Spontaneum Genotypes Research Articles

Genetic diversity of wild barley (<i>Hordeum spontaneum</i> K. Koch) in the context of resistance to toxic aluminum ions

Background. The problem of resistance to aluminum toxicity of soils is very relevant for the cultivated type of barley. The area of acidic soils in Russia is about forty percent of the total area of arable land, so the toxicity of aluminum is one of the main factors that reduce the yield of barley. The study of wild relatives of the main crops, including barley, is of considerable interest for the development of stress-resistant cultivars. Wild barley Hordeum spontaneum K. Koch has biological characteristics similar to the cultivated H. vulgare L., grows in various ecogeographic zones, and is well adapted to local soil and climate conditions. All this makes it possible to use it as a new donor of source material for breeding high-yielding cultivars adapted to certain environmental conditions. The objective of this work was to search for H. spontaneum genotypes highly resistant to ionic (Al3+) toxicity.Materials and methods. One hundred accessions of H. spontaneum from the collection of the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) were examined. The resistance of barley accessions to toxic aluminum ions was studied at the early stages of plant development by the root test method (185 mcМ Al3+, pH 4.0) with the calculation of root and sprout length indices.Results and conclusions. The studied fragment of the wild barley collection demonstrated broad genetic diversity in terms of resistance to phytotoxic aluminum ions. Laboratory assessment allowed us to identify barley genotypes differing in the reaction of their roots and sprouts at the early phases of ontogenesis. The identified genotypes with a high level of resistance to ion stress can be used as a valuable source of genetic material to improve existing cultivars and develop new ones by introgression of foreign resistance genes.

Cold-Induced Physiological and Biochemical Alternations and Proteomic Insight into the Response of Saccharum spontaneum to Low Temperature.

Sugarcane, a cash crop, is easily affected by low temperature, which results in a decrease in yield and sugar production. Breeding a new variety with cold tolerance is an essential strategy to reduce loss from cold stress. The identification of germplasms and genes/proteins with cold tolerance is a vital step in breeding sugarcane varieties with cold tolerance via a conventional program and molecular technology. In this study, the physiological and biochemical indices of 22 genotypes of S. spontaneum were measured, and the membership function analysis method was used to comprehensively evaluate the cold tolerance ability of these genotypes. The physiological and biochemical indices of these S. spontaneum genotypes showed a sophisticated response to low temperature. On the basis of the physiological and chemical indices, the genotypes were classified into different cold tolerance groups. Then, the high-tolerance genotype 1027 and the low-tolerance genotype 3217 were selected for DIA-based proteomic analysis by subjecting them to low temperature. From the four comparison groups, 1123, 1341, 751, and 1693 differentially abundant proteins (DAPs) were identified, respectively. The DAPs based on genotypes or treatments participated in distinct metabolic pathways. Through detailed analysis of the DAPs, some proteins related to protein homeostasis, carbohydrate and energy metabolism, amino acid transport and metabolism, signal transduction, and the cytoskeleton may be involved in sugarcane tolerance to cold stress. Furthermore, five important proteins related to cold tolerance were discovered for the first time in this study. This work not only provides the germplasms and candidate target proteins for breeding sugarcane varieties with cold tolerance via a conventional program and molecular breeding, but also helps to accelerate the determination of the molecular mechanism underlying cold tolerance in sugarcane.

Differences in sugarcane stool branching within Saccharum spontaneum genotypes and compared to Saccharum officinarum and commercial varieties

