Characterization of wheat-Thinopyrum bessarabicum genetic stock for stripe rust and Karnal bunt resistance / Caracterização do estoque genético de trigo-Thinopyrum bessarabicum para resistência de ferrugem e Karnal bunt

Abstract Utilization of modern breeding techniques for developing high yielding and uniform plant types ultimately narrowing the genetic makeup of most crops. Narrowed genetic makeup of these crops has made them vulnerable towards disease and insect epidemics. For sustainable crop production, genetic variability of these crops must be broadened against various biotic and abiotic stresses. One of the ways to widen genetic configuration of these crops is to identify novel additional sources of durable resistance. In this regard crops wild relatives are providing valuable sources of allelic diversity towards various biotic, abiotic stress tolerance and quality components. For incorporating novel variability from wild relative's wide hybridization technique has become a promising breeding method. For this purpose, wheat-Th. bessarabicum amphiploid, addition and translocation lines have been screened in field and screen house conditions to get novel sources of yellow rust and Karnal bunt resistant. Stripe rust screening under field conditions has revealed addition lines 4JJ and 6JJ as resistant to moderately resistant while addition lines 3JJ, 5JJ, 7JJ and translocation lines Tr-3, Tr-6 as moderately resistant wheat-Thinopyrum-bessarabicum genetic stock. Karnal bunt screening depicted addition lines 5JJ and 4JJ as highly resistant genetic stock. These genetic stocks may be used to introgression novel stripe rust and Karnal bunt resistance from the tertiary gene pool into susceptible wheat backgrounds.

Resumo A utilização de técnicas modernas de melhoramento para o desenvolvimento de tipos de plantas uniformes e de alto rendimento, em última análise, estreitando a composição genética da maioria das culturas. A composição genética restrita dessas plantações tornou-as vulneráveis a doenças e epidemias de insetos. Para uma produção agrícola sustentável, a variabilidade genética dessas culturas deve ser ampliada contra vários estresses bióticos e abióticos. Uma das maneiras de ampliar a configuração genética dessas culturas é identificar novas fontes adicionais de resistência durável. A esse respeito, os parentes selvagens das culturas estão fornecendo fontes valiosas de diversidade alélica para vários componentes de qualidade e tolerância ao estresse abiótico e biótico. Para incorporar a nova variabilidade da ampla técnica de hibridização de parente selvagem tornou-se um método de reprodução promissor. Para esse efeito, trigo-Th. As linhas anfiploides, de adição e translocação de bessarabicum foram selecionadas em condições de campo e de casa de tela para obter novas fontes de ferrugem amarela e resistência ao bunt de Karnal. A triagem de ferrugem em faixas em condições de campo revelou as linhas de adição 4JJ e 6JJ como resistentes a moderadamente resistentes, enquanto as linhas de adição 3JJ, 5JJ, 7JJ e as linhas de translocação Tr-3, Tr-6 como estoque genético de trigo-Thinopyrum bessarabicum moderadamente resistente. A triagem Karnal bunt descreveu as linhas de adição 5JJ e 4JJ como estoque genético altamente resistente. Esses estoques genéticos podem ser usados para introgressão da nova ferrugem e resistência ao bunt de Karnal do pool genético terciário em origens de trigo suscetíveis.

Advances in identification methods of alien genomic components in plants / 生物工程学报

Plants with alien genomic components (alien chromosomes / chromosomal fragments / genes) are important materials for genomic research and crop improvement. To date, four strategies based on trait observation, chromosome analysis, specific proteins, and DNA sequences have been developed for the identification of alien genomic components. Among them, DNA sequence-based molecular markers are mainly used to identify alien genomic components. This review summarized several molecular markers for identification of alien genomic components in wheat, cabbage and other important crops. We also compared the characteristics of nine common molecular markers, such as simple sequence repeat (SSR), insertion-deletion (InDel) and single nucleotide polymorphism (SNP). In general, the accuracy of using a combination of different identification methods is higher than using a single identification method. We analyzed the application of different combination of identification methods, and provided the best combination for wheat, brassica and other crops. High-throughput detection can be easily achieved by using the new generation molecular markers such as InDel and SNP, which can be used to determine the precise localization of alien introgression genes. To increase the identification efficiency, other new identification methods, such as microarray comparative genomic hybridization (array-CGH) and suppression subtractive hybridization (SSH), may also be included.

