors in shaping the genetic structure and adaptability of wild soybean populations. Furthermore, it emphasizes the value of wild soybean as a crucial genetic resource for enhancing the adaptability of cultivated soybeans, which have experienced a loss of genetic diversity due to domestication and intensive breeding practices. The insights gained from our research provide valuable information for the protection, conservation, and utilization of this important genetic resource.

Study of the specific features in the histological structure of the longissimus muscle dorsi in animals of the genus <i>Ovis</i>

Relevance. Interspecific hybridization of domestic animals with wild related species is considered as one of the promising directions in animal husbandry in the framework of improving the quality and nutrient biodiversity of livestock products. The article shows the research results of the specific features in the histological structure of the longissimus muscle dorsi in animals of the genus Ovis with different genotypes.Methods. The object of research was sheep of the Romanov breed and interspecific hybrids of domestic sheep (Romanov breed) with argali. Histological studies of the longissimus dorsi muscle of purebred and hybrid animals at the age of 12 months were carried out in a comparative aspect. The thickness and area of muscle fibers, muscle bundles, the number of muscle fibers per unit cross-sectional areas were studied.Results. Differences in a number of morphometric parameters in the main structural units of the longissimus dorsi muscle in hybrid animals depending on the genotype were revealed. In hybrid animals, in comparison with purebred sheep, a decrease in the thickness and area of muscle fibers by 12% and 25% was found (p < 0.01). An increase in the number of muscle fibers per 1 mm2 of the cut and a decrease in the proportion of connective tissue in the structure of the longissimus dorsi muscle in interspecific hybrids were shown in comparison with those in sheep of the Romanov breed (p < 0.01). These biological features of hybrid animals should be taken into account when breeding, selecting and using them to obtain meat and meat products.

Review of the book: Minarchenko V.M. et al. “Atlas of morphological and anatomical features of raw materials of wild related species of medicinal plants of Ukraine”

Review of the book: Minarchenko V.M. et al. “Atlas of morphological and anatomical features of raw materials of wild related species of medicinal plants of Ukraine”

Analysis of the 2OG‐Fe (II) oxygenase family reveals new insights associated with flowering regulation in Saccharum spontaneum

AbstractPlant flowering is a crucial phenomenon affecting crop yield and crossbreeding. Saccharum spontaneum is the closest wild relative sugarcane species widely used in sugarcane genetic improvement. However, the molecular interactions among the components of the flowering regulatory network of S. spontaneum are still unclear. In this study, we conducted a transcriptome sequencing approach to analyze the expressed genes on four developmental stages of panicle samples in S. spontaneum. The weighted gene co‐expression network analysis (WGCNA) results suggested that genes from the MEred (p = 3 × 10−4) module were significantly enriched in pathways of ABC transporters, photosynthesis, and circadian rhythm‐plant. Thus, 23 genes associated with flower development‐related genes were screened, including 7 AGL24, 1 FLC, 3 VIN3, 3 GA20ox, and 9 ELF3. In the gibberellic acid (GA) synthesis pathway, GA20ox, GA3ox, and GA2ox were the three enzymes that catalyzed later reactions of GA biosynthesis and belong to the 2‐oxoglutarate Fe (II) oxygenase (2OG) superfamily. Flavonoid synthesis was promoted by 2‐oxoglutarate Fe (II) oxygenase genes, a flowering hormone, which catalyzed and oxidized naringenin to dihydrokaempferol, an important precursor of florigen. Genome‐wide analysis revealed that 122 Ss2OG genes were identified in S. spontaneum, of which 99 genes were enriched in the panicle transcriptome. Furthermore, a quantitative reverse transcription polymerase chain reaction analysis showed that Ss2OG‐FeII_Oxy90, Ss2OG‐FeII_Oxy47, and Ss2OG‐FeII_Oxy89 could introduce the flower development, while Ss2OG‐FeII_Oxy34, Ss2OG‐FeII_Oxy37, and Ss2OG‐FeII_Oxy50 inhibited it. These findings provide new clues and resources for exploring the molecular mechanism of flowering regulation in S. spontaneum and promoting sugarcane breeding.

