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The efficiency of CO2 flux in the leaf is hindered by a several structural and biochemical barriers which affect the overall net photosynthesis. However, the dearth of information about the genetic control of these features is limiting our ability for genetic manipulation. We performed a comparative analysis between three-week-old plants of a Mesoamerican and an Andean cultivar of Phaseolus vulgaris at variable light and CO2 levels. The Mesoamerican bean had higher photosynthetic rate, maximum rate of rubisco carboxylase activity and maximum rate of photosynthetic electron transport at light saturation conditions than its Andean counterpart. Leaf anatomy comparison between genotypes showed that the Mesoamerican bean had smaller cell sizes than the Andean bean. Smaller epidermal cells in the Mesoamerican bean resulted in higher stomata density and consequently higher stomatal conductance for water vapor and CO2 than in the Andean bean. Likewise, smaller palisade and spongy mesophyll cells in the Mesoamerican than in the Andean bean increased the cell surface area per unit of volume and consequently increased mesophyll conductance. Finally, smaller cells in the Mesoamerican also increased chlorophyll and protein content per unit of leaf area. In summary, we show that different cell sizes controls the overall net photosynthesis and could be used as a target for genetic manipulation to improve photosynthesis. [ABSTRACT FROM AUTHOR]

The efficiency of CO2 flux in the leaf is hindered by a several structural and biochemical barriers which affect the overall net photosynthesis. However, the dearth of information about the genetic control of these features is limiting our ability for genetic manipulation. We performed a comparative analysis between three-week-old plants of a Mesoamerican and an Andean cultivar of Phaseolus vulgaris at variable light and CO2 levels. The Mesoamerican bean had higher photosynthetic rate, maximum rate of rubisco carboxylase activity and maximum rate of photosynthetic electron transport at light saturation conditions than its Andean counterpart. Leaf anatomy comparison between genotypes showed that the Mesoamerican bean had smaller cell sizes than the Andean bean. Smaller epidermal cells in the Mesoamerican bean resulted in higher stomata density and consequently higher stomatal conductance for water vapor and CO2 than in the Andean bean. Likewise, smaller palisade and spongy mesophyll cells in the Mesoamerican than in the Andean bean increased the cell surface area per unit of volume and consequently increased mesophyll conductance. Finally, smaller cells in the Mesoamerican also increased chlorophyll and protein content per unit of leaf area. In summary, we show that different cell sizes controls the overall net photosynthesis and could be used as a target for genetic manipulation to improve photosynthesis.

The presence of epistasis in complex traits can be significant and affect the selection of segregating populations undesirably. The purpose of this study was to determine the epistatic genetic components that influence root and shoot traits of common bean and identify their effect on the performance of segregating populations. The field experiment consisted of 49 treatments (backcross progenies, parents and segregating populations in the F2 and F3 generations). The cross P1-BAF53 (Andean) × P2-IPR 88 Uirapuru (Mesoamerican) as reference. Six traits were taken into consideration: root distribution (%), first pod length (cm), number of grains (plot), plant height (cm), reproductive cycle (days) and number of basal branches (plot). For root distribution, first pod length and number of grains, the additive and additive × additive components were significant. On the contrary, for plant height, reproductive cycle and number of basal branches, no interaction component was observed. These results can be explained by the magnitude of variance determined for these traits. The additive × additive epistasis had a negative influence on the mean performance of segregating progenies. Contrariwise, transgressive segregation effects on plant height were observed as a function of genetic dominance deviation. Thus, additive × additive epistasis can hamper the success of a breeding program, for being associated with low-variability traits. This fact may be related with the number of crosses and/or the choice of genetically more distant parents for the program, and possibly with the presence of linked genes. [ABSTRACT FROM AUTHOR]

Simple Summary: The smooth-shelled marine mussel Mytilus galloprovincialis maintains its genetic integrity as a species on a worldwide scale. Current population genetic analyses confirm the largest divergence of M. trossulus compared to the rest of congeneric species and place M. chilensis as an intermediate taxon between M. galloprovincialis and M. edulis. Unlike previous reports, M. galloprovincialis from the Atlantic Northeast is the most likely source of exotic settlements worldwide. As a super-adaptive species, M. galloprovincialis should not be considered invasive in a human-like supremacist manner, but rather as a flexible evolutionary species (FES). The worldwide distribution of this species suggests that it is naturally endowed with plastic adaptation. Therefore, it could counteract stressful conditions and provide intergeneric ecological opportunities in the face of climatic rarefaction of world coasts. The Mediterranean mussel Mytilus galloprovincialis is distributed in both hemispheres either natively or introduced. The updated population genetic distribution of this species provides a useful knowledge against which future distribution shifts could be assessed. This study, performed with seven microsatellite markers and three reference species (M. edulis, M. chilensis and M. trossulus), aimed to determine the scenario of genetic divergence between 15 samples of M. galloprovincialis from 10 localities in Europe, Africa, Asia, Australia, North America and South America. In agreement with previous data, M. trossulus was the most divergent taxon of the genus, but M. chilensis appeared as an intermediate taxon between M. edulis and M. galloprovincialis, though closer to this latter. M. galloprovincialis from the Atlantic Northeast appears as the most likely source of worldwide exotic settlements instead of the previously thought Mediterranean population. The successful worldwide establishment of M. galloprovincialis suggests it is a flexible evolutionary species (FES), i.e., a species or population whose genetic background allows it to rapidly adapt to changing environments. This natural endowed plastic adaptation makes it a candidate resilient species amidst the ongoing climatic change. [ABSTRACT FROM AUTHOR]

