Genetical investigations into β-glucan content in barley

Summary Random inbred lines produced by doubled haploidy (DH) and single seed descent (SSD) have been used to investigate the genetics of -glucan (gum) content in barley (Hordeum vulgare). Genetical analyses indicated that gum content is controlled by a simple additive genetic system. Significant negative genetic correlations were observed between -glucan content, thousand grain weight and height in the DH samples. These correlations were much reduced in the SSD samples and would suggest linkage of the genes controlling these characters. The presence of repulsion linkages could be exploited in a barley breeding programme by producing F1 derived DH to generate recombinants with high thousand grain weight and low -glucan content. Genetical parameters estimated from DH and F3 samples have successfully been used to predict the number of inbred lines transgressing the parental range for -glucan content and bivariate combinations involving -glucan.     

大麦胶含量的遗传分析

本文通过Hayman等人的双列分析系统对籽粒大麦胶含量进行了遗传研究。结果表明,控制大麦胶含量的基因系统符合加性-显性模型。大麦胶含量受微效多基因控制,加性效应起着主要的作用,也存在显性效应,而上位效应不明显。显性方向不十分一致,但总的趋势是低大麦胶含量为部分显性。环境对大麦胶含量有一定影响,但基因型—环境互作效应不显著。大麦胶含量与淀粉含量呈负相关(P<0.01);与株高呈弱正相关(P<0.05);而与千粒重、蛋白质含量无相关。     

Genetic diversity in morphological characters and phenolic acids content resulting from an interspecific cross between eggplant,Solanum melongena,and its wild ancestor (S. incanum)

Solanum incanum, the wild ancestor of eggplant, Solanum melongena, has been considered as a source of variation for high content of phenolic acid conjugates in breeding programmes aimed at improving the functional quality of eggplant. We have evaluated the morphological and phenolic acids content in an interspecific family including S. incanum (P1), S. melongena (P2), their interspecific hybrid (F1), progeny from the selfing of the F1 (F2) and the backcross of the F1 to P2 (BC1P2). Many morphological differences were found between parents, while the F1 was intermediate for most traits. However, F1 plants were taller and pricklier and presented higher fruit flesh browning than any of the parents. F2 and BC1P2 were morphologically highly variable and the results obtained suggest that a rapid recovery of the characteristic combination of S. melongena traits can be achieved in a few backcross generations. Segregation for prickliness was found to be compatible with simple genetic control, prickliness being dominant over non‐prickliness. A total of 16 phenolic acid conjugates were studied, of which chlorogenic acid (5‐O‐(E)‐caffeoylquinic acid) was the most common compound in all samples, averaging 77.8% of all hydroxycinnamic acid derivatives. Contents of total phenolic acid conjugates were much higher in S. incanum than in S. melongena fruit flesh, and no major differences were found in the profile of phenolic acids among parents. The interspecific hybrid (F1) was intermediate between the two parents in phenolic acids content. Non‐segregating generations presented considerable variation in phenolic acids content, but the range of variation was wider in segregating F2 and BC1P2 generations. Additive genetic effects were the most important in explaining the results obtained for the phenolic acids content. A number of BC1P2 plants presented a good combination of phenolic acids content and fruit weight or flesh browning. Overall, the results demonstrate that improvement of functional quality in S. melongena can be obtained using S. incanum as a donor of alleles for high phenolic acids content.     

Quantification of Fusarium culmorum in Wheat and Barley Tissues Using Real-Time PCR in Comparison with DON Content

A real‐time polymerase chain reaction (PCR) assay was developed for the specific detection of Fusarium culmorum in infected seeds. Primers and TaqMan minor groove binder probe were derived from the sequences of a F. culmorum specific PCR product. The specificity of the assay was confirmed by test in seven Fusarium species and 21 non‐Fusarium fungal species. With serial dilutions of purified genomic DNA from F. culmorum isolate B as the template, the detection limit of the assay was found to be 0.9 pg of fungal genomic DNA per reaction. A significant correlation ( = 0.982) and collinearity was found between DNA concentration and Ct (cycle threshold) values of real‐time PCR assay with serial diluted DNAs extracted from three seed samples with different deoxynivalenol (DON) content. Eight barley and nine wheat varieties infected by F. culmorum isolate B were evaluated in 1 (barley samples) and in 4 years (wheat samples). The results of real‐time PCR analysis and enzyme‐linked immunosorbent assay testing for DON content were compared and a significant correlation was found for barley samples (r² = 0.935). Concerning wheat we found rather complicated relationship between Ct values and DON contents influenced by environmental conditions of field trials. The real‐time PCR assay was found to be highly specific and sensitive. It could be used in phytopathological studies and praxis.     

