Genetic relationships among nine cultivated taxa of Calliandra Benth. (Leguminosae: Mimosoideae) using random amplified polymorphic DNA (RAPD) markers

Random amplified polymorphic DNA (RAPD) marker was used to assess genetic diversity and inter-specific relationships among nine taxa of Calliandra (Leguminosae: Mimosoideae) grown in Indian gardens. DNA from leaf sample was isolated and RAPD analysis was performed using 22 primers. The genetic similarities were analyzed from the dendrogram constructed by the RAPD data using a similarity index which supported the segregation of the nine taxa of the genus into two groups; the sect. Androcallis with seven taxa, viz. C. haematocephala, C. haematocephala var. alba, C. surinamensis, C. tweedii, C. tergemina var. emarginata and C. selloi and sect. Calliandra having two species namely, C. inermis and C. calothyrsus. The intra-generic classification and phylogeny inferred from molecular markers supported the traditional classification of the genus based on morphological characters at the level of sections and series except in case of C. selloi (C. brevipes) which did not show much genetic similarity with C. tweedii and C. surinamensis; all the three species being members of the sect. Androcallis series Androcallis.     

Estimating the genetic relationships of Chinese water chestnut (Eleocharis dulcis (Burm. f.) Hensch) cultivated in Australia,using random amplified polymorphic DNAs (RAPDs)

Summary

Chinese water chestnut is a crop new to Australia. To establish a reputable industry, the influence of both genotype and environment on yield and quality need to be evaluated. To that end, the genetic relationships of cultivated Chinese water chestnut in Australia were investigated using random amplified polymorphic DNA (RAPD) analysis. Initial problems with inhibition of RAPD reactions were solved by precipitation of polysaccharides with 1 M NaCl and the subsequent addition of 0.4.mg ml-¹ bovine serum albumin (BSA) in RAPD reactions. Nearly all DNA extracts from then onwards were RAPD-amplifiable. Ninety-six RAPD markers generated by 14 primers separated the samples from Taiwan (cv. Shu-Lin), Hangzhou of mainland China (cv. Da Hong Pao), New South Wales of Australia (unknown cv.) and the USA (unknown cv.) from the remainder of the samples from Australia. These remaining samples were too closely related to be differentiated. The dissimilarity observed between these remaining samples (0.78–4.4%) may be due more to scoring errors of undetectable bands and sampling error rather than to real genetic variation. It is therefore suggested that the observed morphological and physiological variations in Chinese water chestnuts produced in Australia (e.g. corm sweetness) are phenotypic and reflect the differences of environment and cultivation rather than genetic diversity.     

Genetic similarities among cocoyam cultivars based on randomly amplified polymorphic DNA (RAPD) analysis

Eighteen cultivars of cocoyam (Xanthosoma spp.) and two cultivars of taro (Colocasia esculenta (L.) Schott) from the USDA/ARS germplasm collection were evaluated for genetic relatedness using RAPD data. Seven random primers generated 40 RAPD loci. Of the 18 cultivars screened, 11 (61%) were identical at all RAPD loci evaluated. A similarity matrix was constructed on the basis of the presence or absence of bands. Among cocoyam cultivars the genetic similarity ranged from 0.86 to 0.97 with a mean of 0.91. Cluster analysis identified two main clusters with some unexpected groupings. These data indicate that very little genetic variation exists within the accessions used in this study and that this Xanthosoma spp. collection is of limited value as a genetic resource.     

Assessment of genetic diversity in common bean (Phaseolus vulgaris L.) germplasm using amplified fragment length polymorphism (AFLP)

AFLP technique was applied to assess genetic diversity among 44 common bean accessions that included 6 exotic accessions, 15 Indian land races and 23 released varieties. Eight AFLP primer pairs were used that produced 820 products of which 698 were polymorphic (85.12%). Wide variations were observed among all the accessions for the number of amplification products, percent polymorphism and average polymorphism information content (PIC). The Jaccard's similarity indices (J) based on the AFLP profiles were subjected to UPGMA cluster analysis. The dendrogram generated revealed seven major groups. Seventeen out of 23 released varieties were restricted to clusters VI and VII. The value of r = 0.934 in Mantel's test for cophenetic corrlelation applied to the cluster analysis indicated the high fitness of the accessions to a group. The germplasm used in the present study had narrow genetic base, although moderate to high genetic diversity was observed. The details of diversity analysis and the potential use of Indian common bean accessions in common bean breeding programme are provided in the present study.     

