利用抑制性消减杂交技术分离草莓抗炭疽病相关基因

利用抑制性消减杂交技术（suppression subtractive hybridization,SSH）,比较接种炭疽病菌与未接菌草莓之间的基因表达差异,筛选抗草莓炭疽病菌的差异表达基因片段,为草莓抗炭疽病遗传育种提供理论依据。分别提取接种草莓与未接种草莓叶片的总RNA,分离mRNA,逆转录成cDNA,利用Rsa I进行酶切,然后以接种叶片酶切cDNA为试验方（tester）,以未接菌草莓叶片酶切cDNA为驱动方（driver）,构建了草莓抗炭疽病基因消减文库。菌落PCR结果表明,插入片段大部分在100~1000 bp之间,文库质量好。对文库中1500个阳性克隆进行测序,共得到了1377个有效的ESTs序列。利用NCBI数据库进行Blast同源性比较发现,这些ESTs可能与胁迫反应、信号转导、蛋白合成、蛋白相互作用、物质代谢、跨膜通道、转录因子、金属转运及未知或假定蛋白等有关,ESTs序列的获得为后续草莓抗炭疽病相关基因的克隆、表达和转基因研究提供了参考。     

Variation among heritability estimates for strawberries obtained by offspring-parent regression with relatives raised in separate environments

Summary Data on fruit yield, fruit size and a commercial appearance score were collected for strawberry seedlings from biparental progenies planted at two test locations. Similar data for 8 advanced selections from the California Strawberry Improvement Program were collected, with selections each subjected to three preplanting cold storage treatments and planted at a single location. Each progeny tested had at least one of the 8 selections as a parent. Offspring-parent regression heritabilities were computed using data from each combination of offspring location and parental treatment. Heritability estimates for yield and appearance differed significantly when different combinations of data were used; corresponding estimates for fruit size were unaffected. Gains predicted using heritabilities estimated by the convenient procedure of regressing unselected seedling values on those for vegetatively propagated parents will be reliable only for traits that are robust to rank shifts induced by planting/propagation treatments.     

Genetic advance for chip colour in potatoes

Summary The objective of this study was to investigate the response to selection for chip colour after harvest (CH), storage at 12.8°C (CR) and at 3°C (CC) in three hybrid populations. Population 1 was derived from crossing ND860-2 (cold chipper) with F58089 (regular chipper), Population 2 was obtained from crossing ND860-2 with Russette (nonchipper), and Population 3 was derived from crossing Russette with F58089. Eighty-five to ninety-six random clones for each population plus ten check cultivars were planted in 1991 at two locations in East Canada. For CH, Population 3 had the highest predicted gain. No genetic variation for this trait was detected in Population 1. The potential genetic advance by selection within Population 1, as measured by the predicted mean of the selected clones, however, was similar to the others because Population 1 has a higher mean. For CR, Populations 2 and 3 had similar expected response estimates. Population 1 had no genetic variation for CR but showed similar potential advance to Population 2 and higher than Population 3. For CC, Population 2 had the highest predicted gain. The predicted means of selected clones of Populations 1 and 2 were higher than that of Population 3. Consequently, Populations 1 and 2 had greater potential for improvement for CC than Population 3.     

Breeding strawberries for Eastern Central Canada

Summary Canada imports more than 21,000 tonnes of strawberries annually, of which approximately 5,000–6,000 tonnes are frozen berries used for processing at a cost of more than $ 10 million. These could be replaced by Canadian grown fruit if improved cultivars, and suitable for mechanical harvesting, processing and fresh market adapted to canadian climatic conditions would be available. For many years producers in Quebec have grown the cultivar ‘Redcoat’ (Sparkle × Valentine) released in 1957 by Agriculture Canada, Ottawa. Redcoat is now rapidly being replaced by ‘Kent’, (`K68-58 × Raritan’) released in 1981 by Agriculture Canada, Kentville. Despite Quebec's preeminant position in Canada as a strawberry producing region, no strawberry cultivars have ever been bred specific for Quebec conditions. In 1982 a breeding program was initiated at Agriculture Canada St-Jean. This program was terminated in 1986 without any material having been tested sufficiently for release. In 1987 a joint project between McGill University and Agriculture Canada initiated to continue the breeding program and develop cultivars particularly suitable for mechanical harvesting and processing, resistant to disease and adapted to local conditions. Agriculture Canada, St-Jean-sur-Richelieu, Contribution No. 335/93.12.02R     

Inheritance of petal colour and its independent segregation from seed colour in Brassica rapa

