bluuebunny/crossref_metadata_2025 huggingface dataset:
Hybridizations among Brassica napus, B. rapa and B. juncea and their two weedy relatives B. nigra and Sinapis arvensis under open pollination conditions in the field
Authors: Bing D. J. , Downey R. K. , Rakow G. F. W.
Published: April 2006

The rate of natural crosses occurring among the cultivated Brassica species B. napus, B. rapa, and B. juncea and their two weedy relatives B. nigra and Sinapis arvensis was studied in co‐cultivation experiments under field conditions in Saskatchewan, Canada, with special reference to evaluation of the possibility of transgene escape from the cultivated to the weedy species. Natural crosses occurred among B. napus, B. rapa, and B. juncea, indicating that hybridizations among these three species do occur under field conditions. On the other hand, no natural crosses occurred between the cultivated species and B. nigra or S. arvensis. It is concluded that the crosses between the cultivated and weedy species are practically impossible under field conditions in Saskatchewan, and that the escape of transgenes from transgenic cultivars of B. napus, B. rapa and B. juncea into B. nigra and S. arvensis is basically zero in this region.
Seed protein content of soybean as affected by spatial variation in field experiments
Authors: Vollmann J. , Hadad T. El , Gretzmacher R. , Ruckenbauer P.
Published: April 2006

The variation of soybean seed protein content has been investigated in performance trials of maturity group 000 to I genotypes at different locations in the eastern part of Austria between 1992 and 1994. In all experiments evaluated, significant portions of spatial variation were identified which affected seed protein content in the range of −25 to +30 g/kg. Lattice and neighbour analysis were more efficient than the randomized complete block design in reducing error variance in most experiments. Neighbour analysis was superior to the lattice design when soil trends were changing over short distances or in both longitudinal and latitudinal directions. In most instances, neighbour analysis based on two or three neighbouring plots at each side of a test plot was more efficient than an analysis using only the nearest neighbours. Residuals derived from neighbour analysis were also used to visualize spatial heterogeneity, and clear trends of protein content were identified for particular experimental sites. The ranking of genetic entries was considerably biased by spatial variations, which would have reduced the efficiency of selection for high protein content if genotype performance was not adjusted for field variation.
An extended genetic map of rye (Secale cereale L.)
Authors: Senft P. , Wricke G.
Published: April 2006

A genetic linkage map of rye consisting of 92 markers was constructed by using isozyme and molecular marker techniques. For this purpose an F2 population of 137 individuals was established on which RFLP studies with homologous and heterologous probes were performed. After establishing a reliable polymerase chain reaction (PCR) protocol, 280 random primers were screened for polymorphisms and 17 random amplified polymorphic DNA (RAPD) loci were mapped. The digestion of the template DNA prior to PCR increased the degree of polymorphism. Previously published markers could also be integrated into this map by using the JoinMap computer program. The resulting linkage map comprises a total of 127 markers and spans a distance of about 760 cM.
The use of bulked segregant analysis to accumulate RAPD markers near a locus for beet cyst nematode resistance in Beta vulgaris
Authors: Halldén C. , Säll T. , Olsson K. , Nilsson N.‐O. , Hjerdin A.
Published: April 2006

Bulked segregant analysis (BSA) was used to accumulate RAPD markers near the beet cyst nematode resistance locus Hslpro‐1 of sugar beet (Beta vulgaris L.). Graphical genotypes constructed from RFLP data were utilized to select F2 individuals in (1) the construction of pools of plants used in the initial screening for polymorphisms, and (2) the selection of individual plants used to confirm the potential linkage. The pooled DNA samples were screened for polymorphisms using 668 RAPD primers. Forty‐four candidate markers potentially linked to the region were analysed further using 14 segregating individuals. Close linkage was confirmed for 17 of the markers. Four of the RAPD markers were assigned map coordinates within the RFLP map. Three of these markers extended the RFLP map by 3cM. Altogether, the 8cM target interval contains 10 RFLP and 17 RAPD markers, corresponding to an average marker density of 0.3cM in the Hslpro‐1 region.
Combining different linkage maps in sugar beet (Beta vulgaris L.) to make one map
Authors: Schumacher K. , Schondelmaier J. , Barzen E. , Steinrücken G. , Borchardt D. , Weber W. E. , Jung C. , Salamini F.
Published: April 2006