Commercial sugarcane varieties are hybrids between Saccharum officinarum, known for its high sucrose content but poor ratooning growth, and Saccharum spontaneum, known for its low sucrose but greater propensity to produce tillers and better disease resistance. While only 20% of the Saccharum hybrid genome originates from S. spontaneum, the genes underlying the ability to produce more tillers over successive harvests have historically been associated with this species. In order to assess the variation in stool branching and tiller recruitment, 10 genotypes were assessed, including four S. spontaneum, two S. officinarum, two recent S. spontaneum introgressed lines and 2 commercial hybrids. Differences in branching were observed amongst the S. spontaneum genotypes; while all were classified as sympodial rhizome types lacking a terminal bud, there were differences in the degree of branching and the lengths of the underground internodes, with some classified as sprawling (with seven levels of branching) and others as clumping (with four to five levels of branching) depending on the stem nodes. In contrast, the S. officinarum genotypes had limited branching, expanding to only three levels. The S. hybrids and S. spontaneum backcrosses had greater similarity to the clumping S. spontaneum genotypes than to the S. officinarum genotypes. Principal component analysis separated the genotypes of sprawling S. spontaneums, clumping S. spontaneum, hybrids/introgressed lines and S. officinarum. The variation in stool branching may be used to select S. spontaneum parents that would yield better ratooning abilities in their hybrids with S. officinarum, without the ‘weediness’ associated with sprawling rhizomes, for commercial sugarcane production.

Mitochondrial genome SNPs analysis of eight barley genotypes displaying hot spot regions, phylogenetic relationships and heteroplasmy

Organellar genomes are small, circular entities that provide unique advantages as compared to the nuclear genome. The present study was aimed at evaluating the efficiency of utilizing mitochondrial single nucleotide polymorphisms (SNPs) approach in separating barley cultivars. Sequences generated via next-generation sequencing were further utilized to confirm the incidence of heteroplasmy in barley mitochondrial genome. The analysis involved seven cultivated barley (Hordeum vulgare subsp. vulgare) (VG) and one wild (H. vulgare subsp. spontaneum) (SP) genotypes. A total of 73 million paired-end reads per mitochondrial genomes across the eight barley genotypes were generated using Illumina HiSeq 2000 platform. Sequences of each genotype were separately aligned to the published barley mitochondrial reference genome, thus SNPs were detected. The overall results indicated the efficiency of using mitochondrial SNPs as a molecular marker in distinguishing among barley genotypes. Unique SNPs were determined in six out of the eight genotypes, where Giza131 and Giza129 had no specific mitochondrial SNPs, while Giza130 showed the largest number of unique mitochondrial SNPs. The phylogenetic tree indicated the close relationship between Giza129 and Giza130. Interestingly, SP was not clearly discriminated among genotypes.

Identification of Barley Landraces and Wild Barley (Hordeum spontaneum) Genotypes Resistant to Rhynchosporium commune

Barley scald is caused by the fungal pathogen Rhynchosporium commune. This disease causes substantial losses in barley production areas of the world. In this study, seedling resistance of 198 barley landraces, 104 wild barley (Hordeum spontaneum) genotypes and two susceptible Turkish cultivars (Bülbül 89 and Efes 3) to 6 R. commune isolates was assessed in greenhouse experiments. Virulence differences among the R. commune isolates were observed. One sixrowed barley landrace (Yeşilköy 9052) was resistant to all six isolates. Another six-rowed barley landrace (genotype no 17) showed resistant reaction to 5 isolates. Fourteen barley landraces were resistant and susceptible to 4 and 2 isolates, respectively. Twenty seven genotypes of H. spontaneum numbered as 5, 6, 7, 8, 9, 11, 16, 20, 30, 31, 36, 37, 48, 50, 51, 56, 58, 59, 60, 62, 67, 79, 80, 83, 90, 94 and 101 were found resistant to all six isolates of R. commune. Apart from these genotypes, 19 genotypes numbered as 1, 2, 32, 33, 34, 42, 43, 49, 52, 64, 66, 76, 77, 78, 96, 97, 102, 104 and 107 showed resistance to 5 isolates and susceptibility to only 1 isolate. Two susceptible Turkish cultivars Bülbül 89 and Efes 3 were found susceptible to 96% of the scald isolates. Resistant barley landraces and Hordeum spontaneum genotypes can be used as sources of resistance against R. commune.

