A set of accessions of lettuce landrace ‘Ljubljanska ledenka’ (
Lactuca sativa
L.) was characterized by morphological and molecular markers and for resistance to
Bremia lactucae
, with the aim of ...assessing the variability of the collection, exploring the genetic structure and potentially identifying the characters responsible for differentiation of the accessions. Wide phenotypic variation was observed among 51 accessions screened for 26 morphological and phenological traits. UPGMA cluster analysis and principal component analysis based on phenotypic data enabled the studied accessions to be divided into four clusters. The most important character by which the largest two clusters were differentiated was anthocyanin coloration. The clustering pattern of the AFLP dendrogram where two major clusters were identified was similar but not identical to the pattern of the phenotypic dendrogram. The Mantel test showed a high correlation between the phenotypic and the molecular data obtained (r = 0.67). In spite of the weak genetic differentiation between the accessions, STRUCTURE analysis based on AFLP data provided a clear indication for the existence of sub-groups within the two clusters. Thirty-four accessions were screened for resistance to 12 races of
B. lactucae
. The results show that the accessions very frequently express various reaction patterns of race specificity. Expression of race-specificity was not uniform across the set of accessions and at least 11 different reaction patterns were recorded, indicating that different race-specific resistance factors (R-factors) or genes (
Dm
genes) could be expected. This conclusion is supported by the results obtained in morphological and molecular studies, showing that lettuce landrace ‘Ljubljanska ledenka’ is not genetically uniform and is represented by a variety of genotypes.
The present-day diversity of European flora in temperate mountain ranges was mainly formed by the negative effects of Pleistocene glaciation, which caused extinctions, restricted survival
, and ...subsequent re-colonization. Only rarely can we find species that have retained the molecular information of
survival. One such example is the extremely rare
Rchb., a monotypic genus and a narrow endemic of a mountain plateau south-east of the Julian Alps (Slovenia). We investigated the germination behavior and dispersal indications, which are often closely related to rarity and persistence and thus valuable for species conservation. Additionally, results about
help us to understand better what kind of species survived glaciations in Europe
. Our results show that these seeds have an underdeveloped embryo and require an ecologically relevant moist chilling period of about 100 days. The temperature sequence of the colder period that
seeds received in nature was 20/15 °C (52 days), 10/5 °C (40 days), 5/0 °C (65 days), 10/0 °C (45 days), 15/5 °C (21 days). The germination rate was high, significantly increased by scarification, and therefore prevented long-term seed bank establishment. We found cryptic seed differences expressed by two types of dormancy, each related to the order of the umbel: simple and complex morphophysiological dormancy for the lateral and the main umbel, respectively. Seed dispersal was very much influenced by precipitation in autumn. The germination and dispersal characteristics could explain the rarity and at the same time the persistence of
Understanding the genetic background of drought tolerance in common bean (Phaseolus vulgaris L.) can aid its resilience improvement. However, drought response studies in large seeded genotypes of ...Andean origin are insufficient. Here, a novel Andean intra-gene pool genetic linkage map was created for quantitative trait locus (QTL) mapping of drought-responsive traits in a recombinant inbred line population from a cross of two cultivars differing in their response to drought. Single environment and QTL × environment analysis revealed 49 QTLs for physiology, phenology, and yield-associated traits under control and/or drought conditions. Notable QTLs for days to flowering (Df1.1 and Df 1.2) were co-localized with a putative QTL for days to pods (Dp1.1) on linkage group 1, suggesting pleiotropy for genes controlling them. QTLs with stable effects for number of seeds per pod (Sp2.1) in both seasons and putative water potential QTLs (Wp1.1, Wp5.1) were detected. Detected QTLs were validated by projection on common bean consensus linkage map. Drought response-associated QTLs identified in the novel Andean recombinant inbred line (RIL) population confirmed the potential of Andean germplasm in improving drought tolerance in common bean. Yield-associated QTLs Syp1.1, Syp1.2, and Sp2.1 in particular could be useful for marker-assisted selection for higher yield of Andean common beans.
In South-Eastern Europe, the majority of runner-bean (Phaseolus coccineus L.) production is based on local populations grown mainly in home gardens. The local runner-bean plants are well adapted to ...their specific growing conditions and microclimate agro-environments, and show great morpho-agronomic diversity. Here, 142 runner-bean accessions from the five South-Eastern European countries of Slovenia, Bosnia and Herzegovina, Serbia, North Macedonia and Romania were sown and cultivated in their respective countries and characterised using 28 quantitative and qualitative morpho-agronomic descriptors for Phaseolus spp. based on inflorescences, leaves, plants, pods and seeds. For each of these morpho-agronomic descriptors, the accessions can be classified into two or three specific groups. The highest correlations were observed within the fluorescence, seed and pod traits. The highest variability, at 76.39%, was between the different countries, representing different geographic origins, while the variability within the countries was 23.61%. Cluster analysis based on these collected morpho-agronomic data also classified the accessions into three groups according to genetic origins. The data obtained serve as useful genetic information for plant breeders for the breeding of new bean varieties for further studies of the morpho-agronomic traits of the runner bean.