Several genetic maps for sugar beet (Beta vulgaris L.), from different German research groups, have been published and it is now possible to consider combining them with the aid of the common markers. The computer program JOINMAP (versions 1.3 and 2.0) was used for pair‐wise combination of three populations. Several problems arose: the genetic background of the populations, different population structures (F2 versus F1× F1), different number of polymorphic loci for common probes in the populations to be combined, different estimates of the recombination rates between the same markers and differences between the JoinMap versions. The maps from two F2 populations could be integrated into a single map, but it was more appropriate to construct separate maps for the F2 populations and the F1× F1 population using common markers as reference points only.
Evaluation of random amplified polymorphic DNA (RAPD) markers in Hevea brasiliensis
Authors: Varghese Y. A. , Knaak C. , Sethuraj M. R. , Ecke W.
Published: April 2006

The applicability of random amplified polymorphic DNA (RAPD) markers in the cultivated rubber tree, Hevea, was evaluated using 43 decamer oligonucleotide primers in a set of 24 clones selected in different South‐East Asian countries. A total of 220 0.35–3.5 kb DNA fragments were amplified, of which 111 were polymorphic. Of these, 80 fragments (RAPD markers) which were repeatable and clearly scorable across all genotypes were used to estimate genetic distances among the clones tested. The estimated genetic distances ranged from 0.05 (RRII 308 and PB 5/51) to 0.75 (RRIC 100 and SCATC 88–13). A mean genetic distance of 0.5 indicates a rather high genetic variability among the tested clones. As expected, because of the breeding history of Hevea, UPGMA cluster analysis and Principal Coordinate Analysis (PCoA) indicated the absence of a distinct geographical grouping. The possible application of RAPD markers for clone identification and also for analysis of genetic relationships among Hevea clones is discussed.
Heritability estimates of field resistance to spot blotch in four spring wheat crosses
Authors: Sharma R. C. , Dubin H. J. , Devkota R. N. , Bhatta M. R.
Published: April 2006

Spot blotch of wheat (Triticum aestivum L.), caused by Bipolaris sorokiniana (Sacc. in Sorok.) Shoem., is a major disease in South Asia. Popular commercial cultivars have low levels of resistance to spot blotch. Information on the inheritance of spot blotch resistance in wheat is lacking. Field studies were conducted in four wheat crosses, each involving a Chinese hexaploid parent with high levels of resistance and a commercial cultivar with low to intermediate levels of resistance to spot blotch. Data were recorded in the F2, F3 and F4 generations to estimate heritability. Field studies were conducted in three years (1992–94) at Rampur. Nepal, involving 150 lines in each cross. The spot blotch score was recorded as the percentage necrosis and associated chlorosis of the two upper most leaf surface. In the F2 generation three spot blotch readings on the flag leaf were taken whereas in the F3 and F4 generations four readings were recorded at 5‐day intervals on the flag and the penultimate leaves. The highest disease score (HDS) and the area under disease progress curve (AUDPC) were analysed. Heritability (h2) estimates for spot blotch resistance were intermediate to high measured in terms of HDS (0.47 < h2 < 0.67) and also AUDPC (0.58 < h2 < 0.77) both in F3 and F4 generations in each of the four crosses. Heritability values were somewhat higher for AUDPC than HDS. There were significant negative correlations (r) of days to heading with HDS (‐0.186 < r < ‐0.515) and AUDPC (‐0.218 < r < ‐0.623). One‐hundred kernel weight was significantly negatively correlated to AUDPC (‐0.245 < r < ‐0.454) in all crosses in each generation. The results suggest that selection for resistance to spot blotch could be effective in the segregating populations generated from hexaploid wheat parents having different levels of resistance. Although AUDPC appeared to be a better measure to determine genetic differences for spot blotch in wheat, HDS would be adequate in screening trials for resistance to spot blotch.
Effect of variation at Glu‐D1 on club wheat end‐use quality
Authors: Jones S. S. , Cadle M. M.
Published: April 2006