Limited historical admixture between European wildcats and domestic cats

Domestic cats were derived from the Near Eastern wildcat (Felis lybica), after which they dispersed with people into Europe. As they did so, it is possible that they interbred with the indigenous population of European wildcats (Felis silvestris). Gene flow between incoming domestic animals and closely related indigenous wild species has been previously demonstrated in other taxa, including pigs, sheep, goats, bees, chickens, and cattle. In the case of cats, a lack of nuclear, genome-wide data, particularly from Near Eastern wildcats, has made it difficult to either detect or quantify this possibility. To address these issues, we generated 75 ancient mitochondrial genomes, 14 ancient nuclear genomes, and 31 modern nuclear genomes from European and Near Eastern wildcats. Our results demonstrate that despite cohabitating for at least 2,000 years on the European mainland and in Britain, most modern domestic cats possessed less than 10% of their ancestry from European wildcats, and ancient European wildcats possessed little to no ancestry from domestic cats. The antiquity and strength of this reproductive isolation between introduced domestic cats and local wildcats was likely the result of behavioral and ecological differences. Intriguingly, this long-lasting reproductive isolation is currently being eroded in parts of the species' distribution as a result of anthropogenic activities.

Phylogenetic analysis of endogenous viral elements in the rice genome reveals local chromosomal evolution in Oryza AA-genome species.

Rice genomes contain endogenous viral elements homologous to rice tungro bacilliform virus (RTBV) from the pararetrovirus family Caulimoviridae. These viral elements, known as endogenous RTBV-like sequences (eRTBVLs), comprise five subfamilies, eRTBVL-A, -B, -C, -D, and -X. Four subfamilies (A, B, C, and X) are present to a limited degree in the genomes of the Asian cultivated rice Oryza sativa (spp. japonica and indica) and the closely related wild species Oryza rufipogon. The eRTBVL-D sequences are widely distributed within these and other Oryza AA-genome species. Fifteen eRTBVL-D segments identified in the japonica (Nipponbare) genome occur mostly at orthologous chromosomal positions in other AA-genome species. The eRTBVL-D sequences were inserted into the genomes just before speciation of the AA-genome species. Ten eRTBVL-D segments are located at six loci, which were used for our evolutionary analyses during the speciation of the AA-genome species. The degree of genetic differentiation varied among the eRTBVL-D segments. Of the six loci, three showed phylogenetic trees consistent with the standard speciation pattern (SSP) of the AA-genome species (Type A), and the other three represented phylogenies different from the SSP (Type B). The atypical phylogenetic trees for the Type B loci revealed chromosome region-specific evolution among the AA-genome species that is associated with phylogenetic incongruences: complex genome rearrangements between eRTBVL-D segments, an introgression between the distant species, and low genetic diversity of a shared eRTBVL-D segment. Using eRTBVL-D as an indicator, this study revealed the phylogenetic incongruence of local chromosomal regions with different topologies that developed during speciation.

Effects of cytoplasm from the related wild species <i>Aegilops mutica</i> on agronomic characters in Japanese bread wheat cultivars

Effects of cytoplasm from the related wild species <i>Aegilops mutica</i> on agronomic characters in Japanese bread wheat cultivars

Allele mining of eukaryotic translation initiation factor genes in Prunus for the identification of new sources of resistance to sharka

