bluuebunny/crossref_metadata_2025 huggingface dataset:
Localization of a resistance gene and identification of sources of resistance to barley leaf stripe
Authors: Thomsen S. B. , Jensen H. P. , Jensen J. , Skou J. P. , Jørgensen J. H.
Published: April 2006

In order to determine more precisely the location of the barley leaf stripe gene, called the ‘Vada‐resistance gene’, on barley chromosome 2, 63 chromosome‐doubled barley lines were tested. Using data on known chromosome 2 genetic markers, the ‘Vada‐resistance gene’ was estimated to be located between the markers MSU21 and Xris45b, and at a distance of about 20% recombination from the powdery mildew resistance gene MILa. We suggest that the ‘Vada‐resistance gene’ is designated Rdg1a and that all former leaf stripe resistance gene designations should be rejected.

To identify possible new sources of resistance, 11 barley cultivars/lines known to possess leaf stripe resistance and originating from different parts of the world, were tested with one Danish and two Syrian isolates of the leaf stripe fungus. Three apparently genetically different sources of race‐specific resistance were found. The ‘Vada‐resistance’ in the cultivar ‘Golf was effective against seven out of eight isolates’ populations of the leaf stripe fungus differing in geographical origin.
Identification of RAPD markers closely linked to the mlo‐locus in barley
Authors: Manninen O. M. , Turpeinen T. , Nissilä E.
Published: April 2006

Developing resistance to powdery mildew, Erysiphe graminis f.sp. hordei, is a major goal of many barley breeding programmes. Several resistance genes have been tagged or mapped with molecular markers. The mlo gene confers durable resistance towards all known isolates of the pathogen. In this study, RAPD markers and bulked segregant analysis were used to determine PCR‐based markers linked to the mlo‐locus. Sixty doubled haploid lines from a cross between an isogenic line of ‘Ingrid’ carrying the mlo11 allele and a susceptible cv. ‘Pokko’ were used as plant material. Seven linked RAPD markers were found, the closest lying 1.6 cM away from the resistance gene. When eight barley varieties were assayed for the presence of this band, F4‐980, it was found in the resistant varieties but not in the susceptible ones. The linked marker bands could be amplified from DNA‐samples prepared by using three different methods, including a quick squash technique. PCR‐based markers linked to the resistance gene can be used as tools for selection in breeding programmes.
Inheritance and chromosome location of Alp, a gene controlling aluminum tolerance in ‘Dayton’ barley
Authors: Minella E. , Sorrells M. E.
Published: April 2006

Aluminum (Al) toxicity is a major limiting factor in acid soils and more adequate genetic tolerance is needed to improve barley adaptation and production in affected regions. To study the inheritance and chromosome location of the Alp gene controlling Al tolerance in ‘Dayton’ barley the primary trisomics of sensitive ‘Shin Ebisu 16’ were crossed to ‘Dayton’. Parental, F1 and F2 seedlings were grown in nutrient solution containing 0.03, 0.06 and 0.09mM Al. and classified for tolerance by haematoxylin staining of the roots. In diploid F2 progeny, Alp was inherited as a single gene, dominant at 0.06mM and recessive at 0.09 mM concentrations, as indicated by the 3:1 and 1:3 (tolerant: sensitive) segregation ratios, respectively. Segregation of the trisomic Frderived F2 seedlings at 0.06mM Al deviated significantly from the 3:1 only for the triplo 4/‘Dayton’ cross. Data for this cross fit the expected trisomic ratios, indicating that the Alp gene is distally located from the centromere on chromosome 4. These results confirm that tolerance is simply inherited, but expression of tolerance is dependent on Al concentration and allele dose.
Genetic and phenotypic correlations in plantain‐banana euploid hybrids
Authors: Ortiz R.
Published: April 2006

The objective of this work was to determine intraclass correlations for growth and yield traits, as well as associations between them, in segregating hybrids. Diploid, triploid and tetraploid hybrids were obtained from triploid‐diploid crosses between plantains and bananas. These hybrids were evaluated as plants and as ratoon crops on a humid forest site. Significant differences between ploidy within crosses were observed for most traits. The tetraploids were taller, had longer production cycles but a shorter fruit filling time, and heavier bunches than the diploids. There were significant differences between clones of the same ploidy within crosses. Hence, individual selection within ploidy will be effective for the improvement of plantain. Most of the bunch and fruit traits were positively and significantly associated, especially at the tetraploid level. Selection for large fruit at the diploid and tetraploid levels may lead to heavy fruits, thereby resulting in hybrids bearing heavy bunches. Significant and positive correlations between plant height and bunch weight at the tetraploid level suggest that selection of dwarf plantains with heavy bunches may be difficult.
Yield performance of interspecific F1 hybrids of the greek mountain tea, Sideritis spp. L.
Authors: Goliaris A. H. , Roupakias D. G.
Published: April 2006

