A Single Locus Is Responsible for Salinity Tolerance in a Chinese Landrace Barley (Hordeum vulgare L.)

Introduction

Salinity and waterlogging are two major abiotic stresses severely limiting barley production. The lack of a reliable screening method makes it very hard to improve the tolerance through breeding programs.

Methods

This work used 188 DH lines from a cross between a Chinese landrace variety, TX9425 (waterlogging and salinity tolerant), and a Japanese malting barley, Naso Nijo (waterlogging and salinity sensitive), to identify QTLs associated with the tolerance.

Results

Four QTLs were found for waterlogging tolerance. The salinity tolerance was evaluated with both a hydroponic system and in potting mixture. In the trial with potting mixture, only one major QTL was identified to associate with salinity tolerance. This QTL explained nearly 50% of the phenotypic variation, which makes it possible for further fine mapping and cloning of the gene. This QTL was also identified in the hydroponic experiment for different salt-related traits. The position of this QTL was located at a similar position to one of the major QTLs for waterlogging tolerance, indicating the possibility of similar mechanisms controlling both waterlogging and salinity tolerance.

Conclusion

The markers associated with the QTL provided a unique opportunity in breeding programs for selection of salinity and waterlogging tolerance.     

Allelic Diversity of Hrd A and Hrd B Hordein-Coding Loci in Wild (Hordeum spontaneum C. Koch) and Cultivated (Hordeum vulgare L.) Barley from Israel and Palestine

Russian Journal of Genetics - Polymorphism of hordeins encoded by the Hrd A and Hrd B loci was studied using starch gel electrophoresis in 13 barley landrace accessions and in 31 wild barley...     

Allozyme Variation in Turkmenian Populations of Wild Barley, Hordeum spontaneum Koch.

The extent and structure of genetic variation in 720 individualsrepresenting 36 populations of wild barley, Hordeum spontaneum,from Central Asia (Turkmenistan) were determined using starchgel electrophoresis of eight water soluble leaf proteins encodedby 13 loci. The populations were grouped into seven ecogeographicregions. The study found: (a) a similar amount of within populationgenetic diversity (H_e = 0.106), but lower total genetic diversity(H_T = 0.166) to that reported for Middle East populations ofH. spontaneum; (b) of the total genetic diversity, 61% was attributableto variation within populations, 27% between populations ofa region, and 12% among regions; (c) of the 42 alleles found,11 were ubiquitous, 22 were widespread and common, three localand common and seven local and rare; (d) there was a poor correlationbetween population genetic and geographic distances; and (e)the frequencies of only a few alleles correlated significantlywith climatic or geographic parameters. The extent and structureof genetic variation of Turkmenian populations, which representthe Central Asian part of the species' range, were significantlydifferent in some important aspects from Middle Eastern andeastern Mediterranean populations. The mosaic pattern of geneticvariation found in wild barley in the Middle East is less pronouncedin populations from Central Asia where there is less geneticdifferentiation among populations and regions, and more ubiquitousor common and fewer localized alleles. Copyright 2001 Annalsof Botany Company Allozyme, Central Asia, genetic diversity, Hordeum spontaneum, wild barley     

Identification and Validation of a Major Quantitative Trait Locus for Slow-rusting Resistance to Stripe Rust in Wheat

Stripe (yellow) rust,caused by Puccinia striiformis Westend.f.sp.tritici Eriks (Pst),is one of the most important wheat (Triticum aestivum L.) diseases and causes significant yield losses.A recombinant inbred (RI) population derived from a cross between Yanzhan 1 and Xichang 76-9 cultivars was evaluated for resistance to wheat stripe rust strain CYR32 at both the seedling and adult plant stages.Four resistance quantitative trait loci (QTLs) were detected in this population,in which the major one,designated as Yrq1,was mapped on chromosome 2DS.The strategy of using the Brachypodium distachyon genome,wheat expressed sequence tags and a draft DNA sequences (scaffolds) of the D-genome (Aegilops tauschii Coss.) for the development of simple sequence repeat (SSR) markers was successfully used to identify 147 SSRs in hexaploid wheat.Of the 19 polymorphic SSRs in the RI population,17 SSRs were mapped in the homeologous group 2 chromosomes near Yrq1 region and eight SSRs were genetically mapped in the 2.7 cM region of Yrq1,providing abundant DNA markers for fine-mapping of Yrq1 and marker-assisted selection in wheat breeding program.The effectiveness of Yrq1 was validated in an independent population,indicating that this resistance QTL can be successfully transferred into a susceptible cultivar for improvement of stripe rust resistance.     

