bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of bunt infection on the frost resistance of wheat varieties and of lines containing Bt genes
Authors: B. Veisz O. , Szunics Lu. , Szunics L.
Published: April 2006

In artificial infection experiments carried out in the nursery in Martonvásár in 1991, 1992 and 1993, studies were made on the bunt infection of wheat varieties bred in Martonvásár and of monogenic lines containing known resistance genes (Bll to Btl0, respectively). This was followed in 1993 by tests on the frost resistance of healthy wheat seedlings and wheat seedlings artificially infected with bunt in the frost‐testing chamber of the Martonvásár phytotron.

During the period of the experiment, the local pathogen population was avirulent to genes Bt9 and Btl0, and virulent to Bt7. Monogeniclines containing resistance genes Bt4, Bt5, Bt6 and Bt8 had good resistance, while that of lines containing Bt1, Bt2 and Bt3 was only moderate. Among the cultivated varieties, only three proved to be moderately resistant (Martonvásári 17′,‘Martonvásári 23′,‘Fatima 2′), while the remainder were susceptible or very susceptible. The frost resistance of plants infected with bunt was significantly lower, over an average of the varieties, than that of healthy plants. A close (r = 0.890) correlation was found between the bunt susceptibility of the varieties tested and the increase in frost kill due to infection, while no correlation was observed in this respect for monogenic lines containing various resistance genes (Bt).
Tritipyrum, a potential new salt‐tolerant cereal
Authors: King I. P. , Law C. N. , Cant K. A. , Orford S. E. , Reader S. M. , Miller T. E.
Published: April 2006

Salt‐affected soil is a major world‐wide problem with many hectares of land lost to cultivation each year .To combat this problem, the development and assessment of a novel salt tolerant cereal, tritipyrum, was carried out. This is a hybrid between wheat and Thinopyrum bessarabicum. a very salt‐tolerant member of the Triticeae.

A range of tritipyrums derived from crosses between tetraploid wheat, Triticum durum, and Th. bessarabicum was produced. Although meiosis in ihe tritipyrums was generally regular, chromosome pairing failure was observed in each of the genotypes. In addition, the level of fertility was relatively low, the fertility of bagged spikes ranging from 29% to 51%. One iritipyrum produced multiple seeds in some florets. Three tritipyrums selected at random performed better than their wheat parents in hydroculture experiments in each of three treatments (150, 200 and 250 mol/ m3 Nacl). The potential for the exploitation of tritipyrum in salt‐affected soils is discussed.
Barley mutant heterosis and fixation of‘F1‐performance’in doubled haploid lines
Authors: Polok K. , Szarhjko I. , Maluszynski M.
Published: April 2006

The phenomenon of mutant heterosis was studied in barley using F1 hybrids developed from crosses involving two mutants derived from the same parent variety (067AR× 032AR), or from crosses of mutants with their parent varieties (Diva × 228DV; 437MG × Mg 4170). The agronomic performance (plant height, tillers per plant, kernel number and weight per plant) of F1 hybrids was evaluated in relation to the corresponding parent variety used for mutant development. Wide‐space sowing (0.O6 m2/plant) was applied to allow the full expression of hybrid vigour. The hybrids significantly exceeded their parent varieties in various yield parameters in each year of the experiment, Depending on the cross, the level of heterosis ranged from 39.45% to 82.1% for kernel number and from 44.45% to 91.2% for kernel weight, as an average of observations over three years. The increased yield of hybrids was accompanied by an increase in spikes/plant, without significant changes, in most cases, in yield components such as kernels/spike and 1000 kernel weight. The height of F1 plants remained similar to the corresponding parent variety. Doubled haploicls (DH) were developed through anther culture from three F1 hybrids to determine whether the heterotic effect could be fixed, even partly, in homozygous lines. Twenty‐eight, 42 and 68 DH lines per cross were produced, and evaluated in the field, space‐planted at 0.06 m2/plant, together with hybrids and parent varieties. The best‐performing DH lines were evaluated again the following season in a conventional field trial. We were able to select 1.5 ‐14.3% of‘F1,‐performing’DH lines per hetorotic cross combination, which, in two years of studies, reached the yield of heterotic hybrids and significantly out‐yielded the parent variety in plot. The yield potential of DH lines was better expressed under a wide sowing density, but even under normal growing conditions, the yield of the best selected DH lines surpassed their corresponding parent varieties by 17.77ndash;30.1%.
Mapping of QTL controlling NIR predicted hot water extract and grain nitrogen content in a spring barley cross using marker‐regression
Authors: Bezant H. , Laurie D. A. , Pratchett N. , Chojecki J. , Kearsey M. J.
Published: April 2006

A restriction fragment length polymorphism (RFLP) map constructed from 99 doubled haploid lines of a cross between two spring barley varieties (‘;Blenheim’×‘Kym’) was used to map QTL controlling hot water extract and grain nitrogen content (predicted by analysis with near‐infrared reflectance spectroscopy). Eight QTL affecting predicted hot water extract were identified by a marker‐regression approach. The largest effects were found on chromosomes 3HL, associated with the denso dwarfing gene which is present in‘Blenheim’and conferred poorer predicted hot water extract quality, and 4HL. Other QTL were detected on chromosomes IHS. IHL. 2HS, 2HL. 5HL and 6HS. Analysis of single markers by analysis of variance detected an additional effect on chromosome 1H. Eight QTL affecting predicted grain nitrogen content were identified by marker‐regression, on chromosomes 1HS, 1HL. 2HL. 5HS, 6H, 7HS and 7HL. There was also evidence for an additional QTL on chromosome 5HL. The positions of the grain nitrogen content QTL on 5HS and 5HL are comparable to QTL on wheat chromosomes 5A and 5D that affect grain protein content. The denso gene had no detectable effect on grain nitrogen content.
An improved protocol for androgenesis in cauliflowers (Brassica oleracea var. botrytis)
Authors: Stipic M. , Campion B.
Published: April 2006