The effect of Tyrophagus putrescentiae on Fusarium poae transmission and fungal community in stored barley in a laboratory experiment

The effect of Tyrophagus putrescentiae on Fusarium poae transmission and fungal community composition was studied in nonsterile barley grain. The experiments included following treatments： control barley without mites; barley containing l0 or 50 mites without preincubation on E poae （Tpl0 and TpS0）; barley containing 10 or 50 mites after preincubation on E poae （FTp 10 and FTp50）. The number of mites, suc cessful transfer of E poae, and changes in the fungal communities were examined after 21 d of experiment. Increase of deoxynivalenol （DON） content in the barley was chosen as a criterion of successful Epoae transfer. The preincubation of T. putrescentiae on Epoae increased DON level approximately to 800 and 300μg/kg of grain for FTpl0 and FTpS0, respectively. T. putrescentiae population growth in FTpl0 was lower than in Tpl0, while no difference was found between FTp50 and Tp50. Fungal communities were compared by amplification, cloning and sequencing of ITS fragments, and operational taxonomic units （OTU） analysis. The OTU analysis did not support the transfer ofF. poae via mites. From the analyzed clones, only 13 cloned sequences clustered with E poae in an OTU defined at distance level 0.07. The related clones originated from FTpl0, Tpl 0, Tp50 and control treatments, but not from FTp50. However, the presence of E poae in FTp50 was confirmed by PCR amplification with specific primers. The observation may be explained by different effect of mite population density, that is, in the high density, （FTp50 treatment） the fungus was overgrazed, while the lower population density （FTp 10） supported E poae transfer.     

The sugar and nitrogen content of the gums of Acacia species in the Mountain Ash and Alpine Ash forests of central Victoria and its potential implications for exudivorous arboreal marsupials

Abstract Chemical analysis of the total sugar and total nitrogen content of Acacia dealbata, Acacia obliquinervia and Acacia frigescens gum exudate was completed. These trees were located within stands of 53 year old Mountain Ash, Eucalyptus regnans and Alpine Ash, Eucalyptus delegatensis forest in the Central Highlands of Victoria, southeastern Australia. Values for sugar content ranged from 24 to 68% per sample. Gum samples that were collected in E. regnans forests had a significantly lower (P<0.05) sugar content than those from stands dominated by E. delegatensis. Statistical analyses using Scheffe's S-test indicated that there was a significant difference in the sugar content of gums between A. dealbata and A. frigescens but not between A. dealbata and A. obliquinervia or A. obliquinervia and A. frigescens. Values for the nitrogen content of Acacia gum varied from 0.2 to 0.7% per sample. Statistical analyses revealed that nitrogen content was significantly influenced (P<0.05) by a combination of three interacting factors: (i) Acacia species; (ii) tree diameter; and (iii) forest type. Therefore, the findings of this study indicate that the sugar and nitrogen content of Acacia gum may vary between forest types and tree species. The gum of Acacia species is an important source of food for several species of arboreal marsupials, and differences in sugar and nitrogen content could be a factor potentially influencing the distribution and abundance of these animals.     

High-density AFLP map of nonbrittle rachis 1 (<Emphasis Type="Italic">btr1</Emphasis>) and 2 (<Emphasis Type="Italic">btr2</Emphasis>) genes in barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.)

Wild relatives of barley disperse their seeds at maturity by means of their brittle rachis. In cultivated barley, brittleness of the rachis was lost during domestication. Nonbrittle rachis of occidental barley lines is controlled by a single gene (btr1) on chromosome 3H. However, nonbrittle rachis of oriental barley lines is controlled by a major gene (btr2) on chromosome 3H and two quantitative trait loci on chromosomes 5HL and 7H. This result suggests multiple mutations of the genes involved in the formation of brittle rachis in oriental lines. The btr1 and btr2 loci did not recombine in the mapping population analyzed. This result agrees with the theory of tight linkage between the two loci. A high-density amplified fragment-length polymorphism (AFLP) map of the btr1/btr2 region was constructed, providing an average density of 0.08 cM/locus. A phylogenetic tree based on the AFLPs showed clear separation of occidental and oriental barley lines. Thus, barley consists of at least two lineages as far as revealed by molecular markers linked to nonbrittle rachis genes.Electronic Supplementary Material Supplementary material is available for this article at An erratum to this article can be found at     

Photosynthetic performance and fluorescence in relation to antenna size and absorption cross-sections in rye and barley grown under normal and intermittent light conditions