Lysine Biosynthesis in Barley (Hordeum vulgare L.)

Lysine biosynthesis in seedlings of barley (Hordeum vulgare L. var. Emir) was studied by direct injection of the following precursors into the endosperm of the seedlings: acetate-1-¹⁴C; acetate-2-¹⁴C; pyruvate-1-¹⁴C; pyruvate-2-¹⁴C; pyruvate-3-¹⁴C; alanine-1-¹⁴C; aspartic acid-1-¹⁴C; aspartic acid-2-¹⁴C; aspartic acid-3-¹⁴C; aspartic acid-4-¹⁴C; α-aminoadipic acid-1-¹⁴C; and α, ε-diaminopimelic acid-1-(7)-¹⁴C. The distribution of activity in the individual carbon atoms of lysine in the different biosynthetic experiments was determined by chemical degradation. The incorporation percentages and labeling patterns obtained are in agreement with the occurrence of the diaminopimelic acid pathway. The results do not fit the incorporation percentages and labeling patterns expected if the α-aminoadipic acid pathway was operating. However, the results show that barley seedlings are able to convert a small part of the α-aminoadipic acid administered directly to lysine.     

Lysine Catabolism in Barley (Hordeum vulgare L.)

Lysine catabolism in seedlings of barley (Hordeum vulgare L. var. Emir) was studied by direct injection of the following tracers into the endosperm of the seedlings: aspartic acid-3-(14)C, 2-aminoadipic acid-1-(14)C, saccharopine-(14)C, 2,6-diaminopimelic acid-1-(7)-(14)C, and lysine-1-(14)C. Labeled saccharopine was formed only after the administration of either labeled 2,6-diaminopimelic acid or labeled lysine to the seedlings. The metabolic fate of the other tracers administered also supported a catabolic lysine pathway via saccharopine, and apparently proceeding by a reversal of some of the biosynthetic steps of the 2-aminoadipic acid pathway known from lysine biosynthesis in most fungi. Pipecolic acid seems not to be on the main pathway of l-lysine catabolism in barley seedlings.     

大麦花药离体诱导的基因型稳定性和培养基的环境指数分析

本研究以湖北啤酒大麦优良新品种（系）为材料,分析了基因型的稳定性、培养基的环境指数以及基因型与培养基的互作效应.各基因型花药愈伤组织诱导率的稳定性分析表明,E2具有较强的普遍适应性,但稳定性好的材料愈伤组织诱导率并不一定最高,各种配方培养基的环境指数值大小不同,方向也有正有负,基因型效应以及基因型和培养基的互作效应均达极显著水平。     

Phosphoinositides in Barley (Hordeum vulgare L.) Aleurone Tissue

[3H]Inositol labeling of barley (Hordeum vulgare L. cv Himalaya) aleurone layers and analysis of phospholipids by deacylation revealed the presence of phosphatidylinositol (PtdIns), PtdIns3P, and PtdIns4P but not PtdInsP2 species. In contrast to an earlier report (P.P.N. Murthy, G. Pliska-Matyshak, L.M. Keranen, P. Lam, H.H. Mueller, N. Bhuvarahamurthy [1992] Plant Physiol 98: 1498-1501) systematic chemical degradation of PtdIns revealed no evidence of a second isomer of PtdIns. Evidence of the widespread occurrence of 3-phosphorylated PtdIns within the plant kingdom is presented.     

Root-Tiller Interrelationships in Spring Barley (Hordeum distichum (L.) Lam.)

