Seed protein variation for identification of common buckwheat (Fagopyrum esculentum Moench) cultivars

Summary Total seed proteins of 24 common buckwheat cultivars and cultivated populations within a molecular weight range of 30 to 54 kDa were analysed by SDS-PAGE. Single seed analysis of six cultivars identified a total of 18 alternative protein bands with different mobilities. Differences of individual protein band frequencies extracted from single seeds among six buckwheat cultivars varied distinctively, indicating high intravarietal polymorphism. The relation between frequencies of protein bands revealed by single seed analysis and their appearance on the bulk seed analyses was demonstrated. Regarding to band mobility rate and relative band intensity among 24 bulk samples analysed, 14 had distinctive electrophoregrams while the other 10 were ranged into four distinct groups. Analysis of endosperm and cotyledon proteins showed that proteins stored in these main seed parts are tissue specific. The observed electrophoretic polymorphism related to proteins stored in the cotyledons while there was no apparent variability with endosperm proteins.     

Inter-varietal variations of rutin content in common buckwheat flour (Fagopyrum esculentum Moench.)

Summary To improve the quality of buckwheat flour, we investigated the effect of the cropping season on the rutin content in various cultivars of common buckwheat (Fagopyrum esculentum Moench.). Thirty cultivars of buckwheat were grown under both long day conditions (the summer cropping) and short day conditions (the late summer cropping). The inter-varietal variations and the effect of the cropping season on the rutin content were examined. The rutin content was determined by high performance liquid chromatography (HPLC). Results show that the average rutin content in the late summer cropping was about half that of the summer cropping. There were wide inter-varietal variations of rutin content in the summer cropping. The differences in rutin content in the late summer cropping were less pronounced. Rutin content was closely correlated with the flowering period in summer (r=0.735^***). The later flowering cultivars produced a higher content of rutin than the earlier flowering cultivars in the summer cropping. The differences in the cumulative solar radiation received in the two seasons seems to be a reasonable explanation for this increase in the rutin content of the buckwheat flour. The rutin content of early flowering cultivars, which are suitable for long day conditions, is positively correlated with yield in the summer cropping. However, the rutin content in the intermediate and late summer ecotype cultivars, which are suitable for short day conditions, shows no correlation with yield in the late-summer cropping. In conclusion, there are wide inter-varietal variations of rutin content in buckwheat flour and the rutin content increases under long day conditions.     

Flavonoid content of flaxseed. Influence of cultivar and environment

Summary Two studies, one with four cultivars grown at four locations during 1989 to 1993, and the second with a transgenic and its non-transformed parent cultivar grown at three locations for three years, were undertaken to explore the variation in total flavonoid content of flaxseed (Linum usitatissimum). Results of the analyses of variance for the first study showed significant cultivar as well as environmental effect on flavonoid content. Cultivar NorLin displayed the highest flavonoid content across the sites with a mean of 71 mg/100 g, and Omega, a yellow-seeded flaxseed cultivar, the lowest with a mean of 35 mg/100 g. There was no significant difference between a transgenic flaxseed and its non-transformed parent for total flavonoid content except for one location in 1991. Flavonoid content was inversely related to the protein content and there was a weak positive correlation between flavonoid and oil levels.     

High-performance liquid chromatographic analysis of anthocyanins in Japanese garden iris and its wild forms

Summary Following bud pollination of tartary buckwheat (Fagopyrum tataricum) with pollens from common buckwheat (F. esculentum), cv. Mancan, 31% of the ovaries began to grow but all turned brown and withered after 6 to 14 days. Fluorescence microscopy of the growing ovaries showed the pollen-tube entering the embryo-sac. The ovules from the growing ovaries failed to produce any embryo in the culture medium in which the immature embryos from the self-pollinated (compatible) tartary flowers were able to mature and germinate. No embryo development was observed after cross-pollination. The interspecific incompatibility is attributed to the failure of gametes to fuse.Abbreviations BAP benzylaminopurine - IAA indoleacetic acid     

Rapid genotyping with DNA micro-arrays for high-density linkage mapping and QTL mapping in common buckwheat (Fagopyrum esculentum Moench)

For genetic studies and genomics-assisted breeding, particularly of minor crops, a genotyping system that does not require a priori genomic information is preferable. Here, we demonstrated the potential of a novel array-based genotyping system for the rapid construction of high-density linkage map and quantitative trait loci (QTL) mapping. By using the system, we successfully constructed an accurate, high-density linkage map for common buckwheat (Fagopyrum esculentum Moench); the map was composed of 756 loci and included 8,884 markers. The number of linkage groups converged to eight, which is the basic number of chromosomes in common buckwheat. The sizes of the linkage groups of the P1 and P2 maps were 773.8 and 800.4 cM, respectively. The average interval between adjacent loci was 2.13 cM. The linkage map constructed here will be useful for the analysis of other common buckwheat populations. We also performed QTL mapping for main stem length and detected four QTL. It took 37 days to process 178 samples from DNA extraction to genotyping, indicating the system enables genotyping of genome-wide markers for a few hundred buckwheat plants before the plants mature. The novel system will be useful for genomics-assisted breeding in minor crops without a priori genomic information.     