The size of the Photosystem II light harvesting antenna and the absorption cross-sections of PS I (_PSI) and PS II (_PSII) were examined in relation to photosynthetic performance fluorescence. Wild-type (WT) rye (Secale cereale) and barley (Hordeurn vulgare) as well as the barley chlorophyllb-less chlorina F2 mutant were grown under control and intermittent light (IML) conditions. (_PSII) in control barley F2 was similar to IML grown WT rye and barley, which, in turn was 2.5 to 3.5 times smaller than for control WT plants. In contrast, _PSI was similar for all control plants. This was 2.5 to 4 times larger than for IML-grown WT plants. IML-grown barley mutant plants had the smallest absorption cross-sections. Photosynthetic light response curves revealed that the barley chlorina F2-mutant had rates of oxygen evolution on a per leaf area basis that were only slightly lower than control WT rye and barley while IML-grown plants had strongly reduced photosynthetic performance. Convexity () for control barley chlorina F2-mutants was equal to the WT controls (0.6–0.7), while all IML-grown plants had a of 0. This indicates that, in contrast to control barley mutants, IML-plants were limited by PS II turn-over rates at all irradiances. However, on a per leaf Chl-basis the IML-grown plants exhibited the highest photosynthetic rates. Thus, the comparatively poor photosynthetic rates for IML-grown plants on a per leaf area basis were not due to less efficient photosynthetic reaction centers, but may rather be due to an increased limitation from PS II turn-over and a reduction in the number of reaction centers per leaf area.     

The effect of pollen irradiation on segregation in spring barley crosses

Observations on the Ml, M2 and M3 generations from three barley crosses confirmed that pollen irradiation can cause deviations from expected segregation ratios for certain characters. The reduced fertility observed in the Ml and M2 generations of these crosses could be problematical in breeding programmes. It was of particular interest that at the highest dose rate used for the cross TS117 × Scots Bere there was no expression of the 6-row character, which is controlled by a recessive paternal factor.     

Changes in in vivo fluorescence quenching in rye and barley as a function of reduced PSII light harvesting antenna size

The relationship between the size of the light harvesting antenna to photosystem II (LHCII) and quenching of non-photochemical and dark level fluorescence was studied in wild-type rye (Secale cereale L. cv. Musketeer) and barley (Hordeum vulgare L. cv. Gunilla) as well as in the barley chlorophyll b-less chlorina F2 mutant (H. vulgare L. cv. Dornaria, chlorina-F2). Exposure for 10 min to an irradiance of 500 μmol m^?2 s^?1 resulted in a strong (0.71–0.73) non-photochemical (q_s) quenching of the fluorescence yield in wild-type (WT) material, while the barley chlorina F2-mutant was quenched to 75% of this level. Relaxation of q_s in darkness revealed a fast initial decay, related to relaxation of the high-energy-state dependent (q_E) part of q_s. Etiolated seedlings of rye and barley exposed to intermittent light (IML) for 36 cycles of 2 min light and 118 min darkness had suppressed Chl b and LHCII-production in both WT rye and barley, while the barley chlorina F2-mutant became totally devoid of all LHCII-polypeptides. It was found that the levels of q_s and q_s were similar in control grown barley chlorina F2 and IML-grown WT rye and barley, but q_s was reduced by 30 to 35% and q_s by 50 to 65%, respectively, as compared to control-grown. WT plants. No significant q_s could be detected in IML-grown barley chlorina F2. It is clear, from these changes in in vivo fluorescence quenching in rye and barley that a significant level of q_s is detectable even in the absence of LHCII. Only when the proximal antennae are totally absent, does q_E completely disappear. We conclude that the presence of LHCII is not an absolute requirement for q_E-quenching and suggest that distal as well as proximal antenna may contribute to q_E in vivo.     

Xanthan gum production by altered pathogenicity variants of Xanthomonas campestris

Summary Several morphologically different isolates of Xanthomonas campestris pv. campestris were obtained by treatment with N-methyl-N-nitro-N-nitrosoguanidine. These variants were used to infect Brassica plants where several degrees of virulence were found. The strains were cultured in order to produce polysaccharide, which was recovered by precipitation and subjected to physical and chemical characterization. A relationship was noted between virulence and parameters such as the final viscosity of the culture, the viscosifying capacity of the polymer and the amount of acetyl substituents in the gum. Infrared spectral analysis revealed that intramolecular interaction of gum constituents could play a significant role in virulence. It is suggested that the degree of virulence could be used as a criterion for selecting and isolating producers of high quality xanthan gum.     

