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Dwarf coconut tree is the main variety for commercial use in Brazil, which ranks fourth in world coconut production. However, the genotypes used still have limitations and genetic variability is required. The aim of this study was to estimate the genetic variability in dwarf coconut accessions preserved at the Germplasm Bank of Brazil at different harvesting times and using agronomic descriptors of plant and fruits. The accessions Brazilian Green Dwarf-Jiqui, Cameroon Red Dwarf, Malayan Red Dwarf, Brazilian Red Dwarf-Gramame, Brazilian Yellow Dwarf-Gramame, and Malayan Yellow Dwarf were assessed by means of 30 descriptors Variance analysis was performed and the genetic diversity was quantified by using the Mahalanobis’ generalized distance and expressed by means of UPGMA clusters, Tocher optimization, and canonical variables. The maximum likelihood analysis was used to estimate the components of variance with the data of each plant in a sample of 11 descriptors of great importance for the genetic improvement of the coconut tree. A phenotypic divergence was found among the accessions using the UPGMA clusters, Tocher optimization and graphic dispersion obtained with canonical variables. The use of the maximum likelihood analysis confirms the existence of genetic variability in the accessions for the descriptors fruit polar and equatorial diameter, nut polar diameter, total fruit weight, and epicarp thickness, which presented a heritability varying from 0.17 to 0.39. There is a possibility of genetic gains with the selection of these traits for use of accessions in breeding programs.

Carotenoid quantification in foods can be performed by various techniques, such as spectrophotometry, mass spectrometry, high performance liquid chromatography, gas chromatography and colorimetry. The objective of this study was to verify the feasibility of indirect selection of total carotenoids in pumpkin accessions. The experimental design was in complete randomized blocks with two replications and three plants per plot. The treatments consisted of 51 Cucubita moschata Duch accessions from the DCAF/UFERSA Cucurbitaceae germplasm collection and a commercial C. maxima Duch cultivar. After maturation, the fruits were harvested and colorimetric and total carotenoid contents were evaluated. Pulp color intensity parameters and hº angle indicated the possibility of indirect selection of accessions with higher total carotenoid contents. The ABO22 access presented higher total carotenoid content under the evaluation conditions of the experiment. Highlights There is variability in the total carotenoid content in pumpkin accessions. The pumpkin accessions studied have potential for food biofortification. Feasibility of indirect selection in pumpkin accessions for high total carotenoid content.

The tall coconut (Cocos nucifera L.) has great socioeconomic importance in Brazil and was first introduced on the coast of the north-eastern region, where it has been exploited in a semi-extractivist manner. The goal of this study was to quantify the genetic divergence between accessions introduced and preserved at the International Coconut Genebank for Latin America and the Caribbean, estimate the efficiency of descriptors used in the discrimination of the accessions, and indicate the essential descriptors for the activities of characterisation and evaluation. The accessions used were: Polynesia Tall; Tonga Tall; West African Tall; Rennel Tall; Rotuma Tall; Vanuatu Tall; Malayan Tall and Brazilian Tall Praia-do-Forte. Thirty-five quantitative descriptors recommended for the species were used. Genetic divergence was estimated by the Mahalanobis’s generalised distance and the cluster analysis was performed using the unweighted pair group method with arithmetic mean (UPGMA). The relative importance of the descriptors was measured according to Singh and Jolliffe’s methods, and the variables were selected taking into consideration the matching information in the two methods, eliminating those that were discarded in the two procedures. The agronomic characteristics indicated that the first canonical variable explained 90.25% of total variance. The most efficient descriptors for detecting the genetic divergence were: fruit equatorial circumference; nut polar and equatorial circumference; quantity of liquid endosperm; total fruit weight; nut weight; stem height; girth of stem at 1,5m height; number of leaflets; and number of bunches. The most dissimilar accessions according to the agronomic characteristics were Rotuma Tall and West African Tall, which can be primarily indicated as genitors for the formation of segregating populations in breeding programmes.

The aim of this study was to evaluate the storage potential of the pollen grains of Brazil Green Dwarf (BGD), Brazilian Tall (BRA) and Cameroon Red Dwarf (CRD) coconut accessions under different storage conditions. Representative plants of BGD, BRA and CRD accessions were selected from the Coconut Active Germplasm Bank of Embrapa Coastal Tablelands. The pollen grains were collected, placed in cryotubes and maintained under the following storage conditions: T1, refrigerator (-4°C); T2, freezer (-20°C); T3, ultra-freezer (- 80°C) and T4, liquid nitrogen (-196°C). The pollen grain viability was determined by staining with 1% acetic carmine and in vitro germination in a Lora culture medium at 30 and 60 days after the storage. Storage under refrigerator (-4°C), freezer (-80°C) and liquid nitrogen (-196°C) conditions promoted a better pollen grain viability of the Brazilian Tall coconut accession. Storage under freezer (-20°C) and liquid nitrogen (-196°C) conditions promoted a better pollen grain viability of the Cameroon Red Dwarf coconut accession. Storage under freezer (-20°C and-80°C) and liquid nitrogen (-196°C) conditions promoted a better pollen grain viability of the Brazil Green Dwarf coconut accession. The pollen grain viability of the Brazilian Tall coconut accession is stable after 30 and 60 days of storage.