Identificación de marcadores moleculares (SNP) y genes candidatos asociados a la tolerancia genética al complejo mancha de asfalto en variedades nativas de maíz (Zea mays L) / Identification of molecular markers (SNP) and candidate genes associated to genetic tolerance to tar spot complex disease in maize (Zeamays L) landraces

El complejo mancha de asfalto (CMA) en maíz (ZeamaysL.), causado por los hongos Phyllachora maydis Maubl. Y Monographella maydis Müller & Samuels, es una enfermedad de importancia económica en Guatemala, que ha causado pérdida en el rendimiento entre 30 a 50%, inclusive del 100% si las condiciones son favorables. El objetivo de esta investigación fue identificar marcadores de un solo nucleótido o SNP (Single Nucleotide Polymorphism, por sus siglas en inglés) y genes candidatos asociados a la tolerancia genética al CMA. Para ello se analizaron 463 poblaciones nativas y 329,692 SNP, y se compararon dos modelos genómicos, single markery BayesB, para la identificación de regiones asociadas a la tolerancia genética al CMA. Se identificaron 40 marcadores SNP asociados significativamente a la tolerancia genética al CMA con ambos modelos. La proporción de variación fenotípica total explicada (PVE) por los 40 SNPs fue de 56%, atribuida a efectos genéticos aditivos. Múltiples genes de resistencia a enfermedades fueron identificados en las regiones señaladas por los marcadores SNP. Sus funciones principales son receptores y transductores de señal, factores de transcripción que regulan positivamente la expresión de genes de tolerancia y genes de la familia kinasa, por lo que potencialmente están involucrados en el mecanismo de defensa al CMA.

The tar spot complex (TSC) diseasein maize (ZeamaysL.), caused by the fungi Phyllachora maydis Maubl. And Monographella maydis Müller & Samuels, is an economic important disease in Guatemala, producing yield losses between 30 to 50%, inclusive of 100% if the conditionsare favorable. The objective of this researchwasto identify single nucleoti depolymorphism markers (SNP) and candidate genes associated withgenetictoleranceto TSC. Asetof 463 native populations and 329,692 SNP were analyzed with two genomic models, single marker and BayesB, for the identification of regions associated with genetic tolerance to TSC. Forty SNP markers were significantly associated with the genetic tolerance to TSC with both models. The proportion of total phenotypic variation explained (PVE) by the 40 SNPs was 56%, attributed to additive genetice ffects. Multiple candidate genes for disease resistance were identified in the región sindicated by the SNP markers. Their main functionsare signal transducersand receptors, transcription factors that positively regulatethe expression of tolerance genes and family kinase genes, there fore, they are potentially involved in the defense mechanism to TSC.

Molecular and cytogenetic identification of Triticum aestivum-Leymus racemosus translocation line T6DL·7LrS / 生物工程学报

Leymus racemosus had a high resistant capacity to wheat scab (Fusarum head blight). The transfer of scab resistant gene from L. racemosus to Triticum aestivum is of great significance for broadening the germplasm of wheat resistance. To obtain Triticum aestivum-Leymus racemosus translocation line with scab resistance, we irradiated the pollen of T. aestivum-L. racemosus disomic addition line DA7Lr by ⁶⁰Co-γ-rays 1 200 R (100 R/min) prior to pollinating to emasculation T. aestivum cv. Chinese Spring. One plant with one translocation chromosome was detected in the M1 by GISH. The plant with one translocation chromosome was self-pollinated, and at meiotic metaphase I its progenies with two translocation chromosomes were analyzed for chromosome pairing behavior in their pollen mother cells (PMCs). One rod bivalent was observed at meiotic metaphase I, indicating that the plant with two translocation chromosomes was one translocation homozygote. Sequential GISH-FISH analysis, using Oligo-pAs1-2 and Oligo-pSc119.2-2 as probe, translocation line was confirmed as T6DL·7LrS. The translocation line had higher resistance to wheat scab and feasibility to be used as a new source in wheat breeding resistant to scab disease.