Club wheats (Triticum aestivum L.), having the allele at the C locus conferring short spike rachis internodes and giving compact appearance of spikes, which have unique and highly desirable soft white wheat end‐use quality characteristics are a vital submarket class of soft white wheat in the US Pacific Northwest. Two important varieties, ‘Tyee’ and ‘Albit’, are heterogeneous for high molecular weight glutenin subunits 2 + 12 and 5 + 10 encoded by the Glu‐D1 locus. Replicated near‐isogenic lines (NILs) of club wheats ‘Tyee’ and ‘Albit’ were grown in four field environments and used to determine the effect of Glu‐D1 coded high molecular weight glutenin subunits (HMWGS) 5 + 10 and 2 + 12 on various end‐use quality traits. The greatest effect of variation at this locus was observed for mixing time to peak, where there was significant variation (P < 0.01) between each 5 + 10 and 2 + 12 NIL group in each environment. Mixing time values for the 2 + 12 NILs for both ‘Albit’ and ‘Tyee’ ranged from 0.60 to 1.23 min lower than the 5 + 10 NILs. Mean values for traits mixing time to peak, cake volume, and viscosity were more favourable for the 2 + 12 NIL groups for all genotypes in all environments. No effects of these HMWGS were detected for test weight, kernel hardness, whole wheat protein, flour yield, ash, flour protein or cookie diameter. Selection for HMWGS 2 + 12 in club wheat breeding programmes should have positive effects on end‐use quality.
Methods for screening maize against downy mildew Peronosclerospora sorghi
Authors: Cardwell K. F. , Kling J. G. , Bock C.
Published: April 2006

Methods of inoculum delivery and timing of test‐row planting were assessed for efficacy in promoting development of downy mildew (Peronosclerospora sorghi) in susceptible maize, and for cost of implementation in terms of personnel and labour. Direct inoculation of pre‐germinated seed of spreader rows resulted in consistent and high incidence of downy mildew infected plants and required substantially less labour and inoculum than the spray inoculation of spreader rows. The optimum time to plant test rows was around 15 days after inoculation of spreader rows. Eight breeding lines were screened for resistance to downy mildew using the revised inoculation method. After one cycle of screening with the new method, resistance levels improved by a range of 0–44% over the previous cycle.
Intrachromosomal mapping of genes for dwarfing (Rht12) and vernalization response (Vrn1) in wheat by using RFLP and microsatellite markers
Authors: Korzun V. , Röder M. , Worland A. J. , Börner A.
Published: April 2006

For intrachromosomal mapping of the dominant GA‐sensitive dwarfing gene Rht12 and the vernalization response gene Vrn1 on chromosome 5 A, an F2 population was established using a wide (synthetic) wheat cross. In addition to restriction fragment length polymorphism (RFLP) probes four microsatellite markers were incorporated. Rht12 was mapped distally to four RFLP loci (Xmwg616, Xpsr164, Xwg114, Xpsr1201) and three microsatellite markers (Xgwm179, Xgwm410, Xgwm291), known to be located on the segment of chromosome SAL which was ancestrally translocated and is homoeologous to Triticeae 4 L. The map position of Rht12 suggests that it is homoeologous to the dominant GA‐sensitive dwarfing gene Ddw1, present on chromosome 5RL. The vernalization response gene Vrn1 showed linkage to Xwg644, as might be expected from comparative maps.
Identification of powdery mildew resistance genes in common wheat (Triticum aestivum L. em Thell.). IX. Cultivars, land races and breeding lines grown in China
Authors: Huang X. Q. , Hsam S. L. K. , Zeller F. J.
Published: April 2006

The objective of the study was to provide information about the occurrence and distribution of resistance genes in wheat cultivars, including old cultivars, land races and advanced breeding lines grown in China. Ninety‐four accessions were analysed with a set of 11 differential powdery mildew isolates. Forty‐four cultivars did not possess any major mildew resistance genes. Thirty cultivars revealed the response pattern of individual resistance genes. The most frequently encountered gene was Pm8, which occurred singly in 11 cultivars, combined either with Pm4a in three cultivars or with Pm4b in another three cultivars. However, 12 cultivars possessing the wheat‐rye translocated chromosome pair T1BL‐1RS did not express Pm8. Gene Pm2 was found in four cultivars and in combination with Pm6 in one cultivar. Genes Pm4a and Pm4b were observed in four and five cultivars, respectively. Another six cultivars carried Pm5. A gene combination of Pm2+Pm4b+Pm6 was found in one cultivar. Twelve cultivars and breeding lines exhibited a response pattern that could not be assigned to resistance genes or gene combinations present in the differential cultivars. Five out of these 12 cultivars/lines showed resistance to all the isolates tested. There is an urgent need to search for novel sources of mildew resistance in order to sustain resistance to existing and emerging powdery mildew pathogens.
Inheritance of partial rust resistance in pearl millet
Authors: Wilson J. P.
Published: April 2006