The genotypic responsiveness to androgenesis and the effect of two exposure times of cultured anthers to auxins (12 days and the entire period of culture) were studied in three lines of cauliflower (one spring ‐ and two winter‐types). The anthers of all genotypes responded to the protocol by producing embryos (0.2 ‐25.3%), 44.2% of which regenerated plantlets through organogenesis on a regulator‐free B5 medium containing 40 g/l of sucrose and 800mg/l of L‐glutamine. Embryo yield improvement, recently achieved on solid medium with the addition of 125mg/l silver nitrate, was not observed in liquid cultures. Mean frequencies of androgenic embryos, as affected by the duration of auxin supply to the culture, were always significantly higher (6.6‐ and 8.1‐fold.) in the‘12 days of exposure’treatment than in the‘entire period of culture’treatment. The resolution of the parameter‘embryo percentage’into its two components (% of responsive anthers and number of embryos per responsive anther) gave evidence of a highly significant increase in the percentage of responsive anthers, whereas the number of embryos per responsive anther did not change statistically. The percentage of embryos regenerating plants was not influenced by the duration of auxin supply during anther culture. Chromosome count analysis revealed a haploid/diploid/polyploid plant ratio of 6:79:15. Of the 78 androgenic plants (RO generation) grown in the field, only 14 were fertile and produced seeds. RAPD analysis showed that none of the seven polymorphic loci out of 23 analysed expressed polymorphism within the RI progenies of 11 anther culture‐derived lines.
Identifying plant architectural traits associated with yield under intercropping: Implications of genotype‐cropping system interactions
Authors: Nelson S. C. , Robichaux R. H.
Published: April 2006

Increased yields of some crops have resulted from indirect selection of plant architectural traits related to yield. This study examines the potential relationship between plant architecture and yield for a legume grown under intercropping, Field experiments were conducted in 1991 to examine the response of two cowpea (Vigna unguiculata (L.) Walp.) genotypes with contrasting plant habits to sole crop and intercrop with pearl millet (Pennisetum americanum (L.) Leeke), and to identify cowpea traits associated with yield under intercropping. The cultivur with a bush‐type habit was higher‐yielding in sole crop, whereas the cultivar with a spreading habit was higher‐yielding in intercrop. For F2 cowpea populations, pod number was most highly correlated with seed yield in intercrop. The number of branches and nodes, particularly in areas with increased access to light, and increased internode length were also important in intercrop. Selection for improved yield in sole crop may not necessarily lead to improved yield in intercrop, and different plant traits may be more appropriate for cultivars intended for use in inter‐crop than for those intended for use in sole crop.
Interspecific crosses between Pelargonium×hortorum and P. quinquelobatum using embryo rescue and molecular characterization of hybrids by an endogenous chs probe
Authors: Denis‐Peixoto L. , Cadic A. , Renou J. P.
Published: April 2006

Interspecific hybridizations were performed between pelargonium × hortorum (subgenus Ciconium) and a yellow‐flowered species. Pelargonium qitinquelobatum(subgenus Eumurpha). Hybrids, using embryo rescue, were obtained only when P. quinquelobatum was used as the female parent. A polymerase chain reaction (PCR) cloned Pelargonium chs gene fragment was used as probe to characterise hybrids hy restriction fragment length polymorphism (RFLP) analysis. Chromatographic flavonoid analysis showed that hybrids could synthesize both flavonol glycosides and anthocyanin in the petals which were pale yellow to pale pink from the proximal to the distal part.
Indirect selection for persistence and seed yield in large‐leaved white clover
Authors: Annicchiarico P.
Published: April 2006

High persistence and seed yield are important targets in white clover breeding but their assessment is expensive. The efficiency of indirect selection for these traits performed on characters recorded during a medium‐term dry matter (DM) yield evaluation was verified for large leaved populations in separate experiments for medium‐term (three‐year) and long‐term (fourth and fifth year) DM yield (Trial 1) and seed yield (Trial 2). The best results were provided by stolon density observed at the end of the third cropping year for prediction of long‐term yield, and by the product of number of heads times number of florets per head assessed prior to mowing in Trial 1 for prediction of seed yield in Trial 2. Indirect selection was about as efficient as direct selection in these cases. Predictions of persistence from three‐year or third year DM yield, and seed yield from single seed yield components in Trial 1 were less accurate.
Morphological and molecular analysis of androgenetic, selfed and backcrossed plants produced from a Hordeum vulgare x H, bulbosum hybrid
Authors: Gilpin M. J. , Pickering R. A. , Fautrier A. G. , Mcneil D. L. , Szigat G. , Hill A. M. , Kynast R. G.
Published: April 2006