Karyotype analysis in Bignonieae (Bignoniaceae): chromosome numbers and heterochromatin

ABSTRACT Chromosome numbers and heterochromatin banding pattern variability have been shown to be useful for taxonomic and evolutionary studies of different plant taxa. Bignonieae is the largest tribe of Bignoniaceae, composed mostly by woody climber species whose taxonomies are quite complicated. We reviewed and added new data concerning chromosome numbers in Bignonieae and performed the first analyses of heterochromatin banding patterns in that tribe based on the fluorochromes chromomycin A3 (CMA) and 4'-6-diamidino-2-phenylindole (DAPI). We confirmed the predominant diploid number 2n = 40, as well as variations reported in the literature (dysploidy in Mansoa [2n = 38] and polyploidy in Dolichandra ungis-cati [2n = 80] and Pyrostegia venusta [2n = 80]). We also found a new cytotype for the genus Anemopaegma (Anemopaegma citrinum, 2n = 60) and provide the first chromosome counts for five species (Adenocalymma divaricatum, Amphilophium scabriusculum, Fridericia limae, F. subverticillata, and Xylophragma myrianthum). Heterochromatin analyses revealed only GC-rich regions, with six different arrangements of those bands. The A-type (one large and distal telomeric band) were the most common, although the presence and combinations of the other types appear to be the most promising for taxonomic studies.

In vitro regeneration and ploidy level analysis of Eulophia ochreata Lindl.

Various parameters including explant-type, medium compositions, use of phytohormones and additives were optimized for direct and indirect regeneration of E. ochreata, a medicinal orchid under threat. Protocorm-like-bodies (PLBs) proved to be the best explants for shoot initiation, proliferation and callus induction. Murashige and Skoog’s (MS) medium containing 2.5 mg L-1 6-benzylaminopurine (BAP), 1.0 mg L-1 kinetin (Kin) and additives (adenine sulfate, arginine, citric acid, 30 mg L-1 each and 50 mg L-1 ascorbic acid) was optimal for shoot multiplication (12.1 shoots and 7.1 PLBs per explant with synchronized growth), which also produced callus. Shoot number was further increased with three successive subcultures on same media and ~40 shoots per explant were achieved after 3 cycles of 30 days each. Additives and casein hydrolysate (CH) showed advantageous effects on indirect shoot regeneration via protocorm-derived callus. Optimum indirect regeneration was achieved on MS containing additives, 500 mg L-1 CH, 2.5 mg L-1 BAP and 1.0 mg L-1 Kin with 30 PLBs and 6 shoots per callus mass (~5 mm size). The shoots were rooted (70% frequency) on one by fourth-MS medium containing 2.0 mg L-1 indole-3-butyric acid, 200 mg L-1 activated charcoal and additives. The rooted plantlets were hardened and transferred to greenhouse with 63% survival rate. Flow-cytometry based DNA content analysis revealed that the ploidy levels were maintained in in vitro regenerated plants. This is the first report for in vitro plant regeneration in E. ochreata.

Optinization of rapid propagation technique and induction and identification of autotetraploid of Polygonum multiflorum / 中国中药杂志

<p><b>OBJECTIVE</b>To establish and optimize the rapid propagation system of Polygonum multiflorum, as well as explore method for induction and identification of autotetraploid.</p><p><b>METHOD</b>Propagation medium was optimized by orthogonal test. The buds were immersed in colchicine solution with different concentrations for different time to select induction conditions for autotetraploid of P. multiflorum.</p><p><b>RESULT</b>The most appropriate propagation medium was MS medium supplemented with 1.0 mg x L(-1) 6-BA, 0.3 mg x L(-1) NAA, and 0.4 mg x L(-1) PP333. That the buds were soaked in 0.2% colchicine solution for 30 h, or soaked in 0.3% colchicine solution for 18 h, was optimal condition to induce autopolyploid of P. multiflorum with induction rate as high as 16.7%.</p><p><b>CONCLUSION</b>Rapid propagation of P. multiflorum could be achieved by tissue culture. Furthermore, colchicine was an effective inducer of polyploidy, and 25 tetraploid lines were obtained through chromosome identification. The experiment laid a foundation for the wild resource conservation, superior varieties breeding of P. multiflorum.</p>

Production and characterization of a somatic hybrid of Chinese cabbage and cabbage / 生物工程学报