Genetic variation, real-time PCR, metabolites and mycotoxins ofFusarium avenaceum and related species

In this paper the latest studies dealing with genetic variation and mycotoxins ofF. avenaceum and related species are reviewed and compared to the data from chromatographic image analyses. Forty-three European strains ofFusarium avenaceum and related species were classified by chromatographic image analysis on full chromatographic matrices. The results were in most cases in agreement with those from morphological and molecular analyses and supported the separation betweenF. avenaceum, F. arthrosporioides andF. tricinctum and betweenF. avenaceum groups I and II. The mycotoxin profiles of the FinnishF. avenaceum, F. arthrosporioides andF tricinctum strains were very similar to each other. Moniliformin and enniatins were the main mycotoxins produced. A fluorogenic TaqMan PCR assay (qPCR) was used for the detection ofF. avenaceum/ F. arthrosporioides DNA in Finnish barley and wheat. The qPCR results obtained from grain samples were compared to mycotoxin levels. A correlation was found betweenF. avenaceum/F. arthrosporioides DNA and moniliformin (MON) and enniatin (ENNs) levels in barley. A correlation was also found between the combinedF. avenaceum/F. arthrosporioides/F. tricinctum contamination and MON and ENNs levels in barley in 2002, but not in 2003. This was probably due to the higher MON and ENNs levels in 2002 than in 2003. It was possible to use the DNA levels ofF. avenaceum/F. arthrosporioides to distinguish between most barley samples containing high amounts of MON and ENNs from those containing low levels of the mycotoxins. Presented at the EU-USA Bilateral Workshop on Toxigenic Fungi & Mycotoxins, New Orleans, USA, July 5–7, 2005 Financial support: Grants from the National Technology Agency of Finland (No. 40168/03) and the Academy of Finland (No. 52104); travel grants from NorFA and the European Commission to the Laboratory of Dr. Ulf Thrane     

嗜卷书虱气调抗性形成过程中能源物质的积累与利用

报道了嗜卷书虱对高二氧化碳,低氧气调抗性形成过程中能源物质的积累以及抗性形成后在气调胁迫下能源物质的利用情况。结果表明随着抗性水平的提高。嗜卷书虱体内甘油三酯,多糖以及游离氨基酸含量均显升高。在气调胁迫环境下,嗜卷书虱抗性品系能源物质的消耗率明显低于敏感品系,甘油三酯的积累以及在气调摁迫下缓慢消耗可能是其抗气调性的主要内在机理之一。     

On the origin of six-rowed barley with brittle rachis, agriocrithon [Hordeum vulgare ssp. vulgare f. agriocrithon (Aberg) Bowd.], based on a DNA marker closely linked to the vrs1 (six-row gene) locus

The origin of six-rowed cultivated barley has been revealed to be more complex since the discovery of agriocrithon, a six-rowed barley with brittle rachis. The present study investigates whether such six-rowed brittle barley is wild or hybrid in nature, by analyzing genetic diversity at the cMWG699 marker locus, which is closely linked to the vrs1 (six-row gene) locus. DNA sequence analysis for 42 accessions showed only three types in six-rowed brittle barleys; in contrast, nine sequence types were found in ten wild barleys, ssp. spontaneum, in our previous study. Nucleotide diversities for the six-rowed brittle barley were 2.8–4.5 times lower than that for the ssp. spontaneum at this marker locus. The three sequence types found in the six-rowed brittle barley also appeared in the six-rowed cultivated barley. A cross-allelism test confirmed that the six-rowed character of the six-rowed brittle barley was controlled by the vrs1 locus. The nucleotide diversity and genealogy demonstrated that f. agriocrithon does not have the same level of diversity as found in wild barley, ssp. spontaneum. Consequently, f. agriocrithon does not appear to represent genuinely wild populations, but more probably originated from hybridization between ssp. spontaneum and six-rowed cultivated barley.     

A cDNA clone from barley encoding the precursor from the photosystem I polypeptide PSI-G: Sequence similarity to PSI-K

A cDNA clone encoding the photosystem I subunit, PSI-G was isolated from barley using an oligonucleotide specifying a partial amino acid sequence from a 9 kDa polypeptide of barley photosystem I. The 724 bp sequence contains an open reading frame encoding a precursor polypeptide of 15 107 kDa. Import studies using the in vitro expressed barley PsaG cDNA clone demonstrate that PSI-G migrates with an apparent molecular mass of 9 kDa on SDS-polyacrylamide gels together with PSI-C (subunit-VII). The previous assignment of the gene product of PsaG from spinach as subunit V (Steppuhn J, Hermans J, Nechushtai R, Ljungberg U, Thümmler F, Lottspeich F, Herrmann RG, FEBS Lett 237: 218–224, 1988) needs to be re-examined. The expression of the psaG gene is light-induced similar to other barley photosystem I genes. A significant sequence similarity to PSI-K from Chlamydomonas reinhardtii was discovered when a gene database was searched with the barley PSI-G amino acid sequence. Extensive sequence similarity between the nuclear-encoded photosystem I subunits has not previously been found. The observed sequence similarity between PSI-G and PSI-K suggests a symmetric location of these subunits in the photosystem I complex. The hydropathy plot of the barley PSI-G polypeptide indicates two membrane-spanning regions which are also found at the corresponding locations in the PSI-K polypeptide. PSI-G and PSI-K probably have evolved from a gene duplication of an ancestral gene.     

