Hybridization between Triticum aestivum L. and Agropyron michnoi Roshev.

Summary Intergeneric hybrids between Triticum aestivum cv Chinese Spring (2n=6x=42, AABBDD) and Agropyron michnoi Roshev. (2n=4x=28, PPPP) were obtained by embryo culture. Their spike characteristics were similar to those of common wheat but, unlike their parents, they were long-awned. The average meiotic chromosome pairing at MI of F₁ hybrids was: 6.39 I +3.75 rodII+8.64 ringII+0.81 III+0.30 IV+0.04 V, the bivalent and multivalent formation of which was much higher than expected from the genomic formulae. It is especially worthwhile to note that the F₁ hybrids were self-fertile, self set being 0.15%, and seeds were easily obtained from the backcross of f₁ plants with hexaploid and tetraploid wheats; here the seed set was more than 20.0%. The polyploid taxa and the position of A. Michnoi in Agropyron are discussed.     

Genetic control for resistance to leaf rust in wheat-Agropyron lines: Agro 139 and Agro 58

Leaf rust resistance lines of Triticum aestivum carry highly effective Lr genes from Agropyron intermedium (Host) Beauv. This Agro 58 and Agro 139 resistance segregated independently of Agropyron leaf-rust resistance genes Lr-19, Lr-24 and Lr-9 from Ae. umbellulata. Monosomic analysis showed that the Lr gene in Agro 139 was incorporated into wheat chromosome 6D. C-banding analysis could not determine the C-banding pattern of A. intermedium in wheat -Agropyron lines Agro 58 and Agro 139. It is assumed that the transfers occurred from the euchromatin regions of the Agropyron chromosomes to the euchromatin regions of the wheat chromosomes. It is suggested that the Lr gene from Agro 139 be designated LrAg ⁱ-1 and the Lr gene from Agro 58 designated LrAg ⁱ-2.     

Inflorescence culture of wheat-Agropyron hybrids: Callus induction,plant regeneration,and potential in overcoming sterility barriers

Segments of young inflorescences of Triticum aestivum cv. Chinese Spring (CS), its F₁ hybrids with Agropyron trachycaulum and A. scirpeum and backcross derivatives with A. yezoense, A. intermedium and A. junceum, and of a A. yezoense x T. aestivum cv. Wichita hybrid were cultured. Different parts of young spikelets of A. trachycaulum x CS F₁ and A. yezoense x Wichita F₁ 's were also cultured. Percent callus induction was lower in wheat than in the wheat-Agropyron hybrids or backcross derivatives. Percent callus induction from different organs in both hybrids was in the descending order of whole spikelet, spikelet without glumes, rachis, and glumes. No plants could be regenerated from calli of wheat and backcross derivatives except those of CS x A. intermedium combination. Callus induction in hybrids varied from 54 to 84% and plant regeneration from 14 to 31%. The regenerants required no vernalization. Variants including one with top-dense spikes and another with elongated spikelets were recovered. Out of eight A. trachycaulm x CS hybrid regenerants, one had anthers and stigma as opposed to neutral flowers of the original hybrid.     

Relationships of Agropyron intermedium chromosomes determined by chromosome pairing and alcohol dehydrogenase isozymes in common wheat background

Summary The relationships of Agropyron intermedium chromosomes in two wheat-Agropyron addition series were determined. Chromosome pairing behaviour revealed that the alien chromosome in lines TAF-2 and L7 of Vilmorin-A. intermedium set are homologous to the alien chromosomes in lines P and C of the Caribo-A. intermedium set respectively. Localization of alcohol dehydrogenase isozyme genes in Vilmorin-Agropyron addition line L4 and in Caribo-Agropyron line O indicated relationships with wheat chromosomes of homoeologous group 4.     