Quantitative disease resistance should be exploited to complement the use of genes for qualitative or hypersensitive resistance. The expression and inheritance of partial rust resistance of pearl millet inbreds 700481‐21‐8 and ‘ICMP 501’ crossed to moderately susceptible Tift 383’ were evaluated in seedling assays in the greenhouse and in generation mean and single‐seed descent populations in the field. Uredinium sizes on seedling leaves of hybrids were generally intermediate to those of the parental inbreds and consistent differences could be discerned in uredinium lengths. Area under the disease progress curves (AUDPCs) of individual plants of the parents, F1, F2, and backcross F1S to each parent were determined from field trials. Broad‐sense heritability estimates for both crosses were 43%. In generation mean analyses, additive genetic effects were significant in the cross of 700481–21–8 × Tift 383′, whereas additive, dominance, and dominance × dominance epistatic effects were significant for ‘ICMP 501’×‘Tift 383’. The number of genes conferring partial resistance was estimated to be two for 700481–21–8 and 2.5 for ‘ICMP 501’. A hierarchical single‐seed descent analysis revealed significant differences in AUDPC among F3‐derived F4 progenies in the F6 generation. Selection for progenies with greater resistance should be possible among F4 families. Higher levels of resistance were observed in progeny derived from ‘ICMP 501’. Because segregation of resistance differed among progeny derived from 700481–21–8 and ‘ICMP 501’, the genetic basis for resistance probably differs between the two inbreds.
Cytogenetics and morphology of the pentaploid hybrid between Brassica napus and Orychophragmus violaceus and its progeny
Authors: Wu J. G. , Li Z. , Liu Y. , Liu H. L. , Fu T. D.
Published: April 2006

A pentaploid hybrid plant (2n= 50, AACCO) between Brassica napus (AACC) and Orychophragmus violaceus (OO) showed matroclinous morphology and some patroclinous characters. Cloned progenies were mixoploid, consisting of various cells with 38–53 chromosomes, half of the cells with 50 chromosomes. The 50 chromosomes were mainly paired as 25 bivalents and segregated as 25:25 or 22:28; many other segregations were observed in some cells. Progenies produced by selfing had 38–47 chromosomes. Plants with 38 chromosomes were cytologically stable; in all other plants the chromosome number of individual cells varied between the genotype‐specific maximum number and 38, indicating loss of chromosomes during mitosis. The mixoploid plants with 44 chromosomes mainly produced two kinds of mixoploid progenies with 44 and 41 chromosomes, respectively. All plants with 2n= 38 had the same morphology as the parental B. napus and were normal in fertility. These chromosome pairings and segregations in the pentaploid and its progeny support the hypothesis that O. violaceus is a natural polyploid species with a basic chromosome number of 3.
Genetic variation and response to selection for resistance to root‐knot nematodes in oil radish (Raphanus sativus ssp. oleiferus)
Authors: Bünte R. , Müller J. , Friedt W.
Published: April 2006

Based on a preliminary screening of a collection of cruciferous crops, such as oilseed rape (Brassica napus L. ssp. oleifera Metzg.), oil radish (Raphanus sativus L. ssp. oleiferus DC.), and yellow mustard (Sinapis alba L.), some plants within the oil radish varieties showed resistance to the root‐knot nematodes Meloidogyne hapla Chitwood and M. incognita (Kofoid & White) Chitwood. Resistance tests of S1 progeny of these selected genotypes revealed a quantitative nature of resistance to M. hapla. Only a few resistant individuals were found, but a significant effect of selection was observed. In contrast, the progenies of plants resistant to M. incognita showed a very low number of egg masses, suggesting that this resistance may be conferred by dominant major gene(s). The results indicate that resistance of oil radish to root‐knot nematodes may be effective and may thus provide new possibilities for the management of M. hapla and M. incognita.
Diploid, tetraploid, and octoploid plants from anther culture of tetraploid orchard grass, Dactylis glomerata L.
Authors: Christensen J. R. , Borrino E. , Olesen A. , Andersen S. B.
Published: April 2006

This report describes a study of androgenesis in Dactylis glomerata, where the main aim was to find anther culture‐responsive clones. Two types of media and two sugars were compared for their effectiveness in anther culture induction and subsequent plantlet production.