4个太湖流域粳稻地方品种抗稻瘟病性的遗传分析

以太湖流域粳稻地方品种薄稻、铁杆青、江南晚和缺儿糯等广谱、高抗稻瘟病为材料, 与高感稻瘟病品种苏御糯杂交, 获得杂交F1、F2 , 分别接种日本稻瘟病鉴别菌系北1和中国稻瘟病菌生理小种ZE3、ZG1, 根据P1、P2、F1和F2等不同世代植株的抗、感反应, 分析地方品种对不同稻瘟病菌生理小种(菌系)的抗性遗传机理。结果表明: 薄稻、铁杆青及缺儿糯对北1菌系的抗性均可能由一对显性基因控制, 江南晚对北1的抗性则可能由两对抑制基因互作控制; 铁杆青及缺儿糯对ZE3小种的抗性均可能由一对显性基因控制, 薄稻和江南晚对ZE3小种的抗性可能分别由两对显性基因和两对抑制基因互作控制; 铁杆青对ZG1小种的抗性可能是由一对显性主基因控制, 薄稻和江南晚对ZG1小种的抗性则可能由两对抑制基因互作控制。进一步将薄稻与12个日本稻瘟病菌鉴别品种杂交,用北1菌系接种不同组合的F1和F2 , 进行抗病基因的等位性测定。结果表明, 薄稻对北1菌系的抗性基因与12个鉴别品种所携带的已知抗稻瘟病基因是不等位, 将该基因暂定为Pi-bd1(t)。     

Development and In Vivo Floating Behavior of Verapamil HCl Intragastric Floating Tablets

A novel gastro retentive controlled release drug delivery system of verapamil HCl was formulated in an effort to increase the gastric retention time of the dosage form and to control drug release. Hydroxypropylmethylcellulose (HPMC), carbopol, and xanthan gum were incorporated for gel-forming properties. Buoyancy was achieved by adding an effervescent mixture of sodium bicarbonate and anhydrous citric acid. In vitro drug release studies were performed, and drug release kinetics was evaluated using the linear regression method. The optimized intragastric floating tablet composed of 3:2 of HPMC K4M to xanthan gum exhibited 95.39% drug release in 24 h in vitro, while the buoyancy lag time was 36.2 s, and the intragastric floating tablet remained buoyant for >24 h. Zero-order and non-Fickian release transport was confirmed as the drug release mechanism from the optimized formulation (F7). X-ray studies showed that total buoyancy time was able to delay the gastric emptying of verapamil HCl intragastric floating tablet in mongrel dogs for more than 4 h. Optimized intragastric floating tablet showed no significant change in physical appearance, drug content, total buoyancy time, or in vitro dissolution pattern after storage at 40°C/75% relative humidity for 3 months.     

Specific Isozyme Marker of a Virus Resistant Barley Derived from Interspecies Cross Between Hordeum vulgare and H. bulbosum

A diploid barley cultivar "Supi 1" was crossed with a tetraploid Hordeum bulbosum “GBC141” to transfer the disease resistant traits. Eleven viable triploid F1 plants were produced by means of embryo rescue technique. The resulting triploid hybrids were backcrossed to diploid barley, and seven BC1 plants were obtained. One of the BC1 plants exhibited barley yellow mosaic virus (BaYMV) resistance when grown in the diseased nursery. Isozyme analysis of H. vulgate, H. bulbosum and their backcross hybrids were made via slab polyacrylamide gel electrophoresis technique. The primary results showed that zymogram variation could be obviously found between diploid barley "Supi 1' and tetraploid H. bulbosurn "GBC141”. A peroxidase isozyme (Rf=0.47) from H. bulbosum was detected in the peroxidase isozyme zymogram of young roots of backcross hybrid BC1-2. This peroxidase isozyme was related to the BaYMV resistance but the linkage relation will be determined by the genetic analysis of the F2 population in the future. The BaYMV resistant line of the backcross with isozyme marker is the important resource of barley disease-resistant breeding.