Biochemical evidence of homoeology between Triticum aestivum and Agropyron intermedium chromosomes

Summary The alcohol dehydrogenase (ADH), phosphoglucose mutase (PGM), glucosephosphate isomerase (GPI), glutamic oxaloacetic transaminase (GOT), malate dehydrogenase (MDH), leaf esterases (ESTL), leaf acid (ACPH) and endosperm alkaline (PHE) phosphatases, leaf peroxidases (PERL) zymogram phenotypes of Triticum aestivum, Agropyron intermedium, Triticum aestivum — Agropyron intermedium octoploids and six Agropyron intermedium chromosome additions to Triticum aestivum and two ditelocentric addition lines were determined. It was found that the six disomic chromosome addition lines and one ditelocentric chromosome addition line could be distinguished from one another and from the other possible lines on the basis of the zymogram phenotypes of these isozymes. The structural gene Acph-X1 was located on Agropyron chromosome L1, the genes Got-X3 and Mdh-X2 on chromosome L2, the gene Gpi-X1 on chromosome L3, the genes Adh-X1, Pgm-X1 and Phe-3 on chromosome L4, gene Perl-1 on chromosome L5 and the gene Estl-2 on chromosome L7 and chromosome arm L7d2. These gene locations provide evidence of homoeology between Agropyron chromosomes L1, L2, L3, L4, L5 and L7 and the Triticum aestivum chromosomes of homoeologous groups 7, 3, 1, 4, 2 and 6, respectively.     

New hybrids between Agropyron and wheat

Summary Intergeneric hybrids of Triticum aestivum (2n=42,AABBDD) with Agropyron ciliare (2n= 28,SSYY), A. trachycaulum (2n=28,SSHH), A. yezoense (2n=28,SSYY) and A. scirpeum (2n=28) are reported for the first time. F₁ hybrids of T. aestivum were also produced with A. intermedium (2n=42,E₁E₁E₂E₂Z₁Z₁) and A. junceum (2n=14,JuJu). All wheat-Agropyron hybrids were obtained by embryo rescue technique. Cultivars and reciprocal crosses differed for seed set, seed development and F₁ plant production. The F₁ hybrids were sterile. Attempts to obtain amphiploids were unsuccessful. However, backcross derivatives were obtained with wheat as the recurrent parent.The level of chromosome pairing in A. trachycaulum x wheat, A. yezoense x wheat and wheat x A. junceum hybrids provided no evidence of homologous or homoeologous pairing. Mean pairing frequencies in A. ciliare x wheat, wheat x A. scirpeum and wheat x A. intermedium hybrids indicated homoeologous or autosyndetic pairing. Ph gene was more effective in regulating homoeologous pairing in A. yezoense x wheat hybrids than in A. ciliare x wheat hybrid. Chromosome pairing data of BC₁ derivatives indicated that either some of the wheat chromosomes were eliminated or Agropyron chromosomes caused reduced pairing of wheat homologues.Contribution No. 82-653-J, Department of Plant Pathology, Kansas State Agricultural Experiment Station, Manhattan, Kan, USA     

Identification of wheat-Agropyron cristatum monosomic addition lines by RFLP analysis using a set of assigned wheat DNA probes

A non-radioactive digoxigenin-labelled DNA method was used successfully to identify RFLP markers in 54 Triticum aestivum cv Chinese Spring — Agropyron cristatum (2n=28, genome PPPP) P-genome monosomic addition lines. Southern analysis using a set of 14 DNA probes identifying each homoeologous chromosome arm, combined with two restriction enzymes HindIII and EcoRI, indicated that six A. cristatum chromosomes (1P, 2P, 3P, 4P, 5P and 6P) and five A. cristatum chromosome arms (2PS, 2PL, 5PL, 6PS and 6PL) have been individually added to the wheat genome. The added chromosomes of three lines were Agropyron translocated chromosomes. It was also found that two addition plants possessed an Agropyron-wheat translocation. These results showed that RFLP analysis using the set of assigned wheat probes was a powerful tool in detecting and establishing homoeology of alien A. cristatum chromosomes, or arms, added to wheat, as well as in screening the alien addition material. The creation of the monosomic addition lines should be useful for the transfer of disease-resistance genes from A. cristatum to wheat.     