Embryo formation from the cultured anthers was obtained from 28 of the 108 cloned genotypes using two different substrates, R2M and FW. Both induction media supported the formation of embryos from the cultured anthers, but around 4.5 times more embryos (0.81 embryos per 100 anthers) were obtained with R2M compared with FW, and R2M also gave 5.5 times more green plants (0.054 green plants per 100 anthers) than the FW substrate.

In the investigation of a carbohydrate source, responsive clones from the genotype study were tested using maltose as a substitute for sucrose in R2M. Using maltose instead of sucrose increased embryo formation so that 133 embryos per 100 anthers were obtained compared with 7.1 embryos per 100 anthers obtained with sucrose. The total number of green plants obtained was also improved with maltose compared with sucrose, resulting in 66.3 and 1.9 green plants per 100 cultured anthers, respectively.
Evaluation of soybean cultivars using parametric and nonparametric stability estimates
Authors: Yue G. L. , Roozeboom K. L. , Schapaugh W. T. , Liang G. H.
Published: April 2006

High and stable yield is a very desirable attribute of soybean (Glycine max (L.) Merr.) cultivars. Stable yield of a cultivar means that its rank relative to other cultivars remains unchanged in a given set of environments. To characterize 12 soybean cultivars chosen from performance trials, data were obtained from 10 environments (five locations in 2 years). Six stability parameters from four statistical models were derived for each cultivar. Regression coefficients were significantly and positively correlated only with coefficients of variation; they are useful in characterizing whether cultivars responded well in favourable or poor environments. Nassar and Huhn's nonparametric measures, Si(1) and Si(2), were significantly and positively correlated with Eberhart and Russell's sdi2 and Wricke's ecovalence (Wi). The stability measures are useful in characterizing cultivars by showing their relative performance in various environments. Results revealed that high‐yielding cultivars also can be stable cultivars. Correlations between stability parameters obtained from individual years over the same set of locations and cultivars were very low and nonsignificant, suggesting that single‐year data are not reliable as basis for selection. To provide an additional guide for selection, Kang's rank‐sum approach was applied, in which both yield (in rank) and measured nonparametric stability (in rank) were considered. In general, selection for yield only would sacrifice stability to some degree, and selection for stability only would sacrifice a certain amount of yield. The rank‐sum approach reconciles the two and appeared to provide a useful means to characterize soybean cultivars.
Inheritance of resistance to phomopsis (Diaporthe helianthi) in sunflower
Authors: Vear F. , Garreyn M. , de Labrouhe D. Tourvieille
Published: April 2006

The inheritance of resistance of sunflower to phomopsis (Diaporthe helianthi) was studied on 10 inbred lines representing a range of resistance and susceptibility levels, and 25 hybrids from a factorial cross of these lines. Analyses of observations over a 3‐year period, of semi‐natural infection (presence of stem lesions greater than 5 cm) on the hybrids indicated that additive gene control was predominant, with no significant interactions between parental effects. Correlations between infection of parental lines and the mean of their hybrids were not always significant, with certain inbreds which appeared quite susceptible giving hybrids with good levels of resistance. In order to predict hybrid values, it appears necessary to determine the general combining abilities of parental lines. Some inbreds gave very high levels of resistance, others gave very high levels of susceptibility. A test measuring the rate of extension of D. helianthi mycelium on leaves was significantly correlated with the results of natural infections. In particular, it permitted distinction of the most susceptible genotypes, and thus could be used in first generations of breeding to eliminate the most susceptible plants.
Fusarium resistance in Gladiolus: Selection in seedling populations
Authors: Straathof Th. P. , Jansen J. , Roebroeck E. J. A. , Löffler H. J. M.
Published: April 2006

A test to select Fusarium resistant seedlings of Gladiolus is described. Seedlings of 37 populations, obtained from an incomplete diallel between eight parents with different levels of Fusarium resistance, were used. Significant differences in Fusarium infection between and within populations were detected. Most of the descendants selected had a resistant G. dalenii genotype as one of the parents. The resistance level of the parents was associated with the general combining ability for Fusarium resistance based on the seedling test. Implications for resistance breeding are discussed.
Genetic investigation of three lines with recessive genie male sterility in Brassica napus L.
Authors: Yang G. S. , Fu T. D.
Published: April 2006