The inheritance of petal (flower) colour and seed colour in Brassica rapa was investigated using two creamy‐white flowered, yellow‐seeded yellow sarson (an ecotype from Indian subcontinent) lines, two yellow‐flowered, partially yellow‐seeded Canadian cultivars and one yellow‐flowered, brown‐seeded rapid cycling accession, and their F₁, F₂, F₃ and backcross populations. A joint segregation of these two characters was examined in the F₂ population. Petal colour was found to be under monogenic control, where the yellow petal colour gene is dominant over the creamy‐white petal colour gene. The seed colour was found to be under digenic control and the yellow seed colour (due to a transparent coat) genes of yellow sarson are recessive to the brown/partially yellow seed colour genes of the Canadian B. rapa cvs.‘Candle’ and ‘Tobin’. The genes governing the petal colour and seed colour are inherited independently. A distorted segregation for petal colour was found in the backcross populations of yellow sarson × F₁ crosses, but not in the reciprocal backcrosses, i.e. F₁× yellow sarson. The possible reason is discussed in the light of genetic diversity of the parental genotypes.     

Morphological traits and high resolution RAPD markers for the identification of the main strawberry varieties cultivated in Argentina

Eight genotypes of the main Fragaria×ananassa cultivars grown in Argentina were analysed using the random amplified polymorphic DNA (RAPD) technique combined with electrophoresis in polyacrylamide gels. The high resolution of this procedure allowed the detection, with only 13 random primers, of 37 genotype‐specific bands that can be used as markers for verifying the identity of cultivars. By using this approach, three different accessions of the cultivar ‘Pájaro’ exhibited differences in amplification profiles, confirming the need for DNA analysis to prevent misidentification of cultivars. In addition, RAPD bands and morphological traits were used to assess genetic relatedness among cultivars. Comparison of both dendrograms revealed that there is no correlation between the clustering obtained with molecular and morphological characters.     

Influence of pollination modes on yield components in strawberry (Fragaria×ananassa Duch.)

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

QTL mapping for flour and noodle colour components and yellow pigment content in common wheat

Improvement of flour colour is an important breeding objective for various wheat-based end-products. The objectives of this study were to identify quantitative trait loci (QTL) for flour colour components and yellow pigment content (YPC), using 240 recombinant inbred lines (RILs) derived from a cross between the Chinese wheat cultivars PH82-2 and Neixiang 188. Field trials were performed in a Latinized α-lattice design in Anyang and Jiaozuo, Henan Province and Taian, Shandong, in the 2005–2006 and 2006–2007 cropping seasons providing data for six environments. One hundred and eighty-eight polymorphic SSR markers, rye secalin marker Sec1, STS markers YP7A for a phytoene synthase gene (Psy-A1), and four glutenin subunit markers, were used to genotype the population and construct the linkage map for subsequent QTL analysis. Two major QTL were detected for YPC, associated with 1RS (1B.1R translocation) and the Psy-A1 (7A) gene, explaining 31.9% and 33.9% of the phenotypic variances, respectively. 1RS also had large influences on Fa*, Fb*, KJ, NL*and Nb*, and Psy-A1 genes showed large effects on Fa*, Fb*, Kj, Fci, NL*, Na* and Nb*, explaining from 4.5 to 26.1% and 4.3 to 35.9% of the phenotypic variances, respectively. In addition, QTL for flour colour parameters and yellow pigment content were also detected on chromosomes 1A and 4A, accounting for 1.5–4.1% of the phenotypic variance. The genetic effect of the 1B.1R translocation on flour colour parameters was also discussed.     

Using colour image analysis for quantitative assessment of powdery mildew on cucumber

Summary Visual assessment, black & white image analysis and colour image analysis of the severity of powdery mildew (Sphaerotheca fuliginea) infection on leaves of cucumber (Cucumis sativus) were compared. The extent of infection with powdery mildew was expressed as the number of spores per cm². Statistical treatment of the data showed colour image analysis to be superior to the other two methods of evaluation. Major veins, light reflections and variations in the colour of leaves can degrade the accuracy of colour image analysis somewhat. These problems are, however, surmountable. Colour image analysis qualifies as a valuable new tool for accurate, objective, reproducible and detailed quantitative assessment of disease on leaves of plants.Abbreviations H hue - I intensity - IA image analysis - PM powdery mildew - S saturation     

Seed colour assessment in Brassica napus using a Near Infrared Reflectance spectrometer adapted for visible light measurements