黑莓RuMYB10基因的克隆和表达

【目的】从黑莓中克隆RuMYB10的编码区全长序列,并分析其在黑莓果实发育过程中的表达情况与果实花青素苷积累的关系。【方法】以黑莓基因组DNA为模板,通过同源克隆和SON-PCR技术获得了RuMYB10基因全长编码序列(Accession No.:JQ359611);并以黑莓果实mRNA为模板进行验证。采用实时定量PCR技术检测该基因在果实不同发育阶段的表达水平。【结果】结果表明,该基因编码区全长共1 837 bp,编码216个氨基酸,推导蛋白分子质量为24 863 Da。具有MYB转录因子家族特有的R2R3保守序列。含有两个内含子,第2个内含子长度为750 bp,占全长40.8%;在R3重复单元中存在与bHLH因子互作的‘[DE]Lx2[RK]x3Lx6Lx3R’序列;而促进花青素苷合成的MYB转录因子3个特征氨基酸残基中的丙氨酸(A)被丝氨酸(S)取代。RuMYB10基因在黑莓果实发育后期,即果实变红到最后变黑的过程中大量表达,与花青素苷的积累相一致。【结论】从黑莓中克隆到包含完整ORF的转录因子基因RuMYB10,具有MYB因子家族结构特征和bHLH因子结合域,且在果实花青素苷积累高峰期表达量最高。     

Assessment of genetic diversity among mango (Mangifera indica L.) genotypes using RAPD markers

Knowledge about the extent of genetic diversity/relatedness in mango germplasm is vital for developing coherent strategies for future gains in productivity. The genetic diversity/relatedness among mango cultivars/genotypes developed in Pakistan has not been investigated previously. We have assessed the genetic diversity among 25 mango genotypes/cultivars using randomly amplified polymorphic DNA (RAPD). Sixty random ten-mer primers were surveyed, out of which 45 yielded amplicons in all the genotypes. Genetic similarity between genotypes/cultivars was in the range of 64–89% with an average of 74%. Similarly, the genetic relatedness among all variants derived from a mango cultivar Chaunsa was in the range of 81.18–88.63%. These coefficients were utilized to construct a dendrogram using the unweighted pair group of arithmetic means (UPGMA). The genotypes were grouped into three (A, B, C) clusters. Generally, genotypes originating from Pakistan were grouped in cluster ‘A’ while cluster ‘B’ primarily composed of southern India as well as Florida cultivars. Kensington Pride was the most distantly related genotype which grouped with Maya and Yakta, forming a distinct cluster ‘C’.     

不同树莓品种中非花色苷酚的鉴定与分析

以19个树莓品种为试材,采用超高效液相色谱-质谱联用技术,定性定量分析了树莓果实中的非花色苷酚类物质,以期为寒地树莓新品种的选育提供技术指导,为寒地树莓的栽培生产及应用提供参考依据.结果 表明:树莓果实中共鉴定出31种非花色苷酚类化合物,不同树莓品种果实中非花色苷酚含量为24.75～154.06 μg·g-1;黄烷-3-醇、黄酮醇和黄烷酮对树莓非花色苷酚的组成起重要作用;19个品种可聚为2类,第1类树莓果实中非花色苷酚的种类较多且相对含量较高,第2类树莓果实中非花色苷酚的种类较少且相对含量较低.     

Impact of genetic and environmental variation on development of flavonoids and carotenoids in pepper (Capsicum spp.)

Peppers (Capsicum spp.) were grown for phytochemical analyses at three different locations including a greenhouse at College Station and field plots at Uvalde and Weslaco, Texas. Cultivar effects were significant at each location for all compounds. The best sources of β-carotene were mature greenhouse-grown fruit of Fidel (23.7 μg/g) and C 127 (22.3 μg/g). Mature greenhouse fruit of Tropic Bell (10.1 μg/g) and PI 357509 (9.2 μg/g) had high lutein, but Uvalde field-grown mature fruit of these lines were low in this compound, (1.4 and 0.5 μg/g, respectively). MJ 201 fruit had the highest zeaxanthin levels (10 μg/g) at both College Station and Uvalde. The best sources of quercetin over all locations were the yellow wax types, Banana Supreme (186 μg/g), PI 357509 (86 μg/g) and Rio Grande Gold (26 μg/g). Fidel (37 μg/g) and Banana Supreme (21.5 μg/g) were the best sources of luteolin. Immature fruit generally contained lower levels of lutein and xeaxanthin than mature, colored fruit. These differences were not always statistically significant. Greenhouse-grown peppers at College Station contained more carotenoids than the field-grown peppers in Uvalde and Weslaco, but there were no significant differences among locations for flavonoid concentrations. Several good candidate parents were identified for the breeding program to develop novel pepper varieties with increased health benefits. Families of these varieties are currently being examined to assess the impact of specific environmental factors and identify genes involved in regulating synthesis of these beneficial phytochemicals.     