Variation in pollen performance among plants of Fagopyrum esculentum

Summary In genetically-heterogeneous outcrossing species, there is the opportunity for selection based on the male gamete. Buckwheat (Fagopyrum esculentum Moench) is self-incompatible with one ovule per flower, so pollen competition at each ovule can be studied. The occurrence of selection among pollen parents was determined, as well as the relative importance of prezygotic and post-zygotic selection. Mixed pollinations from two donors produced nonrandom paternity, with one of the donors being favored about 2:1 on several females. Individual plants showed significant variation in the speed of pollen-tube growth. Therefore, prezygotic selection is likely to have occurred based on the speed of pollen tube growth. In single-donor pollinations, donors had equal success as expected in the absence of post-zygotic selection among donors. However, a significant male x female interaction was found, consistent with postzygotic selection against particular parental combinations. To test whether male fitness is reduced by increased allocation to seed filling during pollen production, large- and small-seeded lines were compared, both as pollen donor and as pollen recipient. The large-seeded line was better in both roles, thus there was no evidence that greater allocation to seeds reduced the quality of the pollen.     

The effect of pollen load and pollen grain competition on fertilization success and progeny performance inFagopyrum esculentum

Summary Flowers of cultivated buckwheat (Fagopyrum esculentum Moench) often receive natural pollen loads of fewer than 10 pollen grains. The cultivated varieties also have high genetic variability. These observations raise the question of whether seed production in buckwheat is often limited by pollen delivery, and whether small increases in pollen load could result in gametophytic selection through pollen grain competition. In greenhouse-grown buckwheat plants, embryo sac penetration by pollen tubes was universal with 10 or more pollen grains. However, seed production increased with pollen load up to 30 grains per flower. Larger pollen loads, which intensify selection among gametophytes, resulted in more vigorous progeny. Seedlings produced from high pollen load (15–20 pollen grains) were larger (40% by weight) than those from low pollen load (5 pollen grains). These results are evidence that pollen grain competition can occur in buckwheat with benefits for progeny performance.     

Two independent gene loci controlling non-brittle pedicels in buckwheat

The shattering habit in buckwheat occurs because of brittle or weak pedicels. Brittle pedicels are observed in wild buckwheat but not in cultivated buckwheat. Using 2 self-compatible lines, 01AMU2 with brittle pedicels and Kyukei SC2 (KSC2) with non-brittle pedicels, produced by an interspecific cross between Fagopyrum esculentum cv Botansoba (non-brittle) andF. homotropicum (brittle), we investigated the inheritance of brittle pedicels. F₁ plants derived from crosses between Botansoba × 01AMU2 and Botansoba × KSC2 had brittle pedicels. The F₂ population derived from the cross between Botansoba × 01AMU2 showed segregation of brittle and non-brittle pedicels that fit the expected 3:1 ratio, suggesting that non-brittle pedicel in Botansoba is controlled by a single recessive gene (sht1). Another F₂ population, derived from the cross between Botansoba × KSC2, showed segregation of brittle and non-brittle pedicels that fit an expected ratio of 9:7,suggesting that non-brittle pedicel in KSC2is controlled by a different single recessive gene (sht2). Thus, brittle pedicel is achieved by 2 complementary genes Sht1 and Sht2. The sht1 locus is linked to the S locus with a recombination frequency of5.46±1.18 (%). We investigated whether common buckwheat has the allele sht2by crossing 6 common buckwheat lines withKSC2. An analysis of the preliminary data showed that some of the F₁ had brittle pedicels and others had non-brittle pedicels, suggesting that some common buckwheat lines possess both the allelesSht2 and sht2. This revised version was published online in July 2006 with corrections to the Cover Date.     