Cytogenetic studies in the genus Zea

Summary New cytological evidence supporting x = 5 as the basic chromosome number of the genus Zea has been obtained as a consequence of our analysis of the meiotic configurations of Zea mays ssp. mays, Z. diploperennis, Z. perennis and of four F₁ artificial interspecific hybrids. Z. mays ssp. mays (2n = 20) presents regular meiosis with 10 bivalents (II) and is considered here as a typical allotetraploid (A₂A₂B₂B₂). In Z. diploperennis (2n = 20) 10II are formed in the majority of the cells, but the formation of 1III + 8II + 1I or 1III + 711 + 3I in 4% of the cells would indicate its segmental allotetraploid nature (A₁A₁B₁B₁). Z. perennis (2n = 40) had 5IV + 10II in 55% of the cells and would be considered as an auto-allooctoploid (A₁A₁A'₁A'₁C₁C₁C₂C₂). Z. diploperennis x Z. mays ssp. mays (2n = 20) presents 10II in ca. 70% of the cells and no multivalents are formed. In the two 2n = 30 hybrids (Z. mays ssp. mays x Z. perennis and Z. diploperennis x Z. perennis) the most frequent meiotic configuration was 5III + 5II + 5I and in 2n = 40 hybrid (Z. diploperennis x Z. perennis) was 5IV + 10II. Moreover, secondary association was observed in the three abovementioned tetraploid taxa (2n = 20) where one to five groups of two bivalents each at diakinesis-metaphase I was formed showing the affinities between homoeologous genomes. The results, as a whole, can be interpreed by assuming a basic x = 5 in this polyploid complex. The main previous contributions that support this working hypothesis are reviewed and its phylogenetic implications studied are discussed.     

Effectiveness of ph gene in inducing homoeologous chromosome pairing in agrotricum

Summary We observed pairing, when the ph gene was present, between wheat (Triticum aestivum L. em. Thell.) chromosome 4B, and an Agropyron intermedium (Host) Beauv. chromosome (Ai) carrying a gene resistant to wheat streak mosaic (WSM). In a monosomic addition polyhaploid [2n = 22 = 19' + 5B' (ph) + 4B' + Ai'], we recorded an average of 4.1 bivalents and 0.3 trivalents per cell. Induced homoeologous pairing was most effective when both 5B chromosomes carrying ph gene were present. Our data suggest that chromosome 4B of wheat and the Agropyron chromosome (Ai) carrying a gene for resistance to WSM are homoeologous and that it is possible to use either ph mutant or nullisomic 5B stock to induce genetic recombination between the two chromosomes.Contribution No. 1657-j, Kansas State Agric. Expt. Sta., Manhattan, KS. The research is partially supported by a grant from Kansas Wheat Commission     

Cytogenetic studies of the intergeneric hybrids between Secale cereale and Elymus caninus,E. brevipes,and E. tsukushiensis (Triticeae: Poaceae)

Summary Integeneric hybridizations were carried out between Secale cereale L. (2n = 14, RR) and three Elymus species, namely, E. caninus (L.) L. (2n = 28, SSHH), E. brevipes (Keng) Löve (2n = 28, SSYY) and E. tsukushiensis Honda (2n = 42, SSHHYY). Chromosome pairing was studied at metaphase I in the parental species and the hybrids. Meiotic configurations of the hybrids were 20.74 1+0.14 II for E. caninus x S. cereale (SHR), 16.35 I+2.17 II+0.09 III for E. brevipes x S. cereale (SYR) and 25.84 I+1.10 II+0.02 III for E. tsukushiensis x S. cereale (SHYR), in addition to some secondary associations in the different hybrids. It is concluded from the study that (1) a certain, different homoeologous relationship exists among S, H and Y genomes in the investigated Elymus species; (2) low homoeology is present between genomes of Elymus (S or H or Y) and rye (R); (3) the Secale genome affects homoeologous chromosome pairing between different genomes in E. brevipes and E. tsukushiensis.     

Production and cytogenetic analysis of BC1, BC2, and BC3 progenies of an intergeneric hybrid between Triticum aestivum (L.) Thell. and tetraploid Agropyron cristatum (L.) Gaertn.