In order to broaden Chinese cabbage gene pool, we conducted interspecific somatic hybridization between Chinese cabbage (Brassica campestris, 2n=20, AA) and Cabbage (B. oleracea, 2n=18, CC). Protoplasts were isolated from 10-day-old cotyledons and hypocotyls of young seedlings, and fused by 40% polyethylene glycol (PEG). Fused cells were cultured in modified K8p liquid medium supplemented with some plant growth regulators. Fusion products were characterized by their morphological, cytological and molecular biological traits. The results showed that, a total of 35 regenerated green plants were obtained from 320 calli, the plant regeneration frequency was 10.94%, and eleven of which were survived in greenhouse. All regenerants were true hybrids as confirmed by randomly amplified polymorphic DNA (RAPD) and genomic in situ hybridization (GISH) analysis. Ploidy levels of hybrid plants were determined by chromosome counting and flow cytometry. The sum of the chromosome number (2n = 38) from the two fusion patents were found in 36.4% of regeneratns; another 36.4% had chromosomes range to 58-60; 27.2% had more chromosomes ranges to 70-76. All regenerated plants produced normal flowers. We investigated the pollen fertility and seed set after self-pollination and backcrossing with the parental species. For hybrids with chromosomes more than 38 it was possible to obtain some seeds when they after self-pollination. Within the group of hybrids with 38 chromosomes, seed set were very variable, only 0.11 seeds per pod by self-pollination, 0.23-0.76 by open-pollination, 0.02-0.04 by backcrossing with Chinese cabbage. Progeny lines obtained by self-pollination had larger leaves and leaf shapes intermediate of the parental species. Pollen fertility was gradually recovered in the first and second progenies. The backcrossing progeny lines, as a whole, exhibited morphologies were similar to Chinese cabbage. Morphological variations were observed among the somatic hybrids and their progenies.

Karyomorphology research in seven kinds of dandelion in Northeast / 中国中药杂志

<p><b>OBJECTIVE</b>To determine cytology chromosome numbers, doubling, type, karyotype formulae of seven kinds of Taraxacum.</p><p><b>METHOD</b>Seven kinds of dandelion in Northeast China were karyomorphologically studied by conventional pressed slice method.</p><p><b>RESULT</b>The interphase nuclei and prophase chromosomes of all species were found to be of the complex chromocenter type and the interstitial type respectively. The somatic chromosomes showed polysomaty within or among species. The range of chromosome numbers was from 16 to 32, and 24 was preponderant. It is firstly confirmed that the chromosome numbers of T. ohwianum were 2n = 2x = 16 of and those of T. variegatum 2n = 4x = 32 of, and those of other five kinds of dandelion 2n = 3x = 24. Karyotype was diverse and consisted of metacentric, submetacentric and satellites. The relative lengh of chromosome varies from 3.74 to 27.68, asymmetry index was between 59.68% and 64.02%; The karyotype type was belonged to "1A", "2A"and "2B" extensively, to ensure the T. ohwianum and T. variegatum evolutional karyotype type and genetic inheritance pattern.</p><p><b>CONCLUSION</b>According to results of the cytology karyotype we suggest that T. antungense and T. urbanum could be merged, the result was consistent with Flora Reipublicae Popularis Sinicae (FRPS). This paper reports systematically cytology karyotype feature of seven kinds of dandelions in Northeast, provides the cytology theoretical basis for further development and use of the resource and genetic breeding research of dandelions.</p>

Karyotype analysis and its systematic implications of Pterocypsela formosana and P. elata / 中国中药杂志

Pterocypsela is a very important traditional Chinese medicine from the tribe Cichorieae of Asteraceae. Mitotic chromosome numbers and karyotypes are reported for P. formosana and P. elata from Hunan and Hubei province, China. The former is new and the latter provide confirmation of previous reference. All P. taxa are diploidy with 2n = 18 and their basic number is tentatively suggested as x = 9. Karyotype of Pterocypsela is 2A and P. formosana with a karyotype formula of 2n = 2x = 18 = 4m + 14sm, and 2n = 2x = 18 = 2m + 8sm +8st for P. elata. It is the first time to report the AI value for Pterocypsela in this paper. Cytological data of chromosomal numbers and karyotypes were used to discuss the close relationships of the Pterocypsela genus and the taxonomy of the medicinal plants.