Root-tiller relations were investigated in spring barley grownin soil in deep pots. The total dry wt of the root system reachedits maximum 6 weeks from sowing, when the shoot weight was only50 per cent of its value at maturity. Seminal and nodal rootscomprised 40 and 60 per cent, respectively, of the total rootdry wt at maturity; the majority of the nodal root weight wasassociated with the main shoot. The main shoot had approximatelytwice as many nodal roots as either of the first two primarytillers (T1 and T2), and the primary and secondary tillers appearinglater were very poorly rooted. Some tillers, especially secondarytillers that died prematurely, produced no nodal roots. Theweight of the seminal roots and nodal roots attached to themain shoot continued to increase up to maturity but the drywt of nodal roots on tillers declined with time. This patternof growth was closely related to the pattern of ¹⁴C assimilateddistribution within the root system. A very small proportionof ¹⁴C assimilated by the main shoot and T1 and T2 was exported.The majority of the exported assimilate went to the seminalroot system and to nodal roots attached to the main shoot. Individualnodal and seminal roots seemed to have different roles in supplyingnutrients to the shoot system, with the former mainly providing³²P-phosphate to its tiller of origin and the latter generallysupplying the main shoot and primary tillers. Hordeum distichum. (L.) Lam., barley, root growth, nodal roots, seminal roots, tillering, assimilate distribution, ³²P-distribution     

A Nitrate Reductase-Inactivating Factor from Barley (Hordeum distichum L.) Leaves

A nitrate reductase-inactivating factor (NR-IAF) was detectedin a crude extract from 8-day-old barley (Hordeum distichumL. cv. Daisen-gold) leaves by chromatofocusing. The factor seemedto be a proteolytic enzyme with a cysteine residue at its activesite because 1) it was thermo-labile, and trypsin treatmentcaused loss of activity; 2) p-chloromercuribenzoic acid andiodoacetamide inhibited its activity; 3) leupeptin, an inhibitorof trypsin-like enzymes, also inhibited its activity; and 4)proteolytic activity toward azocasein was detected for the factorpreparation. The factor did not affect the activities of nitritereductase, glutamate dehydrogenase and xanthine oxidase. (Received March 22, 1983; Accepted July 30, 1983)     

Characterization of the Major Protein Component from Aleurone Cells of Barley (Hordeum vulgare L.)

Comparison of the SDS-PAGE patterns of salt-soluble proteinsfrom aleurone protoplasts, enriched aleurone layers preparedby pearling, and isolated embryos of mature barley showed threegroups of bands that reacted with antiserum raised against the7S globulins of oat embryos. These had M_rs of about 50 000,40 000 and 25 000. The enriched aleurones also contained a thirdgroup of immunoreactive bands (M_r about 70 000), which did notco-purify when the proteins were fractionated by ammonium sulphateprecipitation, ion exchange chromatography and immunoaffinitychromatography. The purified protein gave a single sharp peakon RP-HPLC, and contained a fourth minor group of subunits ofM_r about 20 000, in addition to those of M_rs about 50 000, 40000 and 25 000. The holoprotein and the ‘major groups’ of subunitsall had similar major N-terminal amino acid sequences whichwere related to the N-terminal amino acid sequences of pea andbean vicilins, and to sequences in the putative N-terminal regionsof the mature 7S ¹-globulins of cottonseed, confirming the homologywith these groups of proteins. Key words: Barley, seeds, 7S globulin, vicilin, ¹-globulin, amino acid sequence, protein homology     

A structured mutant population for forward and reverse genetics in Barley (Hordeum vulgare L.)

Two large-scale ethylmethanesulfonate (EMS) mutant populations from barley (Hordeum vulgare L.) cv. Optic have been developed to promote both forward and reverse genetics in this crop. Leaf material and seed from approximately 20 000 M(2) plants were individually harvested, freeze-dried and archived. DNA was isolated from 9216 plants from the 20 and 30 mm EMS treatments and assembled into 1152 eight-plant pools. To facilitate PCR-based mutation scanning an approach has been employed that combines cleavage of heteroduplexes using the Cel nuclease (Cel I), post-cleavage intercalating dye labeling and the subsequent detection of cleaved products on a Transgenomic WAVE-HS. The populations were evaluated by screening for induced mutations in two genes of interest and the induced mutations were validated by sequence analysis. To enhance the screening process, 12-16 M(3) progeny from each of the M(2) plants were assessed for visible phenotypes and the data entered into a web accessible database (http://bioinf.scri.sari.ac.uk/distilling/distilling.html).     