Summary Intergeneric hybrids between Triticum aestivum cv Chinese Spring and Agropyron cristatum 4x (2n= 5x=35, ABDPP genomes) with a high level of homoeologous meiotic pairing between the wheat chromosomes were backcrossed 3 times to wheat. Pollination of the F₁ hybrid with Chinese Spring resulted in 22 BC₁ seeds with an average seed set of 1.52%. Five BC₁ plants with 39–41 chromosomes were raised using embryo rescue techniques. Chromosome pairing in the BC₁ was characterized by a high frequency of multivalent associations, but in spite of this there was no evidence of homoeologous pairing between chromosomes of wheat and those of Agropyron. All of the plants were self sterile. The embryo rescue technique was again essential to produce 39 BC₂ plants with chromosome numbers ranging from 37 to 67. The phenomenon of meiotic non-reduction was also observed in the BC₃ progenies. In this generation male and female fertility greatly increased, and meiotic pairing was fairly regular. Some monosomic (2n=43) and double monosomic (2n=44) lines were produced. Analysis of these progenies should permit the extraction of the seven possible wheat-Agropyron disomic addition lines including those with the added chromosomes carrying the genes involved in meiotic non-reduction and in suppression of Ph activity.     

Diploidization and chromosomal pairing affinities in the tetraploid wheats and their putative amphiploid progenitor

Summary The genomes of the diploid wheats Triticum boeoticum and T. urartu are closely related, giving 7II in the f₁ hybrid (T^bT^u) and 8.4 (0–14) II + 2.5 (0–7) IV in the derived amphiploid (T^bT^bT^uT^u). The genomes of the tetraploid wheats are also closely related, giving up to 7II at the polyhaploid level (AB) in the absence of the gene Ph but 14II at the tetraploid level (AABB) in the normal presence of Ph. If the amphiploid is the progenitor of the tetraploids, one or the other homoeologue (T^b or T^u) in each of the 7 homoeologous groups (the 7 potential IV) must have differentiated with respect to pairing affinity in order to account for 14II in the tetraploid. Consequently, in tetraploid X amphiploid hybrids (T^bT^uAB) carrying the Ph gene from the tetraploid, the seven differentiated chromosomes (B) would be expected to give 7I while, on the basis of their observed chiasma frequency, T^b, T^u and the less differentiated A would be expected to give 4.17I + 3.57II + 3.23III), assuming homoeologous pairing. The expected chromosomal configuration freqencies at MI (11.17I + 3.57II + 3.23III) closely fit the observed values (11.22I + 3.45II + 3.19III + 0.071IV) for such hybrids (X² = 0.0046; P>0.99). Thus diploidization of the boeoticum-urartu amphiploid clearly could account for the origin of the tetraploid wheats. Furthermore, T. aestivum X amphiploid hybrids (T^bT^uABD) with and without Ph indicated that B as well as A chomosomes tended to pair with their presumed T^bT^u homologues in the absence of Ph. Other tests showed that the tetraploid wheats could not plausibly have originated from any postulated Triticum-Sitopsis (TTSS) parental combinations with or without such chromosomal differentiation.     

Genes encoding α-amylase inhibitors are located in the short arms of chromosomes 3B, 3D and 6D of wheat (Triticum aestivum L.)

Summary Three -amylase inhibitors, designated Inh. I, II and III have been purified from the 70% ethanol extract of hexaploid wheat (Triticum aestivum L.) and characterized by amino acid analysis, N-terminal amino acid sequencing and enzyme inhibition tests. Inhibitors I and III have identical N-terminal sequences and inhibitory properties to those of the previously described 0.19/0.53 group of dimeric inhibitors. Inhibitor II has an N-terminal sequence which is identical to that of the previously described 0.28 monomeric inhibitor, but differs from it in that in addition to being active against -amylase from Tenebrio molitor, it is also active against mammalian salivary and pancreatic -amylases. Compensating nulli-tetrasomic and ditelosomic lines of wheat cv. Chinese Spring have been analysed by two-dimensional electrophoresis, under conditions in which there is no overlap of the inhibitors with other proteins, and the chromosomal locations of the genes encoding these inhibitors have been established: genes for Inh. I and Inh. III are in the short arms of chromosomes 3B and 3D, respectively, and that for Inh. II in the short arm of chromosome 6D.     

Hexacyanoferrate (III) stimulation of elongation in coleoptile segments fromZea mays L.