Members of the eukaryotic translation initiation complex are co-opted in viral infection, leading to susceptibility in many crop species, including stone fruit trees (Prunus spp.). Therefore, modification of one of those eukaryotic translation initiation factors or changes in their gene expression may result in resistance. We searched the crop and wild Prunus germplasm from the Armeniaca and Amygdalus taxonomic sections for allelic variants in the eIF4E and eIFiso4E genes, to identify alleles potentially linked to resistance to Plum pox virus (PPV). Over one thousand stone fruit accessions (1397) were screened for variation in eIF4E and eIFiso4E transcript sequences which are in single copy within the diploid Prunus genome. We identified new alleles for both genes differing from haplotypes associated with PPV susceptible accessions. Overall, analyses showed that eIFiso4E is genetically more constrained since it displayed less polymorphism than eIF4E. We also demonstrated more variations at both loci in the related wild species than in crop species. As the eIFiso4E translation initiation factor was identified as indispensable for PPV infection, a selection of ten different eIFiso4E haplotypes along 13 accessions were tested by infection with PPV and eight of them displayed a range of reduced susceptibility to resistance, indicating new potential sources of resistance to sharka.

Genetic Diversity of New Almond Accessions from Central Asian and Cold-adapted North American Germplasm

We evaluated the genetic diversity of a newly available collection of 94 almond [Prunus dulcis (Mill.) D.A. Webb] accessions from the former Improving Perennial Plants for Food and Bioenergy (IPPFBE) Foundation. Most of the collection (87 accessions) were collected as seeds from trees growing in the central Asian nations of Kyrgyzstan, Tajikistan, and Uzbekistan, and included several examples of Prunus bucharica (Korsh.) Hand.-Mazz, and related wild species. Of the remaining accessions, six were sourced from a nursery in northern Utah in the United States, and one was a seedling of ‘Nonpareil’, a major commercial cultivar. DNA fingerprints were generated from 10 simple sequence repeat markers. To evaluate the comparative diversity of these new accessions, 66 accessions from the US Department of Agriculture, National Plant Germplasm System (NPGS) almond germplasm collection near Davis, CA, USA, were also included. These NPGS accessions were chosen to represent those collected in similar regions of Central Asia and the Caucasus. The fingerprints were analyzed via hierarchical clustering, principal components analysis (PCA), and discriminant analysis of principal components (DAPC). Hierarchical clustering suggested that half of the Utah-sourced accessions are closely related to each other and to the ‘Nonpareil’ seedling. Additional close relationships were detected (including at least one duplication or mislabeling), and two P. bucharica accessions from the IPPFBE collection were separated from the rest of the collection. A plot of the first two principal components clearly separated wild almond relatives (P. bucharica and Prunus fenzliana Fritsch) from the remaining accessions. PCA after removal of the wild species separated the ‘Nonpareil’ seedling, the Utah-sourced accessions, and many of the IPPFBE accessions (mostly from Uzbekistan) from nearly all other individuals. The third principal component identified an additional population structure that separated groups of predominantly IPPFBE or NPGS accessions. DAPC showed a considerable admixture of accessions from Azerbaijan, and a little to no admixture of accessions from Georgia and Tajikistan. These results suggest that central Asian/Caucasian almond germplasm is generally distinct from ‘Nonpareil’ and its relatives, and that although there is overlap between the NPGS and IPPFBE collections from this region, the IPPFBE collection does enhance the diversity of available almond germplasm.

Variation in ripe fruit volatiles across the tomato clade: an evolutionary framework for studying fruit scent diversity in a crop wild relative.

The scents of volatile organic compounds (VOCs) are an important component of ripe fleshy fruit attractiveness, yet their variation across closely related wild species is poorly understood. Phylogenetic patterns in these compounds and their biochemical pathways offer insight into the evolutionary drivers of fruit diversity, including whether scent can communicate an honest signal of nutrient content to animal dispersers. We assessed ripe fruit VOC content across the tomato clade (Solanum sect. Lycopersicon), with implications for crop improvement since these compounds are key components of tomato flavor. We analyzed ripe fruit volatiles from 13 species of wild tomato grown under common garden conditions. Interspecific variation in 66 compounds and their biochemical pathways was assessed in 32 accessions, with an accession-level phylogeny accounting for relatedness. Wild tomato species can be differentiated by their VOCs, with Solanum pennellii notably distinct. Phylogenetic conservatism exists to a limited extent. Major clade-wide patterns corresponded to divergence of the five colored-fruited species from the nine green-fruited species, particularly for nitrogen-containing compounds (higher in colored-fruited) and esters (higher in green-fruited), the latter appearing to signal a sugar reward. We established a framework for fruit scent evolution studies in a crop wild relative system, showing that each species in the tomato clade has a unique VOC profile. Differences between color groups align with fruit syndromes that could be driven by selection from frugivores. The evolution of colored fruits was accompanied by changes in biochemical pathways underlying esters and nitrogen-containing compounds, volatiles important to tomato flavor. This article is protected by copyright. All rights reserved.