Interspecific F1 hybrids were produced after artificial intercrossing of six Sideritis species indigenous to Greece, namely: S. athoa, S. euboea, S. syriaca, S. raeseri, S. scardica, S. clandestina and a cultivated clone of S. raeseri. It was found that all species cross with each other, but the level of crossability varied with the cross‐combination. In the yield evaluation experiments, the interspecific hybrids with a common female parent were considered as a group. It was observed that yield during the year of establishment was relatively low, but the interspecific hybrids out‐yielded the control in both fresh and dry weight. All hybrids produced higher yields in the following years and their productivity started to decline after the fifth year. All hybrids produced higher yields than the control in all six years of the experiment. The highest yield over the years, in fresh and dry weight, was produced by the group Sideritis raeseri cultivated clone (cc) ×Sideritis spp. This yield, however, was not always significantly different from the yield produced by the second in the rank group (S. clandestina×Sideritis spp.). A high correlation (r > 0.99) between fresh and dry weight was observed. The two groups with the highest yield also had the highest essential oil content. In addition, all the interspecific hybrids had a higher essential oil content than the control species. Furthermore, the essential oil content of the selected individual hybrid plants ranged between the midparental value to a value higher than the high‐parental species, indicating an additive and dominance gene action. It was also found that the content of the essential oil in the seven most important components (pinene, lemonene, cynene, menthone, copaene, caryophyllene and valerianic ester) varied from hybrid to hybrid. Given that Sideritis reproduces mainly asexually, the direct use of individual interspecific hybrids with higher yield and content in essential oil than the control species is possible in cultivation.
Resistance of early‐maturing European maize germplasm to sugarcane mosaic virus (SCMV) and maize dwarf mosaic virus (MDMV)
Authors: Kuntze L. , Fuchs E. , Grüntzig M. , Schulz B. , Klein D. , Melchinger A. E.
Published: April 2006

Sugarcane mosaic virus (SCMV) and maize dwarf mosaic virus (MDMV) are the most important viruses of maize in Europe. In field and greenhouse experiments, 122 early‐maturing European maize inbreds (45 flint and 77 dent lines) were evaluated for their reaction to artificial inoculation by SCMV and MDMV. Three dent inbreds (D21, D32, FAP1360 A) with complete resistance and four dent inbreds (D06, D09, R2306, FAP1396A) with partial resistance against both potyviruses under both greenhouse and field conditions were identified. All other inbreds were highly susceptible to both SCMV and MDMV. Selection for virus resistance in maize breeding could be performed with only one virus at a time because all inbreds resistant to SCMV were also resistant to MDMV. Rank correlations between percentages of infected plants in greenhouse and field trials ranged from 0.51 to 0.72 for both SCMV and MDMV, suggesting that prescreening of breeding materials for virus resistance can be performed in the greenhouse but final evaluation in multilocation trials in the field is recommended.
Evidence for genetic control and media effect on haploid regeneration in the anther culture of hexaploid wheat (Triticum aestivum L.)
Authors: Moieni A. , Lokos‐Toth K. , Sarrafi A.
Published: April 2006

Crosses were made between seven hexaploid wheat genotypes. Twenty‐one F1 hybrids and their parents were grown in a greenhouse with 16 h day/8 h night at 25°C and 15°C, respectively. The experiment was a complete randomized block design with three replications. Each replication consisted of one pot with three plants. Anther culture was performed in two different induction media (CHB and W14) and androgenetic traits were studied. Statistical analysis was carried out separately for each induction medium. Genetic variation was highly significant for androgenetic traits and the best parent (IBPT 19) produced 68 embryos and 9.3 green plants per 100 anthers in CHB medium. Genetic components were affected by induction media and some components were significant in one medium and non significant in the other. General combining ability (GCA) was significant for all androgenetic traits, except for albino plant regeneration in both media and total plant regeneration in CHB medium, whereas specific combining ability (SCA) was not significant for the traits studied. Narrow sense heritability was high for embryo induction frequency and green and total plant regeneration. All our results indicate that androgenetic parameters can be improved in hexaploid wheat by genetic means.
Evidence of allelism between genes Pm8 and Pm17 and chromosomal location of powdery mildew and leaf rust resistance genes in the common wheat cultivar‘Amigo'
Authors: Hsam S. L. K. , Zeller F. J.
Published: April 2006

TIBL‐1RS wheat‐rye translocation cultivars utilized in wheat programmes worldwide carry powdery mildew resistance gene Pm8. Cultivar‘Amigo’possesses resistance gene Pm17 on its TIAL‐1RS translocated chromosome. To be able to use Pm17efficiently in breeding programmes, this gene was transferred to a TIBL‐1RS translocation in line Helami‐105, and allelism between Pm8 and Pm17was studied. The progenies of the hybrids in the F2 generation and F3 families provided evidence that the two genes are allelic. Genetic studies using monosomic analyses confirmed that in cultivar‘Amigo', Pm17 and leaf rust resistance gene Lr24 are located on a translocated chromosome involving 1 A and 1B, respectively.
Genetics of resistance to kernel infection by Aspergillus flavus in maize *
Authors: Zhang Y. , Kang M. S. , Magari R.
Published: April 2006

Although kernel infection by Aspergillus flavus Link ex Fries and subsequent pre‐harvest aflatoxin contamination of maize (Zea mays L.) grain are major production problems in the south‐eastern United States and elsewhere in the world, limited progress has been made in developing and identifying sources for resistance. Genetics of kernel infection by A. flavus remains poorly understood. A 10‐parent diallel experiment was conducted in 1992 and 1994 to study the genetic nature of percentage kernel infection (PKI) by A. flavus. General combining ability (GCA), specific combining ability (SCA), and reciprocal mean squares for PKI were significant. The GCA and SCA sums of squares were about equal. The GCA, SCA, and reciprocal effects varied across years, which implied that percentage kernel infection was greatly influenced by environments. The percentage kernel infection was always greater when Mo 17 was the male parent in a cross than when it was the female parent. The percentage kernel infection mean for female Mo 17 was 38.5% lower than that for male Mol7. Similarly, percentage kernel infection mean for female L668 was 23.7% lower than that for male L668. The use of inbred lines L729 and B73 as female parents should be avoided, as they showed significant, positive maternal reciprocal effects.
Genetic control of alcohol dehydrogenase, malate dehydrogenase, and phosphoglucomutase isozymes in lima bean (Phaseolus lunatus L.)
Authors: BI I. Zoro , Maquet A. , Wathelet B. , Baudoin J. P.
Published: April 2006