Anther culture (AC) was carried out on a fertile triploid hybrid between Hordeum vulgare L. (cultivated barley) and H. bulbosum L, (bulbous barley grass) to determine whether AC‐derived regenerants differed from progeny obtained through selfing and backcrossing. Chromosome counts were carried out on all plants and DNA was extracted from them to prepare Southern blots for molecular analysis. To identify true recombinants, the blots were probed with rye repetitive sequence probes (pSc119.1 and pScl19.2). which hybridize strongly and specifically to H. bulbosum DNA. Twenty probes that detect single‐ or low‐copy sequences were hybridized with Southern blots containing restricted DNA extracted from 25 AC‐derived plants, 11 selfed and six backcrossed progeny that showed hybridizations with pScll9. Although restriction fragment length polymorphisms (RFLPs) were only observed using probes that map to four of the possible 14 chromosome arms, an introgression associated with chromosome 6HS was frequently observed among plants derived from AC. selfing and backcrossing. Plants from AC differed from selfed and backcrossed progeny in their chromosome number; unique RFLP bands that were occasionally observed may indicate chromosomal rearrangements.
Duplication of the Bx7 high‐molecular‐weight glutenin subunit gene in bread wheat (Triticum aestivum L.) cultivar‘Red River 68′
Authors: D'Ovidio R. , Masci S. , Porceddu1 E. , Kasarda D. D.
Published: April 2006

SDS‐PAGE analysis of seed proteins of the cultivar‘Red River 68’showed a considerably higher staining intensity of the band corresponding to HMW‐GS Bx7 relative to the equivalent band in the cultivars‘Chinese Spring’and‘Cheyenne’. Southern blots of restriction enzyme fragments from DNA of these three cultivars were analyzed densitometrically to reveal that the band corresponding to the Bx7 gene of‘Red River 68’had a double staining intensity compared to the equivalent bands from the other two cultivars, which indicates that in‘Red River 68’a duplication of the Bx7 gene has occurred. Although the possibility of the gene copy being a pseudogene was not ruled out, the greater amount of protein corresponding to Bx7 in‘Red River 68’most likely is in accord with an increase in active gene number. SDSPAGE analysis of the proteins showed also that the mobility of Bx7 in‘Cheyenne’was slightly different from the mobilities of the Bx7 subunits of‘Red River 68’and‘Chinese Spring’. The same difference was observed at the gene level by PCR amplification of the genes encoding these subunits.
Resistance and tolerance to leaf rust in Ethiopian tetraploid wheat landraces
Authors: Andenow Y. , Hullukal M. , Belay G. , Tesemma1 T.
Published: April 2006

Infection type to leaf rust (Puccinia recondita f. sp. tritici) in Ethiopian tetraploid wheat (Triticum turgidum L.) landraces is almost invariably susceptible and disease severity is usually high. However, such wheats produce a stable yield and seeds are less shrivelled, relative to disease severity. Using 10‘pure‐line’genotypes, the effect of the disease on kernel weight and grain yield was studied to detect whether some form of incomplete resistance or tolerance was involved. Genotypes exhibited significant differences for mean disease severity. Percentage losses varied from 3.9 to 14.4% for kernel weight and from 2.8 to 31.3% for grain yield. Regression analysis revealed a significant linear relationship (r = 0.66, P < 0.05) between mean percentage loss and mean disease severity for kernel weight but not for grain yield. Only one genotype sustained significant losses of both kernel weight and grain yield, and was therefore classified as susceptible. Genotypic differences for both traits and the negative correlation (r = ‐0.87, P < 0.01) between them complicated interpretation of the data. Generally, however, the results indicated that incomplete resistance, possibly partial resistance, is present when one considers kernel weight. For grain yield, tolerance was also implicated since the variation could not be explained by differences in disease severity, and percentage loss did not appear to be a function of disease severity.
Comparative seed yield performance of high‐by‐high and low‐by‐high crosses in flax *
Authors: Tadesse1 N. , Lay C. , Dybing C. D.
Published: April 2006

Successful identification of a desirable segregant depends partly on the parents chosen to make the crosses. This experiment was conducted to compare performance and genetic variability for seed yield, yield components, agronomic traits and harvest index of lines derived from low‐ and high‐yielding flax (Linum usitatissimum L.) crosses, and to identify important yield components for flax seed yield improvement. The lines chosen as high yielding parents for this experiment were‘Linott’and 'Summit; and the low yielding parents were‘Grant’and Ci2395. The high‐yielding lines produced significantly more seeds per boll and had a higher harvest index than the low‐yielding lines. Evaluation of 161 F2:6 lines from four crosses among these lines showed that the greatest genetic variability, highest cross average, and highest F6 line seed yield occurred in the low x high cross,‘Grant’x‘Linott’. All low X high crosses exhibited higher genetic variances for seed yield than the high x high crosses. The high x high cross 'Summit’x‘Linott’had low genetic variance for seed yield. Number of bolls per area was determined by linear regression, path coefficient analysis, and stepwise multiple regression analysis to be the most important component of seed yield. This study showed that hybridization of low and high‐yielding flax lines may be useful to increase genetic variability and obtain high‐yielding flax lines.
A specific PCR assay for resistance to biotypes 1 and 2 of the rosy leaf curling aphid in apple based on an RFLP marker closely linked to the Sd1 gene
Authors: Rochf1 P. , Arke G. van , Vanheusden A. W.
Published: April 2006