The majority of common bean plants are cultivated under drought conditions. Maintaining crop yields under drought stress is thus one of the biggest challenges facing bean production. In order to ...improve our understanding of the complex mechanisms involved in the response of common bean (Phaseolus vulgaris) to drought stress, a proteomic approach was used to identify drought-responsive proteins in leaves of two cultivars differing in their response to drought, Tiber and more sensitive Starozagorski čern. 2D-DIGE was used to compare differences in protein abundance between control and stressed plants. Fifty-eight proteins whose abundance changed significantly were identified by LC-MS/MS in Tiber and 64 in Starozagorski čern. The majority of identified proteins were classified into functional categories that include energy metabolism, photosynthesis, ATP interconversion, protein synthesis and proteolysis, stress and defence related proteins. Details of the function of the identified proteins and their abundance profiles in Tiber and Starozagorski are discussed. Interactions between identified proteins were demonstrated by bioinformatics analysis, enabling a more complete insight into biological pathways and molecular functions affected by drought stress. The results form the basis for a further understanding of the biochemical mechanisms of drought response in common bean.
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► 2D-DIGE approach is used to reveal changes in protein levels of common bean under drought. ► Leaves of two cultivars with contrasting response to drought are analyzed. ► Proteins with different biological functions are identified. ► A protein–protein interaction network is proposed for both cultivars.
Trypsin inhibitors could limit utilization of legumes in human nutrition, but they could also have beneficial health effects. The objective of this study was to measure trypsin inhibitor activity (
...TIA
) of different legumes using microtiter plate method and to identify factors that contribute to uncertainty of
TIA
measurement.
TIA
measurements were performed on seeds of faba bean, pea, common vetch, soybean, and common bean cultivars. The significant effect of legume crop on
TIA
measurement uncertainty was confirmed with
P
= 0.045. Certain sources of measurement uncertainty were related with the content of trypsin inhibitors (Tis) in legume seeds. In respect to that, significant effect of level of sample dilution (
P
˂ 0.001) was confirmed. Significant influence of the repeated absorbance measurement of sample reaction mixture on uncertainty of
TIA
measurement was identified (
P
˂ 0.001), and it took 60% of overall
TIA
measurement uncertainty for soybean cultivars.
TIA
of soybean cultivars exceeded 90 TUI/mg. Repeated absorbance measurement of positive control reaction mixture took 70% of
TIA
measurement uncertainty of cultivars with
TIA
lesser than 4.5 TUI/mg. Graduated cylinder used for preparation of the final sample solutions took the range from 45 to 90% of overall
TIA
measurement uncertainty of the cultivars whose
TIA
were in the middle of previously mentioned. The uncertainty of
TIA
measurement of legume crops was not studied before; thus, this study pointed out that acquiring insight into factors contributing to uncertainty of
TIA
measurement could give directions for improvement of
TIA
testing if microtiter plate method is used.
Common bean (Phaseolus vulgaris L.) is an important crop from the Fabaceae family that is cultivated worldwide for human consumption. It is also widely exposed to drought. The identification of genes ...whose expression is altered under conditions of drought is an important first step towards understanding the response of this species. Such a study has recently been published on roots of P. vulgaris (Torres et al. 2006, Plant Sci 171:300-307) and a complementary study is here reported on leaves. 19-day-old plants of 8 cultivars grown in a growth chamber and 21-day-old plants of four of these cultivars grown in a greenhouse under conditions nearer to those in the field, were subjected to progressive water withdrawal. Changes in gene expression in their leaves at different levels of dehydration were identified by differential display reverse transcriptase PCR and confirmed by quantitative real-time PCR. The levels of 15 transcripts were changed significantly (P < 0.05) in all cultivars under both growth conditions, 8 being increased and seven decreased. All these transcripts were related by blastp search to known plant proteins. At least six transcripts corresponded to those whose expression is altered under drought in Arabidopsis thaliana. Five of the genes identified have not previously been reported as being influenced by drought. The identified genes were different from those influenced by drought in roots of P. vulgaris. Only minor differences in expression of these 15 genes were found between the different cultivars.
Drought is an abiotic stress that strongly influences plant growth, development and productivity. Proteome changes in the stem of the drought-tolerant common bean (Phaseolus vulgaris L.) cultivar ...Tiber have were when the plants were exposed to drought. Five-week-old plants were subjected to water deficit by withholding irrigation for 7, 12 and 17days, whereas control plants were regularly irrigated. Relative water content (RWC) of leaves, as an indicator of the degree of cell and tissue hydration, showed the highest statistically significant differences between control and drought-stressed plants after 17days of treatment, where RWC remained at 90% for control and declined to 45% for stressed plants. Plants exposed to drought for 17days and control plants at the same developmental stage were included in quantitative proteomic analysis using in-gel stable isotope labeling of proteins in combination with mass spectrometry. The quantified proteins were grouped into several functional groups, mainly into energy metabolism, photosynthesis, proteolysis, protein synthesis and proteins related to defense and stress. 70kDa heat shock protein showed the greatest increase in abundance under drought of all the proteins, suggesting its role in protecting plants against stress by re-establishing normal protein conformations and thus cellular homeostasis. The abundance of proteins involved in protein synthesis also increased under drought stress, important for recovery of damaged proteins involved in the plant cell's metabolic activities. Other important proteins in this study were related to proteolysis and folding, which are necessary for maintaining proper cellular protein homeostasis. Taken together, these results reveal the complexity of pathways involved in the drought stress response in common bean stems and enable comparison with the results of proteomic analysis of leaves, thus providing important information to further understand the biochemical and molecular mechanisms of drought response in this important legume.
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