A suitable electrophoretic separation method for alcohol dehydrogenase (ADH). malate dehydrogenase (MDH). and phosphoglucomutase (PGM) from P. lunatus has been developed. Two loci (Adh‐2 and Pgm‐2) showed codominant inheritance and fitted Mendelian ratio. ADH isozyme banding patterns indicate a dimeric quaternary structure. while those of PGM were in agreement with a monomeric nature. The cytoplasmic location of two MDH isozymes (Mdh‐1 and Mdh‐2) selectively inactivated by homogenization in an ascorbic acid solution was demonstrated. However. distorted ratios were observed for Mdh‐2 segregation. On the basis of MDH isozyme banding patterns observed in five progeny families, il is suggested that this enzyme system is a dimeric protein encoded by at least three codominant genes (Mdh‐1 .Mdh‐2 and Mdh‐3). Joint segregation tests between pairs of segregating loci (Adh‐2, Mdh‐2, and Pgm‐2) indicated that each of them is inherited independently.
Genetic and non‐genetic factors affecting germination and vitality in spring barley seed
Authors: Chloupek O. , Ehrenbergerová J. , ŠEVČIK R. , PAŘIZIK P.
Published: April 2006

Germination of eight spring barley varieties, grown in two years at eight different locations in State varietal trials in the Czech republic, was analysed. All the combinations were tested under optimal conditions for germination as recommended by ISTA and also at low temperatures (5 and 10°C), and underwater stress (‐ 2 and ‐ 4 bar). Germination under low temperature and water stress was considered as a character of seed vitality.

Varieties in nearly all experiments were a significant source of variation and their relative contribution to the total variation was higher for vitality (5.7–38.7%) than for germination (2.0–4.3%). However, the percentage of germination were not related to the percentage of vitality.

The location in nearly all the experiments caused the greatest variation and the impact was greater for germination than for vitality. Provenance effects were different for germination and for vitality; grains harvested in the lowland had the highest germination values, but not the highest vitality values.

The results should encourage breeding for seed vitality and some reconsideration of provenance effects on seed vitality.
Comparison of salt tolerance of GPert and non‐GPert barleys
Authors: Pakniyat H. , Thomas W. T. B. , Caligari P. D. S. , Forster B. P.
Published: April 2006

A salt tolerance experiment was performed to study the effect of the GPert mutation in different genetic backgrounds of spring barley, Hordeum vulgare. L. Twenty‐one lines carrying GPert along with 20 related non‐GPert lines were grown for 4 weeks in low salt (25 mol m−3 NaCI) and salt stress (175 mol m−3 NaCI) hydroponic cultures. Shoot Na+ content was taken as a measure of salt tolerance. Salt tolerance of the two groups (GPert versus non‐GPert) was compared, as was the performance of individual GPert lines with their non‐GPert parental lines. The results show that GPert has a general positive effect on salt tolerance in reducing shoot Na+ content, but that this is regulated by genetic background.
Prospects of polyploidizing cassava, Manihot esculenta Crantz, by unreduced microspores
Authors: Nassar N.M. A. , Freitas M.
Published: April 2006

Eleven interspecific hybrids of cassava with the wild relatives Manihot glaziovii, M. pseudoglaziovii. M. dichotoma and M. anomala were examined to detect unreduced microspores. The frequency of dyads and triads was counted, as well as pollen viability. Of these hybrids, the second generation progeny of cassava×M. glaziovii showed a high frequency of unreduced microspores (3.7%) permitting their selection for further manipulation of this character. An association of vegetatively‐reproduced genotypes and the occurrence of unreduced microspores has also been observed.
Genetic analysis of resistance to Phoma tracheiphila in three Citrus and Poncirus progenies
Authors: Recupero G. Reforgiato , Gentile A. , Russo M. P. , Domina F.
Published: April 2006

Mal secco is a serious tracheomycosis, caused by the fungus Phoma tracheiphila (Petri) Kanc, et Ghik., which attacks some species of the genus Citrus. The considerable amount of time and space required to evaluate host plant response has discouraged research on the mechanism of inheritance involved in the susceptibility to this disease. The aim of the present work was to study segregation of the resistance trait in three progenies obtained by crossing Citrus latipes (Swing.) Tan., as a female parent, with the male parents Poncirus trifoliata (L.) Raf., C.aurantium L. and C. volkameriana Pasq. Resistance determination was based on natural infections observed over 10 years. Results allowed us to hypothesize three alternative genes (A, B and C) which determine dominant resistance as opposed to susceptibility: the presence of a single allele can thus confer resistance. In addition, we suggest the existence of a fourth gene which, in conditions of dominance, is able to determine susceptibility by nullifying the action of the dominant B allele. Response to the pathogen was also associated with the production of chitinase a PR (pathogenesis‐related) protein reported to be present in great quantities in mal secco‐resistant Citrus genotypes. Segregation analysis of one F2 progeny confirmed the hypothesis that the resistance trait is controlled by at least two dominant genes. Further evidence is needed to ascertain whether this hypothesis is applicable to other Citrus species, in which the possibility of other genetic mechanisms being implicated cannot be ruled out, thus making the genetic basis of mal secco resisance more complex.
Agronomic performance and molecular assessment of tissue culture‐derived barley lines
Authors: Todorovska E. , Trikonova1 A. , Petrova M. , Vitanova1 Z. , Marinova E. , Gramatikova3 M. , Valcheva D. , Zaprianov3 S. , Mersinkov3 N. , Atanassov A.
Published: April 2006