This report describes the conversion of a restriction fragment length polymorphism (RFLP) marker (the 2B12a locus). linked to the Sd1 aphid resistance gene, to a polymerase chain reaction (PCR) based marker. A section of the 2BI2 probe was sequenced and two primers were designed lo amplify this sequence in the cultivars‘Prima’and‘Fiesta’: all the amplification products were the same size. After sequencing. two specific 24‐mer oligonueleotides were synthesized (DdARM‐51 and DdAR.M‐32) to exploit a single base‐pair difference. These primers were used to screen 44 plants from the‘Prima’x‘Fiesta’family and generated a single amplification product (196bp). in approximately half of the seedlings, which was linked to the resistance gene Sd1,. The DdARM primer combination was used to evaluate a range of apple cultivars and selections, including some varieties derived from‘Cox’and alternative sources of resistance reported in the literature. In parallel with this work, the phenotypic response of the same genotypes was either confirmed or determined in replicated glasshouse tests. The sequence characterized amplified regions (.SCAR) marker was amplified in all the resistant plants, with the exception of‘Northern Spy’and 3760 (the sources of Sd2 and Sd3 resistance, respectively), but never in the susceptible plants. The possible role of this marker in a marker‐assisted breeding strategy, and its compatibility with a SCAR marker linked to the I, gene for resistance to apple scab. is discussed.
Pollen‐mediated gene flow in an autogamous crop: Foxtail millet (Setavia italica)
Authors: WANG T. Y , CHEN H. B. , DARMENCY H.
Published: April 2006

Gene How is a key concern associated with the eonlamination of seed multiplication iields and the use of transgenic crops. The release of herbicide‐resistant germplasnis and the use of male‐sterile varieties make foxtail millet (Sviaria ilalicii) an appropriate material to inves‐tigate this concern. Pollen dispersal from pollen donor sources and gene tlow in fertile and male‐slerile varieties of fortail millet were investigated in experiments in China and France. Although foxtail millel is mainly autogamous (less than 2% oiitcrossing), pollen from a 5m diameter plot could fertilize a tertile variety up to 24 ni away, and a male‐sterile variety up to 40m. Negative exponential and WeibuU fnnctions were used to tit the relationships between percentage and number i.A iubrids per cm of ear with distance from the pollen source. Wind velocity and direction resulted in variations of gene How intensity, but did nol change liie slope ofthe regression equations. Pollen competition for available target ovules was observed up to 2 m away from a 1 m diameter pollen source. The percentage of pollen grains that fertilized ovules outside the pollen donor source was 1.4% of the total pollen grain produetion. For every iflO pollen grains released under lieid conditions 1.5 seeds were produced. The probability funetion of pollen dispersal for one donor plant was calculated. It allowed predictions of gene How accord‐ing to lield shapes, estimations of isolation distances to preserve /ariety purity against pollen contamination, and the fornuiiation of efficient male/female ratios Ibr hybrid seed production.
Heritility of field resistance to potato leafroU virus in cultivated potato
Authors: BROWN C. R. , CORSINI D. , PAVEK J. , THOMAS P. E.
Published: April 2006

Potato progenies in a line x tester mating design and the clonal parents were screened for field resistance to potato leafroll virus (PLRV) to determine the heritability of this trait. Twelve advanced potato clones or varieties were crossed as pistillate parents to two pollen testers. The seedling progenies and clonal parents were exposed to aphid‐transmitted potato leafroll virus for two growing seasons. Cumulative infection by potato leafroll virus was determined by post‐season sero‐logical indexing of foliage grown from sprouted tubers after 2 years of exposure. Narrow‐sense heritability was estimated from regression of mid‐parent on progeny as h = 0.72. This estimate indicates a high level of useabie genetic variance for PLRV resistance in advanced breeding materials. Although variation in resistance to PLRV appears to be a quantitative trait in susceptible and moderately resistant clones, per‐formance of the most resistant parents suggests that genes with major effects may be present. These results are similar to the conclusions of other researchers who found one or two genes controlling the pheno‐types of extreme resistance, resistance to infection, or suppression of virus titre.
Response to early generation selection for grain yield and harvest index in bread wheat (T, aestivum L.)
Authors: Borghi B. , Accerbi M. , Corbellini M.
Published: April 2006

The availability of a reliable selection criterion for the identification of the most productive genotypes in early generations represents a crucial point in many breeding programs. The findings reported in the literature concerning the effectiveness of early generation testing for grain yield (GY) or harvest index (HI) are contradictory.

In this work, we measured the response to selection for GY and HI applied in different generations, from F2 to F6 in nine segregating populations previously screened in F2 by means of visual selection. Genetic variability for HI and GY was found in most of the segregating populations. However, GY of spaced plants in F6 and F3 generations was weakly correlated with yield of F4 and successive generations grown at normal seed density. HI was of limited value as an indicator of yield potential.
Molecular breeding for the BaMMV/BaYMV resistance gene ym4 in winter barley
Authors: Tuvesson S. , Post L. V , ÖHlund R. , Hagberg P. , Graner A. , Svitashev S. , Schehr M. , Elovsson R.
Published: April 2006

The aim of this investigation was to develop a procedure for the largescale molecular breeding for ym4, allowing resistance to BaMMV/BaYMV to be fixed in early breeding generations of winter barley. A codominant STS marker derived from the restriction fragment length polymorphism marker MWG838 for the ym4 resistance gene was combined with a new and easy procedure for preparing leaf samples for polymerase chain reaction (PCR), theoretically allowing one person to extract DNA from 5000 samples in a single day. In the procedure for molecular breeding for ym4, all steps, including leaf sampling, DNA extraction, PCR amplification and digestion with restriction enzyme were assembled in microtitre plates allowing multipipetting throughout the procedure, including the loading of gels. The method is amenable to further automation with the aid of a robot arm. Double haploid (DH) lines, as well as F2 and F4 breeding lines were analysed and, based on markers, homozygous and heterozygous BaMMV/BaYMV resistant plants were identified for further breeding. The winter barley breeding programmes were modified to include marker‐based selection for BaMMV/BaYMV resistance on DH or on F2 individuals, which had been preselected for mildew and leaf rust resistance.
Identification of two new genes conferring resistance to rice blast in the Chinese native cultivar ‘Maowangu’
Authors: Pan Q. H. , Wang L. , Ikehashi H. , Yamagata H. , Tanisaka T.
Published: April 2006