Summary The influence of exogenous potassium hexacyanoferrate (III) (HCF III) on elongation of maize (Zea mays L.) coleoptile segments was investigated. Addition of HCF III led to a strong stimulation of growth both in the presence and absence of indole-3-acetic acid (IAA). The magnitude of growth stimulation was dependent on the presence of IAA, HCF III concentration, incubation time, and phase growth. The reduced form, potassium hexacyanoferrate (II), was without effect on growth. In the presence of HCF III, elongation was suppressed when coleoptile segments were treated with N,N-dicyclohexylcarbodiimide, cycloheximide or atebrine (quinacrine). The addition of HCF III stimulated the IAA-induced proton extrusion, and the e^–/H⁺ ratio decreased with incubation time. HCF III also strongly stimulated elongation ofAvena saliva L. coleoptile segments andGlycine max L. hypocotyl segments. These results suggested that a plasma membrane redox system (NADH oxidase type I) may be involved in the regulation of growth through the activity of the plasma membrane-bound ATPase.Abbreviations CH cycloheximide - DCCD N,N-dicyclohexylcarbodiimide - HCF III potassium hexacyanoferrate (III) (potassium ferricyanide) - HCF II potassium hexacyanoferrate (II) (potassium ferrocyanide) - IAA indole-3-acetic acid     

Phenotypic Features of Ferroplasma acidiphilum Strains YT and Y-2

Earlier, we described a new family of mesophilic, strictly autotrophic Fe²⁺-oxidizing archaebacteria, Ferroplasmaceae, which belongs to the order Thermoplasmales and includes the genus Ferroplasma and the species F. acidiphilum (strain Y^T) [1]. The present work is concerned with a comparative study of phenotypic characteristics of the type strain Y and a new strain, F. acidiphilum Y-2, isolated from dense pulps during oxidation of gold-containing arsenopyrite/pyrite concentrates from the Bakyrchikskoe (Kazakhstan) and Olimpiadinskoe (Krasnoyarsk krai) ore deposits, respectively. The G+C content of DNA from strains Y^T and Y-2 comprised 35.1 and 35.2 mol %, respectively; the level of DNA–DNA homology between the strains was 84%. Restriction profiles of chromosomal DNA from both strains exhibited a similarity coefficient of 0.87. Genotypic characteristics of these strains indicate their affiliation to the same species. The cells of both strains are polymorphic and lack cell walls. Strains of F. acidiphilum oxidized ferrous iron and pyrite as the sole source of energy and fixed carbon dioxide as the sole carbon source. The strains required yeast extract as a growth factor. Optimum pH for cell growth ranged from 1.7 to 1.8; the temperature optima for the growth of strains Y^T and Y-2 were 34–36 and 40–42°, respectively. Comparative analysis of the total lipids revealed their close similarity in the strains; two glycophospholipids comprised 90% of the total lipids: lipid I, -D-glucopyranosylcaldarchaetidylglycerol (about 55%), and lipid II, trihexosylcaldarchaetidylglycerol (26%), whose isopranyl chains contained no cyclopentane rings. The carbohydrate fraction of lipid I hydrolysate contained only D-glucose, whereas hydrolysate of lipid II contained both D-glucose and D-galactose in a molar ratio of 2 : 1. Thus, it was established that the intraspecies phylogenetic divergence within F. acidiphilum is manifested in the two strains by different temperature optima against a background of similarity in other phenotypic properties.     

Recovery of normal photosynthesis and respiration in common wheat with Agropyron cytoplasms by telocentric Agropyron chromosomes

Summary Alloplasmic common wheat (Triticum aestivum L. cultivais Penjamo 62 and Siete Cerros 66) with cytoplasms of wheatgrass (Agropyron trichophorum and Ag. glaucum) showed two aberrant phenotypes, i.e., gross reduction in plant vigor and male sterility. Plant vigor and male fertility were restored by cytoplasm-specific telocentric chromosomes (telosomes). Studies on carbon assimilation and consumption and on oxygen evolution and uptake showed that maximum rates of apparent photosynthesis were significantly lower in the alloplasmic lines than in their corresponding euplasmic lines and that the telosomes restored a normal level of photosynthesis. The decreased apparent photosynthetic rates in the alloplasmic lines were shown to be not due to decreased rates of true photosynthesis but to increased rates of dark respiration in the green leaves. In contrast, dark respiration in the roots was significantly low in the alloplasmic lines. The alloplasmic lines also showed decreased rates of respiratory consumption of new photosynthates. These results suggest that growth depression and male sterility in the alloplasmic lines are related to aberrant mitochondrial function, which is compensated for by cytoplasm-specific telosomes.     