Salinity tolerance of wild barley Hordeum vulgare ssp. spontaneum

AbstractSalinity tolerance of 47 wild barley genotypes and six barley cultivars was evaluated under control and salinity stress (300 mM NaCl) conditions. Shoot and root dry weight (DW), plant height, membrane stability index (MSI), relative water content, survival rate, leaf malondialdehyde (MDA) and proline contents, root and leaf Na, K, Ca and K/Na ratio, and chlorophyll a fluorescence were measured. Salinity stress caused significant increase in the MDA, proline content, Na and Ca concentrations of the roots and leaves, but resulted in a decrease in the other traits. H. spontaneum genotypes were considerably less affected by the salinity than the genotypes of H. vulgare. Plant survivability was negatively correlated with the Na concentration (r =−.66) but positively correlated with the leaf K/Na ratio (r = .67) and MSI (r = .68). Tolerance mechanisms such as ion exclusion (Na) were likely to be present in the wild barley causing K/Na homeostasis as well as the much lower root and shoot Na, resulting in the higher survival rate.

Phenotypic and Molecular Characterization of a Core Collection of Saccharum spontaneum L. in China

Saccharum spontaneum L. is widely used in developing new sugarcane (Saccharum spp. hybrids) cultivars due to its ability to transmit high vigor, ratooning ability, and increased tolerance to various biotic and abiotic stresses. Interspecific hybridization helps to broaden the genetic diversity of modern sugarcane cultivars, but there is a continual need to collect and characterize new sources of germplasm. The objective of this study was to evaluate a primary core collection of 92 S. spontaneum genotypes (82 were of Chinese origin) using 29 phenotypic traits and 15 simple sequence repeat markers. There was considerable morphological variation among the S. spontaneum genotypes. Principal component and heatmap analyses indicated that the genotypes could be separated into four groups using two major traits related to yield (stalk length, stalk diameter, and stalk weight) and juice quality traits (juice Brix, juice fiber, juice sucrose, and apparent purity). Genotypes collected from the same geographic location did not cluster together, so geography alone was not a good predictor of genotypic divergence in this collection. Phenotypic trait data alone failed to fully differentiate genotypes, but a combination of phenotypic and molecular data was useful in characterizing the genotypes. The phenotypic and molecular characterization of unexploited S. spontaneum germplasm will facilitate in the identification of potential parents for introgression and identification of high-yielding, disease-resistant cultivars, energy canes, and cultivars suited for abiotic stresses, thereby increasing the economic sustainability of sugarcane.

Identification of Hordeum spontaneum Genotypes Resistant to Net Blotch Disease

Wild barley (Hordeum spontaneum) is a progenitor of cultivated barley and naturally grows in Turkey. H. spontaneum genotypes possess superior characteristics for biotic and abiotic stress tolerance factors. In this study, 3 virulent Pyrenophora teres f. maculata and 3 virulent P. teres f. teres isolates were tested under greenhouse conditions in order to find net blotch resistant H. spontaneum genotypes. A total of 104 H. spontaneum genotypes were used. Twenty-six H. spontaneum genotypes which corresponded to 25% of the genotypes (genotypes numbered 8, 13, 14, 16, 22, 24, 27, 31, 37, 44, 47, 54, 58, 62, 65, 66, 69, 74, 78, 81, 89, 94, 99, 102, 104 and 107) exhibited reactions classified in the resistant group to 3 virulent P. teres f. maculata isolates. Eight H. spontaneum genotypes which corresponded to 7.6% of the genotypes (genotypes numbered 24, 27, 29, 33, 44, 54, 89 and 94) exhibited reactions classified in the resistant group to 3 virulent P. teres f. teres isolates. Six H. spontaneum genotypes which corresponded to 5.7% of the genotypes (genotypes numbered 24, 27, 44, 54, 89 and 94) exhibited reactions in the resistant group to both 6 virulent P. teres f. teres and P. teres f. maculata isolates. In addition, a considerable number of genotypes exhibited resistant group reactions to one or two isolates of both forms of the pathogen. These genotypes could be used for developing net blotch resistant barley cultivars.