野生二棱大麦种子休眠型态与农艺性状及生态地理因素相关性研究

对来自以色列不同地区16个生态型野生二棱大麦种子的休眠型态与其农艺性状及起源地生态地里因素的相关性进行了研究。结果表明：高温（40℃）储藏可以打破种子的休眠;16个生态型种子在高温处理下的萌发率表现出显著差异,其休眠打破过程显示出不同型态的对数生长曲线：8个旱生生态型为S型,而8个湿生生态型为倒L型。休眠深度用实际达到最大萌发率的时间度量,最低休眠深度（15·6d）是来自湿润地区＂进化峡谷＂的生态型37-N,而最深休眠深度（103·1d）是来自干旱地区Ein-Zukim（死海附近）的生态型32-6。此外,对11个物候及农艺性状指标与休眠深度做斯皮尔曼秩相关分析,结果有9个显示出显著相关,尤其是粒重与休眠深度有极显著相关性。同时,休眠深度与起源地15个生态地理因素中的9个有显著相关,种子休眠主要受其起源地的地理位置、温度和水分条件等影响。可见,野生二棱大麦自然选择进化了休眠特性去应对干热环境而繁衍生息。本研究结果可用于进一步遗传研究和现代栽培大麦品种的改良。     

Apoplast Acidification in Growing Barley (Hordeum vulgare L.) Leaves

Apoplast acidification associated with growth is well documented in roots, coleoptiles, and internodes but not in leaves. In the present study, advantage was taken of the high cuticle permeability in the elongation zone of barley leaves to measure apoplast pH and growth in response to application of test reagents. The role of the plasma membrane H⁺-ATPase (PM-H⁺-ATPase) and K⁺ in this process was of particular interest. pH microelectrodes and an in vitro gel system with bromocresol purple as pH indicator were used to monitor apoplast pH. Growth was measured in parallel or in separate experiments using a linear variable differential transformer. Test reagents that blocked (vanadate) or stimulated (fusicoccin) PM-H⁺-ATPase or that reduced (Cs⁺, tetraethylammonium) K⁺ uptake were applied. Apoplast pH was lower in growing than in nongrowing leaf tissue and increased in the elongation zone with increasing apoplast K⁺. Vanadate increased apoplast pH and reduced growth, whereas fusicoccin caused the opposite effects. It is concluded that barley leaves exhibit acid-growth-type mechanisms in that apoplast pH is lower in elongating leaf tissue. Both growth and apoplast pH depend on the activity of the PM-H⁺-ATPase and K⁺ transport processes. However, not all of the growth displayed by leaves is dependent on a lower apoplast pH in the elongation zone; up to 50 % of growth is retained when apoplast pH in the elongation zone increases to a value observed in mature tissue.     

Comparison of Screening Methods for Resistance to Fusarium Root Rot in Common Beans (Phaseolus vulgaris L.)

Root rot, caused by Fusarium solani f. sp. phaseoli, is one of the main root diseases impacting production of common beans throughout the world. Because resistance of common beans to root rot is a quantitative trait that is strongly influenced by environmental factors, reproducible methods to screen bean plants for resistance to root rot are critical to the selection process. In this study, we adapted the inoculum layer method (ILM) developed for screening soybeans for resistance to Phytophthora rot and compared it with the traditional liquid inoculum method (LIM) for screening common beans for resistance to Fusarium root rot. In addition, two methods of evaluating resistance using the ILM were compared. The most significant Pearson correlation coefficient between trials involving 80 recombinant inbred lines was achieved with the ILM and counting discoloured vascular bundles in the lower stem (r_p = 0.7113***) compared to rating the discoloration on root and hypocotyl (r_p = 0.5555***). The traditional (LIM) screening method and rating the discolouration on roots resulted in a non‐significant correlation between trials (r_p = 0.1084).     