Gladiolus palustris (marsh Gladiolus) of wet grasslands is an extremely rare and highly endangered species in Central Europe. Ongoing loss of habitat, population fragmentation, drought, and higher mean annual temperatures caused by global warming have all contributed to a severe decline in its population over the past few decades. Additionally, hybridization with other species, such as G. imbricatus and G. illyricus, and genetic depletion may pose a significant threat to the species' survival. The focus of this study is to characterize major gene pools of the species in southern and southwestern Germany. Using molecular AFLP markers and ITS DNA sequencing, this study shows that past hybridization and introgression in Central Europe are more extensive than previously thought, posing a challenge to conservation strategies targeting taxonomically defined species. The region of the Rhine River in southwestern Germany (Upper Rhine Valley) has seen the emergence of various scattered populations of G. palustris over the past three decades, which are believed to have been introduced by humans. Introduced populations in this area (comprising the German Federal States of Baden–Württemberg and Rhineland–Palatinate) likely descend from a large source population near Lake Constance. Therefore, the study suggests promoting and protecting these new populations, given their long-standing presence in the region. Furthermore, the research proposes that naturally occurring hybrids and introgressed populations should also be the primary target of conservation efforts. [ABSTRACT FROM AUTHOR]

The Institute of Evolution's (IoE's) Wild Lettuce Gene Bank (WLGB), established in the mid 1990s, contains new and extensive collections of five wild Lactuca relatives (WLRs) originating from Israel and Armenia: L. serriola, L. aculeat a, L. georgica, L. altaica , and L. saligna. The objectives of the WLGB relate to the identification, collection, distribution, conservation, and characterization of the population genetic structure of these unique germplasms for crop improvement. Comprehensive studies are ongoing to determine the taxonomic position and crossing potential of the critical mass of collected species with domesticated lettuce, L. sativa , based on: (i) select morphological and phenological characteristics; (ii) molecular data; (iii) downy mildew resistance and (iv) variation in biologically active secondary metabolite content. In this review we present an overview of our key findings and highlight the advances in knowledge on these themes. Our germplasm collections and novel results, obtained by detailed, large-scale screening of natural populations and individuals for genetic variation, will considerably advance crop breeding research and practices. In addition, we critically summarize the recent literature and findings relating to three additional WLRs: L. dregeana, L. scarioloides , and L. azerbaijanica. The main long-term purpose of our research is to facilitate broadening of the genetic variation of domesticated lettuce by using new and adaptive germplasm in interspecific hybridization of lettuce. [ABSTRACT FROM AUTHOR]

Context: Chickens are the most important livestock in the Democratic Republic of Congo in particular and in Africa in general; they are kept for their meat and eggs for nutrition and economic status. The availability of chicken diversity information is very important in selection of breeds and in conservation of genetic resources. Aims: This study aimed to determine allelic variability, genetic diversity, and genetic relationships of the indigenous chicken populations from the South Kivu region to support breeding programs and genetic resource conservations. Methods: The LEI0258 microsatellite marker within the major histocompatibility complex gene region was used for genotyping. The LEI0258 locus amplicon sequences of 163 indigenous chickens were analysed. Key results: The number of R13 and R12 repeats varied from 1 to 21 and from 3 to 21 respectively, whereas several combinations of indels and single-nucleotide polymorphisms were observed in the microsatellite flanking regions. In total, 45 different LEI0258 alleles ranging from 193 to 473 bp were determined, including 14 private alleles (N p). Expected heterozygosity (H e) varied from 0.864 (Mwenga) to 0.938 (Bukavu), with a mean of 0.911, and observed heterozygosity (H o) ranged from 0.417 (Uvira) to 0.667 (Mwenga), with a mean of 0.519. The analysis of molecular variance (AMOVA) showed higher genetic variation within individuals (56%) than among individuals (43%) and among chicken populations (1%). Clustering into three admixed gene pools (K = 3) showed the relationships among the chicken populations. Conclusion: The present study showed the existence of high genetic diversity in chicken populations from South Kivu. Implications: This study provides information useful for better conservation and breeding strategies of indigenous chicken populations in South Kivu. A polymorphism marker showed high genetic variation among indigenous chicken in South Kivu (Africa). The South Kivu chicken populations' genetic material is composed of three gene pools and 14 specific alleles of the microsatellite locus LEI0258. Our result suggests that most chickens from South Kivu have been exposed to Newcastle disease and may have developed enhanced immune resistance to the disease. Findings will contribute to improved breeding and conservation programs. [ABSTRACT FROM AUTHOR]

The Mediterranean mussel Mytilus galloprovincialis is distributed in both hemispheres either natively or introduced. The updated population genetic distribution of this species provides a useful knowledge against which future distribution shifts could be assessed. This study, performed with seven microsatellite markers and three reference species (M. edulis, M. chilensis and M. trossulus), aimed to determine the scenario of genetic divergence between 15 samples of M. galloprovincialis from 10 localities in Europe, Africa, Asia, Australia, North America and South America. In agreement with previous data, M. trossulus was the most divergent taxon of the genus, but M. chilensis appeared as an intermediate taxon between M. edulis and M. galloprovincialis, though closer to this latter. M. galloprovincialis from the Atlantic Northeast appears as the most likely source of worldwide exotic settlements instead of the previously thought Mediterranean population. The successful worldwide establishment of M. galloprovincialis suggests it is a flexible evolutionary species (FES), i.e., a species or population whose genetic background allows it to rapidly adapt to changing environments. This natural endowed plastic adaptation makes it a candidate resilient species amidst the ongoing climatic change.