Identification and characterization of lactic acid bacteria in ragi tape

One hundred and eighteen lactic acid bacteria (LAB) were isolated from five different types of ragi tape, a traditional dry-starter of Balinese rice wine. The isolates could be classified into three groups based on the cell shape and capability to produce gas from glucose. Group I contained 66 homofermentative cocci, group II contained seven homofermentative rods, and group III contained 45 heterofermentative rods. Among these 118 isolates, 21 isolates representing these groups were selected and were first identified using phenotypic characters. The identification performed phenotypically was confirmed by sequencing of variable region 8 (V8) of the 16S rDNA. The comparative studies led to the identification of Pediococcus pentosaceus, Enterococcus faecium, Lactobacillus curvatus, Weissella confusa, and W. paramesenteroides from the ragi tape examined.     

C-banding pattern and polymorphism of Aegilops caudata and chromosomal constitutions of the amphiploid T. aestivum — Ae. caudata and six derived chromosome addition lines

Summary C-banding patterns were analysed in 19 different accessions of Aegilops caudata (= Ae. markgrafii, = Triticum dichasians) (2n = 14, genomically CC) from Turkey, Greece and the USSR, and a generalized C-banded karyotype was established. Chromosome specific C-bands are present in all C-genome chromosomes, allowing the identification of each of the seven chromosome pairs. While only minor variations in the C-banding pattern was observed within the accessions, a large amount of polymorphic variation was found between different accessions. C-banding analysis was carried out to identify Ae. caudata chromosomes in the amphiploid Triticum aestivum cv Alcedo — Ae. caudata and in six derived chromosome addition lines. The results show that the amphiploid carries the complete Ae. Caudate chromosome complement and that the addition lines I, II, III, IV, V and VIII carry the Ae. caudata chromosome pairs B, C, D, F, E and G, respectively. One of the two SAT chromosome pairs (A) is missing from the set. C-banding patterns of the added Ae. caudata chromosomes are identical to those present in the ancestor species, indicating that these chromosomes are not structurally rearranged. The results are discussed with respect to the homoeologous relationships of the Ae. caudata chromosomes.     

SYNTHETIC HYBRIDS OF NEW WORLD AND OLD WORLD AGROPYRONS. IV. TETRAPLOID AGROPYRON SPICATUM F. INERME X TETRAPLOID AGROPYRON DESERTORUM

Emasculated and unemasculated crosses of tetraploid A. spicatum f. inerme X A. desertorum yielded four hybrids. The hybrids were morphologically intermediate between the parent species but resembled A. desertorum more closely than A. spicatum. Both parents behaved cytologically as autoploids. Mean chromosome associations of 0.04 I, 8.60 II, 0.01 III, and 2.67 IV were observed at diakinesis in the 28-chromosome A. spicatum. The A. desertorum parent contained 30 chromosomes, 2 of which were likely supernumeraries, and averaged 0.03 I, 9.85 II, and 2.57 IV at diakinesis. Three hybrids contained 30 chromosomes, and one had 29. The most common chromosome association in the 30-chromosome hybrids was 2 I and 14 II; and the average was 3.00 I, 13.40 II, 0.06 III, and 0.01 IV. A. spicatum and A. desertorum chromosomes were usually distinguishable from each other in the hybrid cell on the basis of size. All pairing in the hybrids was attributed to autosyndesis within parental genomes. A. spicatum, A. desertorum, and their hybrids were represented by genome formulas of SSSS, CCCC, and SSCC, respectively. The hybrids produced 5 to 439 seeds under open pollination. Three controlled crosses between the hybrids yielded 2, 5, and 23 seeds, respectively, on 10 maternal spikes in each cross. The prospects of developing a fertile, cytologically stable allotetraploid species from the hybrids appear favorable.