The Chinese native rice cultivar ‘Maowangu’ expresses a high level of resistance to many races of rice blast (Pyricularia grisea) collected from North China and Japan. ‘Maowangu’ was crossed with 10 Japanese differential cultivars and the susceptible Chinese cultivar ‘Lijiangxintuanheigu’ (LTH). Allelism tests were conducted in the F2 populations with rice blast races. The resistance of ‘Maowangu’ was governed by two dominant genes which were non‐allelic to the resistance genes at seven loci: Pi‐a, Pi‐i, Pi‐k, Pi‐z, Pi‐ta, Pi‐b, and Pi‐t. To identify the two resistance genes, two F3 lines of ‘Shin 2/Maowangu’ segregating 3R:1S were selected for linkage tests in 1994. One was linked to marker genes C and Amp‐3 on chromosome 6 with recombination frequencies of 35.8 ± 6.4% and 42.1 ± 6.2%, respectively, and the other to Amp‐1 on chromosome 2 with a recombination frequency of 37.6 ± 6.0%. To confirm these results, two F3 lines of ‘LTH/Maowangu’ were selected for linkage tests in 1995. The one was linked to Amp‐3, and other was linked to Amp‐1, with recombination frequencies of 36.9 ± 3.1% and 34.3 ± 3.2%, respectively. The two genes on chromosomes 6 and 2 were designated Pi13(t) and Pi14(t), respectively.
Patterns of genetic diversity in landraces of common bean (Phaseolus vulgaris L.) from Galicia
Authors: Escribano M. R. , Santalla M. , Casquero P. A. , de Ron A. M.
Published: April 2006

Knowledge of patterns of genetic diversity among existing cultivars helps to broaden the genetic base of new cultivars and maximizes the use of available germplasm resources. This study examined the organization of diversity for morphological traits in 66 landraces of cultivated common bean (Phaseolus vulgaris) from Galicia and its relationship with phaseolin seed protein diversity. Data on growth habit, seed and pod traits obtained from field evaluations at two locations during the 1989—91 cropping seasons were subjected to multivariate statistical analysis. Cluster analysis based on 14 quantitative variables and five qualitative variables identified 11 groups. The landraces were also characterized by phaseolin electrophoresis. The results allowed separation of these landraces into Middle and Andean American groups, which could be further divided into at least eight groups within the Andean American cultivars and three within the Mesoamerican cultivars. These groups in turn corresponded to the previously described races Nueva Granada and Peru of South American origin, and races Durango, Jalisco and Mesoamerica from the Middle American domestication centre. These results confirm the existence of two major groups of germplasm in the cultivated common bean landraces from Galicia, Mesoamerican vs. Andean American.
Identification of lily cultivars using isoelectric focusing of proteins from bulb scales and tissue culture bulblets
Authors: Booy G. , Wouters T. C. A. E. , Kleyn‐Noordijk Y.
Published: April 2006

An efficient procedure is described for cultivar identification in lily, based on polymorphism in bulb scale proteins analysed by isoelectric focusing (IEF). Seventy (84%) out of 83 cultivars from which in vivo bulbs were analysed showed a unique banding pattern. Analysis of in vitro bulblets from 62 commercial cultivars resulted in 47 (76%) unique banding patterns. Cultivars with identical protein patterns always belonged to the same cultivars classification group (i.e., Asiatic hybrids, Oriental hybrids or Lilium longiflorum). Protein bands characteristic for the cultivar groups have been found. The protein patterns appeared to be very consistent and were not affected by the soil‐type on which the bulbs were grown, long‐term bulb storage, different protein sample storage methods, in vitro growing conditions, or in vitro bulblet storage. However, in six out of 10 cultivars from which in vivo bulbs and in vitro bulblets were analysed, protein patterns from in vivo bulbs consisted of a greater number of, and/or more intensely stained bands than those from in vitro bulblets of the same cultivar. The protein patterns appeared to be unsuitable markers for selection of reference cultivars for distinctness, uniformity and stability (DUS) testing as no relation was found between morphological characters and protein patterns. Cultivars with identical or very similar protein patterns were generally clearly distinct on the basis of morphological characters.
Association of leaf rust and powdery mildew resistance in a recombinant derived from a Hordeum vulgare × Hordeum bulbosum hybrid
Authors: PICKERING R. A. , STEEFFENSON B. J. , HILL A. M. , BOROVKOVA I.
Published: April 2006

While studying powdery mildew resistance in a recombinant line (code 81882) derived from a Hordeum vulgare (cv. ‘Vada’) ×Hordeum bulbosum hybrid, a low infection type of resistance to leaf rust was observed. To determine the mode of inheritance of the leaf rust resistance and whether there was linkage between the two resistances, F2 and F3 progenies from crosses between 81882 and ‘Vada’ were inoculated with the leaf rust and powdery mildew pathogens. Southern blots were prepared using restricted DNA extracted from leaves of 82 F2 plants and four chromosome 2HS sequences were hybridized with the blots to define the length of the introgression. The leaf rust resistance appears to be inherited as a single dominant gene on chromosome 2HS, which co‐segregates with the powdery mildew resistance. There was an almost complete association between the resistances and the respective molecular markers, but it is likely that the strong linkage results from the frequent inheritance of the introgressed H. bulbosum DNA as an intact segment of chromatin with only low levels of recombination within the segment.
Increasing erucic acid content in Ethiopian mustard through mutation breeding
Authors: VELASCO L. , FERNÁNDEZ‐MARTINEZ J. M. , HARO A. de
Published: April 2006