Common valerian (Valeriana officinalis L.) is an important medicinal plant revealing sedative, hypotensive, anti-spasmodic and anxiolytic activity. The purpose of the study was to determine the intraspecific variability of the common valerian growing wild in Poland and the 'Lubelski' landrace, as to their developmental traits, chemical composition and selected genetic parameters. Both wild-growing populations (19) and the landrace (1) were evaluated under ex situ conditions. Observations of the underground organs parameters, both developmental and chemical (according to the European Pharmacopoeia) were carried out in the first year of the plant's development, while the characteristics of the aboveground organs, followed by the sowing value of seeds (according to the International Seed Testing Association)—in the second year. The genetic analyses were performed using the NGS-DArT-seq method. Results indicate the presence of five different gene pools covering the regions of population's origin, with a gene flow within and between them. A high level of developmental and chemical variabilities among the wild-growing populations was noticed, however without a clear relation to the region of the origin. The mass of underground organs ranged from 107.4 to 403.6 g FW × plant−1 with the content of sesquiterpenic acids at the level of 0.004–0.094%. Population no 18 was distinguished by the highest content of sesquiterpenic acids and the relatively high mass of underground organs, followed by the admixture of the gene pool, typical for the 'Lubelski' landrace. Unlike the 'Lubelski' landrace, the wild-growing populations were characterized by a high amount of an essential oils (3.90 to 10.04 mL/kg), which may be promising from the perspective of their potential use. In turn, the sowing value of the seeds obtained from the populations, expressed as the germinability, was rather low (25.25–62.25%). [ABSTRACT FROM AUTHOR]

Gladiolus palustris (marsh Gladiolus) of wet grasslands is an extremely rare and highly endangered species in Central Europe. Ongoing loss of habitat, population fragmentation, drought, and higher mean annual temperatures caused by global warming have all contributed to a severe decline in its population over the past few decades. Additionally, hybridization with other species, such as G. imbricatus and G. illyricus, and genetic depletion may pose a significant threat to the species’ survival. The focus of this study is to characterize major gene pools of the species in southern and southwestern Germany. Using molecular AFLP markers and ITS DNA sequencing, this study shows that past hybridization and introgression in Central Europe are more extensive than previously thought, posing a challenge to conservation strategies targeting taxonomically defined species. The region of the Rhine River in southwestern Germany (Upper Rhine Valley) has seen the emergence of various scattered populations of G. palustris over the past three decades, which are believed to have been introduced by humans. Introduced populations in this area (comprising the German Federal States of Baden–Württemberg and Rhineland–Palatinate) likely descend from a large source population near Lake Constance. Therefore, the study suggests promoting and protecting these new populations, given their long-standing presence in the region. Furthermore, the research proposes that naturally occurring hybrids and introgressed populations should also be the primary target of conservation efforts.

Abstract Background Predicting the eye and hair color from genotype became an established and widely used tool in forensic genetics, as well as in studies of ancient human populations. However, the accuracy of this tool has been verified on the West and Central Europeans only, while populations from border regions between Europe and Asia (like Caucasus and Ural) also carry the light pigmentation phenotypes. Results We phenotyped 286 samples collected across North Eurasia, genotyped them by the standard HIrisPlex-S markers and found that predictive power in Caucasus/Ural/West Siberian populations is reasonable but lower than that in West Europeans. As these populations have genetic ancestries different from that of West Europeans, we hypothesized they may carry a somewhat different allele spectrum. Thus, for all samples we performed the exome sequencing additionally enriched with the 53 genes and intergenic regions known to be associated with the eye/hair color. Our association analysis replicated the importance of the key previously known SNPs but also identified five new markers whose eye color prediction power for the studied populations is compatible with the two major previously well-known SNPs. Four out of these five SNPs lie within the HERС2 gene and the fifth in the intergenic region. These SNPs are found at high frequencies in most studied populations. The released dataset of exomes from Russian populations can be further used for population genetic and medical genetic studies. Conclusions This study demonstrated that precision of the established systems for eye/hair color prediction from a genotype is slightly lower for the populations from the border regions between Europe and Asia that for the West Europeans. However, this precision can be improved if some newly revealed predictive SNPs are added into the panel. We discuss that the replication of these pigmentation-associated SNPs on the independent North Eurasian sample is needed in the future studies.

Seedlings of 431 accessions representing six and five Armenian natural populations of the wild Lactuca georgica and L. altaica, respectively, and 32, 23, and 20 populations of L. saligna, L. serriola, and L. aculeata, respectively (mostly Israeli natural populations), were screened at seedling stage for resistance to six highly virulent races of Bremia lactucae - the causal of lettuce downy mildew - that were found on several widely grown cultivars and represent the virulence spectrum in the main lettuce production areas in Europe and California. This study is likely the first detailed screening of resistance to B. lactucae races in natural populations of L. georgica and L. altaica. The highest average resistance probability and frequency of highly resistant accessions across races were detected in L. georgica. These were even higher than those shown by the germplasm of known non-host resistance (NHR) species L. saligna, which classified to the secondary lettuce gene pool (LGP-2). Thus, we suggest that L. georgica is a new LGP-2 source of resistance to B. lactucae. Our findings also support previous observations that L. aculeata, a species within the LGP-1, should be prioritized as a source of downy mildew resistance in domesticated lettuce (L. sativa) breeding programs, since some L. aculeata accessions expressed highly resistance across races. For L. serriola, the closest relative of cultivated lettuce, and for L. altaica, also a closer or even a primitive form of L. sativa, probabilities of resistance to each of the investigated B. lactucae races were very low. [ABSTRACT FROM AUTHOR]

