Genetic divergence among maize hybrids by morphological descriptors

Two experiments with 25 maize commercial hybrids were carried out in a direct sowing system in Southern Brazil in the harvests of 2009/2010 and 2010/2011. Quantitative descriptors were used with the objective of determining the genetic divergence and the relative contributions of traits among hybrids for extraction of inbred lines. This study was carried out in Oxisol soil using a randomized block design with four replicates. Data were subjected to combined analysis of variance, and based on the multivariate analyses, Tocher and average linkage (UPGMA) cluster analyses, based on generalized distance of Mahalanobis, to quantify divergence in addition to Singh criterion to validate trait with the most contribution. The multivariate methods were consistent with each other, and the weight of 100 grains was the trait that contributed most to the divergence and had similar behavior in grain yield between hybrids in both years. Furthermore, this descriptor representing significant genetic variability for crossings and lines extraction to hybridization between BM 3061, ATL 200 and P 30B39 Y.

Genetic diversity of mango accessions (Mangifera indica) using new microsatellite markers and morphological descriptors.

Genetic diversity estimates based on morphological and molecular data can provide different information on the relationship between cultivars of a species. This study aimed to develop new microsatellite markers as additional tools in genetic studies on mangoes (Mangifera indica L.), and to analyze the genetic variability of 20 mango cultivars based on morphological descriptors and microsatellite markers. We aimed to better understand the cultivars enhanced breeding histories and to support crossbreeding planning. Positive clones were selected from a DNA library enriched for microsatellite regions for sequencing and primer design. Four plants of each of the 20 accessions were used for observations, based on 48 morphological descriptors. Twenty accessions were analyzed using 27 microsatellite markers, of which 16 were developed during this study. The clusters, based on the morphological descriptors by Ward - MLM strategy and the microsatellite markers, suggested that Brazilian mango cultivars have extensive genetic diversity and are related to cultivars with different provenances, demonstrating their different enhanced breeding histories.

Automated analysis of non-mass-enhancing lesions in breast MRI based on morphological, kinetic, and spatio-temporal moments and joint segmentation-motion compensation technique

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) represents an established method for the detection and diagnosis of breast lesions. While mass-like enhancing lesions can be easily categorized according to the Breast Imaging Reporting and Data System (BI-RADS) MRI lexicon, a majority of diagnostically challenging lesions, the so called non-mass-like enhancing lesions, remain both qualitatively as well as quantitatively difficult to analyze. Thus, the evaluation of kinetic and/or morphological characteristics of non-masses represents a challenging task for an automated analysis and is of crucial importance for advancing current computer-aided diagnosis (CAD) systems. Compared to the well-characterized mass-enhancing lesions, non-masses have no well-defined and blurred tumor borders and a kinetic behavior that is not easily generalizable and thus discriminative for malignant and benign non-masses. To overcome these difficulties and pave the way for novel CAD systems for non-masses, we will evaluate several kinetic and morphological descriptors separately and a novel technique, the Zernike velocity moments, to capture the joint spatio-temporal behavior of these lesions, and additionally consider the impact of non-rigid motion compensation on a correct diagnosis.

Morphological characterization and reproductive aspects in genetic variability studies of forage peanut

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Assessment and rationalization of genetic diversity of Papua New Guinea taro (Colocasia esculenta) using SSR DNA fingerprinting

Taro (Colocasia esculenta) accessions were collected from 15 provinces of Papua New Guinea (PNG). The collection, totalling 859 accessions was collated for characterization and a core collection of 81 accessions (10%) was established on the basis of characterization data generated on 30 agro-morphological descriptors, and DNA fingerprinting using seven SSR primers. The selection of accessions was based on cluster analysis of the morphological data enabling initial selection of 20% accessions. The 20% sample was then reduced and rationalized to 10% based on molecular data generated by SSR primers. This represents the first national core collection of any species established in PNG based on molecular markers. The core has been integrated with core from other Pacific Island countries, contributing to a Pacific regional core collection, which is conserved in vitro in the South Pacific Regional Germplasm Centre at Fiji. The core collection is a valuable resource for food security of the South Pacific region and is currently being utilized by the breeding programmes of small Pacific Island countries to broaden the genetic base of the crop.

Caracterização morfológica, citogenética e molecular de uma população de tangerineiras híbridas de 'Clementina fina' (Citrus clementina Hort. ex Tan.) e 'Montenegrina' (Citrus deliciosa Ten.)