Genetic relatedness (diversity) and cultivar identification by randomly amplified polymorphic DNA (RAPD) markers in teasle gourd (Momordica dioica Roxb.)

Genetic relationship and variation of 29 accessions of teasle gourd (Momordica dioica Roxb.) and 1 accession of Momordica cochinchinensis Spreng. (wild relatives of teasle gourd) were examined by RAPD analysis using 44 dodecamer oligonucleotide primers. A total of 496 fragments were produced by 44 primers of which 95% bands were polymorphic. Using presence or absence of specific RAPD markers or combination of primers, 23 out of 30 accessions were identified. The genetic relatedness or genetic distance based on Nei and Li's genetic similarity varied from 0.86 to 0.65 with an average of 0.74 among 29 M. dioica accessions (when M. cochinchinensis excluded). In the phenetic dendrogram developed from cluster analysis using UPGMA method, M. cochinchinensis was out grouped as single accession, while others showing relatively weak grouping formed four groups. Clustering pattern did not demonstrate any relationship between geographical origin and genetic diversity. A DNA extraction method has been standardized. This is the first report of using RAPD techniques in teasle gourd. It was concluded that RAPD analysis is a useful tool for genotypic identification and estimation of genetic similarity in teasle gourd.     

Analysis of genetic variation in eggplant and related Solanum species using sequence-related amplified polymorphism markers

Collection and characterization of all sorts of germplasm resources are required for the development of new cultivars. Molecular characterization is more reliable than morphological characterization. Here, we employed sequence-related amplified polymorphism (SRAP) markers to evaluate genetic variation in a diverse collection of 56 Solanum accessions. Fifty-five SRAP primer combinations were used and a total of 635 polymorphic bands were observed. Cluster analysis by the unweighted pair-group method with arithmetic averages based on similarity matrices indicated that there were three clusters: (i) S. melongena; (ii) S. aethiopicum; (iii) S. surattense. The coefficients of genetic similarity among all the accessions ranged from 0.04 to 0.96 with an average of 0.73, and averaged 0.78 among S. melongena accessions originated from China, indicating extensive genetic variation. These results demonstrated that SRAP can be efficiently used to estimate genetic diversity and analyze phylogenetic relationship.     

Assessment of genetic purity of tomato (Lycopersicon esculentum L.) hybrid using molecular markers

Three DNA molecular marker systems, RAPD, ISSR and SSR, were used to test seed genetic purity of two commercial hybrid tomato (Lycopersicon esculentum L.) cultivars ‘Hezuo 903’ and ‘Sufen No. 8’. Genomic DNA from the two F₁ hybrid cultivars and their corresponding parental lines was screened with 218 RAPD decamer primers, 54 ISSR primers and 49 SSR primers. Among the 321 primers, 4 primers for ‘Hezuo 903’ and 3 for ‘Sufen No. 8’, which could produce both female and male parent-specific markers, were selected for testing the genetic purity. A total of 210 hybrid individuals of each cultivar were analyzed using the identified primers. The combined results of the marker analysis showed that eight of the 210 F₁ plants in ‘Hezuo 903’ and 13 of 210 in ‘Sufen No. 8’ were false hybrids, and the overall genetic purity of the two F₁ hybrid seed lots was 96.2 and 93.8%, respectively. This study showed that RAPD and SSR markers could provide a practical and efficient tool in quality control of the tomato commercial hybrid seeds.     