Chickpea is one of the most important grain legume crops in the world. India is the largest producer, consumer as well as importer of chickpea. Cold stress (temperature < 15 °C) is one of the important abiotic stresses limiting chickpea production by hampering its growth and vigor at all phenological stages. This study was aimed to characterize a diverse set of 366 chickpea genotypes for cold tolerance and identify most promising cold tolerant chickpea genotypes in the Western-Himalayas of Jammu and Kashmir, India. The 366 genotypes used during the present study including genotypes belonging to cultivated, primary and secondary gene pools of chickpea. Two important approaches were used including visual screening under field conditions and screening under controlled conditions by measuring cell membrane stability through electrolyte leakage tests. The analysis of trait data collected through both the approaches led to the identification of five most promising/candidate cold tolerant chickpea genotypes including one wild genotype "Ortan-066" from secondary gene pool species (C. echinospermum), one wild genotype "Cudi 1-022" from primary gene pool species (C. reticulatum) and three genotypes (IC 116783, ICC 15200 and AGBLG 170004) from the cultivated species (Cicer arietinum). Wild genotype "Ortan-066" was found best cold tolerance source with the mean Cold Tolerance Rating (CTR) of 2 and Electrolyte Leakage Index (ELI) of 10.82%, followed by wild genotype "Cudi 1-022" (CTR = 3, ELI = 18.89%), and three cultivated genotypes viz., IC 116783, ICC 15200 and AGBL-G-170004, with the mean CTR of 3 and an estimated mean ELI of 21.26%, 21.58% and 21.94%, respectively. The promising, candidate cold tolerant genotypes identified during the present study could be used in chickpea breeding programs aimed at improving cold tolerance of cultivated chickpea worldwide. The candidate lines can be also used for developing bi-parental mapping populations, wild × cultivated introgression lines, transcriptomics and for differential expression analysis of cold tolerant genes in chickpea. [ABSTRACT FROM AUTHOR]

Heterosis has been one of the most studied phenomena since genetic studies were conceived. Knowledge of this phenomenon for the root distribution trait in beans (Phaseolus vulgaris L.) can favour the development of genotypes that are more tolerant to abiotic stresses. This study aimed to verify the occurrence of heterosis for the root distribution trait in hybrid F1 populations of common bean derived from crosses within and between gene groups. Thirty-six populations (six parents and 30 hybrids) were evaluated under field conditions in the agricultural years 2016/17 and 2017/18. The root distribution was assessed with the adapted Bohm method. The genotypes responded similarly to environmental changes (absence of an interaction). However, the root distribution differed significantly between the agricultural years. Comparisons between the mean of hybrids from crosses within each gene pool and the mean of parents did not reveal heterosis. The comparisons between gene groups showed significant differences only between BRS Embaixador x IPR Uirapuru, CBS 14 x IPR Uirapuru, and BAF 53 x IPR Uirapuru and the mean of parents. The absence of heterosis in the root trait can be explained by the degree of kinship between the gene groups, as well as some epistatic interactions. [ABSTRACT FROM AUTHOR]

Heterosis has been one of the most studied phenomena since genetic studies were conceived. Knowledge of this phenomenon for the root distribution trait in beans (Phaseolus vulgaris L.) can favour the development of genotypes that are more tolerant to abiotic stresses. This study aimed to verify the occurrence of heterosis for the root distribution trait in hybrid F1 populations of common bean derived from crosses within and between gene groups. Thirty-six populations (six parents and 30 hybrids) were evaluated under field conditions in the agricultural years 2016/17 and 2017/18. The root distribution was assessed with the adapted Bohm method. The genotypes responded similarly to environmental changes (absence of an interaction). However, the root distribution differed significantly between the agricultural years. Comparisons between the mean of hybrids from crosses within each gene pool and the mean of parents did not reveal heterosis. The comparisons between gene groups showed significant differences only between BRS Embaixador x IPR Uirapuru, CBS 14 x IPR Uirapuru, and BAF 53 x IPR Uirapuru and the mean of parents. The absence of heterosis in the root trait can be explained by the degree of kinship between the gene groups, as well as some epistatic interactions.

Background and aims - The isolation of populations inside forest refugia during past climate changes has widely been hypothesized as a major driver of tropical plant diversity. Environmental conditions can also influence patterns of diversity by driving divergent selection leading to local adaptation and, potentially, ecological speciation. Genetic and phylogenetic approaches are frequently used to study the diversification of African tree clades. However, the environmental space occupied by closely related species or intraspecific gene pools is barely quantified, though needed to properly test hypotheses on diversification processes. Methods - Using species distribution models, we determined the bioclimatic constraints on the distribution of closely related species and intra-specific gene pools. Our study model, Erythrophleum (Fabaceae - Caesalpinioideae), is a tropical tree genus widespread across Africa, and vastly investigated for genetics. Here, we combined the available phylogenetic data with information on niche divergence to explore the role of ecology into diversification at the species and gene pool levels. Key results - Ecological speciation through climate has probably played a key role in the evolution of the Erythrophleum species. The differential climatic niche of the species indicated adaptive divergence along rainfall gradients, that have probably been boosted by past climate fluctuations. At the gene pool level, past climate changes during the Pleistocene have shaped genetic diversity, though within Erythrophleum suaveolens, adaptive divergence also occurred. Conclusions - We believe that ecological speciation is a key mechanism of diversification for tropical African tree species, since such climatic niche partition exist among many other genera. Modelling the environmental niche of closely related taxa, and testing for niche differentiation, combined with divergence dates offered new insights on the process of diversification. [ABSTRACT FROM AUTHOR]

We studied the genetic relationships of Lactuca georgica samples originating in Armenia and the Russian Federation with samples representing four other predominantly self-pollinating wild Lactuca species (L. serriola, L. aculeata, L. saligna, and L. virosa) originating in various countries, as well as with samples representing cultivated lettuce, L. sativa by using 48 TRAP markers. We also visualized their genetic diversity and structure. The present study is likely the first molecular phylogenetic evaluation of a detailed screening of L. georgica germplasm. Data analysis of the three major wild species in this study, L. georgica (134 samples), L. virosa (57 samples), and L. serriola (40 samples) showed that allele frequencies of all 47 polymorphic loci varied significantly among the species. A total of 11, 9, and 10 alleles were unique to L. georgica, L. serriola, and L. virosa, respectively; 71% of TRAP marker diversity was between species. The Neighbor-Joining tree clearly clustered the whole set of 238 samples according to their taxonomic determination. It also reflects the gene diversity as well as the genetic distance values among samples representing the between and within variance of the various species. The L. georgica samples clustered most distantly from the L. sativa samples. The interspecies comparisons between samples belonging to L. georgica with those belonging to L. sativa displayed a high distance, lower only from the interspecies comparisons between samples belonging to L. virosa (in the tertiary gene pool of cultivated lettuce) with those belonging to L. sativa. Thus, additional molecular data with more hybridization experiments are necessary to reconsider if L. georgica is indeed a constituent of the primary gene pool of cultivated lettuce. The L. georgica samples were divided into two sub-clusters, with samples collected in southeast and central Armenia grouping together while all those collected in the north and Dagestan grouped together. [ABSTRACT FROM AUTHOR]