Chromosome and chromosomal arm locations of genes for resistance to Septoria glume blotch in wheat cultivar Cotipora

Summary Septoria glume blotch, caused by Stagonospora nodorum, is an important disease of wheat (Triticum aestivum). Separate genetic mechanisms were found to control flag leaf and spike resistance. Genes for resistance to S. nodorum were located on different chromosomes in the few wheat cultivars studied. These studies only partially agree on the chromosome locations of gene in wheat for resistance to S. nodorum, and chromosomal arm locations of such genes are not known. The objectives of this study were to determine the chromosome and chromosomal arm locations of genes that significantly influence resistance to S. nodorum in wheat cultivar Cotipora. Monosomic analysis showed that flag leaf resistance was controlled by genes on chromosomes 3A, 4A, and 3B whereas the spike resistance was controlled by genes on chromosomes 3A, 4A, 7A, and 3B (P=0.01). Additionally, genes on chromosomes 6B and 5A influenced the susceptibility of the flag leaf and spike reactions, respectively (P=0.01). Telocentric analysis showed that genes on both arms of chromosome 3A, and the long arms of chromosomes 4A and 3B were involved in the flag leaf resistance whereas genes on both arms of chromosome 4A, the short arm of chromosome 3A, and the long arm of chromosome 3B conferred spike resistance.     

Multiplicative models for cultivar by location interaction in testing sugar beets for resistance to beet necrotic yellow vein virus

Summary Sugar beet cultivars were evaluated for resistance to beet necrotic yellow vein virus (BNYVV) on various locations in two consecutive years. Resistance levels of cultivars were measured by virus assays of plants from the field and the greenhouse. Infection levels in the fields were characterised by sampling plants of a susceptible indicator cultivar. For each year, statistical analyses were performed on two-way tables of cultivar by location for yield and quality parameters. In analysis of variance (ANOVA) significant main effects and significant cultivar by location interaction were found for all parameters (P<0.05). Interactions were further investigated by multiplicative models. In the Additive Main effects and Multiplicative Interaction effects (AMMI) model, interaction was written as the product of a cultivar score and a location score. Cultivar interaction scores were highly correlated to virus concentrations of the cultivars, and location interaction scores to virus concentrations of the susceptible indicator cultivar. Main effects of cultivars and locations were less clearly related to virus concentrations than interaction effects. In general, virus concentrations of plants from a greenhouse test gave higher correlations than virus concentrations of plants from the field. In the factorial regression model, virus concentrations were incorporated in the model. The model can be understood as a two-way ANOVA, with greenhouse virus concentrations and virus concentration of the indicator cultivar as concomitant variables on the cultivar and location factor. Results of analyses with both multiplicative interaction models showed that interactions of all yield and quality parameters can be described in terms of virus concentrations. Therefore, the relative performance of susceptible and partially resistant cultivars in infested fields can be estimated by means of three independent parameters, (i) the level of resistance determined in a greenhouse experiment, (ii) the yield and quality in non-infested fields, and (iii) the level of infection in the field.Abbreviations AMMI model Additive Main effects and Multiplicative Interaction effects model - ANOVA analysis of variance - BNYVV beet necrotic yellow vein virus - ELISA enzyme-linked immunosorbent assay - -amino N -amino nitrogen - K Kalium (potassium) - Na Natrium (sodium)     

Phylogenetic analysis of AGAMOUS sequences reveals the origin of the diploid and tetraploid forms of self-pollinating wild buckwheat,Fagopyrum homotropicum Ohnishi

Fagopyrum homotropicum Ohnishi is a self-pollinating wild buckwheat species indigenous to eastern Tibet and the Yunnan and Sichuan Provinces of China. It is useful breeding material for shifting cultivated buckwheat (F. esculentum ssp. esculentum Moench) from out-crossing to self-pollinating. Despite its importance as a genetic resource in buckwheat breeding, the genetic variation of F. homotropicum is poorly understood. In this study, we investigated the genetic variation and phylogenetic relationships of the diploid and tetraploid forms of F. homotropicum based on the nucleotide sequences of a nuclear gene, AGAMOUS (AG). Neighbor-joining analysis revealed that representative individuals clustered into three large groups (Group I, II and III). Each group contained diploid and tetraploid forms of F. homotropicum. We identified tetraploid plants that had two diverged AG sequences; one belonging to Group I and the other belonging to Group II, or one belonging to Group II and the other belonging to Group III. These results suggest that the tetraploid form originated from at least two hybridization events between deeply differentiated diploids. The results also imply that the genetic diversity contributed by tetraploidization of differentiated diploids may have allowed the distribution range of F. homotropicum to expand to the northern areas of China.     