Comportamento meiótico durante a microsporogênese em espécies da família meliaceae / Comportamiento meiótica durante la microsporogénesis en especies de la familia meliaceae / Meiotic behavior during microsporogenesis of some species of meliaceae family

A família Meliaceae inclui espécies de grande interesse agronômico, ecológico, econômico e ornamental de alto potencial madeireiro no mundo. No Brasil ocorrem cerca de seis gêneros e 100 espécies. Considerando a falta de estudos citológicos para esse grupo, este trabalho descreve o comportamento meiótico durante a microsporogênese de seis espécies (Trichilia pallida, Trichilia elegans, Trichilia catigua, Cedrela fissilis, Cabralea canjerana, Guarea guidonea) da família Meliaceae, representando quatro dos seis gêneros que estão presentes no Brasil. Inflorescências foram coletadas e fixadas em etanol/ácido acético (3:1 v/v) por 24 horas, transferidos para álcool a 70%, e acondicionadas sob refrigeração. As lâminas foram preparadas pela técnica de esmagamento, coradas com carmim acético a 1%. A análise citogenética revelou poucas irregularidades meióticas, sendo estas relacionadas a segregação dos cromossomos, fusos irregulares e conexão citoplasmática. Como consequência da segregação irregular dos cromossomos na meiose I e II e da organização irregular dos fusos na meiose II, o padrão de citocinese também foi irregular originando tétrades com micrócitos e tríades, resultando em micrósporos desbalanceados e de núcleo restituído (2n).

The Meliaceae family includes the most important species with great agronomic, ecological, economic and ornamental value and high timber potential in the world. In Brazil, approximately six genera and 100 species are found. Considering the lack of cytological studies for its genera, the present study describes the meiotic behavior during microsporogenesis of six species of the Meliaceae family, representing four of the six genera that are present in Brazil; these species are: Trichilia pallida, Trichilia elegans, Trichilia catigua, Cedrela fissilis, Cabralea canjerana, Guarea guidonea. Inflorescences were collected and fixed in ethanol/acetic acid (3:1 v/v) for 24 hours, transferred to alcohol at 70%, and stored under refrigeration. The slides were prepared by squashing, and stained with acetic carmine 1% and observed under optical microscopy. Cytogenetic analysis revealed few meiotic irregularities, which are related to segregation of chromosome spindles and irregular cytoplasmic connection. As a result of irregular segregation of chromosomes during meiosis I and II and the irregular organization of the spindles in meiosis II, the pattern of cytokinesis was also irregular resulting in microcytic tetrads and triads, unbalanced microspores and restored nuclei (2n).

La familia Meliaceae incluye especies de gran interés agronómico, ecológico, económico y ornamental de alto potencial maderero en el mundo. En Brasil ocurren cerca de seis géneros y 100 especies. Considerando la falta de estudios citológicos para ese grupo, este trabajo describe el comportamiento meiótica durante la microsporogénesis de seis especies (Trichilia pallida, Trichilia elegans, Trichilia catigua, Cedrela fissilis, Cabralea canjerana, Guarea guidonea) de la familia Meliaceae, representando cuatro de los seis géneros que están presentes en Brasil. Inflorescencias fueran colectadas y fijadas en etanol/ácido acético (3:1 v/v) por 24 horas, transferidos para alcohol a 70%, y acondicionadas bajo refrigeración. Las láminas fueron preparadas por la técnica de aplastamiento, coloradas con carmín acético a 1%. El análisis citogenética reveló pocas irregularidades meióticas, siendo éstas relacionadas a la segregación de los cromosomas, fusos irregulares y conexión citoplasmática. Como consecuencia de segregación irregular de cromosomas en la meiosis I y II y de la organización irregular de los fusos en la meiosis II, el estándar de citocinesis también fue irregular originando tétradas con micrófitos y tríades, resultando en micros poros desbalanceados y de núcleo restituido (2n).