Common bean (Phaseolus vulgaris L.) is considered as one of the principal grain legume crops grown in north-western Himalayan state of Jammu and Kashmir (J&K), India. Huge diversity has been observed for this crop in state Jammu and Kashmir. The hilly regions of the state J&K are famous for producing high quality, tasty and highly flavoured beans. In order to characterise this huge diversity and trace the origin of common bean, systematic efforts have been made for the first time in collection, evaluation and characterization of bean collection from Jammu & Kashmir. A set of 428 common bean lines were initially collected/procured and based on cluster analysis using few qualitative traits/site of collection, a diverse set of 96 lines was selected. The PCR assay for phaseolin locus led to the characterization of 96 lines into Meso-american and Andean types. Out of 96 lines tested, 45 possessed “S” type phaseolin and 51 possess “T” type phaseolin. The ITS region of selected local and exotic lines was Sanger sequenced and the sequence analysis of ~ 800 bp long region revealed the presence of 12 SNPs including one promising SNPs showing significant association with phaseolin patterns. The clustering based on ITS sequence data led to the clear cut separation of common bean lines into two distinct clusters based on their phaseolin types. The results of the present study helped to gain insights into the origin of common bean landraces grown in state of J&K, India. [ABSTRACT FROM AUTHOR]

Background and Aims In Central Europe Hypericum perforatum and Hypericum maculatum show significant hybridization and introgression as a consequence of Pleistocene range fluctuations, and their gene pools are merging on higher ploidy levels. This paper discusses whether polyploid hybrid gene pools are trapped in the ecological climatic niche space of their diploid ancestors, and tests the idea of geographical parthenogenesis. Methods DNA sequence information of nuclear ribosomal DNA and plastid loci, ploidy level estimates and ecological niche modelling are used to characterize the various diploid and polyploid gene pools and unravel spatio-temporal patterns of gene flow among them. Key Results On the diploid level, the three gene pools are clearly distinct between and within species of H. perforatum (two gene pools) and H. maculatum, and their divergence dates back to the first half of the Pleistocene. All polyploids in Central Europe show high levels of past and contemporary gene flow between all three gene pools. The correlation of genetic and geographical distances breaks down if the latter is larger than 250 km, indicating recent and ongoing gene flow. The two species are ecologically differentiated, but in particular hybrids among all three gene pools do not show significant niche differences compared to their parental gene pools, except for some combinations with H. maculatum. Conclusions Inter- and intraspecific gene flow between inter- and intra-species gene pools is limited on the diploid level, and the geographical distribution of the diploids largely reflects Pleistocene evolutionary history. Secondary contact promoted hybridization and introgression on the polyploid level, enabling offspring to escape the diploid gene pools. However, the hybrid polyploids do not show significant niche differences compared to their diploid progenitors. It is concluded that the observed absence of niche divergence has precluded further differentiation and geographical partitioning of new polyploid lineages being effectively separated from the parental lines. The predominantly apomictic reproducing polyploids are trapped in the polyploid gene pool and the ecological climatic niche space of their diploid ancestors. [ABSTRACT FROM AUTHOR]

Development of genomic resources in any crop is the pre-requisite for the construction of linkage map and implementation of molecular breeding strategies to develop superior cultivars. Large number of molecular markers are required to enrich the scanty information available in horsegram ( Macrotyloma uniflorum).We employed the next-generation Illumina sequencing platform to develop a large number of microsatellite markers in this species. Of the total 23,305 potential SSRs motifs, 5755 primers were designed. Of these, 1425, 1310, 856, 1276, and 888 were of di-, tri-, tetra-, penta-, and hexa-nucleotide repeats respectively. Thirty polymorphic SSR primers and 24 morphological traits were used in 360 horsegram accessions to detect the genetic diversity and population structure. Thirty primers amplified 170 polymorphic alleles with an average of 5.6 alleles per primer having size 80 to 380 bp. The polymorphism information content (PIC) ranged from 0.15 to 0.76 with an average of 0.50, suggesting that SSR markers used in the study were polymorphic and suitable for characterization of horsegram germplasm. Dendrogram-based on Jaccard's similarity coefficient and neighbor-joining tree grouped the horsegram accessions into two major clusters. Similarly, STRUCTURE analysis assigned genotypes into two gene pools namely Himalayan origin and Southern India. Diversity analysis based on 24 agro-morphological traits also suggested the presence of high level of diversity among the accessions. [ABSTRACT FROM AUTHOR]

Cellulose is the most abundant polysaccharide in the dead plant biomass, and its degradation is an important part of global carbon cycle. β-Glucosidases complete the final step of cellulose hydrolysis by converting cellobiose to glucose. Genetic potential and expression of β-glucosidase genes were studied in the topsoil of a Picea abies forest in two contrasting seasons. These seasons were the summer, representing the peak of plant photosynthetic activity, and late winter, after an extended period with no photosynthate input. Fungal and bacterial β-glucosidase genes belonging to glycoside hydrolase families GH1 and GH3 amplified from DNA and RNA and amplicon pools were analyzed. Transcript pool were largely corresponded to gene pools, although some abundant transcripts were not found in the gene pool. The major reservoirs of β-glucosidase genes were the fungal phylum Ascomycota and Basidiomycota and the bacterial phyla Firmicutes, Actinobacteria, Proteobacteria Acidobacteria and Deinococcus-Thermus. This indicates that a diverse microbial community utilized cellobiose. Seasonality influenced both genetic diversity of β-glucosidase genes and their expression. The results indicate that a complex community of bacteria and fungi expresses β-glucosidases in forest soils. Even β-glucosidase genes showing low abundance in DNA may be functionally important as revealed by their high expression especially in basidiomycota. The functional diversity in the studied ecosystem clearly exhibited a seasonal pattern. [ABSTRACT FROM AUTHOR]