O objetivo deste trabalho foi estimar parâmetros genéticos em caracteres associados com a produção de feijão fresco em 14 genótipos de feijão-caupi de vagem roxa e grãos brancos. Foram conduzidos três experimentos: dois sob irrigação (2004 e 2005) e um em condições de sequeiro (2005), no campo experimental da Embrapa Meio-Norte, em Teresina-PI, em delineamento de blocos completos casualizados com quatro repetições. Foram avaliados os seguintes caracteres: número de dias para a colheita de vagens frescas (NDCVF), comprimento de vagens frescas (CVF), número de grãos por vagem fresca (NGVF), peso de cem grãos frescos (P100GF), produtividade de vagens frescas (PVF), produtividade de grãos frescos (PGF), índice de grãos frescos (IGF), valor de cultivo (VC) e porte da planta (PP). As correlações genotípicas foram superiores às fenotípicas e ambientais, destacando-se as correlações entre VC e PVF (100%). O coeficiente de variação genético variou de 6,58% (IGF) a 31,62% (PGF), com destaque também para PVF (30,16%). No geral, todos os caracteres exibiram alto componente genético na expressão do caráter, com destaque para o CVF (98,72%). Existe um alto componente genético na expressão fenotípica de todos os caracteres estudados, com grande probabilidade de ganhos genéticos em ciclos adicionais de seleção com base no fenótipo. A seleção de genótipos de feijão-caupi de alta produtividade e precoces é mais fácil do que a seleção de genótipos de alta produtividade e tardios, para o melhoramento do feijão fresco.The aim of this work was to estimate genetic parameters in traits associated with the production of fresh southern pea in 14 cowpea genotypes of purple pod and white grains. Three experiments were carried out: two under irrigation (2004 and 2005) and one in rainfed conditions (2005), at Embrapa Mid-North experimental field, in a randomized complete block design with four replications. The correlations, genetic variation and determination coefficients were estimated for the following traits: number of days for the harvest of fresh seed (NDHFS), fresh pod length (FPL), number of seeds for fresh pod (NSFP), weight of one hundred fresh seed (WHFS), fresh pod yield (FPY), fresh seed yield (FSY), fresh seed index (FSI), value of crop (VC) and plant type (PT). The genotypic correlations were superior to phenotypic and environment correlations, being distinguished the correlations between VC and FPY (100%). The genetic variation coefficient varied from 6.58% (FSI) to 31.62% (FSY), with highlight also for FPY (30.16%). All characters showed high genetic component in the expression of the character, with highlight for the FPL (98.72%). There is a high genetic component in the phenotypic expression of all the traits studied, with a high probability of genetic gains in additional cycles of selection based on phenotype. Selection of cowpea genotypes for high yield and early is easier than selection of genotypes with high yield and late in the fresh southern pea breeding.

O objetivo deste trabalho foi avaliar a adaptabilidade e a estabilidade da produtividade de grãos de 20 genótipos de feijão-caupi de porte semi-ereto, utilizando o modelo de efeitos aditivos principais e interação multiplicativa. Os ensaios foram conduzidos em 16 ambientes da Região Nordeste do Brasil. Os efeitos de genótipos, ambientes e da interação genótipo x ambiente, e os três primeiros eixos da análise de componentes principais (ACP) foram significativos. Os dois primeiros eixos da ACP explicaram juntos 55,11% da soma de quadrados da interação, correspondendo a 83,20% do padrão da interação genótipo x ambiente. As linhagens TE-97-321G-4, EVX-92-49E e EVX-63-10E apresentaram alta adaptabilidade, mas somente a última foi altamente previsível. A cultivar BRS Guariba e as linhagens EVX-92-49E e TE97-321G-4 expressam melhor potencial genético em ambientes de alta produtividade.The objective of this work was to evaluate the adaptability and the stability of the grain yield of 20 semierect cowpea genotypes, using the additive main effect and multiplicative interaction model. The trials were carried out in 16 environments of the Northeast Region of Brazil. The genotypes, environments and genotype x environment interaction, as well as the first three axes of the principal components analysis (PCA) were significant. The first two axes of the PCA explained 55.11% of the sum of squares of the genotype x environment interaction, corresponding to 83.20% of the pattern of genotype x environment interaction. TE97-321G-4, EVX-92-49E and EVX-63-10E lines were highly adaptable, but only the last one was highly predictable. BRS Guariba cultivar as well as EVX-92-49E and TE97-321G-4 lines best express their genetic potential in environments of high yield.

ABSTRACT: Seed size and its physiology are a barrier for the exchange of coconut genetics resources and the tissue culture techniques can assist the germplasm bank enrichment. The aim of this study was to evaluate the effect of transport and storage procedures of zygotic embryos to promote the exchange of coconut accessions. Mature zygotic embryo from Cameroon red dwarf (CRD), Malayan yellow dwarf (MYD) and Malayan red dwarf (MRD) were used. The following treatments were evaluated: T1-storage of endosperm disc in plastic bags at 10±2°C for 5 days; T2 - 8 days; T3 - 12 days; T4 - embryo excised and inoculated in micro tube with Y3 culture medium with no sucrose for 2 days and T5 - five embryos inoculated in Y3 culture medium without sucrose in Petri dish for 2 days. T5 treatment resulted in low bacterial contamination.

Avaliaram-se dezessete clones de capim-elefante (Pennisetum purpureum Schum.) num delineamento em blocos ao acaso, no esquema de parcelas subdivididas, com 4 repetições, de fevereiro de 1995 a dezembro de 1997, totalizando 12 cortes (medidas repetidas no tempo), no município de Campos dos Goytacazes, RJ. Objetivou-se obter estimativas de parâmetros genéticos e de coeficientes de repetibilidade das variáveis produção de matéria seca (PMS), altura média das plantas (ALT), diâmetro médio do colmo (DC) e número de perfilhos por metro linear (NP). Os valores de coeficiente de determinação genotípica (H2) variaram amplamente, desde 33,49% para PMS até 84,34% para ALT. Devem ser realizadas, pelo menos, nove, cinco, três e duas medições considerando as características PMS, ALT, DC e NP, respectivamente, para predizer o valor real dos genótipos, com base no coeficiente de determinação preestabelecido de 80%