Ethylmethane sulphonate (EMS) was applied to seeds of the Ethiopian mustard (Brassica carinata A. Braun) line C‐101. Bulk samples of M3 seeds from 8331 M2 plants were evaluated for the fatty acid composition of their oil by near‐infrared reflectance spectroscopy (NIRS) and by further gas chromatography on selected samples. A putative mutant, N2‐6230, showing very low oleic acid content (4.7% vs. average of 8.6% in C‐101) and erucic acid content within the range of variation of the line C‐101 (40‐49.3%) was identified. The M3 progeny of this mutant showed a wide segregation for erucic acid content (39.1‐57.9% vs. 41.8‐50.3% in C‐101), and maintained levels of oleic acid lower than in line C‐101. Selection for high erucic acid content in the M3 and M4 generations led to the fixation of this mutation in the M5 generation (52.2‐59.3% vs. 39.0‐47.6% in C‐101). This is the first high erucic acid line obtained in Brassica species through mutation breeding. Its utility in future programmes to develop very high erucic acid lines is discussed.
Identification of RAPD markers linked to the Ns locus in potato
Authors: Marczewski W. , Ostrowska K. , Zimnoch‐Guzowska E.
Published: April 2006

Using the RAPD method and bulked segregant analysis we identified four RAPD markers linked to a dominant gene Ns, responsible for a hypersensitive reaction of potato (Solanum tuberosum L.) to potato virus S (PVS) infection. The markers OPE15550, OPJ13500, OPG17450 and OPH19900 were found to be closely linked to the Ns gene in diploid potato clones. They are situated at 2.6, 3.3, 4.6 and 6.6 cM from Ns, respectively. As a source of the gene, clone G‐LKS 678147/60, which is known to carry Ns transferred from S. tuberosum ssp. andigena was used. These RAPD markers were not amplified in resistant tetraploid clones containing Ns derived from the clone MPl65 118/3, also having an andigenum origin. This suggests that there may be two separate loci of Ns in the sources identified, or different alleles with the same specificity at a single locus, or that the genetic background of tetraploids tested results in different RAPD amphlification patterns.
Analysis of total glucosinolate content and individual glucosinolates in Brassica spp. by near‐infrared reflectance spectroscopy
Authors: Velasco L. , Becker H. C.
Published: April 2006

This study was conducted to test the applicability of near‐infrared reflectance spectroscopy (NIRS) for estimating the total glucosinolate (GSL) content in samples of intact seed from a wide range of Brassica species, and to develop calibration equations to estimate simultaneously the percentage of individual GSLs. A total of 290 samples from 15 different Brassica species were scanned by NIRS and analysed for glucosinolate content by high‐pressure liquid chromatography (HPLC). A calibration equation for total GSL content was developed using 270 samples of 14 species in a range between 6 and 193μmol/g seed, resulting in an r2 of 0.99 in calibration and cross‐validation, and 0.95 in independent validation with 20 samples of Brassica rapa, a species not represented in the calibration. Furthermore, calibration equations to estimate the relative amount (mol/mol) of progoitrin, sinigrin, and gluconapin were successfully developed (r2 > 0.85 in cross‐validation) and validated with samples from species not included in the calibration. It was also possible to discriminate between entries with high and low values of glucoiberin, 4‐hydroxyglucobrassicin and glucoerucin.
Reciprocal performance of winter wheat in Hungary and Oklahoma, USA
Authors: Carver B. F. , Bona L.
Published: April 2006

International wheat (Triticum aestivum L.) performance trials have revealed adaptive responses in vernalization and photoperiod for certain Eastern European cultivars when field‐tested in Oklahoma in south central USA. Common experiments were conducted in Hungary and Oklahoma with 12 elite germplasm varieties or lines from each locale to uniformly and directly compare the agronomic potential of hard red winter (HRW) North American wheat and Hungarian bread wheat and to identify potential benefits or hazards for introducing germplasm into reciprocal breeding programmes. Results from four Oklahoma and six Hungarian environments showed that non‐native cultivars were 14% and 25% lower in grain yield than native ones in Hungary and Oklahoma, respectively, although one HRW cultivar (2163) exhibited exceptional yield potential in both locations. The lower grain yield potential of Hungarian genotypes in Oklahoma was reflected primarily in lower spike production at harvest. Yield performance in one location did not correlate with performance in the other. Greater consistency between locales was found for test weight (r = 0.6, P < 0.05) and heading date (r = 0.9, P < 0.01); thus, screening for those traits prior to introduction of parent material may be useful. Although some recovery of the genetic yield potential of native material will be necessary, intergroup crossing between these apparently distinct gene pools should provide a new and valuable resource for bread wheat cultivar development.
Diallel analysis of four resistance components to Septoria tritici in six crosses of wheat (Triticum aestivum)
Authors: Simon M. R. , Cordo C. A
Published: April 2006

