bluuebunny/crossref_metadata_2025_split huggingface dataset:
Breeding aspects of clustering winter wheat cultivars for yield response
Authors: Meinel A. , Richter C. , Bätz G. 
Published: April 2006

AbstractThe objective of this study was to compare the yield response of several present day winter wheat cultivars of different origin with the aim of broadening breeders' information from multi‐year/location tests by using an appropriate cluster procedure. Yield response of 18 cultivars was analysed using data from two series of official yield performance tests in Germany. Similarity of yield response between two cultivars is defined by a positive correlation coefficient (nearly one) for the yields over all test environments. A hierarchical agglomerative procedure was used to establish clusters of similarly responding cultivars. The smallest distances in yield response were established between closely related cultivars of equal maturity. Clusters of cultivars with distinct maturity and also the groups of East and West German cultivars tested exhibited clear differences in yield response.
Spike pretreatments, anther culture conditions, and anther culture response of 17 German varieties of spring wheat (Triticum aestivum L.)
Authors: Stober A. , Hessu D. 
Published: April 2006

AbstractThe aim of this work was to establish an in vitro regeneration system from anther cultures of different German varieties of spring wheat (Triticum aestivum L.). Using ‘Nandu’ the most widely grown spring wheat cultivar in Germany, different culture conditions were investigated with regard to their influence on anther culture response. The best results were obtained when applying a cold pretreatment to the donor spikes and using the synthetic L3 induction medium, liquid or solidified with gelrite. The highest rates obtained in these experiments with ‘Nandu’ were 8.6% responding anthers, 22.3% embryoid induction, 15.3% albino regeneration and 5.5% green plant regeneration (all rates related to the number of cultured anthers). Of the ‘Nandu’ plants analysed, 51.1% were haploid and 44.3% were diploid, probably as a consequence of spontaneous chromosome doubling.When screening a further 16 commercial German varieties of spring wheat, 10 exhibited good anther culture response and four of these (‘Eta’‘Jondolar’, ‘Mieka’, and ‘Star’) proved to be highly responsive, reaching embryoid induction rates between 4.3 and 10.3% and rates of green plant regeneration between 5.4 and 10.7%.
Genetic variation of yellow‐seeded rapeseed lines (Brassica napus L.) from different genetic sources
Authors: Tang Z. L. , Li J. N. , Zhang X. K. , Chen L. , Wang R. 
Published: April 2006

AbstractIn order to breed yellow‐seeded rapeseed, 16 yellow‐seeded lines of Brassica napus L. derived from eight genetic sources were used. The genetic variation of the seedcoat ratio, the cellulose content of the seedcoat, the oil content of the seedcoat and of the embryo, and also the correlations between these characters of the yellow‐ and brown‐seeded plants from the same line, were analysed by variance analysis and path analysis. The results show that the seedcoat ratio and cellulose content of brown seeds are 4.2% and 17.74%, respectively, higher than that of yellow seeds and the oil content of the seedcoat of brown seeds is 3% lower than that of the yellow seeds, these differences all being highly significant. However, the differences between yellow and brown seeds in 1000‐seed weight and oil content of the embryo were very small. Both characters are determined mainly by the genetic background and not by seed colour or seedcoat thickness. The correlation analysis revealed that the seedcoat thickness has a highly significant positive correlation with the cellulose content of the seedcoat and is highly significantly negatively correlated with the seedcoat oil content and the 1000‐seed weight. The oil content of the embryo alone has a highly significant negative correlation with 1000‐seed weight. In yellow seeds, the seedcoat thickness has a large and directly positive effect on the oil content of the embryo whereas the 1000‐seed weight has a negative one; the opposite was found in brown seeds. Selection objectives in breeding yellow seeds in Brassica napus are also discussed.
Verification of the parthenogenetic capability of unreduced eggs in an alfalfa mutant by a progeny test based on morphological and molecular markers
Authors: Barcaccia G. , Tavoletti S. , Falcinelli M. , Veronesi F. 
Published: April 2006