Presence of seventeen genes potentially involved in cold tolerance in sugarcane and Saccharum spontaneum genotypes

Presence of seventeen genes potentially involved in cold tolerance in sugarcane and Saccharum spontaneum genotypes

Assessment of genetic diversity among Jordanian wild barley (Hordeum spontaneum) genotypes revealed by SSR markers

Wild barley, Hordeum spontaneum is the progenitor of cultivated barley. The center of diversity is in the Fertile Crescent in the Near East, where wild barley grows under a wide range of environmental and climatic conditions. Jordan wild barley is expected to harbor important genes that could be used for the improvement of the cultivated varieties especially in their tolerance to drought. To assess genetic diversity and allelic variation of Jordanian wild barley, 103 wild barley genotypes collected from different parts of Jordan along with 29 cultivated barley genotypes were analyzed for diversity by means of Simple Sequence Repeats (SSR). The spontaneum genotypes were grouped into six populations according to their longitude, latitude, altitude, and rainfall zone of the sites from where they have been collected, and the cultivated in one population. All barley genotypes were analyzed with 11 SSR markers with known sequences and chromosomal locations. The 11 microsatellite markers revealed 237 alleles, with an average of 21.5 alleles per locus. In spontaneum genotypes, 209 alleles were identified with an average of 19 alleles per locus, whereas, cultivated genotypes had 95 alleles with an average of 8.6 alleles per locus. Moreover, 52 alleles were identified in spontaneum (22 %) of the total alleles and 22 alleles in cultivated barley (9 %). The level of genetic diversity was very high; in fact, mean in total gene diversity (Ht) was 0.86 ranging from 0.72 to 0.94. Average gene diversity (H) was 0.79 ranging from 0.74 to 0.82. Genetic variation within population was much higher than among populations at molecular levels: this was also supported by the finding that morphological characters such as awn length, plant height, days to maturity, peduncle length, peduncle extrusion and tillering number, showed higher variation within populations than among populations. Clustering of populations was according to their ecological geographical pattern.

Sequence Characteristics and Phylogenetic Implications of the nrDNA Internal Transcribed Spacers (ITS) in Protospecies and Landraces of Sugarcane (Saccharum officinarum L.)

Internal transcribed spacers (ITS) of nuclear ribosomal DNA (nrDNA) cistrons were studied in 19 protospecies and 11 landraces of Saccharum spp. The purpose of the present study was to investigate genetic variability and genetic divergence among the 30 genotypes of Saccharum officinarum L. for exploitation of potential parent resources in sugarcane breeding. ITS region analysis revealed the length of the ITS sequences from 589 to 590 bp, G+C content from 64.01 to 65.03 % (ITS1: 207 bp, G+C: 62.8–65.22 %; ITS2: 218–219 bp, G+C: 69.27–70.78 %; and 5.8S: 164 bp, G+C: 57.32–57.93 %). The ITS1 and ITS2 regions showed variable sequence lengths and G+C content. The 5.8S region was found to be more conserved (99.39 %). ITS1 recorded highest percentage of variation sites (90.48 %), high number of transitions and transversions. The neighbor-joining (NJ) method was used to assess the phylogenetic relationship based on the combined nucleotide sequence data of ITS1, 5.8S and ITS2, and the 30 accessions were divided into two clades. Clade I included all the 11 S. spontaneum accessions, and clade II consisted of S. officinarum, S. barberi, S. sinense, S. robustum and endemic species. Eleven accessions of S. spontaneum were clustered into several subclasses, indicating that the genetic diversity of S. spontaneum genotypes is abundant. Six landraces namely Hongpi S17, Tuojianghong, Loethers, Guzhizhe, Mango, Guilin Zhuzhe in the present study were closely related to S. spontaneum species, which may be used as available resources. This study validates the utility of rDNA-ITS region as a reliable indicator of phylogenetic relationships, especially ITS1 as probable DNA barcode at higher levels and can serve as an additional approach for studying genetic diversity in sugarcane and related relatives. The analysis on ITS sequences could provide a reference for exploitation of potential parent resources in sugarcane breeding.