In order to assess the genetic variability among regenerants. field trials were conducted with 64 barley lines derived from tissue culture (TCD lines) of four Bulgarian barley varieties. The results indicate that the agronomic performance was altered by tissue culture regeneration and the frequency of variation was cultivar dependent. Seven TCD lines showing desirable agronomic characters were selected in the SC16 progeny. Molecular markers (protein, restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD) have used applied to determine the variability induced by tissue culture. Polymorphism was detected in sequences coding for C‐hordeins in line 70 derived from cv.‘Jubiley’Two lines from cv.‘Ruen’exhibited polymorphic bands after hybridization with a mitochondrial DNA probe. RAPD assays have been carried out using 20 different l0‐mer primers. Heritable polymorphisms in several TCD lines have been observed.
Comparative osmotic adjustments in barley and tetraploid wheats
Authors: Teulat1 B. , Rekika D. , Nachit M. M. , Monneveux P.
Published: April 2006

Five barley (Hordeum rulgare L.), five durum wheat (Triticum turgidum concar. durum L.) and one wild emmer wheat (Triticum turgidum conrar dicoccoides) genotypes from different origins and differing for drought tolerance and potential yield, were studied for their osmotic adjustment capacity at the same stage and under similar water stress conditions. Differences for water status parameters between barley and tetraploid wheat genotypes were noted and discussed. The lowest osmotic adjustment capacities were noted in drought susceptible varieties, while a high capacity was found in genotypes exhibiting a high yield stability across contrasting environments. Relative water content, leaf osmotic potential and accumulation of soluble sugars were found to be highly related with osmotic adjustment: they could be used as criteria for a rapid evaluation of osmotic adjustment in segregating populations.
About the origin of 1RS.1BL wheat‐rye chromosome translocations from Germany
Authors: Schlegel1 R. , Korzun V.
Published: April 2006

In order lo investigate the origin of two of the German 1RS. 1BL wheat‐rye translocations used world‐wide in breeding, a number of DNA probes were considered which (a) were critical for the short arm of the rye chromosome 1 R and (b) should show a specificity for the gene pool of Petkus rye. The DNA probe CDO580 was revealed as a specific one. (1) It clearly differentiated 1RS.1AL (‘Amigo’). 1RS.lBL (‘Salmon’) and 1RS.1DL (‘Gabo’) from the two German sources. (2) Both translocation wheats deriving from the Weihenstephan (Munich) and from the Salzmünde (Halle/S.) origin showed an identical DNA fragment which was typical for the gene pool of Petkus rye. It is supposed that both German sources have one progenitor in common.
Yielding ability, yield stability, and quality of exotic durum wheat germplasm in Sicily
Authors: Boggini G. , Doust M. A. , Annicchiarico P. , Pecetti2 L.
Published: April 2006

A set of 20 accessions of durum wheat (Triticum turgidum L., durum group), which mostly included exotic landraces from various Mediterranean countries, and four Italian improved varieties were evaluated for grain yield in five environments and for quality traits in two environments of Sicily. Glutenin composition was also assessed electro‐phoretically on six seeds per entry. The cultivars differed (P ≤ 0.01) for yield, protein content and sodium dodecyl sulphate (SDS‐sed) sedimentation volume, in the presence of significant (P ≥ 0.001) genotype‐environment interaction effects. These effects were large for yield and moderately large for protein content relative to genotype main effects following estimation of variance components. Most exotic cultivars yielded comparably with, and some of them showed greater stability than, the best yielding Italian variety 'Simeto. Some exotic cultivars combined outstanding yield, protein content and SDS‐sedimentation values and represent therefore extremely valuable germplasm sources to broaden the local genetic base. The glutenin composition LMW‐2 and HMW 7 + 8 was positively associated with gluten quality. Six entries showed heterogeneous electrophoretic patterns, suggesting the presence of different genotypes within the cultivar.
Wide mapping of a T‐DNA insertion site in oilseed rape using bulk segregant analysis and comparative mapping
Authors: Barancer A. , Delourme R. , Foisset N. , Eber F. , Barret P. , Dupuis P. , Renard M. , Chevre A. M.
Published: April 2006

Doubled haploid oilseed rape lines segregating for a transgene inducing herbicide resistance (bar gene) were investigated for the wide mapping of the T‐DNA insertion site. Bulk segregant analysis using presence/absence and intensity polymorphisms between the bulks, as well as comparative mapping with a linkage group deriving from another cross, led to the identification of 11 random amplified polymorphic DNA (RAPD) markers tightly or loosely linked to the bar gene. Ten RAPD loci out of 11 were located on the same side of the bar locus, strongly suggesting that the T‐DNA integrated in a telomeric or subtelomeric position. The eleventh RAPD marker exhibited a strong segregation distortion, which could be the result of a heteroduplex formation. Comparison of the linkage groups obtained from the two crosses showed different recombination rates between markers, possibly reflecting differences in parental genetic backgrounds. Consequences and potential applications in transgene dispersal safety assessment studies are discussed.
Genetic diagnosis of Rehmannia species micropropagated by tip tissue culture and an F1 hybrid by RAPD analysis
Authors: Hatano M. , Nakai R. , Kawanishi2 F. , Kedo2 K. , Shoyama1 Y.
Published: April 2006