A produção citrícola se encontra dispersa por todos os continentes e no Brasil, os citros são a produção frutícola de maior volume de produção. A produção de citros de mesa, como as tangerinas, possibilita ao produtor obter maior valor pelo seu produto. O mercado consumidor é ávido por novas variedades e para tanto, um programa de melhoramento deve estar sempre em busca de genótipos que atendam ao mercado consumidor, bem como a cadeia produtiva. Na Estação Experimental Agronômica da Universidade Federal do Rio Grande do Sul, está localizada uma população de tangerineiras híbridas oriundas do cruzamento da tangerineira ‘Clementina Fina’ (Citrus clementina Hort. ex Tan.) e ‘Montenegrina’ (Citrus deliciosa Ten.) a qual foi caracterizada neste estudo, avaliando-se características morfológicas de acordo com os descritores propostos pelo International Board for Plant Genetic Resources, além da identificação da época de maturação, viabilidade de pólen, número cromossômico e caracterização molecular, utilizando marcadores do tipo microssatélites. Através da análise morfológica foi possível distinguir todas as 96 plantas avaliadas, porém não foi possível agrupar a F1 em grupos distintos de cada um dos genitores. A época de maturação de frutos das plantas se concentra entre a primeira quinzena de abril até a primeira quinzena de agosto. Todas as plantas analisadas apresentaram um alto grau de viabilidade de pólen, variando entre 79,04 e 98,08 %. Todas as plantas avaliadas são diplóides com um número cromossômico de 2n=18. Utilizando 12 pares de primers de microssatélites foi possível diferenciar 90 acessos do estudo, e agrupar a F1 em indivíduos mais próximos do genitor feminino e do genitor masculino. O PIC (Conteúdo de Informação de Polimorfismo) dos primers variou de 0,27 a 0,65. Não foi possível estabelecer uma relação entre a caracterização utilizando marcadores morfológicos e a caracterização utilizando marcadores moleculares.

Caracterização morfológica de plantas de rambutan

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estatística multivariada na discriminação de raças amazônicas de pupunheiras (Bactris gasipaes Kunth) em Manaus (Brasil)

As raças e populações de pupunheiras ao longo dos rios Amazonas e Solimões apresentam grande variabilidade genética ainda não totalmente caracterizada. Neste estudo, foram aplicadas técnicas estatísticas multivariadas a 15 descritores morfológicos numa tentativa de caracterizar, morfometricamente, três raças existentes ao longo da Bacia desses rios. As três análises em conjunto permitiram uma discriminação das raças, mostrando também que os descritores mais importantes nessa seleção foram: número de espigas, comprimento da ráquis, peso do fruto, espessura das cascas, facilidade para descascar os frutos, peso das cascas, sabor dos frutos, espessura da polpa, distância morfológica dos frutos e peso da semente.

Caracterização morfológica, química e conservação in vitro de Pfaffia glomerata(Sprengel)Pedersen

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterizações morfológica e molecular de acessos de pimenta (Capsicum chinense Jaqc.)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Genetic variation of the Ananas genus with ornamental potential

Brazil is one of the main centers of origin of pineapple species presenting the largest genetic variation of the Ananas genus. Embrapa Cassava and Fruits is a Brazilian Agricultural Research Corporation and has an ex-situ collection of 678 accessions of the Ananas genus and some other Bromeliaceae. The use of ornamental pineapple has increased in the last years demanding new varieties, mainly for the external market, due to the originality and colors of its tiny fruits. The main aim of the present study was describing accessions from the pineapple gene bank in order to quantify their genetic variation and identify possible progenitors to be used in breeding programs of ornamental pineapples. Eighty-nine accessions of Ananas comosus var. comosus, A. comosus var. bracteatus (Lindl.) Coppens et Leal, A. comosus var. ananassoides (Baker) Coppens et Leal, A. comosus var. erectifolius (L. B. Smith) Coppens et Leal, A. comosus var. parguasensis (Camargo et L. B. Smith) Coppens et Leal and A. macrodontes Morren were evaluated with 25 morphological descriptors. According to the results, the evaluated accessions were separated into the following categories: landscape plants, cut flower, potted plants, minifruits, foliage and hedge. The genetic distance among accessions was determined using the combined qualitative and quantitative data by the Gower algorithm. The pre-selected accessions presented genetic variation and ornamental potential for different uses. The multicategory analysis formed seven clusters through a classification method based on the average Euclidean distance between all accessions using the cut-point of genetic dissimilarity (D dg = 0.35). The genotypes A. comosus var. erectifolius were selected to be used as landscape plants, cut flower, minifruits and potted plants. Accessions of A. comosus var. bracteatus and A. macrodontes were selected as landscape plants and hedge. The highest variation was observed in A. comosus var. ananassoides genotypes, which presented high potential for use as cut flowers.