Sequencing of Chloroplast Genomes from Wheat, Barley, Rye and Their Relatives Provides a Detailed Insight into the Evolution of the Triticeae Tribe

Using Roche/454 technology, we sequenced the chloroplast genomes of 12 Triticeae species, including bread wheat, barley and rye, as well as the diploid progenitors and relatives of bread wheat Triticum urartu, Aegilops speltoides and Ae. tauschii. Two wild tetraploid taxa, Ae. cylindrica and Ae. geniculata, were also included. Additionally, we incorporated wild Einkorn wheat Triticum boeoticum and its domesticated form T. monococcum and two Hordeum spontaneum (wild barley) genotypes. Chloroplast genomes were used for overall sequence comparison, phylogenetic analysis and dating of divergence times. We estimate that barley diverged from rye and wheat approximately 8–9 million years ago (MYA). The genome donors of hexaploid wheat diverged between 2.1–2.9 MYA, while rye diverged from Triticum aestivum approximately 3–4 MYA, more recently than previously estimated. Interestingly, the A genome taxa T. boeoticum and T. urartu were estimated to have diverged approximately 570,000 years ago. As these two have a reproductive barrier, the divergence time estimate also provides an upper limit for the time required for the formation of a species boundary between the two. Furthermore, we conclusively show that the chloroplast genome of hexaploid wheat was contributed by the B genome donor and that this unknown species diverged from Ae. speltoides about 980,000 years ago. Additionally, sequence alignments identified a translocation of a chloroplast segment to the nuclear genome which is specific to the rye/wheat lineage. We propose the presented phylogeny and divergence time estimates as a reference framework for future studies on Triticeae.

Characterization of Saccharum Species Germplasm for Starch Content

The renewed interest in wild Saccharum species germplasm across sugarcane breeding programs has been necessitated by the need to widen the genetic base of breeding populations. Modern sugarcane cultivars were derived from inter-specific hybridization between S. officinarum and S. spontaneum. Very few genotypes were used in the initial hybridization event in 1900s resulting in narrow genetic diversity in modern sugarcane cultivars. Characterization of genotypes in the Saccharum collections would aid its utilization. Starch is considered as an impurity in sugarcane juice because it adversely affects the quantity and quality of sugar products, refining processes and is negatively associated with sucrose content. Therefore knowledge about the starch content of S. spontaneum and other related species would be of interest to breeders. The objective of this study was to characterize the United States of America (USA) sugarcane wild germplasm and related species for starch content. The juice samples used in this study were collected at the United State Department of Agriculture, Agricultural Research Services (USDA-ARS) Sugarcane Research Station at Houma, Louisiana; Canal Point and Miami, Florida germplasm collections. There were highly significant (P<0.001) differences in starch content among species and genotypes within species. There was a non-discrete distribution for starch within the species providing an opportunity for identifying low starch genotypes for use in germplasm enhancement programs. S. spontaneum genotypes produced the greatest variability for starch providing an opportunity for identifying low starch genotypes for use as parents. Cultivated species such as S. officinarum and S. robustum produced low starch indicating that low starch offered advantages for sucrose production. The results of this study would be more useful for parent selection within germplasm for introgression breeding.