Four resistance components, i.e. incubation period, latent period, maturation period and pycnidial coverage, were studied in a diallel cross of four wheat cultivars differing in susceptibility to Septoria tritici. Inoculations and evaluations were carried out at the fourth leaf stage for two years. A combined ANOVA for both years exhibited a significant interaction between crosses and years for maturation period. A separate ANOVA for each year was done for this trait. The combined ANOVA showed that crosses were significantly different for incubation, latent period and pycnidial coverage. Cross effects were also significant for maturation period in each year for the separate ANOVA. Year effects were significant for latent period and maturation period. General combining ability (GCA) was significant and preponderant for incubation period, latent period and pycnidial coverage. For maturation period, the separated ANOVA showed the significance of the GCA for both years. Specific combining ability (SCA) was significant for incubation and pycnidial coverage and for maturation in one year. The preponderance of the additive genetic variance for all traits indicates the possibility of selecting for them in order to obtain improved cultivars. Incubation period was inherited independently of maturation period and pycnidial coverage, indicating that combinations of some of those characters may lead to more effective and durable resistance.
RFLP variability in apricot (Prunus armeniaca L.)
Authors: de Vicente M. C. , Truco M. J. , Egea J. , Burgos L. , Arús P.
Published: April 2006

The level of polymorphism of the restriction fragment length polymorphisms (RFLPs) detected by 33 almond genomic and cDNA probes was studied in a set of 52 European and North‐American apricot cultivars. Eighteen of these probes were polymorphic and yielded a total of 48 scorable bands, allowing the identification of 45 different phenotypes. Most cultivars (43) had an individually distinguishable RFLP phenotype, and three of the five clusters with the same phenotype contained cultivars that were likely to be synonymous. The group of Spanish cultivars (25) had a lower level of polymorphism than the others, suggesting that bottlenecks may have occurred in the recent history of the apricot that have eroded its genetic variability.
Chromosomal location of genes for resistance to powdery mildew in cultivated oat (Avena sativa L.). 1. Gene Eg‐3 in the cultivar ‘Mostyn’
Authors: Hsam S. L. K. , Zeller F. J.
Published: April 2006

The cultivar ‘Mostyn’ of hexaploid oat (Avena sativa L.) possesses a dominant gene conferring resistance to powdery mildew caused by Erysiphe graminis avenae. The resistance gene, designated Eg‐3, was derived from the wild oat Avena sterilis L. var. ludoviciana. Monosomic analysis revealed that this gene was located on chromosome 17, which corresponds to the missing chromosome in the ‘Kanota’ monosomic line Kl1. This chromosome is associated with the homoeologous group 1 of the Triticeae.
Seed storage potential of population varieties and hybrid varieties and their breeding components in rye (Secale cereale L.)*
Authors: Stahl M. , Steiner A. M.
Published: April 2006

Seeds of population varieties, hybrid varieties, cytogenetic male sterility (CMS) single cross lines and CMS inbred lines of rye (Secale cereale L.) were stored to determine the respective rates of germination loss with a view to their storage potential. The seeds were stored under controlled conditions at a seed moisture content of 14% and a temperature of 30°C for periods of up to 80 days. The storage potential decreased in the order: hybrid varieties > population varieties > CMS single cross lines > CMS inbred lines. However, the rates of germination loss showed no differences within the respective categories. The inferences drawn for seed storage potential hold for seed vigour potential.
Low level of polymorphism detected by SSR probes in bread wheat
Authors: Varshney R. K. , Sharma P. C. , Gupta P. K. , Balyan H. S. , Ramesh B. , Roy J. K. , Kumar A. , Sen A.
Published: April 2006

In‐gel hybridization patterns were studied in a set of nine diverse bread wheat (Triticum aestivum L. em. Thell) genotypes using 23 simple sequence repeat (SSR) probes in combination with 14 different restriction enzymes. Multilocus fingerprints due to SSR probes, shown earlier to be characteristic of a majority of plant genomes, were not obtained and only a very low level of polymorphism was detected when using as many as 142 probe‐enzyme combinations. The hybridization of a prominent solitary high molecular weight fragment (> 23 kb) with a number of SSR probes suggested the presence of these SSRs (microsatellites) within the long stretches of repeated DNA sequences. This indicates that the genome of bread wheat differs from that of other plants in the organization and distribution of SSRs and that SSR probes detect very little polymorphism.
RFLP mapping of a new cereal cyst nematode resistance locus in barley
Authors: Barr A. R. , Chalmers K. J. , Karakousis A. , Kretschmer J. M. , Manning S. , Lance R. C. M. , Lewis J. , Jeffries S. P. , Langridge P.
Published: April 2006

Cereal cyst nematode (CCN) (Heterodera avenae Woll.) is an economically damaging pest of barley in many of the worlds cereal growing areas. The development of CCN‐resistant cultivars may be accelerated with the application of molecular markers. Three resistance genes against the pest have been mapped previously to chromosome 2 (Ha1, Ha2 and Ha3). In this study, a third gene present in the Australian barley variety ‘Galleon’ derived from the landrace ‘CI3576’ was located. Segregation analysis of CCN resistance data derived from doubled haploid populations of the cross ‘Haruna Nijo’×‘Galleon’ identified a single major locus controlling CCN resistance in the variety ‘Galleon’. This locus mapped to the long arm of chromosome 5H estimated to be 6.2 cM from the known function restriction fragment length polymorphism marker XYL (xylanase). While five genes for CCN resistance, including Ha2, have been mapped to group 2 chromosomes in the Triticeae, no gene other than Ha4 has been identified on group 5 chromosomes.
Cytoplasmic effects on the regeneration ability of sunflower
Authors: Nestares G. , Zorzoli R. , Mroginski L. , Picardi L.
Published: April 2006