Orobanche cumana Wallr. (sunflower broomrape) is a holoparasitic weed that infects roots of sunflower in large areas of Europe and Asia. Two distant O. cumana gene pools have been identified in Spain, one in Cuenca province in the Centre and another one in the Guadalquivir Valley in the South. Race F has been hypothesized to have arisen by separate mutational events in both gene pools. In the Guadalquivir Valley, race F spread in the middle 1990’s to become predominant and contained so far with race F hybrids. Recently, enhanced virulent populations of O. cumana have been observed in commercial fields parasitizing race F resistant hybrids. From them, we collected four independent populations and conducted virulence and SSR marker-based genetic diversity analysis. Virulence essays confirmed that the four populations studied can parasitize most of the race F resistant hybrids tested, but they cannot parasitize the differential inbred lines DEB-2, carrying resistance to race F and G and, and P-96, resistant to F but susceptible to races G from other countries. Accordingly, the new populations have been classified as race GGV to distinguish them from other races G. Cluster analysis with a set of populations from the two Spanish gene pools and from other areas, mainly Eastern Europe, confirmed that race GGV populations maintain close genetic relatedness with the Guadalquivir Valley gene pool. This suggested that increased virulence was not caused by new introductions from other countries. Genetic diversity parameters revealed that the four populations had much greater genetic diversity than conventional populations of the same area, containing only alleles present in the Guadalquivir Valley and Cuenca gene pools. The results suggested that increased virulence may have resulted from admixture of populations from the Guadalquivir Valley and Cuenca followed by recombination of avirulence genes.

Chickpea (Cicer arietinum L.), commonly known as ‘gram’ is one of the major pulse crops of India covering 7.97 m ha areaproducing 7.06 m t of the grains and registering all time productivity of 885 kg/ha during 2008-09. This has become possible due todevelopment and popularization of high yielding varieties insulated well against various biotic and abiotic stresses for various partsof the country. Some of these high yielding are GNG 158, Vijay, DCP 92-3, Rajas, Digvijay, KWR 108, H 82-2, RSG 888, JG 315,Vijay, JG 16, ICCV 10, JG 11, KGD 1168, GNG 469, Pusa 372, KPG 59, ICCV 2, Shubhra (IPCK 2002-29), BGD 128, PusaChamatkar (BG 1053), JGK 1 and Pusa kabuli 1003 which have stable resistance against wilt. Similarly PBG 5, GNG 469, PBG 1,Pusa 413, Pusa 408, Pusa 417 and Himachal chana 1 have resistance against ascochyta blight besides high yield potential. Littleefforts have been made in vast variability present among germplasm accessions, which are available with several International andNational Institutes. Inter-mating between accessions/elite lines of same origin or inter-varietal crosses led varieties development hasresulted in narrow genetic base of existing cultivars. Little efforts have been made in exploitation of wild Cicer and exoticcollections also. Concerted and systematic efforts are required to harness the potential of this vast variability. In view of the changingclimatic and global scenario there is urgent need to reorient breeding programme so that desired level of genetic enhancement can beachieved. Genetic options for mitigating terminal soil moisture stress and high temperature, both at reproductive and vegetativestage, development of genotypes with high nutrient efficiency need care in breeding programmes. Besides, biotic and abiotic stressesnow trade has become more important. Ttherefore development varieties possessing consumers’ preferred traits like seed size inkabuli and milling quality in desi chickpea need special attention. With the advent of powerful non-conventional approaches fortransferring genes from wild sources and even other genera, it has become possible to develop resistant cultivars for dreaded insectpest like gram pod borer, Helicoverpa armigera Hubner. Hence potential of biotechnological tools must be exploited. The potentialof molecular marker technology in transferring of targeted traits with utmost efficiency or QTLs/ targeted genes has been discussedalong with efforts on mapping and tagging of genes conferring resistance/tolerance to major diseases and abiotic stresses. Thepresent paper deals with the accomplishments’ made and the research agenda for genetic enhancement of grain yield and productionof chickpea in India in near future.

Strategies were investigated for improving efficiency in the use of segregating common bean (Phaseolus vulgaris) populations using crosses between the Andean cultivar BRS-Radiante and the Mesoamerican parent cultivar Carioca-MG by developing populations with 12.5%, 25%, 50%, 75% and 87.5% of the allele frequency of one of the parents. For each of the five populations we evaluated for two traits, the number of days to the beginning of flowering and grain yield (g plot-1), in the F2:3 (sown in February 2006) and F2:4 (sown in July 2006) generation progenies using 15 x 15 lattice design experiments, with 44 progenies (n = 220 plants) plus the two parents and three controls being evaluated for each generation. In terms of variability release, the populations with different parental allele frequencies presented no consistent tendency of alteration. In general, genetic variance was stated among progenies in all populations, indicating success with selection. For grain yield, the lowest mean was observed in the populations with 50% of the alleles of both parents. If, for instance, the objective is to develop earlier flowering lines, the best strategy is to perform two, or at least one, backcross with the earliest parent. The most suitable allele frequency is to be determined according to the desired grain type.