Heat Shock Response in Hypocotyl of Barley (Hordeum vulgare L.)

In vivo protein synthesis in barley (Hordeum vulgare L.) hypocotyl was maximum at 35°C and 40°C.HPLC analysis of soluble proteins showed 10 different types of proteins, out of which the peak corresponding to retention time 13.3 min was present at 25°C but was absent at 35°C and 40°C. Instead, another peak with retention time 13.7 min was noticed at 35°C and 40°C. Amino acid analysis showed that heat shock resulted in an increase in lysine and histidine and decrease in arginine. Heat shock also resulted in increase in peroxidase, protease and ribonuclease activity at 35°C and 37°C in comparison to 25°C. The incorporation of (3H)-uridine was significantly decreased at 37°C in comparison to 25°C.     

大麦转基因座位结构的研究

利用质粒营救法获得基因枪法转化的4种转绿色荧光蛋白基因(green fluorescent protein,GFP)大麦的转基因座位序列,序列分析显示4种材料的转基因座位中均有完整栽体的串联重复现象,表明转基因整合是同源重组的结果.同时转基因座位中也存在不完整载体片段、基因组片段的混杂排列,说明转基因整合时也发生异常重组.微粒轰击的转基因整合是由异常重组和同源重组共同完成的.     

Identification and Fine Mapping of a White Husk Gene in Barley (Hordeum vulgare L.)

Barley is the only crop in the Poaceae family with adhering husks at maturity. The color of husk at barely development stage could influence the agronomic traits and malting qualities of grains. A barley mutant with a white husk was discovered from the malting barley cultivar Supi 3 and designated wh (white husk). Morphological changes and the genetics of white husk barley were investigated. Husks of the mutant were white at the heading and flowering stages but yellowed at maturity. The diastatic power and α-amino nitrogen contents also significantly increased in wh mutant. Transmission electron microscopy examination showed abnormal chloroplast development in the mutant. Genetic analysis of F₂ and BC₁F₁ populations developed from a cross of wh and Yangnongpi 5 (green husk) showed that the white husk was controlled by a single recessive gene (wh). The wh gene was initially mapped between 49.64 and 51.77 cM on chromosome 3H, which is syntenic with rice chromosome 1 where a white husk gene wlp1 has been isolated. The barley orthologous gene of wlp1 was sequenced from both parents and a 688 bp deletion identified in the wh mutant. We further fine-mapped the wh gene between SSR markers Bmac0067 and Bmag0508a with distances of 0.36 cM and 0.27 cM in an F₂ population with 1115 individuals of white husk. However, the wlp1 orthologous gene was mapped outside the interval. New candidate genes were identified based on the barley genome sequence.     

Electron-probe Microanalysis Studies of Silica Distribution in Barley (Hordeum sativum L.)

Silicon occurence has been investigated by means of epidermalpeels, cryostat, and ultrathin sections of the internode, nodes,leaves, inflorescence bracts, and caryopsis of Hordeum sativumL. (cultivar Deba Abed) using the electron probe microanalyser.Analyses were made on growth stages during ear emergence andat maturity. The results indicate that silicon is present inthe internode with the highest concentration associated withthe opaline deposits. Detectable quantities are also found inthe outer tangential walls of the long cells, in the walls ofstomata, the sclerenchyma, and all vascular bundle regions.In mature upper internodes, silicifiation is confined to theupper third region, but this limit extends closer to the basalmeristem with increasing age of internode. The nodes have agreater concentration in the radial than in outer tangentialwalls. Heavy deposits are found in the leaves but with considerablevariation between blade and sheath, abaxial and adaxial surfaces,and the leaf position. The flag leaf contained the highest accumulations. In the inflorescence bracts (lemma and palea), silicon is detectableonly in the abaxial epidermis and hypodermis. Awns are alsoheavily silicified with the highest concentrations in the sclerenchymaand trichomes.