Development and characterization of F1 hybrids involving cultivated and related species of okra

Related species of any crop posses the traits of economic importance. It is important to involve the related wild species in the breeding programme to transfer the traits of economic importance to the cultivated species of crop plants. Further, the characterization of interspecific F1 hybrids is required to know the expression of various traits in both parents and their interspecific hybrid. Cultivated species of okra Abelmoschus esculentus was used to develop two interspecific F1 hybrids independently with two wild species, namely A. moschatus and A. tuberculatus. Both the related species were used as the pollen parent and the cultivated okra as the female parent. The interspecific hybrids were intermediate for days to 50% flowering, first flowering node, flower length, fruit length, fruit diameter, internodal length and plant height. The characteristics like early plant vigor, plant growth habit, flower petal color, fruit color and apex shape of fruit for both the interspecific hybrids were similar to cultivated okra parent.

Genetic Analysis of the Cultivars of Ping’ou Hybrid Hazelnut (C. heterophylla Fisch. × C. avellana L.) in China Based on SSR Markers

Ping’ou hybrid hazelnut is one of the most profitable tree nuts in China, but economically important cultivars must first be genetically validated to meet industrial demand. Traditional approaches used for cultivar identification are mainly trait-based and unreliable. Previous approaches at the DNA level, focusing on the identification of species or/and varieties that originated in China, were not used widely in hybrid hazelnut because there was no proper standard sample. In this research, a multiplexed fingerprinting test was conducted to allow for hazelnut cultivar identification using SSR markers derived from European hazelnut. Twenty-seven SSR markers were used to fingerprint 57 genetically unique Ping’ou hybrid hazelnut and related wild species. All markers showed a high level of polymorphism, as indicated by mean values for observed heterozygosity (Ho = 0.84), expected heterozygosity (He = 0.80), and polymorphism information content (PIC = 0.78). A total of 301 alleles were detected, and the number of effective alleles varied from 6 for KG817 and GB818 to 18 for B654, with an average of 11.2 alleles per locus. Moreover, the Shannon’s information index (I) ranged from 1.293 for BR215 to 2.385 for B654, with an average of 1.908. The neighbor-joining tree, principal coordinate analysis, and Bayesian analysis revealed clear separation between hybrid cultivars and wild forms (Cluster/group I), as well as the differentiation within hybrid genotypes (Clusters/groups II and III). Additionally, the NJ dendrogram demonstrated a further split within Clusters/group III (III a and III b). Altogether, with the comparable SSR information of the European hazelnut cultivar ‘Barcelona’, the newly developed marker sets can assist in the germplasm identification of hazelnut cultivars and reproductive materials. Importantly, these combined SSR loci can be applied to characterize the genetic relationships and population structures among wild genotypes and hybrid cultivars, which will then provide information to guide hazelnut breeding based on their genetic background.

Leaf rust resistance genes in Aegilops genus: occurrence and efficiency

Leaf rust is a common and costly wheat disease. The introduction of resistance genes derived from wheat wild relatives is one way to improve disease control. However, due to the rapid development of virulence in the casual pathogen Puccinia triticina, the long-term effectiveness of some leaf rust resistance (Lr) genes is questionable. To assess this, we examined 130 accessions of 13 wheat wild relative species from the Aegilops genus. The presence of 9 Lr genes was determined by PCR using primers complementary to Lr gene markers. The studied individuals were exposed to artificial inoculation with P. triticina under greenhouse and field conditions, respectively. Based on infection rate, the degree of resistance for each individual was estimated. The relationship between the presence of Lr genes and the degree of manifested resistance was assessed using canonical correlation analysis (CCA) and analysis of variance (ANOVA). Our results indicate the effective participation of Lr9 in seedling resistance while Lr58 is involved in adult plant resistance.

