S. R. R. Ramos

Adaptabilidade e estabilidade produtiva de genótipos de feijão-caupi de porte semi-ereto na Região Nordeste do Brasil

O objetivo deste trabalho foi avaliar a adaptabilidade e a estabilidade da produtividade de graos de 20 genotipos de feijao-caupi de porte semi-ereto, utilizando o modelo de efeitos aditivos principais e interacao multiplicativa. Os ensaios foram conduzidos em 16 ambientes da Regiao Nordeste do Brasil. Os efeitos de genotipos, ambientes e da interacao genotipo x ambiente, e os tres primeiros eixos da analise de componentes principais (ACP) foram significativos. Os dois primeiros eixos da ACP explicaram juntos 55,11% da soma de quadrados da interacao, correspondendo a 83,20% do padrao da interacao genotipo x ambiente. As linhagens TE-97-321G-4, EVX-92-49E e EVX-63-10E apresentaram alta adaptabilidade, mas somente a ultima foi altamente previsivel. A cultivar BRS Guariba e as linhagens EVX-92-49E e TE97-321G-4 expressam melhor potencial genetico em ambientes de alta produtividade.

Estimativas de parâmetros genéticos em genótipos de feijão-caupi avaliados para 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.

Genetic Relationships among Tall Coconut Palm ( Cocos nucifera L.) Accessions of the International Coconut Genebank for Latin America and the Caribbean (ICG-LAC), Evaluated Using Microsatellite Markers (SSRs)

The diversity and genetic relationships among two accessions of tall coconut palms collected in Brazil and seven accessions introduced from different geographic regions of the world were analyzed using 25 microsatellite primers, 19 of which were polymorphic and detected between 4 and 10 alleles per locus, with an average of 6.57. The observed and expected heterozygosity ranged from 0.25 and 0.40 in the Rennell Islands Tall (RIT) accession to 0.54 and 0.62 in the Polynesian Tall (PYT) accession. The analysis of genetic structure resulted in the formation of five distinct groups. The first group was formed by the accessions Brazilian Tall—Praia do Forte (BRTPF), Brazilian Tall—Merepe (BRTMe) and West African Tall (WAT); the second group consisted of Malaysian Tall (MLT); the third group of RIT; the fourth group of Vanuatu Tall (VTT); and the fifth group of Rotuman Tall (RTMT), Tonga Tall (TONT) and PYT. The dendrogram based on the nearest-neighbor method detected the formation of two main groups and five subgroups, indicating that the genetic relationships of the accessions are based on their geographic regions of origin. The analyses revealed genetic relationships between the accessions collected in Brazil and the accession from Africa, and among palms from South East Asia and the South Pacific, confirming the common origin of these accessions. The information obtained in this study can guide decisions on germplasm conservation activities and the efficient selection of genetically divergent parents for use in coconut breeding programs in Brazil, which are attempting to select for disease resistance, mainly to lethal yellowing, among other characteristics.

Manitol para a conservação ex situ de coqueiro por crescimento mínimo

The objective of this work was to determine the mannitol concentration for in vitro germination and minimum growth of coconut (Cocos nucifera). The following accessions were used: Brazilian Red Dwarf Gramame (BRDG), Malaysian Yellow Dwarf (MYD), Brazilian Tall (BRA), Polynesian Tall (PYT), and Rennell Island Tall (RIT). Embryos were inoculated in an Y3 culture medium at different mannitol concentrations (0, 0.1, 0.2, 0.3, and 0.4 mol L-1). Inhibition of shoot development was verified at 0.1, 0.2, and 0.3 mol L-1, for MYD and BRDG, and at 0.1 and 0.2 mol L-1, for PYT, BRA, and RIT. Mannitol use is a promising strategy for minimum growth conservation.

DIVERSIDADE GENÉTICA ENTRE ACESSOS DE COQUEIRO-GIGANTE

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.

ALTERAÇÕES EM ABÓBORA APÓS COCÇÃO

A abobora (Cucurbita moschata Duch) e uma olericola de grande aceitacao em todo o Brasil, especialmente na regiao Nordeste. E bastante utilizada na alimentacao diaria do nordestino, onde e conhecida por Jerimum, para elaboracao de diversos pratos e doces, que podem ser caseiros ou industrializados. Durante o processo de coccao, ha perda de nutrientes e alteracao na qualidade do alimento a ser consumido. O trabalho foi desenvolvido com o objetivo de avaliar as alteracoes ocorridas em aboboras crioulas apos a coccao. Os 115 frutos avaliados foram oriundos do programa de melhoramento de abobora da Embrapa Tabuleiros Costeiros (CPATC), colhidos em outubro de 2013, no Campo Experimental Pedro Arle, localizado no municipio de Frei Paulo, Sergipe. As analises foram realizadas na Sala de Pos-colheita do CPATC, em Aracaju. Os pedacos, pesando cerca de 200g foram fervidos em 1L de agua, onde permaneceram por cinco minutos. Antes e apos a coccao, todas as amostras foram avaliadas quanto ao peso da massa fresca, firmeza e teor de solidos soluveis (SS). Foi realizado o teste de Tukey para comparacao de medias, ao nivel de 5% de significância, utilizando-se o programa estatistico SAS. Nao ocorreu perda de massa fresca significativa, que variou de 142,28g (antes) a 138,27 g (apos a coccao). Entretanto, o teor de SS diminuiu significativamente de 11,68 para 11,08oBrix, e a firmeza, de 12,75 a 5,69N. As caracteristicas avaliadas neste trabalho, associadas a outras de importância nutricional e comercial, sao importantes informacoes ao programa de melhoramento da especie.