The male sterility (ms) of three recessive genie ms lines, 117AB, S45AB and 9012AB, was controlled in each case by two recessive male sterility genes. The genes responsible in 117AB and S45AB are the same, but they are genetically different from those in 9012AB.
Analysis of anther culture response in hexaploid triticale
Authors: González M. , Hernádez I. , Jouve N.
Published: April 2006

The androgenic response of five varieties and 10 F1 intervarietal hybrids of 6 × triticale was analysed. The overall response involved three independent phenomena: the production of embryoids, the capability of embryoids to regenerate plants, and the production of green plants. Each of these factors appeared to be controlled by independent genetic systems. From a practical point of view, the product of these three factors, the number of green haploid plants per anther (GPA), is the most reliable variable for the evaluation of genotypes. Positive heterotic effects on GPA were observed in the hybrids, which may indicate that GPA is controlled predominantly by additive genes. No correlation was found between the number of green haploid plants produced by hybrids and that yielded by the best parental line. Therefore, it is difficult to predict the yield of green haploid plants that can be produced by a hybrid simply from the number produced by its parents.
Molecular and biological studies on male‐sterile cytoplasm in the Cruciferae. IV. Ogura‐type cytoplasm found in the wild radish, Raphanus raphanistrum
Authors: Yamagishi H. , Terachi T.
Published: April 2006

The orf138 gene, which is specific to Ogura male‐sterile cytoplasm, was analysed in mitochondrial DNA (mtDNA) of the wild radish, Raphanus raphanistrum, by polymerase chain reaction (PCR), Southern hybridization and sequencing. The effect of R. raphanistrum cytoplasm on the expression of male sterility was also examined in progeny with R. sativus. A PCR‐aided assay and Southern hybridization revealed that three out of six strains analysed included plants with orf138. The sequence of wild type orf138 was same as that of Ogura, except for one or two nucleotide substitutions. Southern hybridization showed a novel mtDNA configuration in R. raphanistrum, in addition to the normal and Ogura types identical to those in R. sativus.

Among interspecific hybrids, all the F1 had normal pollen fertility. In the F2 progeny between female wild plants having orf138 and the maintainer of Ogura male sterility, male‐sterile plants were segregated, fitting the ratio of 3 fertile: 1 sterile plant. R. raphanistrum has cytoplasm that induces male sterility in radishes, and contains a dominant fertility restorer gene.
Genetic diversity in soybean as determined by RAPD and microsatellite analysis
Authors: Doldi M.‐L. , Vollmann J. , Lelley T.
Published: April 2006

The random amplified polymorphic DNA (RAPD) and microsatellite techniques were used to evaluate the genetic diversity among 18 soybean genotypes selected for a breeding programme to increase the protein content of varieties adapted for central European growing conditions. Out of 33 random primers used in RAPD reactions, only 12 showed polymorphism useful for characterization of these genotypes. In contrast, all 12 microsatellite primer pairs used in this study detected polymorphism with 2–6 alleles per locus. Similarity measures and cluster analysis were made using RAPD and simple sequence repeat (SSR) data, separately and together. The resulting dendrograms were compared with each other and with the available pedigree information as a control. The dendrogram derived from RAPD data showed some divergence from the pedigree information available for the lines. The dendrograms based on SSR data and SSR data combined with RAPD gave very good agreement with pedigree information. It can be concluded that the combined use of a limited number of RAPD and SSR markers is a useful and reliable means of evaluating genetic relationships of genotypes in the absence of pedigree data.
Inheritance in seed size of alfalfa: Quantitative analysis and response to selection
Authors: Gjuric R. , Smith S. R.
Published: April 2006

Seed size in alfalfa (Medicago saliva L.) has been positively correlated with seedling vigour and early growth, but there were few published reports on inheritance or selection for this trait. The objective of this research was to estimate components of genetic variance for inheritance of alfalfa seed size and determine the most efficient selection method. Components of genetic variance were estimated on seed and pollen plants of ‘BIC‐7‐WH’ and their progeny arranged in a North Carolina Design II mating design under controlled environmental conditions. Three selection methods, differing in parental control and selection pressure, were used to determine selection response. The seed parent genotype had a major role in determining alfalfa seed size, but the genotype of the seed had no influence. For genetic studies, pollen and seed parent effects on seed size should be measured on seed harvested from progeny plants. Seed size was controlled by additive and non‐additive components of genetic variance. Heritability for seed size was 41.3%. Selection for seed size was effective and a significant shift for larger and smaller seed was attained after one cycle of selection.
Heritability of resistance to brown spot and root rot of narrow‐leafed lupins caused by Pleiochaeta setosa (Kirchn.) Hughes in field experiments
Authors: Cowling W. A. , Sweetingham M. W. , Diepeveen D. , Cullis B. R.
Published: April 2006