In this study, 180 genotypes of cultivated Phaseolus vulgaris from the Caribbean were evaluated with the phaseolin marker. All the accessions belonged to the germplasm collection of the International Center for Tropical Agriculture (CIAT). Beans from Cuba were mostly S phaseolin (68.0 %) type, with small seed size, red and black seed color and type II or type III growth habit. These were followed by beans with T phaseolin (20.0 %) and finally by those with B, CH and Sd phaseolin. In Haiti, the most common phaseolin was T (48.1%), the majority of which were large seeded bush beans, mostly of the red mottled seed color class. Many of the remaining accessions were S phaseolin (42.6%) and had small black seed, although a few had B, Sb and Sd phaseolin (4.6, 2.8 and 1.9% of genotypes, respectively). In Puerto Rico, T phaseolin was in the majority with 57.1%, most of these with large red or red mottled seed. S phaseolin was represented by 42.9 % of landraces some of which had small yellow, black or white seed. In the Dominican Republic, the T phaseolin was very abundant (85.7%) the majority of which were medium to large seeded bush beans all of which were red mottled. A smaller proportion of Dominican landraces had S and B phaseolin (9.5% and 4.8% respectively). Finally, in Jamaica, T phaseolin was found for 40.0 % of the landraces, B phaseolin was equally common and 20% of the landraces had S phaseolin although this was based on a small sample of genotypes. The phaseolin patterns indicated the prevalence of both Andean and Mesoamerican beans in the Caribbean.Se evaluó el tipo de faseolina en 180 accesiones cultivadas de Phaseolus vulgaris del Caribe de la colección del Centro Internacional de Agricultura Tropical (CIAT). En fríjoles de Cuba (25 accesiones) predominó el tipo S (68%, semilla pequeña, roja o negra y hábito de crecimiento de tipos II y III), seguidos por fríjoles con faseolina T (20 %) y con un bajo porcentaje los tipos B, CH y Sd. En Haití (108 accesiones) las faseolinas más comunes fueron T (48.1%, semilla grande, rojo moteado y hábito arbustivo) y S (42.6%, semilla pequeña, negra), y unas pocas mostraron faseolinas B, Sb y Sd. En los fríjoles de Puerto Rico (21 accesiones) las faseolinas más comunes fueron T (57.14%, semilla grande, rojo moteada) y S (42.86%, semilla pequeña amarilla, negra o blanca). En los de República Dominicana (21 accesiones) abundó el tipo T (85.7%, semilla grande o mediana rojomoteada). En los fríjoles de Jamaica (5) predominaron las faseolinas T y B (40% de cada una). Los patrones de faseolina indicaron la prevalencia tanto de fríjoles Mesoamericanos como Andinos.

Se evaluó el tipo de faseolina en 180 accesiones cultivadas de Phaseolus vulgaris del Caribe de la colección del Centro Internacional de Agricultura Tropical (CIAT). En fríjoles de Cuba (25 accesiones) predominó el tipo S (68%, semilla pequeña, roja o negra y hábito de crecimiento de tipos II y III), seguidos por fríjoles con faseolina T (20 %) y con un bajo porcentaje los tipos B, CH y Sd. En Haití (108 accesiones) las faseolinas más comunes fueron T (48.1%, semilla grande, rojo moteado y hábito arbustivo) y S (42.6%, semilla pequeña, negra), y unas pocas mostraron faseolinas B, Sb y Sd. En los fríjoles de Puerto Rico (21 accesiones) las faseolinas más comunes fueron T (57.14%, semilla grande, rojo moteada) y S (42.86%, semilla pequeña amarilla, negra o blanca). En los de República Dominicana (21 accesiones) abundó el tipo T (85.7%, semilla grande o mediana rojomoteada). En los fríjoles de Jamaica (5) predominaron las faseolinas T y B (40% de cada una). Los patrones de faseolina indicaron la prevalencia tanto de fríjoles Mesoamericanos como Andinos.In this study, 180 genotypes of cultivated Phaseolus vulgaris from the Caribbean were evaluated with the phaseolin marker. All the accessions belonged to the germplasm collection of the International Center for Tropical Agriculture (CIAT). Beans from Cuba were mostly S phaseolin (68.0 %) type, with small seed size, red and black seed color and type II or type III growth habit. These were followed by beans with T phaseolin (20.0 %) and finally by those with B, CH and Sd phaseolin. In Haiti , the most common phaseolin was T (48.1%), the majority of which were large seeded bush beans, mostly of the red mottled seed color class. Many of the remaining accessions were S phaseolin (42.6%) and had small black seed, although a few had B, Sb and Sd phaseolin (4.6, 2.8 and 1.9% of genotypes, respectively). In Puerto Rico, T phaseolin was in the majority with 57.1%, most of these with large red or red mottled seed. S phaseolin was represented by 42.9 % of landraces some of which had small yellow, black or white seed. In the Dominican Republic , the T phaseolin was very abundant (85.7%) the majority of which were medium to large seeded bush beans all of which were red mottled. A smaller proportion of Dominican landraces had S and B phaseolin (9.5% and 4.8% respectively). Finally, in Jamaica , T phaseolin was found for 40.0 % of the landraces, B phaseolin was equally common and 20% of the landraces had S phaseolin although this was based on a small sample of genotypes. The phaseolin patterns indicated the prevalence of both Andean and Mesoamerican beans in the Caribbean.

The gene pools of beef cattle breeds bred in Russia were characterized on the basis of inter simple sequence repeat DNA analysis (ISSR analysis). Samples of Aberdeen Angus, Kalmyk, and Kazakh Whitehead breeds from Russia, as well as of Hereford breed, hybrids of Kazakh Whitehead and Hereford breeds, and Kazakh Whitehead breed from the Republic of Kazakhstan, were examined. In the examined breeds, 27 AG-ISSR fragments were identified, 25 of which were polymorphic. The examined breeds were different both in the fragment profiles (the presence/absence of individual ISSR fragments) and in their frequencies. It was demonstrated that the hybrid animals lacked some ISSR fragments that were present with high frequencies in parental forms, suggesting considerable genome rearrangement in the hybrid animals (at the regions of microsatellite localization) in crossings of the individuals from different breeds. The level of genetic diversity in Russian beef breeds was consistent with the values typical of farmed populations (breeds). The genetic diversity parameters assessed by applying Nei's gene diversity index and the Shannon index varied from 0.0218 to 0.0605 and from 0.0225 to 0.0819, respectively. The highest Shannon index value was detected in the Kalmyk breed (0.0837) and Kazakh Whitehead breed from Russia (0.0819), and the highest level of Nei's gene diversity index was found in the Kalmyk breed (0.0562) and in both populations of the Kazakh Whitehead breed (0.0509 and 0.0605). The high level of genetic similarity (according to Nei) was revealed between Russian beef cattle breeds and Hereford cattle: 0.839 (for the Kazakh Whitehead breed from Russia) and 0.769 (for the Kalmyk breed). [ABSTRACT FROM AUTHOR]