Natural Variation in Grain Selenium Concentration of Wild Barley, Hordeum spontaneum, Populations from Israel

Wild barley (Hordeum spontaneum), the progenitor of cultivated barley, is an important genetic resource for cereal improvement. Selenium (Se) is an essential trace mineral for humans and animals with antioxidant, anticancer, antiarthropathy, and antiviral effects. In the current study, the grain Se concentration (GSeC) of 92 H. spontaneum genotypes collected from nine populations representing different habitats in Israel was investigated in the central area of Guizhou Province, China. Remarkable variations in GSeC were found between and within populations, ranging from 0 to 0.387 mg kg−1 among the 92 genotypes with an average of 0.047 mg kg−1. Genotype 20_C from the Sede Boqer population had the highest GSeC, while genotype 25_1 from the Atlit population had the lowest. The mean value of GSeC in each population varied from 0.010 to 0.105 mg kg−1. The coefficient of variation for each population ranged from 12% to 163%. Significant correlations were found between GSeC and 12 ecogeographical factors out of 14 studied. Habitat soil type also significantly affected GSeC. The wild barley exhibited wider GSeC ranges and greater diversity than its cultivated counterparts. The higher Se grain concentrations found in H. spontaneum populations suggest that wild barley germplasm confer higher abilities for Se uptake and accumulation, which can be used for genetic studies of barley nutritional value and for further improvement of domesticated cereals.

Correlation between hordatine accumulation, environmental factors and genetic diversity in wild barley (Hordeum spontaneum C. Koch) accessions from the Near East Fertile Crescent

Wild barley shows a large morphological and phenotypic variation, which is associated with ecogeographical factors and correlates with genotypic differences. Diversity of defense related genes and their expression in wild barley has been recognized and has led to attempts to exploit genes from H. spontaneum in breeding programs. The aim of this study was to determine the variation in the accumulation of hordatines, which are Hordeum-specific preformed secondary metabolites with strong and broad antimicrobial activity in vitro, in 50 accessions of H. spontaneum from different habitats in Israel. Differences in the accumulation of hordatines in the seedling stage were significant between different H. spontaneum genotypes from different regional locations and micro-sites. Variation in the hordatine accumulation within genotypes was between 9% and 45%, between genotypes from the same location between 13% and 38%, and between genotypes from different locations up to 121%. Principal component analysis showed that water related factors explain 39%, temperature related factors explain 33% and edaphic factors account for 11% of the observed variation between the populations of H. spontaneum. Genetic analysis of the tested accessions with LP-PCR primers that are specific for genes involved in the biosynthetic pathway of hordatines showed tight correlations between hordatine abundance and genetic diversity of these markers. Multiple regression analyses indicated associations between genetic diversity of genes directly involved in hordatine biosynthesis, ecogeographical factors and the accumulation of hordatines.

Differences in primary dormancy and seedling revival ability for some Hordeum spontaneum genotypes of Israel

The caryopses of three wild barley (Hordeum spontaneum) genotypes, including xeric and mesic populations in Israel, and a Swedish cultivated barley, 'Mona', were used for the study of the differences in mechanisms of primary dormancy and seedling revival ability from long periods of drought. The results of tests of the cultivar Mona and genotype Sede Boker showed opposite responses of primary dormancy and revival ability. 'Mona' had no primary dormancy and relatively lower revival ability. The Sede Boker genotype had the highest rates of primary dormancy and relatively higher seedling drought tolerance even after 2 years of storage at 5 °C. The intensity of primary dormancy of the other two genotypes, Wadi Kelt and Maalot, fell between the two extremes. The seedling revival ability of Maalot was higher than that of Sede Boker. Irrigation treatments at Sede Boker to the parents from which the caryopses were collected, equivalent to 200 or 400 mm of rain, had no significant effect on the germination and revival ability of the progeny.

Wild and cultivated barleys show differences in the expression pattern of a cold-regulated gene family under different light and temperature conditions.