Monosomic analysis of stem rust resistance in the wheat cultivar Almus

Summary Monosomic analysis of resistance to stem rust, race 11 (isolate G 425) was carried out in the cultivar Almus (GDR) possessing a 1B/1R translocation. F₂ progenies of monosomic and disomic F₁ plants of Almus crossed with 21 monosomic lines of Chinese Spring were tested. Two lines (1B and 6B) differed significantly from the disomic segregation ratio by a higher number of resistant plants and two other lines (1D and 6A) by a lower number of resistant plants. The results fitted a hypothesis comprising the interaction of two genes for resistance and two inhibitors.     

Genetic variation and cultivar identification of Jamaican yam germplasm by random amplified polymorphic DNA analysis

Summary We have used random amplified polymorphic DNA (RAPD) analysis to characterize eleven cultivars of the five economically most important yam species grown in Jamaica (Dioscorea alata, D. cayenensis, D. rotundata, D. trifida and D. esculenta). Amplification of genomic DNA samples with nine different arbitrary 10mer primers revealed a total of 338 different band positions, ranging in size from 0.3 to 2.5 kb. RAPD patterns proved to be highly reproducible and somatically stable. While no variation was observed among plants belonging to the same cultivar, a large number of intervarietal and interspecific polymorphisms enabled us to reliably discriminate between all Jamaican cultivars investigated.     

Utilization of isozyme polymorphism for cultivar identification of 45 commercial peas (Pisum sativum L.)

Forty five Pisum sativum cultivars were analysed by isozyme electrophoresis with the objective to find protein markers for exact and reproducible discrimination of individual genotypes. The combination of six enzyme systems (acid phosphatase, amylase, esterase, leucine aminopeptidase, shikimate dehydrogenase and phosphoglucomutase) with two electrophoretic techniques (NATIVE-PAGE, isoelectric focusing) and use of seed and leaf tissue enabled to identify all 45 studied cultivars. Critical factors which may affect utilization of isozyme electrophoresis for commercial applications in pea breeding and seed production and testing are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Identification of tomato cultivars (Lycopersicon esculentum) by polyacrylamide isoelectric focusing

Summary Isozyme analyses have been used for the definitive identification of many plant cultivars, but not for cultivated tomatoes. Six isozyme systems, namely alcohol dehydrogenase, acid phosphatase, phosphoglucomutase, esterase, phosphoglucoisomerase and 6-phosphogluconate dehydrogenase of tomato seed extracts were resolved by isoelectric focusing on polyacrylamide gels with a narrow pH gradient. Nine alcohol dehydrogenase phenotypes were distinguished which, with three acid phosphatase phenotypes, identified twelve of the seventeen cultivars. Fewer differences were found for the other isozymes. Since this method could differentiate between breeding parents and their progeny it is concluded that further investigations are warranted.Abbreviations APS acid phosphatase - ADH alcohol dehydrogenase - EST esterase - IEF isoelectric focusing - PGI phosphoglucoisomerase - PGM phosphoglucomutase - 6-PGDH 6-phosphogluconate dehydrogenase - RFLP restriction fragment length polymorphism - VOPRI Vegetable and Ornamental Plant Research Institute     

Random amplified polymorphic DNA (RAPD) variation in Fagopyrum tataricum Gaertn. accessions from China and the Himalayan region

The diversity among 52 landraces and cultivars of tartary buckwheat (Fagopyrum tataricum Gaertn.) and one accession of its wild ancestor, F. tataricum ssp. potanini Batalin, from diverse geographic origins was examined using random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) markers. Eighteen primers produced a total of 240 fragments, of which 153 (63.75%) were monomorphic and 87 (36.25%) polymorphic bands. UPGMA-based pairwise Jaccard’s coefficient of similarity was used to deduce the relationships among 53 genetically diverse accessions. The similarity between cultivated tartary buckwheat accessions ranged from 0.61 to 1.00. Four distinct clusters were formed which corresponded well with the geographic distribution of the tartary buckwheat. Nepalese accessions showed maximum diversity followed by Chinese accessions. Tartary buckwheat accessions from the Himalayan region of northwestern India revealed a narrow gene pool. The wild buckwheat accession did not group with any of the three cultivated tartary buckwheat groups, and formed its own single-entry group. Genetic similarity (0.59) of Chinese buckwheat accessions with the wild ancestor reaffirmed that cultivated tartary buckwheat originated in the Yunnan province of northwestern China. Consistent with some earlier reports, our study demonstrated the usefulness of the RAPD technique for the characterization of plant genetic resources and assessment of diversity between species. This revised version was published online in August 2006 with corrections to the Cover Date.     