Summary Improved oil, protein and fibre contents are associated with light seed colour in rapeseed but the lack of reliable and efficient methods to measure seed colour has hindered breeding efforts for this trait. The feasibility of using light reflectance to assess seed colour in Brassica napus was examined using scanning light reflectance spectrophotometry and near infrared reflectance (NIR). Light reflectance by seed samples from 30 doubled haploid (DH) lines segregating for seed colour increased as the wavelength of the illuminating light in the scanning spectrophotometer increased between 550 and 650 nm. The largest reflectance values were measured for the yellow seed samples; the brown seed samples were intermediate and the black seed samples had the lowest reflectance values. The areas under the reflectance curves were used to transform the spectra to single values. Average light reflectance area values for the seed colour classes were significantly different from each other. The DHs and their corresponding light reflectance area values were also used to calibrate a NIR analyzer modified with 670 and 710 nm filters. The best calibration curve used three wavelengths (670, 2190 and 2208 nm) and had a multiple correlation coefficient of 0.987. Light reflectance area values determined with the calibrated NIR analyzer for 30 randomly selected breeding lines could be used to categorize the colour of the seed samples with no discrepancies between the visual and instrument classifications. The results indicate that NIR can be used to assess seed colour in rapeseed.     

Evaluation of the tepal colour of Begonia x tuberhybrida Voss. for DUS testing using image analysis

In the framework of variety testing, evaluation of the flower of Begonia x tuberhybrida Voss. is done by experts. The colours of the flowers are compared with the RHS colour chart. For each flower colour a code is given. This method has several disadvantages (data cannot be statistically analyzed with standard ANOVA techniques, bias by the expert is possible, difficult measurement depending on the light environment, ...) that can be overcome with image analysis. In this study several parameters were tested to distinguish the different varieties. Varieties were split in different colour groups (white, red and yellow–orange) and parameters were analyzed. Parameters based on the green colour plain of the RGB colour space resulted in the largest discriminating power. Parameters based on the HSV colour space performed less well.     

普通小麦粒色的变异及其与蛋白质含量的关系

我们以红、白2色区别普通小麦品种的籽粒颜色。具有一定粒色的品种在不同的生态条件下种植,即进行不同年度的分期播种,结果会在一定比例的播期中改变颜色。整体来看,红粒小麦品种的籽粒蛋白质含量较高。     

Quantitative trait loci (QTL) mapping of silique length and petal colour in Brassica rapa

Recombinant inbred lines (RILs) derived from a cross between Brassica rapa L. cv. ‘Sampad’, and an inbred line 3‐0026.027 was used to map the loci controlling silique length and petal colour. The RILs were evaluated under four environments. Variation for silique length in the RILs ranged from normal, such as ‘Sampad’, to short silique, such as 3‐0026.027. Three QTL, SLA3, SLA5 and SLA7, were detected on the linkage groups A3, A5 and A7, respectively. These QTL explained 36.0 to 42.3% total phenotypic variance in the individual environments and collectively 32.5% phenotypic variance. No additive × additive epistatic interaction was detected between the three QTL. Moreover, no QTL × environment interaction was detected in any of the four environments. The number of loci for silique length detected based on QTL mapping agrees well with the results from segregation analysis of the RILs. In case of petal colour, a single locus governing this trait was detected on the linkage group A2.     

Identification and inheritance of a partially dominant gene for yellow seed colour in Brassica napus

A yellow‐seeded doubled haploid (DH) line no. 2127‐17, derived from a resynthesized Brassica napus L., was crossed with two black‐seeded Brassica cultivars ‘Quantum’ and ‘Sprint’ of spring type. The inheritance of seed colour was investigated in the F₂, and BC1 populations of the two crosses and also in the DH population derived from the F1 of the cross ‘Quantum’× no. 2127‐17. Seed colour analysis was performed with the colorimeter CR‐300 (Minolta, Japan) together with a visual classification system. The immediate F1 seeds of the reciprocals in the two crosses had the same colour as the self‐pollinated seeds of the respective black‐ and yellow‐seeded female parents, indicating the maternal control of seed colour. The F1 plants produced yellow‐brown seeds that were darker in colour than the seeds of no. 2127‐17, indicating the partial dominance of yellow seed over black. In the segregating BC1 progenies of the two crosses, the frequencies of the black‐ and yellow‐seeded plants fit well with a 1 : 1 ratio. In the cross with ‘Quantum’, the frequencies of yellow‐seeded and black‐seeded plants fit with a 13 : 3 ratio in the F₂ progeny, and with a 3 : 1 ratio in the DH progeny. However, a 49 : 15 segregation ratio was observed for the yellow‐seeded and black‐seeded plants in the F₂ progeny of the cross with ‘Sprint’. It was postulated from these results that seed colour was controlled by three pairs of genes. A dominant yellow‐seeded gene (Y) was identified in no. 2127‐17 that had epistatic effects on the two independent dominant black‐seeded genes (B and C), thereby inhibiting the biosynthesis of seed coat pigments.     