Shoot formation was induced from the tip tissue of Rehmannia glutinosa f. hueichingensis on hormone‐free Murashige‐Skoog medium within 4 weeks of culture. Shoots were propagated on Murashige‐Skoog medium supplemented with l.0mg/l benzy0ladenine for 4 weeks. Propagated shoots rooted on the hormone‐free Murashige‐Skoog medium during 4 weeks of culture. Total DNA was extracted from the leaves of a F1 hybrid and its parents. R. glulinosa f. huekliingensis and R. glutinosa var, purpurea. Analysis of random‐amplified polymorphic DNA (RAPD) using 10 arbitrary oligonucleotide 10‐mers. showed the genetic homogeneity ofthe above three species. The F1 hybrid was genetically intermediate between both parental plants, compared with the genetic distance between the F1 hybrid and individual parents. Furthermore, the comparison of the band patterns between the F1 hybrid, obtained from the crossing clearly showed that parts of the bands of both parents. R. glutinosa f. hueichingensis and R. glutinosa var. purpurea, were introduced into the F1 hybrid.
Genetic analysis of fertility restoration against photoperiod‐sensitive cytoplasmic male sterility in Triticum aestivum cv. Norin 61
Authors: Murai K.
Published: April 2006

Triticum aestivum cv. Norin 26 with the Aegilops crassa cytoplasm becomes almost completely male sterile when grown under a long‐day condition (15 h of light or longer), but is highly male fertile under a short‐day condition (14.5h or less). This type of male sterility is called photoperiod‐sensitive cytoplasmic male sterility (PCMS). Genetic analyses were made of the fertility‐restoring (Rf) genes effective against PCMS that are present in T. aestivum cv. Norin 61. Conventional and monosomic studies indicated that restoration of fertility is controlled by multiple Rf genes located on at least four chromosomes: 4 A, 1D, 3D and 5D. The genetic mechanism of fertility restoration by the genes of‘Norin 61’differs from the mechanisms reported for‘Chinese Spring’and a‘Norin 26’mutant line.
Potential use of doubled haploid lines for the screening of resistance to yellow rust (Puccinia striiformis) in hexaploid wheat
Authors: Moieni A. , Vallavieille‐pope C.de , Sarrafi A.
Published: April 2006

Doubled haploid lines derived from anther culture of two Iranian spring wheat genotypes‘Ghods’susceptible and‘9106’resistant to yellow rust in Iranian field conditions, and their F1 hybrids were used in this study. Seedlings of 36 doubled haploid lines, selected out of 96 according to their agronomic traits and the two parental genotypes were inoculated with eight races of yellow rust. The parental genotypes (‘Ghods’and‘9106’) were segregating for some of the races but their doubled haploid lines were either resistant or susceptible to them.‘Ghods’was susceptible to three of the races studied but three doubled haploid lines derived from it were resistant to them. Five selected doubled haploids from the‘9106’genotype and six from F1 hybrid plants were resistant to all eight races tested. After further investigations in Iranian field conditions it was found that some of these lines can be used as donor genotypes for resistance to yellow rust in wheat breeding programmes. Use of these genotypes should be possible if the French yellow rust races used for selection also represent the dominant races in Iran. It can be concluded that anther culture provides an efficient method for fixing genes of resistance to yellow rust and desirable doubled haploids from F1 plants can be derived.
Novel gene for adult plant resistance to Puccinia recondita in the wheat cultivar‘Arjun’
Authors: Sawhney R.N. , Sharma J.B.
Published: April 2006

Inheritance of resistance in the wheat cultivar‘Arjun’(HD 2009) against leaf rust pathotype 77–1 revealed that its durable resistance is attributable to a novel dominant adult plant resistance (APR) gene. Lr13, another gene reported in the cultivar played no role. This new gene is established as different from Lr34, the only effective APR gene from Triticum aestivum known for durability.
Genomic constitution of a partial amphiploid OK7211542 used as a source of immunity to barley yellow dwarf virus for bread wheat
Authors: Chen Qin , Ahmad F. , Collin J. , Comeau A. , Fedak G. , St-Pierre C. A.
Published: April 2006

A combination of genomic in situ hybridization (GISH) and meiotic pairing analysis of crosses between a series of 2n= 56 partial amphiploids confirmed that the alien genome of the BYDV‐immune Agro‐tricum line OK7211542 is derived from Thinopyrum ponticum and not from Thinopyrum intermedium. The evidence from meiotic pairing analysis indicated that the chromosome constitution of OK7211542 is similar to another Agrotricum line, ORRPX, which was derived from a cross of wheat and Th. ponticum, but different from other Agrotricum lines, Zhong 5 and TAF 46 which were derived from the crosses between wheat and Th. intermedium. The GISH analysis confirmed that OK7211542 contained one complete set of 14 Th. ponticum chromosomes, in which no S chromosome was present in the alien genome. GISH also detected a small alien translocation attached to one of the wheat chromosomes, a result that was consistent with the pairing data.
Inheritance of resistance to Rhynchosporium secalis in spring barley (Hordeum vulgare L.)
Authors: Cséleny L. , Ordon F. , Friedt W.
Published: April 2006

The inheritance of durable resistance of selected spring barley varieties to Rhynchosporium secalis was investigated. Data from the F2 generation of a 4 × 4 diallel, without reciprocals and the F4 generation of three crosses selected out of this diallel, suggest that resistance in this sample of varieties tested is complex in inheritance. Significant additive effects were detected indicating that the resistance level of barley cultivars may be improved by the hybridisation of suitable varieties. However, the genes conferring resistance seem to be concealed by the expression of one completely dominant resistance gene in our set of varieties. These results are partly in conflict with previous results on the inheritance of resistance to R. secalis in the breeder's line ‘11258/228613A’ indicating that the effectiveness of this resistance gene may be greatly influenced by the genetic background of the current population of R. secalis.
Early‐maturing dual‐purpose sorghums: Agronomic trait variation and covariation among landraces
Authors: Rattunde H. F. W.
Published: April 2006