Detection of single copy sequences using BAC-FISH and C-PRINS techniques in sunflower chromosomes

Bacterial artificial chromosome-fluorescence in situ hybridization (BAC-FISH) and cycling-primed in situ labeling (C-PRINS) techniques were evaluated for integration of physical and genetic maps of sunflower (Helianthus annuus L.). Single-site SSR markers were selected from three linkage groups of a high-density sunflower genetic map. This selection was based on previously identified QTL associated to S. sclerotiorum. These markers were used to select BACs contaning single copy sequences for BAC-FISH aplication. Blocking of highly dispersed repetitive sunflower sequences reduced unspecific hybridization, and allowed the detection of specific signals for BACs containing SSR markers HA4222 and HA2600, anchored to LG 16 and LG 10, respectively. Single-site FISH signal detection was optimized by adjusting the relative quantity and quality of unlabelled repetitive sequences present in the blocking DNA. The SSR marker ORS1247 anchored to the LG 17 was detected by C-PRINS, which yielded fluorescence signals that were specific and intense. This progress in localizing single-copy sequences using BAC-FISH and indirect C-PRINS strategies in sunflower will facilitate the integration of genetic and physical maps, allowing the identification of chromosomes containing key genes and/or QTL associated to agronomic important traits in sunflower.

Tissue culture and polyploidy induction of Morinda officinalis / 中国中药杂志

<p><b>OBJECTIVE</b>To establish an effective protocol for plant generation and induce polyploidy of Morinda offcinalis.</p><p><b>METHOD</b>Callus was induced from immature embryo of M. officinalis and polyploidy was inducted by using colchicine treatment method. Chromosome was detected by flow cytometry.</p><p><b>RESULT AND CONCLUSION</b>The highest induction rate of polyploidy was 18.40%, which was obtained with 500 mg x L(-1) colchicine treatment for 5 days. Roots of polyploid were bigger than diploid. Advantages of using immature embryo as explants are easy for sterilization, higher rate of callus induction and low degree dedifferentiation. The induced polyploidy of M. officinalis may have a value for spread of cultivation.</p>

Botanical aspects of Heteropterys umbellata (Malpighiaceae): a cytological and palynological approach

The genus Heteropterys is one of the major genera in Malpighiaceae. However, few cytological and palynological studies were reported. The present work described for the first time the chromosome number, heterochromatin pattern, meiotic behavior, pollen viability and palynological aspects of Heteropterys ubellata, a very spread species. One large Brazilian population was evaluated using conventional techniques for meiotic studies and acetolyse to access the pollen morphology. The species showed 2n = 20 chromosomes, normal meiotic development and viable pollens. Great blocks of heterochromatin were observed around the centromers. DAPI staining was positive for centroeric heterochroatin, hile CMA3 ark as observed just at terinal regions of one pair of hoologues chromosomes. This result and the presence of one chromosome pair attached to the nucleoli during the pachytene and diakinesis suggested the presence of only one pair of NORs. Palynological analysis revealed that pollen grains are apolar, 6 porate and with colpoids associated to all pores. The pollen content was positive for the starch test, and the exine was rugulate with little psilate regions.

O gênero Heteropterys é um dos maiores gêneros entre as Malpighiaceae. Entretanto, poucos estudos citológicos e palinológicos foram relatados. O presente trabalho descreveu pela primeira vez o número cromossômico, o padrão heterocromático, o comportamento meiótico, a viabilidade polínica e aspectos palinológicos de Heteropterys umbellata, uma espécie muito disseminada. Uma grande população brasileira foi estudada utilizando técnicas convencionais para o estudo de cromossomos meióticos e acetólise para acessar a morfologia polínica. A espécie apresentou 2n = 20 cromossomos, desenvolvimento meiótico normal e pólens viáveis. Grandes blocos de heterocromatina foram observados ao redor dos cen-trômeros. A coloração com DAPI foi positiva para a hetero-cromatina centromérica, enquanto marcas com CMA3 foram observadas somente em um sítio terminal de um par de cromossomos homólogos. Este resultado e a presença de um par de cromossomos associados a um nucléolo durante o paquíteno e diacinese sugerem a presença de somente um par de RONs. A análise palinológica revelou que os grãos de pólen são apolar, com 6 poros e colpóides associados a todos eles. O conteúdo polínico foi positivo para o teste de amido e a exina mostrou-se rugulada com poucas regiões psiladas.