Assessment of genetic relatedness among mango cultivars of India using RAPD markers

Summary

DNA-based RAPD (Random Amplification of Polymorphic DNA) markers have been used extensively to study genetic relationships in a number of fruit crops. A wide genetic diversity exists in the mango fruit in India. Present day commercial cultivars originated mainly from this subcontinent. In this study, 18 commercial mango cultivars, traditionally grown in western, southern, northern and eastern parts of India, were selected to assess genetic relatedness. Total genomic DNA was extracted and subjected to RAPD analysis using 30 arbitrary 10-mer primers. Of these, 27 primers amplified mango genomic DNA. None of these primers produced unique band pattern for each cultivar. RAPD data were used to calculate a squared Euclidean distance matrix, and based on this cluster analysis was done using a minimum variance algorithm. Cluster analysis clearly showed two groups—the first consisting of western, northern and eastern mango cultivars and the second group consisting of southern cultivars. From the analysis of results, it appears the majority of mango cultivars originated from a local mango genepool and were domesticated later.     

Polymorphisms of amplified mitochondrial DNA non-coding regions in Diospyros spp.

Universal primers were used to amplify mtDNA non-coding regions in Diospyros spp. including 6 related species and 20 genotypes of Diospyros kaki Thunb. The results showed: (1) 32 universal primers successfully amplified either introns or intergenic regions in Diospyros spp. A total of 119 bands were obtained, in which 110 were polymorphic. (2) Twenty three universal primers were used to analysis genetic diversity at the level of intra-specific, which revealed that the mitochondrial genomes had abundant variation during recombination. Chinese, Japanese PCNA genotypes were separated distinctly from each other by clustering analysis. (3) Two Chinese PCNA genotypes of Japanese persimmon, ‘Baogaitianshi’ and ‘Eshi No.1’, have unique bands to other materials, which showed they would have derived from the same female parent according to the maternal inheritance of mitochondrial genome.     

越橘基因组DNA的快速提取及分析

为了从富含多酚、多糖及色素的越橘叶片中提取适用于分子生物学研究的高质量基因组DNA。以越橘幼叶为实验材料,比较了CTAB、SDS、高盐低pH值3种提取方法,获得了一种以CTAB法为基础的分离高质量完整DNA的简便、快速方法。用紫外分光光度计、琼脂糖凝胶电泳、RAPD-PCR、酶切等方法对获得的DNA进行了分析,结果表明,快速CTAB法所提取的DNA产量高、质量好,完全能够满足RAPD、PCR等分子生物学实验的要求。     

Analysis of genetic diversity among Indian short-day onion (Allium cepa L.) cultivars using RAPD markers.

Summary

Randomly amplified polymorphic DNA (RAPD) markers were used to estimate genetic diversity among 24 cultivars of short-day onions. Total genomic DNA was extracted and subjected to RAPD analysis using 90 arbitrary 10-mer primers. Of these, 15 primers were selected which yielded 137 bands, 91.24% of which were polymorphic. None of the primers produced a unique banding pattern for each cultivar. RAPD data were used to calculate a Squared-Euclidian Distance matrix which revealed a minimum genetic distance between cultivars ‘AFLR-722’ and ‘PBR-140’, and a maximum genetic distance between cultivars ‘PBR-139’ and ‘A.Kalyan’, and ‘MS-48’ and ‘A.Kalyan’. Based on the distance matrix, cluster analysis was done using a minimum variance algorithm.The dendrogram thus generated, based on Ward’s method, grouped the 24 onion cultivars into two major clusters. The first cluster consisted of cultivars from the northern region, and the second of cultivars from the southern region of India. The present study shows that there is high diversity among the onion cultivars selected and indicates the potential of RAPD markers for identification and maintenance of onion germplasm for crop improvement purposes.     

Race-specific genetics of resistance to black rot disease [Xanthomonas campestris pv. campestris (Xcc) (Pammel) Dowson] and the development of three random amplified polymorphic DNA markers in cauliflower

Summary

In order to understand the genetics of resistance to black rot disease caused by Xanthomonas campestris pv. campestris (Xcc) (Pammel) Dowson in cauliflower (Brassica oleracea var. botrytis L.) and to identify random amplified polymorphic DNA (RAPD) markers that segregate with the resistance genes, susceptible (‘Pusa Himjyoti’, female parent) and resistant (‘BR-161’, pollen parent) plants were crossed. Six generations of plants (30 P₁, 30 P₂,30 F₁, 120 F₂, 90 B₁, and 90 B₂) were evaluated for the presence or absence of black rot disease in a randomised block design with three replications. The pattern of segregation of resistance was tested by the χ² test at the 5% level of significance. All F₁ progeny plants were resistant, and the segregation of resistant and susceptible plants in the F₂ and two backcross generations (B₁ and B₂) showed that a single dominant gene caused resistance to the black rot pathogen in ‘BR-161’. Three polymorphic RAPD markers (OPO-04₈₃₃, OPAW-20₂₅₃₈, and OPG-25₆₂₅) were found by bulk segregant analysis, which produced unique amplicons 833 bp, 2,538 bp, and 625 bp in length, respectively. These markers were associated in coupling phase to the resistance allele. Best fit ratios of 3:1 (resistant:susceptible) in the F₂ plants with the three RAPD markers, suggested that the markers were linked to the single gene controlling black rot resistance. These markers will be useful to identify more closely-linked markers and to develop black rot-resistant hybrid cauliflower varieties.     