Fast and reliable strawberry cultivar identification using inter simple sequence repeat (ISSR) amplification

ISSR amplification was evaluated for its applicability to strawberry varietalidentification. Eighteen primers based on various di- tri- or tetra- SSR motifswith 3 or 0 5'-selective nucleotides for anchoring were screened against thestrawberry genome by agarose gel electrophoresis. PCR conditions wereoptimised to obtain high quality patterns. Five primers that gave informativepatterns were selected and used to characterise, by polyacrylamide gelelectrophoresis, 30 strawberry varieties of various geographic and geneticorigins. A total of 390 bands, 113 of which were polymorphic (30%),were generated using these five primers. Genetic similarity between varietieswas estimated using Jaccard's coefficient of similarity. The associationsbetween varieties revealed by UPGMA analysis were consistent withpedigree data. With only one primer, all the varieties were distinguishedincluding those with a common pedigree. Banding patterns were highlyreproducible for DNA samples extracted from different tissues (leaves,sepals, and rhizomes) of the same plant, or from different plants (clones)of the same variety. ISSR technique is therefore a potentially useful tool forthe identification of strawberry varieties because it is simple, fast,cost-effective, highly discriminant and highly reliable.     

Bermudagrass cultivar identification by use of isoenzyme electrophoretic patterns

Summary Isoenzyme analysis has been demonstrated as an effective tool for definitive identification of plant cultivars, but it has not been applied to pasture bermudagrass (Cynodon spp.) cultivars in the USA. Polyacrylamide gel electrophoresis (PAGE) was used to study five isoenzyme systems in mitochondrial, microsomal, and soluble cell fractions of actively growing leaves, stems, and roots of seven vegetatively-propagated pasture bermudagrass (Cynodon spp.) cultivars used in the southern half of the USA. Peroxidase, esterase, and, with one exception, acid phosphatase successfully differentiated between the cultivars in all leaf and stem cell fractions. Fewer cultivar differences were found for amino- and endo-peptidases. Only peroxidase and acid phosphatase were resolved from root cell fractions; and only the microsomal fraction differentiated between all cultivars. Within plant parts, cultivars were distinguishable on the basis of peptidase banding in some cellular fractions, but not in others. Plant part and subcellular fraction-specific isoenzyme variations suggest the existence of multiple molecular forms of various enzymes within the same plant.Journal Article 5746 of the Okla. Agric. Exp. Stn.     

Inheritance of anthracnose resistance in the common bean cultivar Widusa

Snap bean (Phaseolus vulgaris L.) cultivar, Widusa, was crossed to Michigan Dark Red Kidney (MDRK), Michelite, BAT 93, Mexico 222, Cornell 49–242, and TO cultivars to study the inheritance of resistance to anthracnose in Widusa. The segregation patterns observed in six F₂ populations supported an expected 3R:1S ratio suggesting that Widusa carries a single dominant gene conditioning resistance to races 7, 65, 73, and 453 of Colletotrichum lindemuthianum, the causal organism of bean anthracnose. Allelism tests conducted with F₂ populations derived from crosses between Widusa and Cornell 49–242 (Co-2), Mexico 222 (Co-3), TO (Co-4), TU (Co-5), AB 136 (Co-6), BAT 93 (Co-9), and Ouro Negro (Co-10), inoculated with races 7, 9, 65 and 73, showed a segregation ratio of 15R:1S. These results suggest that the anthracnose resistance gene in Widusa is independent from the Co-2, Co-3, Co-4,Co-5, Co-6, Co-9, and Co-10 genes. A lack of segregation was observed among 200 F₂ individuals from the cross Widusa/MDRK, and among 138 F₂ individuals from the cross Widusa/Kaboon inoculated with race 65, suggesting that Widusa carries an allele at the Co-1 locus. We propose that the anthracnose resistance allele in Widusa be named Co-1 ⁵ as Widusa exhibits a unique reaction to race 89 compared to other alleles at the Co-1 locus. RAPD marker A18₁₅₀₀ co-segregated in repulsion-phase linkage with the Co-1 ⁵ gene at a distance of 1.2 cM and will provide bean breeders with a ready tool to enhance the use of the Co-1 ⁵ gene in future bean cultivars.     

酚类物质对百合鳞片扦插繁殖的影响

摘要：试验以兰州百合及东方百合‘Sorbonne’为试材,研究了酚类物质对百合鳞片扦插繁殖的影响。结果表明,酚类物质的种类对兰州百合鳞片繁殖小鳞茎大小及生根量的影响大于处理浓度和时间。对羟基苯甲酸促进小鳞茎膨大。进一步研究发现,100 mg/L羟基苯甲酸浸泡鳞片8h更有利于兰州百合和‘Sorbonne’小鳞茎膨大和增重,为提高小鳞茎质量的最佳处理。50 mg/L水杨酸处理8h也可提高小鳞茎质量。