In vitro selection of strawberry (Fragaria × ananassa Duch.) clones tolerant to salt stress

The method of in vitro selection for increased salt tolerance at the seed germination and early growth phase of strawberry seedlings is proposed. Clone Pau/27 was selected on medium containing 200 mM of NaCl from population obtained by free pollination of cv. ‘Paula2019;. Subsequently, on the same medium 18 salt tolerant clones were attained from the population of seeds collected from self pollinated Pau/27 plants. In the next step we examined the influence of a mild salt stress (75 mM of NaCl) on vegetative growth parameters of selected clones and two cvs.; ‘Paula2019; and ‘Senga Sengana’. All materials in the study on the basis of calculated indexes were divided into four groups differing in reaction to salt. First group (clustered together cv. ‘Paula’, Pau/27 and three second generation clones: Pau/27/11, Pau/27/24, Pau/27/30) represents sensitive genotypes. Second group, including ‘Senga Sengana’, Pau/27/06, Pau/27/10, Pau/27/12, Pau/27/13, Pau/27/15, Pau/27/18, Pau/27/20, Pau/27/21, Pau/27/26, Pau/27/27, Pau/27/31 and Pau/27/32 was designated tolerant. Third group contains only one highly tolerant clone Pau/27/08. The last group comprises two highly sensitive clones (Pau/27/01 and Pau/27/03). This revised version was published online in August 2006 with corrections to the Cover Date.     

Association of gene for grain colour with monosome XIV of Avena sativa L.

Summary The F₂'s from crosses between Dyfed (S.240; a black grained cultivar) and monosomics of Sun II (non-black cultivar) were analysed. With the exception of F₂ progenies involving monosomes, II, VI, VII, X, XI, XII, XIII and XIV, all other deviated from the genetic ratio 3 black: 1 non-black. The cytological examination of the non-black individuals belonging to those families that did not deviate from the 3:1 ratio showed that they were either 41- or 42-chromosome plants. However, non-black individuals involving monosome XIV were 40-chromosome plants. The gene conferring the black colour to the grains in Avena sativa cv. Dyfed (S.240) is located on chromosome XIV.Department of Plant Breeding and Genetics, Sind Agriculture University. Tando Jam. Pakistan.     

Simplified AFLP procedure as a tool for identification of strawberry cultivars and advanced breeding lines

DNA polymorphisms among 6 cultivars of Fragaria × ananassa (Duch.) and 13salinity tolerant clones were evaluated using simplified – PstI based Amplified Fragment Length Polymorphism procedure(^PstIAFLP). Out of 129 amplification products obtained with 10 selective primers, 116 markers were polymorphic and could be used to distinguish all analyzed materials. Coordinate and cluster analyses revealed 2 main groups of clones and divided strawberry cultivars (CUL) and tested F₁ hybrids of ‘Sweet Heart’(HYB). Mean genetic similarities in groups of cultivars and selected breeding lines (SEL) were significantly higher (0.722 and0.706, respectively, p < 0.05) than in group of SH hybrids (0.485). Results suggest that ^PstIAFLP method is sufficient for effective identification and useful for assessing the level of genetic diversity in strawberry cultivars and breeding lines. The presented method can bean alternative multilocus marker system to widespread RAPD method. This revised version was published online in July 2006 with corrections to the Cover Date.     

Inheritance of quality traits in processing tomato (Lycopersicon esculentum Mill.)

Summary The genetic basis of pH, colour and soluble solids in processing tomato is examined. In a first experiment, aimed at identifying the base populations with which to start selection, parents, F₁ and F₂ progenies of an 8 × 8 diallel cross without reciprocals were tested.The results indicate that additive, dominance and additive x additive epistatic effects were noticeable for the three characters. Higher order interlocus interactions were also detected.As to the soluble solids, a trait for which higher order epistatic effects were less marked, the breeding potential of the cross combinations was assessed by calculating the expected mean values at the F generation. Some cross populations having C33 or C35 as parent appeared to be superior.A second experiment was conducted to collect data on the heritability of the foregoing qualitative traits by utilizing the regressions of F₃ offspring on F₂ parents. The low heritability coefficients observed would suggest the ineffectiveness of individual selection in early generations.In both the F₂ and F₃ generations rather low correlation coefficients among the three quality traits were observed.