Landrace cultivars represent potentially valuable source material for breeding dual‐purpose (grain and stover) sorghums. To characterize the genetic variation and interrelationships for major agronomic traits among potential dual‐purpose sorghum landraces, 74 accessions, primarily from Southern Africa, the Sudan, and India, were evaluated in five environments at Patancheru, India. These environments, at 17°N with 520‐540 mm rainfall during the growing season, are representative of the major sorghum‐growing areas in India and the Sudanian Zone of Western and Central Africa. Significant genetic variation and high heritabilities (P = 0.01, h2= 0.63‐0.92) were observed for seedling vigour, grain and stover yields, growth rate and harvest index. Time to flower was correlated with stover yield (r = 0.48, P = 0.01) and an index (Iev) of total economic value (r = 0.44, P = 0.01) but not with grain yield (r = 0.22, P = 0.05). Grain and stover yields varied independently (r = 0.22, P = 0.05) and were similarly related to Iev, values (r = 0.79 and r = 0.77 (P = 0.01), respectively). The 13 landraces with the highest Iev values (adjusted for maturity) had above‐average growth rates and harvest indices that ranged from 20 to 38%. Landraces from Botswana and India were more highly represented in the high Iev set than in the full set of accessions.
Fertility and growth in the field of Lolium perenne and Festuca rubra plants regenerated from suspension cultured cells and protoplasts
Authors: Stadelmann F. J. , Boller B. , Spangenberg G. , Kölliker R. , Messerli M. , Wang Z. Y. , Nösberger J.
Published: April 2006

The effect of regeneration of Lolium perenne and Festuca rubra from embryogenic suspension cells and protoplasts on fertility and growth was evaluated. Embryogenic suspension cultures were either routinely subcultured or cryopreserved and re‐established. Phenology, morphology and fertility of regenerated plants were studied for two growing seasons in a replicated field experiment. Most regenerated L. perenne and F. rubra plants showed a delay in inflorescence emergence, a reduced seed yield and differences in morphological traits when compared with seed‐grown plants. For L. perenne, performance of plants regenerated from cryopreserved suspension cultures and protoplasts was similar to that of respective plants regenerated from routinely maintained suspension cultures. However, differences in performance were observed for respective regenerants in F. rubra. The phenotypic deviation observed was partly reflected in the randomly amplified polymorphic DNA (RAPD) analysis performed. However, regenerants of both species showing similar, or even superior performance to the seed‐grown plants were also found. Embryogenic suspension cells and corresponding protoplasts of L. perenne and F. rubra have the potential for producing fertile, well‐performing plants which can be integrated in breeding programs.
Evaluation of different microsatellite motifs for analysing genetic relationships in cultivated sunflower (Helianthus annuus L.)
Authors: Dehmer K. J. , Friedt W.
Published: April 2006

A total of 16 different simple sequence repeat motifs and an M13 repeat sequence were used as hybridization probes in order to examine the molecular relationships between two German inbred and eight North American sunflower lines of known pedigree, and to determine the suitability of the individual short tandem repeats for genetic analyses and their occurrence in the sunflower genome.

Only the oligonucleotides (ACA)6, (CAT)6, (CATA)5, (GACA)4 and (GATA)4 proved to be well suited for the generation of scorable fingerprinting patterns, while the other (microsatellite) sequences were either too abundant or too rare. Although different levels of polymorphism were present in hybridizations with the different simple sequence repeats (SSRs), a clear separation of the German material from the USDA Hnes was feasible not only by evaluating 20 probe‐enzyme combinations, but also by combining every individual probe with four different restriction enzymes. In the American material, the expected relationships could be proved with the single exception of a line that did not group in accordance with its pedigree.
An HPLC investigation of flower colour and breeding of anthocyanins in species and hybrids of Alstroemeria
Authors: Nørbæk R. , Christensen L. P. , Brandt K.
Published: April 2006

The tepals of 28 Chilean species of Alstroemeria and 183 interspecific hybrids were analysed for anthocyanin content by high‐performance liquid chromatography (HPLC). The anthocyanins were identified as 3‐rutinosides of 6‐hydroxydelphinidin, 6‐hydroxyeyanidin, cyanidin, and delphinidin and 3‐glyeosides of cyanidin and delphinidin, some of which were acylated with malonic acid. Comparisons of the anthocyanin contents in parents and offspring showed that no anthocyanidin or acylation pattern was dominant, and that offspring values were close to mid‐parent values for the percentage of malonated anthocyanins, whereas the inheritance of cyanidin, 6‐hydroxycyanidin, and delphinidin seems more complicated. Flower colour, hue, and intensity were measured by CIELab in fresh tepals and compared with their anthocyanin content and the estimated flavonoid concentrations. Colour intensity was positively correlated with anthocyanin concentration. Compared with flowers containing exclusively cyanidin 3‐glycosides, the hues of flowers with delphinidin 3‐glycosides were bluer and with 6‐hydroxycyanidin 3‐glycosides redder, respectively. Both malonation of anthocyanin and co‐pigmentation with flavonoids caused a shift to bluish hues, irrespective of the anthocyanidins. By quantifying both chemical and colorimetric characteristics a model for the effect of anthocyanin on Alstroemeria flower colour was established. Breeding of new cultivars of Alstroemeria is discussed.
Location of the self‐incompatibility gene on the almond linkage map
Authors: Ballester J. , Bošković R. , Batlle I. , Arús P. , Vargas F. , de Vicente M. C.
Published: April 2006