Assessment of genetic diversity and species relationships in eggplant (Solanum melongena L.) using STMS markers

Ninety six accessions including 92 of Solanum melongena and four related non-tuberous species (Solanum insanum, S. incanum, S. integrifolium and S. sysimbriifolium) were taken for the assessment of genetic diversity using 23 STMS primers. Eleven of the 23 primers tested showed polymorphism. The number of alleles per primer ranged from three to six with an average of 4.4. S. melongena had maximum average similarity with its closely related species, S. insanum (0.67) and minimum average similarity with the wild species, S. sysimbriifolium (0.50). The two weedy species S. incanum and S. integrifolium showed more average similarity value of 0.62 and 0.61, respectively with the cultivated S. melongena. S. insanum. S. incanum and S. integrifolium were relatively similar to each other with similarity index value of 0.61 (between S. insanum and S. incanum), 0.63 (between S. insanum and S. integrifolium) and 0.62 (between S. incanum and S. integrifolium). In contrast S. sysimbriifolium was most divergent with the similarity value of 0.49, 0.47 and 0.51 with S. insanum, S. incanum and S. integrifolium, respectively. The closely related species S. insanum and S. incanum, which clustered along with S. melongena accessions, being crossable with cultivated species, constitute important sources of genes that can be introgressed by backcross breeding. Molecular markers can be employed to identify the hybrids and also to monitor introgression of the useful genes.     

Assessment of genetic diversity of Latvian and Swedish sweet cherry (Prunus avium L.) genetic resources collections by using SSR (microsatellite) markers

Three previously described highly polymorphic SSR (microsatellite) primer pairs were tested on 126 sweet cherry (Prunus avium L.) accessions to adapt a fast, reliable method for preliminary screening of sweet cherry germplasm collections and to compare two sweet cherry germplasm collections: at the Latvia State Institute of Fruit-Growing, Dobele (LIFG-Dobele) and at the Division of Horticultural Genetics and Plant Breeding at Balsgård, Department of Crop Sciences, Swedish University of Agricultural Sciences (SLU-Balsgård). The SSR loci were highly polymorphic with 4–10 different alleles and 5–18 genotypes. Heterozygosity values ranged from 0.431 to 0.809, gene diversity (PIC) values ranged from 0.400 to 0.753, and the discriminating power of each locus varied from 0.631 to 0.894. The combined discriminating power of all loci was highly effective (0.996). Sixteen identical accession groups with the same allele profile were discovered in both collections. This study demonstrated that SSR fingerprinting with the three primer pairs tested, can be used for preliminary characterization of sweet cherry germplasm collections.     

香蕉横切薄层培养(tTCL)及植株再生

1　植物名称　香蕉 (Ｍｕｓａｓｐｐ .) ,品种为葳廉斯香蕉 (Ｗｉｌｌｉａｍｓ)、巴西、西贡蕉。2　材料类别　低代香蕉无菌试管苗。3　培养条件　 ( 1 )横切薄层切片芽诱导培养基 :改良的ＭＳ +ＢＡ4 0ｍｇ/Ｌ +ＮＡＡ0 5ｍｇ/Ｌ ;( 2 )丛芽增殖培养基 :改良的ＭＳ+ＢＡ3 5ｍｇ/Ｌ +ＮＡＡ0 3ｍｇ/Ｌ ;( 3)生根培养基 :改良的ＭＳ +ＮＡＡ0 5ｍｇ/Ｌ。以上培养基均附加蔗糖 3% ,琼脂 0 56 % ,ｐＨ5 8。除生根需要在光照下进行培养外 ,其余均进行暗培养 ,培养温度为 30℃。4　芽分化与生长4 1　芽的诱导　在无菌条件下 ,将低代香蕉试…