The Role of Home Gardens in Promoting Biodiversity and Food Security.

Plant genetic resources provide the basis for sustainable agricultural production, adaptation to climate change, and economic development. Many present crop plants are endangered due to extreme environmental conditions induced by climate change or due to the use of a limited selection of plant materials. Changing environmental conditions are a challenge for plant production and food security, emphasizing the urgent need for access to a wider range of plant genetic resources than what are utilized today, for breeding novel crop varieties capable of resilience and adaptation to climate change and other environmental challenges. Besides large-scale agricultural production, it is important to recognize that home gardens have been an integral component of family farming and local food systems for centuries. It is remarkable how home gardens have allowed the adaptation and domestication of plants to extreme or specific ecological conditions, thus contributing to the diversification of cultivated plants. Home gardens can help in reducing hunger and malnutrition and improve food security. In addition, they provide opportunities to broaden the base of cultivated plant materials by harboring underutilized crop plants and crop wild relative species. Crop wild relatives contain a wide range of genetic diversity not available in cultivated crops. Although the importance of home gardens in conserving plant genetic resources is well recognized, there is a risk that local genetic diversity will be lost if traditional plant materials are replaced by high-yielding modern cultivars. This paper provides an overview of home gardens and their present role and future potential in conserving and utilizing plant genetic resources and enhancing food and nutritional security under global challenges.

Evidence of fruit syndromes in the recently diverged wild tomato clade opens new possibilities for the study of fleshy fruit evolution

Societal Impact StatementFleshy fruits provide humans with many flavorful and nutritious crops. Understanding the diversity of these plants is fundamental to managing agriculture and food security in a changing world. This study surveyed fruit trait variation across species of tomato wild relatives and explored associations among color, size, shape, sugars, and acids. These wild tomato species native to South America can be interbred with the economically important cultivated tomato. Beyond its application to tomatoes, deepening our knowledge of how fruit traits evolve together is valuable to crop improvement efforts aimed at breeding more nutritious and appealing varieties of fruits.Summary Fleshy fruits display a striking diversity of traits, many of which are important for agriculture. The evolutionary drivers of this variation are not well understood, and most studies have relied on variation found in the wild. Few studies have explored this question on a fine‐grained scale with a group of recently diverged species while controlling for environmental effects. We developed the tomato clade as a novel system for fruit trait evolution research by presenting the first common garden‐based systematic survey of variation and phylogenetic signal in color, nutrition, and morphology traits across all 13 species of tomato wild relatives (Solanum sect. Lycopersicon). We laid the groundwork for further testing of potential evolutionary drivers by assessing patterns of clustering and correlation among disperser‐relevant fruit traits as well as historical climate variables. We found evidence of two distinct clusters of associated fruit traits defined by color, sugar type, and malic acid concentration. We also observed correlations between a fruit's external appearance and internal nutrient content that could function as honest signals to dispersers. Analyses of historical climate and soil variables revealed an association between red/orange/yellow fruits and high annual average temperature. Our results establish the tomato clade as a promising system for testing hypotheses on the drivers of divergence behind early‐stage fleshy fruit evolution, particularly selective pressure from frugivores.

Plant genetic resources for food and agriculture: novel materials for adapting to changing environmental conditions

Many present crop plants are in danger of failing due to extreme conditions induced by climate change. This along with a rapidly growing world population threatens global food security. In this paper, I provide an overview of different plant genetic resources, of possibilities to broaden their base by including crop wild relative species and other underutilized sources, and of conservation and characterization needs and tools. The increased environmental variability implies that we will need access to an even wider range of plant genetic resources than used today for breeding new crop varieties, which contain useful traits, such as pest and disease resistances and ability to withstand drought or extreme temperatures.