A progeny obtained from the almond cross ‘Ferragnès’×‘Tuono’ (Prunus amygdalus Batsch) was used to study the self‐incompatibility trait in three different ways: fruit set, pollen tube growth and stylar ribonuclease activity. As expected from the genotypes of the parents, all progeny appeared phenotypically as self‐compatible. However, the progeny could be scored for the segregation of stylar ribonuclease isozymes and thus allowed the incompatibility locus to be placed on the almond linkage map.
New C‐banding pattern for chromosome identification in cucumber (Cucumis sativus L.)
Authors: Hoshi Y. , Pląder W. , Malepszy S.
Published: April 2006

A chromosome study of cucumber, C. sativus L., was performed using orcein and C‐banding techniques. The diploid and tetraploid plants investigated here showed the somatic chromosome numbers 2n=14 and 28, respectively. The haploid chromosome complement was composed of five metacentric and two submetacentric chromosomes. All C. sativus chromosomes had clearly visible C‐bands, and each chromosome could be identified unequivocally after C‐banding staining, with 13 C‐bands appearing in the haploid complement. The haploid complement had a 44.9% ratio of total C‐band length to total chromosome length. Chromosomes 1, 2, 4, 5 and 7 had stable C‐bands. Three large, dark C‐bands appeared at the proximal regions of chromosomes 1 and 2. Chromosome I had quite a large C‐band and with a 68.4% ratio of C‐band length to short arm length. Chromosome 2 also had quite a large C‐band in the pericentromeric region with a 57.6% ratio of C‐band length to the full length of this chromosome and possessed an elongated primary constriction in early metaphase. In prometaphase, chromosome 2 showed that the long arm was completely separated from the short arm. The number of secondary constrictions could not be clearly observed because these chromosomes are small and they could not be counted in every metaphase cell. However, six chromosomes seemed to have secondary constrictions in the diploid plants. Two silver‐stained bands were observed at primary constrictions of two of the large chromosomes.
Revival of a well‐known, but ignored correction term for χ2 in linkage analysis with small samples
Authors: HÜHN M.
Published: April 2006

The ‘classical’χ2 test is routinely applied in linkage analysis. The values customarily used, however, are only approximations since continuous χ2 terms are used instead of discrete multinomial terms. This error becomes increasingly important as the sample becomes small. In this note, a well‐known correction term for improvement of this approximation is revived and numerically calculated for some interesting cases from linkage studies.
Frost resistance of ‘Chinese Spring’/‘Cheyenne’ chromosome substitution lines under short‐ and long‐day hardening conditions
Authors: Veisz O. B. , Sutka J.
Published: April 2006

Investigations were carried out under phytotronic conditions to study the effect of daylength on the frost resistance of a ‘Chinese Spring’/‘Cheyenne’ chromosome substitution series. The frost resistance of the 5A, 7A, 4B, 5B, 1D and 5D lines was significantly better when raised and hardened with long‐day (16 h) rather than short‐day (8h) illumination. The frost resistance‐increasing effect of daylength could be demonstrated after freezing lines 5A and 5D at both ‐ 10°C and ‐12°C.

An increase in the duration of illumination in the course of preliminary growth and hardening promoted the development of a higher level of frost resistance. This positive effect was most pronounced for chromosome substitution lines, where the frost resistance was significantly better than that of ‘Chinese Spring’ even with normal daylengths.
Haploid plantlet screening in the development of blackleg resistant DH lines of Brassica napus
Authors: Bansal V. K. , Thiagarajah M. R. , Stringam G. R. , Hardin R. T.
Published: April 2006

This study was conducted to expedite disease‐resistance breeding in canola by screening haploid plants against blackleg disease. Microspore‐derived haploid plantlets from 14 unrelated crosses were inoculated with Leptosphaeria maculans pycnidiospores and were rated as resistant, intermediate or susceptible. Blackleg‐inoculated and control haploid plants were then colchicine‐treated to produce doubled haploid (DH) lines. The DH lines thus produced were again screened against blackleg using the cotyledon bioassay. In general, the proportion of the resistant DH lines derived from selected resistant haploid plants was much higher than the proportion of resistant DH lines from control haploid populations. There was no detrimental effect on the survival of haploid plants after the combined treatment of blackleg inoculation and colchicine. The importance of the micro‐environment on the final outcome of plant‐pathogen interaction in case of non‐obligate pathogens is also discussed.
Hybridization of Thinopyrum distichum and Secale cereale
Authors: Marais G. F. , Marais A. S. , Badenhorst P. C.
Published: April 2006

An attempt was made to determine whether the salt tolerance genes of Thinopyrum distichum would be expressed in the presence of the rye genomes and if it would be possible to improve and utilize its hybrid with rye as a salt‐tolerant fodder crop. Th. distichum florets were pollinated with diploid and tetraploid rye but hybrids were obtained only with tetraploid rye. The F1 had 28 chromosomes and expressed high levels of salt tolerance. Fertility could not be induced through colchicines treatment but the plants produced some apomictic seeds during the summer months. The F2 had 20‐22 chromosomes and retained two complete or near‐complete rye genomes. The F2 plants responded better to colchicine treatment, however, the doubled hybrids remained male sterile. In summer, one F2 plant produced many apomictic seeds with chromosome numbers ranging from 14 to 16 (primarily rye chromosomes). The mechanism that caused the preferential loss of Thinopyrum chromosomes in each apomictic cycle remains unknown. The F3 phenotypically resembled rye, had primarily reductional male meioses and produced seemingly functional pollen, but were self‐sterile.
Bread‐making quality and yield performance of 1BL/1RS wheat isogenic lines
Authors: Bullrich L. , Tranquilli G. , Pfluger L. A. , Suárez E. Y. , Barneix A. J.
Published: April 2006