Ability of Allium cepa L. root tips and Tradescantia pallida var. purpurea in N-nitrosodiethylamine genotoxicity and mutagenicity evaluation

N-nitroso compounds, such as N-nitrosodiethylamine (NDEA), can be formed by the reaction of secundary amines with nitrosating agents, and are suspected to be involved in tumors in humans. NDEA has been considered a weak carcinogen in genotoxic assays probably due to the inefficient nitrosamine activation system that is used and/or to the efficient repair system. In this work, we evaluated the sensibility of Allium cepa L. root tips and Tradescantia stamen hair mutation assay (Trad-SH) using Tradescantia pallida var. purpurea for NDEA (0.1; 0.5; 5 and 25mM) genotoxicity and mutagenicity induction. Allium cepa L. was treated with different NDEA concentrations for 3h, for 3 consecutive days, including negative control (distilled water) and positive control maleic hydrazide (MH 30mg/mL). After treatment, the roots were hydrolyzed, squashed, and the mitotic index (MI) and cytological abnormalities were scored. The results revealed a cytostatic effect of NDEA (0.5 and 5mM), showing a significant reduction in the MI. Chromosome stickiness suggests a NDEA toxic effect. T. pallida purpurea did not respond to mutagens with a dose-dependent pattern. In conclusion, our study indicates that the root tips of Allium cepa L. have sensibility to detect NDEA genotoxicity, but not for Trad-SH test.

Nitrocompostos, como N-nitrosodietilamina (NDEA), podem ser formados pela reação entre uma amina secundária e agentes nitrosantes e são suspeitos de estarem envolvidos na formação de tumores em humanos. NDEA é considerada um carcinógeno fraco e ensaios genotóxicos provavelente pela utilização de um sistema de ativação ineficiente e/ou pela utilização de um eficiente sistema de reparo. Neste trabalho, nós avaliamos a sensibilidade de ensaios com Alliu cepa L. e Tradescantia pallida var. purpurea (Trad-SH) à genotoxicidade e mutagenicidade induzidas por diferentes concentrações de NDEA (0,1; 0,5; 5 e 25mM) por 3h, por 3 dias consecutivos, incluindo controle negativo (água destilada) e controle positivo, hidrazida maleica (MH 30mg/mL). Depois do tratamento, as raízes foram hidrolizadas, esmagadas e o índice mitótico (IM) e anormalidades citológicas foram contadas. Os resultados revelaram um efeito citostático de NDEA (0,5 e 5mM), pela significante redução do IM. Chromosome stickiness sugere um efeito citotóxico de NDEA. T pallida purpurea não respondeu ao mutágeno com um padrão dose dependente. Em conclusão, nossos estudos indicaram que raízes de Allium cepa L. possue sensibilidade na detecção genotóxica de NDEA, mas não para o ensaio Trad-SH.

Molecular authentication of the traditional Chinese medicinal plant Angelica sinensis based on internal transcribed spacer of nrDNA / Autentificación molecular de la planta medicinal tradicional china Angelica sinensis basada en el espaciador interno transcrito del ADNnr

Traditionally, the authentication of the traditional Chinese medicines (TCM), Angelica sinensis, is based on slightly different morphological characters and complex compounds. Usually, those methods are simultaneously affected by several factors, leading to subtle and ambiguous results. In this study, the internal transcribed spacer (ITS) regions of A. sinensis and seven other Angelica species used as adulterants were sequenced. A pair of specific primers was designed from the polymorphic ITS regions to distinguish A. sinensis from the adulterants and regional substitutes. These ITS-derived primers amplified approximately 520 bp specific fragments from the adulterants, whereas no products was amplified with the DNA of A. sinensis. We tested eight commercially crude materials purchased in the market by using these specific primers. The result showed that there were four samples adulterating A. sinensis with regional substitutes. This indicated that A. sinensis could be accurately distinguished from the adulterants and regional substitutes. Therefore, the method of molecular authentication based on the ITS sequences may be contributed to raw material production and quality control of A. sinensis.

Chromosome characteristics of three Coptis species / 中国中药杂志

In the present paper, three Coptis species, collected from Sichuan and Chongqing, China, were used for karyotypic analyses. The results indicated that both C. chinensis and C. omeinensis were diploid with chromosome 2n = 2x = 18, and C. deltoidea was an autotriploid with chromosomes 2n = 3x = 27, which explained why this species was morphologically so isolated from other species and its sterile and narrow distributing regions. The relationship between C. chinensis and C. omeinensis based on chromosome data was discussed. The probable origin of C. deltoidea was also suggested.