Highly varible organogenic regeneration has been obtained in sunflower, depending upon culture conditions, genotype and their interactions and now the effect of cytoplasm upon regeneration ability has been analysed. Six sunflower inbred lines in their male‐sterile and malefertile forms were evaluatedin vitro: HA89, GP762, HA300, RK416, RK456, and KLM280. The basal medium was agar solidified Murashige and Skoog (MS) medium supplemented with plant hormones: KIN 2mg/1 + IAA 1 mg/1 (Ml); BA 0.5mg/1 4‐ IAA 0.5mg/1 (M2). Cotyledons of mature seeds were used as explants. Regeneration ability (R) was evaluated on day 30 after initiation of culture. Significant differences were observed between male‐sterile and male‐fertile forms of some inbred lines for R on M2 medium. The presence of interaction among the factors line‐cytoplasm‐regeneration on M2 was demonstrated by using a G‐test. This nucleus‐cytoplasm interaction affects the regeneration ability of this species and should be taken into account when using tissue culture for crop improvement.
A simple technique for the identification of embryo‐carrying seeds from wheat × maize crosses prior to dissection
Authors: Bains N. S. , Mangat G. S. , Singh K. , Nanda G. S.
Published: April 2006

Embryo rescue is an important step in the wheat x maize system of induced haploidy in wheat. On average, only one‐third of the seeds carry embryos, but they all have to be dissected because no morphological distinction is available to distinguish between seeds with and without embryos. We here report a simple technique in which immature seeds from wheat × maize crosses are placed on a transparent surface and illuminated from above. The free‐floating embryo, settled at the bottom of the seed, can be seen from below or in an image reflected on a plane mirror. Using this technique 97.8% of the embryo‐containing seeds could be detected prior to dissection. The technique will be useful in reducing the time and labour involved in embryo culture, thereby scaling up haploid production.
Cytogenetics of the ‘glandless‐seed and glanded‐plant’ trait from Gossypium sturtianum Willis introgressed into upland cotton (Gossypium hirsutum L.)
Authors: Bi I. Vroh , Baudoin J. P. , Mergeai G.
Published: April 2006

In order to introgress the ‘glandless‐seed and glanded‐plant’ trait from Gossypium sturtianum Willis (2n= 2x= 26, C1 genome) into the cultivated upland cotton Gossypium hirsutum L. (2n= Ax= 52 (AD), genome), two trispecific hybrids have been created using either Gossypium thurberi Torado (2n= 2x= 26, D1 genome) or Gossypium raimondii Ulbrich (2n= 2x= 26, D5 genome) as bridge species. The cross of both trispecific hybrids by G. hirsutum produced the first backcross progenies (BCl). Cytogenetic analysis showed that the trispecific hybrids had 52 chromosomes, their chromosome configurations at metaphase I (Ml) being 15.071 + 15.3411 + 0.93III + 0.69IV + 0.26VI in G. thurberi×G. sturtianum×G. hirsutum (TSH) and 14.421 + 17.0311 + 0.82III + 0.15IV + 0.07VI in G. hirsutum × G. raimondii ×. G. sturtianum (HRS), respectively. Among six BCl plants analysed, the only plant expressing the ‘glandless‐seed and glanded‐plant’ trait had 52 chromosomes and a meiotic configuration of 5.261 + 20.61II + 0.69III + 0.77IV at MI. Pollen fertility was 2.90% in TSH, 8.97% in HRS, and ranged from 0% to 40.28% in the BCl progenies. The introgressed BCl plant is perennial in growth habit. It can be used in breeding programmes aiming at the introgression of the ‘glandless‐seed and glanded‐plant’ trait into a cultivar of upland cotton.
Forage yield potential of alfalfa plants of varying crown size from old stands
Authors: Kimbeng C. A. , Bingham E. T.
Published: April 2006

Alfalfa (lucerne) plants can persist from one growing season to the next because of their perennial crowns. Plants with large crowns often are selected for breeding purposes. The objective of this study was to determine the forage yield potential of plants with a full range of crown sizes sampled from old stands. This was accomplished by field evaluation of clones and S1 progenies derived from plants of different crown sizes obtained from a 1 m2 of 5‐year‐old stands of cultivars ‘Agate’ and ‘Magnum III’. Significant differences (P < 0.05) in dry forage yield (DFY) were found among entries in both tests. However, there was no consistent trend in DEY with respect to the crown size of the parental plants. Although the crown of space‐planted clones dug after 16 months showed a strong association (r > 0.7, P < 0.01) with DFY, the crown size of these clones was poorly correlated with the crown size of their parental plants. These results suggest that selections based on crown size from older stands may not lead to an improvement in either crown size or forage yield. Crown health will remain an important selection criterion when plants are sampled from old stands; crown size, however, may not be as important.
Influence of pollination modes on yield components in strawberry (Fragaria×ananassa Duch.)
Authors: ŻEbrowska J.
Published: April 2006

The effects of self, wind and open pollination on yield components were investigated in five strawberry genotypes, the cultivars ‘Dukat’, ‘Paula’, ‘Redgauntlet’, ‘Senga Sengana’ and the breeding clone B‐302. Investigations were also conducted to look for additional plant characteristics associated with strawberry yield components after various modes of pollination. Such characteristics would facilitate the indirect selection of highly self‐compatible strawberry genotypes. The greatest effect of self pollination was observed in B‐302 and ‘Redgauntlet’, while the least effect of autogamy was shown m Paula. Conversely, the last cultivar revealed the greatest effect of entomophily, whereas the greatest effect of wind pollination was observed in ‘Dukat’. Relationships between yield components and some flower and pollen characteristics after various pollinations indicated that the degree of self compatibility in strawberry can be predicted from the pollen grain length and the pollen size index. Genotypes producing long pollen grains with large size indices exhibited the greatest effect of autogamy. Anther size, especially length. Which correlated more strongly with yield components than width, could also be used as an index of autogamy in the strawberry. Pollen yield per flower an self compatibility.