Isogenic lines were developed in order to assess the precise effects of the 1BL/1RS translocation on quality characteristics and agronomic traits. Results showed that the translocation has a detrimental effect on sodium dodecyl sulphate sedimentation volume, in any background. Yield was similar between translocated and non‐translocated lines; however, lines carrying lBL/1RS showed a significant increase in grain weight, together with a decrease in spike number per plant.
Evaluation of quantitative resistance to yellow rust (Puccinia striiformis f. sp. hordei) in the ICARDA/CIMMYT barley breeding programme
Authors: Sandoval‐Islas J. S. , Broers L. H. M. , Vivar H. , Osada K. S.
Published: April 2006

The resistance to yellow rust (Puccinia striiformis f. sp. hordei) of 500 advanced barley lines from the ICARDA/CIMMYT breeding programme in Mexico was evaluated on seedlings in the greenhouse and on adult plants in the field. A high frequency of advanced lines (85.8%) showed a susceptible reaction (infection type ≥ 7) on seedlings after inoculation with isolate Mex‐1, representing a Mexican variant of race 24. This indicates the absence of effective hypersensitive resistance. In addition, the same advanced lines showed a large variation in disease severity in the field, ranging from 0 to 95%. More than 76% of the advanced lines with a susceptible reaction in the seedling stage demonstrated low disease severity (10% or less in the adult plant). Consequently, these advanced lines possess high levels of quantitative resistance.

Two aspects in the ICARDA/CIMMYT barley breeding programme may explain the large number of advanced lines with high levels of quantitative resistance. First, a recurrent selection approach is applied when advanced (F5) lines reaching homozygosity are intercrossed. Second, low levels of disease are accepted in the selection process instead of selecting the ultimate green plant. Both aspects combined allow the accumulation of quantitative resistance. Certain cultivars released from South‐American national programmes in the late 1970s and early 1980s in Peru (UNA‐80), Bolivia (IBTA 80) and Ecuador (Teran) are still resistant, demonstrating the durable nature of quantitative resistance to yellow rust.
Estimation of parental value for varieties used in plant breeding
Authors: Anoshenko B. Y.
Published: April 2006

A method to estimate variety value directly in a plant breeding process is proposed. The approach is based on frequencies of variety progenies succeeding in breeding trials. The number of crossing combinations is demonstrated to estimate parental breeding values (PBV) more effectively than the number of lines. Because of the possibility of significant sexual effects the parental breeding value is estimated by the square mean of the female and male variety breeding values. For adequate PBV estimation, all the varieties tested should involve an equal number of crossing combinations as male and female parents. The Latin square principle can be used for planning such crosses. The results of barley breeding programmes are used as an example for the application of the proposed method. It is shown that the PBV estimates obtained in a current breeding cycle allow the effectiveness of the following cycles to be increased by better planning of the subsequent crosses.
Effective pairwise combination of long primers for RAPD analyses in roses
Authors: Debener T. , Mattiesch L.
Published: April 2006

Twenty‐four primers of different lengths (eight each of 10, 15 and 20 bp) were tested each in RAPD reactions with DNA of Rosa multiflora and Rosa canina. The reactions with single primers of a particular length were compared with all 28 pairwise combinations within each length class in both single primer reactions and in primer combination reactions. All primer classes produced fragment patterns of comparable complexity. However, the number of new fragment patterns and the number of fragments containing repetitive DNA was dependent on the primer length. Combinations of long 15‐ and 20‐mer primers produced more new fragments and a lower amount of repetitive DNA than shorter 10‐mer primers. Implications for the use of long primer combinations in projects which require large marker numbers are discussed in comparison with other marker systems.
Interspecific hybrids between three eggplant (Solanum melongena L.) cultivars and two wild species (Solanum torvum Sw. and Solanum sisymbriifolium Lam.)
Authors: Bletsos F. A. , Roupakias D. G. , Tsaktsira M. L. , Scaltsoyjannes A. B. , Thanassoulopoulos C. C.
Published: April 2006

Three Greek eggplant cultivars, ‘Langada’, ‘Tsakoniki’ and ‘Emi’ (2n= 24), were crossed with two wild species (Solanum torvum Sw., 2n= 24 and Solanum sisymbriifolium Lam., 2n= 24). Ovules isolated 15‐27 days after pollination were cultured in a modified MS medium at 24°C and a 16h photoperiod. Fifty days later, the ovules were dissected and the interspecific embryos were cultured in the same medium. Interspecific hybrids were achieved only from crosses between the eggplant cultivars and S. torvum. The hybridity of the putative interspecific F1 hybrid (Solanum melongena×S. torvum) was confirmed by using morphological and biochemical (isozyme isocitrate dehydrogenase A, phosphoglucomutase A, phosphoglucose isomerase B, 6‐phosphogluconate dehydrogenase A, 6‐phosphogluconate dehydrogenase B) markers. The F1 plants (‘Langada’×S. torvum) were selfpollinated and backcrossed to both parents. Fruits, however, were produced only when the F1 hybrid was backcrossed as female with the eggplant cultivar ‘Langada’.