Creating farms for sable breeding was associated with the commercial destruction of natural populations and, consequently, the overall decline in the species number. The gene pool of the first farm-bred sable population in Russia, established in the vicinity of Moscow ('Pushkinskiy' fur farm), was formed by crossing of animals removed from nine natural populations. In the first eight years of farm operation, approximately one thousand animals were used for sable breeding; some of these animals were able to adapt to the farm management and, subsequently, to the selection for a number of quantitative traits in the period of industrial domestication. It took about ten years for breeders to work out the breeding and selection technologies, which became successfully employed in the established affiliated sable breeding farms. The main achievement in sable breeding over the 85-year historical period of breeding in Russia is the creation of two unique breeds, black sable (1969) and Saltykovskaya 1 (2007). In general, industrial domestication in fur farming and the subsequent breeding works made the fur of many species (mink, fox, Arctic fox) obtained from natural populations uncompetitive, which undoubtedly reduced the hunting interest in the animals living in the wild. Consequently, hunting for fur-bearing animals of most species decreased and has only local importance. Owing to the specific features of sable biology, the fur of farm-bred animals cannot yet completely replace the furs obtained by hunting; however, the farm-bred sable population is constantly growing. This review presents the results of the analysis of the level of genetic variability in natural and farm populations at nuclear and mitochondrial loci. The comparative analysis makes it possible to estimate the loss of genetic diversity upon the species adaptation to the new conditions of existence. [ABSTRACT FROM AUTHOR]

Orobanche cumana Wallr. (sunflower broomrape) is a holoparasitic weed that infects roots of sunflower in large areas of Europe and Asia. Two distant O. cumana gene pools have been identified in Spain, one in Cuenca province in the Center and another one in the Guadalquivir Valley in the South. Race F has been hypothesized to have arisen by separate mutational events in both gene pools. In the Guadalquivir Valley, race F spread in the middle 1990's to become predominant and contained so far with race F hybrids. Recently, enhanced virulent populations of O. cumana have been observed in commercial fields parasitizing race F resistant hybrids. From them, we collected four independent populations and conducted virulence and SSR markerbased genetic diversity analysis. Virulence essays confirmed that the four populations studied can parasitize most of the race F resistant hybrids tested, but they cannot parasitize the differential inbred lines DEB-2, carrying resistance to race F and G, and P-96, resistant to F but susceptible to races G from other countries. Accordingly, the new populations have been classified as race GGV to distinguish them from other races G. Cluster analysis with a set of populations from the two Spanish gene pools and from other areas, mainly Eastern Europe, confirmed that race GGV populations maintain close genetic relatedness with the Guadalquivir Valley gene pool. This suggested that increased virulence was not caused by new introductions from other countries. Genetic diversity parameters revealed that the four populations had much greater genetic diversity than conventional populations of the same area, containing only alleles present in the Guadalquivir Valley and Cuenca gene pools. The results suggested that increased virulence may have resulted from admixture of populations from the Guadalquivir Valley and Cuenca followed by recombination of avirulence genes. [ABSTRACT FROM AUTHOR]

The Acrocomia aculeata is one of the most promising plants for sustainable production of renewable energy. In order to understand patterns of the distribution of the allelic diversity of A. aculeata ex situ germplasm collection, the present study investigated the hypothesis that the genetic variability of the accessions may match their geographical origin. A genotypic analysis of 77 A. aculeata accessions was conducted with 6 simple sequence repeat markers. A high degree of molecular diversity among the accessions was found, with an average of 9 alleles per locus and a polymorphic information content with a mean of 0.76. A total of 4 clusters was identified by the Bayesian analysis of population structure. The highest subpopulation diversity was identified in Popl, mainly formed by accessions from State of Mato Grosso do Sul. The populations Pop2A, Pop2B, and Pop2C, all from the State of Mmas Gerais, showed high genetic variability as determined by a higher Fst, and a wide genetic variance, which were identified within and among the population by analysis of molecular variance. Based on our results and on Vavilov's theory on crop origins, one possible diversity center fot A. aculeata is proposed to be in a region in southeast Brazil. [ABSTRACT FROM AUTHOR]

Cultivated pigeonpea has a narrow genetic base. Wild relatives play an important role in the efforts to broaden its genetic base. In this report, we present a successful wide-cross between the cultivated pigeonpea and Cajanus lanceolatus, a wild relative from the secondary gene pool, native to Australia, with desirable traits such as frost and drought resistance. A range of F1 progeny were obtained and the resultant F1 hybrid plants set mature pods and seeds. The hybrids had intermediate morphology, sharing the traits of both the parents. All the F1 hybrids flowered profusely. Some of the hybrids were completely male sterile and some were partially fertile with pollen fertility ranging from 35 to 50 %. Meiotic analysis of the fertile F1 hybrids revealed a high degree of meiotic chromosome pairing between the two parental genomes. Meiotic analysis of the sterile F1 hybrids revealed that the breakdown of microsporogenesis occurred at the post-meiotic stage after the formation of tetrads. Fertile plants formed regular bivalents with normal disjunction, except for occasional asynchrony at meiotic II division. [ABSTRACT FROM PUBLISHER]