Pollen viability and stigma receptivity of Salvia miltiorrhiza and its relative / 中国中药杂志

<p><b>OBJECTIVE</b>To provide the basal data for artificial cross breeding of Chinese herb Salvia miltiorrhiza from 7 provinces in China and its 4 relatives.</p><p><b>METHOD</b>The pollen viability was evaluated by TTC (2, 3, 5-triphenylte trazolium chloride) test and the stigma receptivity was evaluated by benzidine-H2O2 method.</p><p><b>RESULT</b>The pollen viability of S. miltiorrhiza from 6 provinces in China and its 4 relatives deceased during time of pollen shedding. Their highest pollen viability was in 2 or 3 days after blooming. But the pollen viability of S. miltiorrhiza (wild and culture) from Hean province in China declined with time after blooming. The most obvious variation of the pollen viability was in S. miltiorrhiza from Shanxi province (RSD 71.3% ) and the least was in wild S. miltiorrhiza from Henan province (RSD 12.4%). The highest average pollen viability was wild S. miltiorrhiza (72.3%) from Henan province while the lowest was S. yunnanensis (38.8%). The stigmas of all the accessions had receptivity when blooming. The stigma receptivity of S. brevilabra was strong in 2 to 4 days after blooming, while the others had less change after blooming. The life span of pollen grains and stigmas could be maintained from 3 to 5 days.</p><p><b>CONCLUSION</b>The optimum artificial pollination time of S. miltiorrhiza and its relatives was 2 to 3 days after blooming.</p>

Chromosome number and microsporogenesis of two accessions of Brachiaria dura Stapf (Poaceae) / Número de cromossomos e microsporogênese de dois acessos de Brachiaria dura Stapf (Poaceae)

The two accessions of B. dura analyzed (DU01 and DU02) are hexaploid (2n = 6x = 54), derived from x = 9. Meiotic abnormalities, such as precocious chromosome migration to the poles, laggards and micronuclei, were recorded in low frequency in both accessions. The few multivalent chromosome association at diakinesis and meiotic stability suggested that hexaploidy probably resulted from chromosome doubling. In DU02, chromosome transfer (cytomixis) among meiocytes, involving part or the entire genome was observed. The implication of these findings for the Brachiaria breeding is discussed.

Os dois acessos de B. dura analisados (DU01 e DU02) são hexaplóides (2n = 6x = 54), derivados de x = 9. Anormalidades meióticas como migração precoce de cromossomos para os polos, cromossomos retardatários e micronúcleos foram observados em baixa frequência em ambos os acessos. A presença de poucas associações cromossômicas em diacinese e a estabilidade meiótica sugere que a hexaploidia provavelmente resultou de duplicação cromossômica. No acesso DU02 observou-se transferência de cromossomos (citomixia) entre meiócitos, envolvendo parte ou todo o genoma. As implicações destes resultados para o melhoramento de Brachiaria são discutidas.

Staining and slide-preparing technique of mitotic chromosomes and application in karyotype determination of Ephedra / 中国中药杂志

<p><b>OBJECTIVE</b>To study the karyotype of four Ephedra plants in order to provide the cytologic evidence for the genetic diversity and identification genetic resources of Ephedra.</p><p><b>METHOD</b>The roots of germinating seeds were used to study the karyotype of four Ephedra plants by staining and slide-preparing technique of mitotic chromosomes.</p><p><b>RESULT</b>the optimal root-sampling time was about 10: 20 - 10:40 am. Using 0.002 mol x L(-1) 8-Hydroxyquinoline to pretreating the intravital root tips, the optimal pretreatment time for E. Sinica, E. intermedina, E. equisetina and E. przewalskii was 4, 5, 4.5 and 3.5 h, respectively. E. przewalskii and E. equisetina were diploid, E. Sinica and E. intermedina were belonged quadruple. The karyotype formulae of the four species were 2n = 2x = 14 = 2M + 8m + 4sm, 2n = 2x = 14 = 10m + 4st, 2n = 4x = 28 = 20m (2SAT) +8st, and 2n = 4x = 28 = 20m (SAT) + 6st + 2sm, respectively.</p><p><b>CONCLUSION</b>All the karyotypes of four Ephedra species were 2A type, which was the symmetric karyotype.</p>