Genetic variability of banana with ornamental potential

The Musa germplasm collection at Embrapa Cassava and Fruits detains accessions from different sections of the Musa genus. The objective of the present study was to identify and morphologically characterize banana accessions from the banana germplasm with ornamental potential, as well as to quantify their genetic variability; and identify possible progenitors to be used in breeding aiming to achieve ornamental crossbreeds. The accessions were evaluated with the use of 32 morphological descriptors. Then, they were the following grouped into categories: landscape plants, cut flower, potted plants, and male inflorescence minifruits. The pre-selected accessions presented great genetic variability and ornamental potential for different uses. The accessions of the Rhodochlamys and Callimusa sections were selected to be used as landscape plants, cut flowers, potted plants, male inflorescence and minifruits. Most of the diploids from the Eumusa section evaluated in this study are indicated for the production of ornamental minifruits, except for 'Lidi' and Cici, which can also be indicated as landscape plants. The BB diploids have great potential for the use of the male inflorescence in floral arrangements, and did not offer any other indication.

Fourier descriptors for morphological analysis of vectorcardiograms

The use of Fourier shape descriptors for morphological studies of vectorcardio-grams (VCGs) is p resented . The FDs can effectively be used as features for classf-fication of VCGs of different clinical categories . In addition , they provide cli-nically significant qualitative shape information for use by the Cardiologist. The initial result sofanalysisof nwrmal and abnormal VCGs areencouraging.

MORPHOLOGICAL DIVERSITY OF MANGO GERMPLASM FROM THE UPPER ATHI RIVER REGION OF EASTERN KENYA: AN ANALYSIS BASED ON NON- FRUIT DESCRIPTORS

Phenotypic variation in plants can be evaluated by morphological characterization using visual attributes. Fruits have been the major descriptors for identification of different varieties of fruit crops. However, even in their absence, farmers, breeders and interested stakeholders require to distinguish between different mango varieties. This study aimed at determining diversity in mango germplasm from the Upper Athi River (UAR) and providing useful alternative descriptors for the identification of different mango varieties in the absence of fruits. A total of 20 International Plant Genetic Resources Institute (IPGRI) descriptors for mango were selected for use in the visual assessment of 98 mango accessions from 15 sites of the UAR region of eastern Kenya. Purposive sampling was used to identify farmers growing diverse varieties of mangoes. Evaluation of the descriptors was performed on-site and the data collected were then subjected to multivariate analysis including Principal Component Analysis (PCA) and Cluster analysis, one- way analysis of variance (ANOVA) and Chi square tests. Results classified the accessions into two major groups corresponding to indigenous and exotic varieties. The PCA showed the first six principal components accounting for 75.12% of the total variance. A strong and highly significant correlation was observed between the color of fully grown leaves, leaf blade width, leaf blade length and petiole length and also between the leaf attitude, color of young leaf, stem circumference, tree height, leaf margin, growth habit and fragrance. Useful descriptors for morphological evaluation were 14 out of the selected 20; however, ANOVA and Chi square test revealed that diversity in the accessions was majorly as a result of variations in color of young leaves, leaf attitude, leaf texture, growth habit, leaf blade length, leaf blade width and petiole length traits. These results reveal that mango germplasm in the UAR has significant diversity and that other morphological traits apart from fruits can be useful in morphological characterization of mango.

Variation in mandible shape in Thrichomys apereoides (Mammalia: Rodentia): Geometric analysis of a complex morphological structure

The model of development and evolution of complex morphological structures conceived by Atchley and Hall in 1991 (Biol. Rev. 66:101-157), which establishes that changes at the macroscopic, morphogenetic level can be statistically detected as variation in skeletal units at distinct scales, was applied in combination with the formalism of geometric morphometrics to study variation in mandible shape among populations of the rodent species Thrichomys apereoides. The thin-plate spline technique produced geometric descriptors of shape derived from anatomical landmarks in the mandible, which we used with graphical and inferential approaches to partition the contribution of global and localized components to the observed differentiation in mandible shape. A major pattern of morphological differentiation in T. apereoides is attributable to localized components of shape at smaller geometric scales associated with specific morphogenetic units of the mandible. On the other hand, a clinal trend of variation is associated primarily with localized components of shape at larger geometric scales. Morphogenetic mechanisms assumed to be operating to produce the observed differentiation in the specific units of the mandible include mesenchymal condensation differentiation, muscle hypertrophy, and tooth growth. Perspectives for the application of models of morphological evolution and geometric morphometrics to morphologically based systematic biology are considered.