Cold acclimation in plants involves the expression of many genes and gene families. The present study reports the expression analysis of three members of the blt14 gene family in barley. Gene-specific antisense oligonucleotides were used as probes in northern experiments so as to follow independently the expression of individual members of the gene family. Each clone revealed different accumulation kinetics when a spring and a winter cultivar were compared, suggesting that the different regulatory mechanisms leading to mRNA accumulation of an individual member of the blt14 gene family are genotype-dependent. In a collection of Hordeum spontaneum genotypes both qualitative and quantitative polymorphisms were found for the accumulation of blt14-related mRNAs, although no clear relationships were found between blt14 expression and frost resistance. The accumulation of the blt14-related mRNAs was also modulated by light and by the albino mutation a(n). The effects of light on the accumulation of the transcripts corresponding to the blt14 gene family were evaluated by comparing etiolated and green plants. Etiolated plants accumulate the blt14-related mRNAs at a detectable level already at 22 degrees C. When the same plants are exposed to cold in absence of light an increased mRNA accumulation above the level present in green cold-treated plants can be detected. On the contrary, etiolated plants showed a reduced blt14 accumulation when exposed to cold in the presence of light. Cold-induced expression of the blt14 gene family was strongly reduced in plants carrying the albino mutation a(n). This mutant showed a defective molecular response to cold even when probed with a cDNA coding for LEA type protein (paf93). The albino mutant a(n) was not able to harden when exposed to low temperature providing a direct evidence of the relationship between expression of cold-regulated (COR) genes and the development of cold hardening. Failure of cold acclimation in the mutant cannot be merely ascribed to the absence of photosynthetic activity, since etiolated wild-type plants accumulated COR mRNAs and improved frost resistance when exposed to cold.

Characterisation of Erianthus sect. Ripidium and Saccharum germplasm (Andropogoneae - Saccharinae) using RFLP markers

A collection of 65 Erianthus Michx. sect. Ripidium Henrard accessions (representing seven accepted species) and 14 Saccharum L. representatives (S. officinarum L. and S. spontaneum L.) were studied by RFLP analysis using 14 dispersed nuclear single-copy probes from maize. An intergeneric distance (1–F) of 0.748 was revealed between Erianthus and Saccharum. Within the Erianthus collection, the greatest distances were found between E. elephantinus Hook f. or E. ravennae (L.) P. Beauv. (the two 2n=20 species), and the rest of the Erianthus collection. The smallest distances were found amongst the E. arundinaceus (Retz.) Jeswiet clones collected in Indonesia ((1–F)=0.005). In addition, a partition based on the geographical origin and consistent with the chromosome numbers, ie E. arundinaceus from Indonesia versus E. arundinaceus and E. procerus from India, was revealed. E. bengalense was intermediate. The study of the Saccharum individuals confirmed the greater variability of S. spontaneum compared to the so called noble cane, S. officinarum. The 2n=80 S. spontaneum genotypes were shown to be closely related to S. officinarum. The implication of these results on the involvement of S. spontaneum and Erianthus sect. Ripidium in the origin of S. officinarum is discussed.

Genetic analysis of the accumulation of COR14 proteins in wild (Hordeum spontaneum) and cultivated (Hordeum vulgare) barley

The cold-regulated (COR14) protein of 14 kDa is a polypeptide accumulated under low-temperature conditions in the chloroplasts of barley leaves. In H. vulgare the COR14 antibody cross-reacts with two proteins, with a slightly different relative molecular weight around the marker of 14.4 kDa, referred to as COR14a and COR14b (high and low relative molecular weight, respectively). In a collection of H. spontaneum genotypes a clear polymorphism was found for the corresponding COR proteins. While some accessions showed the same COR pattern as cultivated barley, in 38 out of 61 accessions examined the COR14 antibody cross-reacted with an additional coldregulated protein with a relative molecular weight of about 24 kDa (COR24). The accumulation of COR24 was often associated with the absence of COR14b; the relationship between the COR14b/COR24 polymorphism and the adaptation of H. spontaneum to different environments is discussed. By studying COR14 accumulation in cultivated barley we have found that the threshold induction-temperature of COR14a is associated with the loci controlling winter hardiness. This association was demonstrated by using either a set of 30 cultivars of different origin, or two sets of frost-tolerant and frost-sensitive F1 doubled-haploid lines derived from the cross Dicktoo (winter type) x Morex (spring type). These results suggest that the threshold induction-temperature of COR14a can be a potential biochemical marker for the identification of superior frostresistant barley genotypes.