AbstractApomixis involves the parthenogenetic development of apomeiotic eggs. It has the potential of cloning plants through seed, and thus furnishes a unique opportunity in breeding of allogamous sexual species, such as alfalfa, for developing superior cultivars with permanently fixed heterosis. Apomixis as a whole has not been detected in the genus Medicago, but components of apomixis have been reported. The formation of unreduced eggs through diplosporic meiosis was documented in a diploid mutant of M. saliva ssp. falcata (L.) Arcang., named PG‐F9. Since in facultative apomictic species non‐reductional meiosis and parthenogenesis could be tightly associated processes, a progeny test based on morphological trait and molecular marker evaluation was carried out to verify the occurrence of parthenogenesis in PG‐F9. Morphological traits such as leaf shape, stipule form, stem pigmentation and flower colour were shown to be effective in the preliminary screening of progenies and most of the plants were classified as non‐maternal (i.e. from sexual reproduction). Molecular investigations by means of random amplified polymorphic DNA (RAPD) fingerprint and heterozygous restriction fragment length polymorphism (RFLP) loci detection conducted on the progenies classified morphologically as maternal allowed two plants, molecularly similar but not identical to PG‐F9, to be discovered. Owing to the high number of molecular markers conserved as in the mother plant, and because of the great discriminating efficiency of the primers and probes used, these progeny plants could most likely be generated through parthenogenesis of diplosporic eggs. In fact, the extraordinary preservation of maternal morphological traits and genomic loci over one generation may be explained only if apomictic reproductive events rarely took place in PG‐F9.
Molecular analysis of the fourth progeny of plants derived from a cytoplasmic male sterile chicory cybrid
Authors: Rambaud C. , Bellamy A. , Dubreucq A. , Bourquin J.‐C. , Vasseur J. 
Published: April 2006

AbstractCytoplasmic male sterile (CMS) chicory cybrids have previously been obtained by fusion between chicory and CMS sunflower protoplasts. Preliminary restriction fragment length polymorphism analysis has shown mitochondrial recombination events in CMS plants and their progeny. The aim of this study was to investigate the fate of the mitochondrial genome of the fourth progeny derived from one CMS cybrid. Southern hybridization using several specific mitochondrial sequences as probes have revealed polymorphic patterns between the plants analysed and, consequently, the genetic instability of this genome. Presence of the sequence responsible for cytoplasmic male sterility in sunflower (orf522) was detected by polymerase chain reaction and confirmed by molecular hybridization in the CMS chicory plants; however, its part in CMS expression in chicory did not appear obvious. Moreover, different flowering phenotypes, including completely fertile plants occurred and no correlation could be established between the different mitochondrial profiles and the flowering types. These results suggested some hypotheses and questions about the molecular determinant of CMS in chicory, its regulation and expression and questions about the mitochondrial‐nuclear interactions.
Transfer of disease resistance genes from Triticum araraticum to common wheat
Authors: Brwon‐Guedira G. L. , Gill B. S. , Cox T.S. , Leath S. 
Published: April 2006

AbstractThe wild tetraploid wheat species Tr$$ (Zhuk) Zhuk Var. araratieum is a source of pest resistance genes for T$$ aesti$$ L. Our objectives were to describe the breeding behaviour of T.arartuititm when backcrossed to common wheat and transfer resistance to leaf rust (caused by Pu$$) and powdery mildew (caused by Blumeria $$wheat. Crosses were made between five wheat genotypes and $$ accessions. Fertifity and chromosome numbers of BC$$; plants were determined. Resistance to leaf rust was transferred toBC2 ‐derived families from 10 different T’ararati$$an accessions. Leaf rust resistance genes in nine T. araratieum accessions can be assigned to at least four loci. Leaf rust resistance transferred from three accessions was inherited in the hexaploid derivatives as a single. $$ gene in each case. Resistance to powdery mildew was also detected in the T. araratie$$ backcross derivatives. Fertile hexaploid derivatives expressing T’araratieum‐derived resistance genes can be recovered after two backcrosses to wheat cultivars.
In vitro morphogenetic responses of mature wheat embryos to different NaCl concentrations and growth regulator treatments
Authors: Kintzios S. E. , Barberaki M. , Aivalak.is G. , Drossopoulos J. , Holevas C. D. 
Published: April 2006

AbstractCallus cultures were initiated from mature excised embryos of winter wheat on Murashige and Skoog (MS) medium supplemented with either 0, 3, 6 or 9g/l NaCl and various combinations of growth regulators. Callus induction rates were virtually 100% on every medium used, while the growth of calli during the induction phase was retarded at higher NaCl concentrations. Application of NaCl and auxin at high concentrations during the induction and proliferation phases strongly inhibited shoot induction. In addition, a competition between root induction and shoot induction was clearly observed. Conversely, rhizogenesis was not significantly decreased under saline conditions and was actually favoured at high NaCl (≥6 g/1) concentrations, especially when 2,4‐D was used as the only auxin for callus induction. Roots induced at lower NaCl levels were significantly longer, thinner, lighter‐coloured and had fewer hairs than roots induced on 6 or 9 g/1 NaCl. Roots induced on NaCl‐free medium also had fewer but larger cortex parenchymatic cell layers and a wider stele compared with roots induced on the highest NaCl level. The best plant regeneration (simultaneous root and shoot formation) rates were observed when calli were induced on 2 mg/1 2,4‐D and subcultured on 1 mg/1 NAA and 3 g/1 NaCl.
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

AbstractIn 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

AbstractSalt‐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

AbstractThe 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

AbstractA 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

AbstractThe 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

AbstractIncreased 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

AbstractInterspecific 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

AbstractHigh 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

AbstractAnther 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.