Resistance to brown spot (BS) and Pleiochaeta root rot (PRR) in narrow‐leafed lupin (Lupinus angustifolius L.) was assessed on a broad range of breeding lines and cultivars in field trials in Western Australia in 1985 and 1986. Both diseases are caused by Pleiochaeta setosa (Kirchn.) Hughes. Lines were grown in 5m × 1m plots in randomized complete block experiments with various disease pressures associated with cropping history — first, second and third successive lupin crops after cereals at one site in 1985, and first and second lupin crops at two sites in 1986. Best linear unbiased predictors (BLUPs) of defoliation caused by BS across experiments ranged from 64% to 123% of ‘Gungurru’, and BLUPs for PRR lesion severity ranged from 82% to 118% of ‘Gungurru’. For both diseases, genotypic variance was several times greater than genotype × environment variance, but error variance was relatively low for BS and high for PRR. Consequently, broad sense heritability (h2) for BS resistance was high in the seven experiments (range 0.89–0.94) but low for PRR resistance (range 0.00–0.53). There was a moderate correlation between BLUPs for resistance to BS and PRR across experiments (r = 0.36, P < 0.05). Genotypic correlations between resistance to BS and PRR were estimated at 0.57 ± 0.20 and 0.75 ± 0.31 in two experiments in 1985. Breeding progress is likely to be high for BS resistance and there may be slight improvements in PRR resistance associated with BS resistance. However, this field technique is not suitable for rapid breeding progress for PRR resistance.
Inheritance of flower colour and flavonoid pigments in Gerbera
Authors: Tyrach A. , Horn W.
Published: April 2006

The flower colour of Gerbera, an important ornamental cut flower, is derived from carotenoids and flavonoids. The knowledge of enzymological and genetic control of flavonoid biosynthesis is still incomplete. The present paper summarizes the results obtained at our institute between 1981 and 1993. The material for the investigation of phenotypic segregation and segregation of flavonoids after chromatographic analysis came from 408 progenies of controlled crosses. Phenotypic segregation analysis showed acyanic genotypes to be homozygous recessive and recessive epistatic over cyanic genotypes, respectively. This was confirmed by the existence of two loci controlling steps in biosynthesis (fht, dfr or ans) showing recessive mutants and complementary gene action after crosses. Flavone formation is effected by one dominant allele (fns+); dominant and recessive genotypes are now available. Regarding anthocyanidin inheritance, an unusual epistasis of 4′‐hydroxylation (pelargonidin formation) over 3′,4′‐hydroxylation (cyanidin formation) was observed. Final proof of the postulated gene actions will come from enzymological and molecular biological investigations of the chemogenetically defined Gerbera genotypes now available.
Inheritance of sexual incompatibility in apricot
Authors: Burgos L. , Ledbetter C. A. , Pérez‐Tornero O. , Ortín‐Párraga F. , Egea J.
Published: April 2006

The study was carried out with 3‐ to 6‐year‐old apricot progenies from the breeding programmes of ARS in Fresno, California, USA and of CEBAS in Murcia, Spain. Progenies from 19 different crosses were studied to determine the inheritance of the genetic incompatibility trait. The 19 crosses included those where both parents were self‐compatible or both self‐incompatible, and also those where a self‐compatible parent and another self‐incompatible were crossed. Segregating progenies were studied either by bagging a sufficiently high number of flowers in balloon stage and determining the percentage of fruit set several weeks later or by following pollen tube growth with fluorescence microscopy. Results indicated that a monofactorial system with a multiallelic series appears to control the trait. Alleles for self‐compatibility would allow the pollen tubes to grow in any style and reach the ovules. Alleles for self‐incompatibility would stop the pollen tube growth if the same allele is present in the pollen grain and in the pistil.
PCR primers for the estimation of contamination by seeds with normal cytoplasm in rapeseed lots bearing male‐sterility‐inducing Ogu‐INRA cytoplasm
Authors: Tinchant C. , Defrance M.‐C. , Budar F.
Published: April 2006

A polymerase chain reaction (PCR)‐based test was developed to detect seeds bearing the ‘so‐called’ normal rapeseed cytoplasm in seed lots with an OGU‐INRA type cytoplasm. The test is based on the amplification of the orfB region of male fertile rapeseed mitochondrial DNA (mtDNA). The amplification reaction uses total nucleic acids of young seedlings, extracted in bulk. After the sequencing of the orfB gene region in the normal Brassica mtDNA, primers were designed for its amplification by PCR. Although the specificity of amplification for the male fertile (mf) rapeseed cytoplasm is partly impaired by the presence of tiny amounts of this fragment in the mtDNA of male sterile (ms) plants, this test proved to be applicable for the estimation of the level of contamination in seed lots in reconstituted mixes as well as in real lots.
Interspecific hybridization between Cicer arietinum and C. pinnatifidum
Authors: Badami P. S. , Mallikarjuna N. , Moss J. P.
Published: April 2006

An interspecific hybrid between Cicer arietinum cv. GL 769 and a wild species C. pinnatifidum was obtained after emasculation, pollination and application of growth regulators. Ovules were cultured and embryos were later dissected to obtain hybrid plants. These plants were albinos and morphologically resembled C. pinnatifidum. Shrivelled seeds were also obtained in 2% of the crosses, which on germination gave rise to albino plants. These plants did not survive beyond 20 days. The hybrid nature of these plants was confirmed by esterase isozyme studies. Hybrid shoots obtained from germinating embryos were cultured on modified ML‐6 medium with BAP 2 mg/1, IAA 0.5 mg/1, where they turned green after 3–4 weeks. Transmission electron microscopy (TEM) studies on leaf sections from green hybrid shoots showed an improvement in the chloroplast structure, with better organized grana.
Selection for reduced linolenic acid content in Ethiopian mustard (Brassica carinata Braun)
Authors: Velasco L. , Fernández‐Martínez J. M. , de Hard A.
Published: April 2006

Reducing linolenic acid content is one of the most important objectives for the development of Ethiopian mustard lines with high oil quality. This work was aimed at searching for variability of the fatty acid composition of oil within a germplasm collection of Ethiopian mustard. A total of 217 lines were analysed by gas‐liquid chromatography (GLC) in 1991, and one was selected as having reduced values of both linolenic acid content (10.2% versus 14.0% of total fatty acids as the collection average) and linoleic acid desaturation ratio (LDR, 0.34 versus 0.45). After 3 years of pedigree selection for low linolenic acid content, this line showed, in 1995, average values of this fatty acid of 5.4% and 2.4% in two different environments, compared with 11.6% and 8.3%, respectively, in the control. The values of the LDR were 0.18 and 0.09, respectively, compared with 0.36 and 0.27 in the control line.
Allelic variation at the storage protein loci of 55 US‐grown white wheats
Authors: Redaelli R. , Ng P. K. W. , Pogna N. E.
Published: April 2006

Fifty soft white and hard white wheat cultivars (Triticum aestivum L.), and five club wheat cultivars (T. compactum L.) were partially characterized in terms of their storage protein compositions, i.e. gliadins, and high molecular weight and low molecular weight glutenin subunits (HMW‐GS and LMW‐GS, respectively). At the Glu‐1 loci, HMW‐GS composition 1,7 + 9,2+ 12 was found to be predominant, being expressed in 11 cultivars out of 55. The most common alleles at the loci coding for gliadins and LMW‐GS were found to be Gli‐A1/Glu‐A3a (43.6%), Gli‐B1/Glu‐B3b (36.4%), Gli‐D1a/Glu‐D3a (38.1%) and Gli‐Dli/Glu‐D3a (21.8%). Two‐dimensional fractionation (acid‐poly‐acrylamide gel electrophoresis (A‐PAGE) × sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE)) of reduced and alkylated glutenins revealed that the number and the relative mobility of LMW‐GS polypeptides were different from those reported for the corresponding Glu‐3 alleles of hard‐bread wheat cultivars. This result could account for the different technological properties of soft white wheats compared with hard‐bread wheat cultivars, owing to the major impact of LMW‐GS on dough quality.
Breeding aspects of clustering winter wheat cultivars for yield response
Authors: Meinel A. , Richter C. , Bätz G.
Published: April 2006

The 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

The 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

In 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

Apomixis 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

Cytoplasmic 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

The 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

Callus 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.