Margarida Agostinho Lemos

Qualidade fisiológica de sementes de araçazeiro durante o armazenamento

O presente trabalho teve como objetivo avaliar diferentes ambientes de armazenamento e embalagens quanto a eficiencia na manutencao da qualidade das sementes de aracazeiro (Psidium guineenseSwartz) durante 180 dias. As sementes foram provenientes de frutos recem-colhidos completamente maduros e de oito acessos do banco ativo de germoplasma do aracazeiro localizado na Estacao Experimental de Itapirema, da Empresa Pernambucana de Pesquisa Agropecuaria - IPA, Goiana, PE, assim denominados: IPA 4, IPA 6, IPA 7, IPA 9, IPA 10, IPA 11, IPA 15 e IPA 16. O experimento foi representado pelas combinacoes dos fatores: sementes de oito acessos do aracazeiro, acondicionadas nas embalagens saco de papel Kraft e vidro, armazenadas nos ambientes normal de laboratorio e no freezer, em Recife, PE, durante 180 dias. A qualidade fisiologica das sementes foi avaliada no inicio e a cada 60 dias de armazenamento, atraves de germinacao e vigor (primeira contagem e indice de velocidade de germinacao) determinando-se tambem o teor de agua das sementes. Os resultados permitiram concluir-se que as sementes dos acessos do aracazeiro tiveram sua qualidade fisiologica reduzida, com perdas significativas na germinacao e vigor, no decorrer do armazenamento. A embalagem de vidro proporcionou maior eficiencia na conservacao da qualidade fisiologica das sementes, sob condicao de alta umidade relativa no interior do freezer, condicao esta que provocou maior deterioracao das sementes acondicionadas em embalagens de papel Kraft. Dentre os ambientes de armazenamento estudados, o mais adequado para conservacao das sementes de aracazeiro foi o ambiente normal de laboratorio, para ambas as embalagens testadas. Os acessos IPA 4 e IPA 6 apresentaram os maiores indices de germinacao e vigor.

Resistência de cultivares e híbridos de cebola a tripes

Resistance to Thrips tabaci was estimated for onion cultivars ValeOuro IPA-11, Roxa IPA-3, Belem IPA-9, Texas Grano-502, Brownsville and Duquesa, and for the hybrids Dessex and Granex Ouro. The experiment was carried out under field conditions in Juazeiro, Bahia State, Brazil, without the use of chemical control. Leaf characters were evaluated at 26; 48 and 69 days after transplanting date (DAT), and yield characters were evaluated at 93 DAT. The experiment design was total randomized blocks with three replications. The cv. Duquesa showed the lowest number of immature forms of T. tabaci, which was associated with the lowest number of leaves and the largest degree of insertion between the central leaves, suggesting a nonpreference type of resistance. The cv. Duquesa and hybrids Granex Ouro and Dessex were mode\rately resistant to the thrips based on yield characters and on the number of immature forms of the insect.

Características físico-químicas de acerola do banco ativo de germoplasma em Pernambuco

Physicochemical characteristics of mature acerola fruits from 12 genotypes cultivated at Active Germoplasm Bank of Universidade Federal Rural de Pernambuco (UFRPE), harvested at winter/1999, summer/2000 and summer/2001, were analyzed. The joint analysis of these fruits showed the following average variation: ascorbic acid 1067 to 1846mg/100g of fruit pulp; total anthocyanins 3.8 to 47.4mg/100g of fruit pulp; total flavonols 7.0 to 18.5 quercetin mg/100g of fruit pulp; titratable acidity (TA) 1.04 to 1.87g of malic acid/100g of fruit pulp; total soluble solids (TSS) 7.0 to 8.4oBrix; TSS/TA ratio 4.4 to 6.9 and pH 3.11 to 3.41. Considering the characteristics analyzed, all genotypes, except 015-CPA, which showed ascorbic acid level lower than the transformation industry standard, are potentially promising.

Correlações entre caracteres agronômicos associados à resistência a tripes em cebola

Genotypic, phenotypic and environmental correlation between agronomic characteristics and Thrips tabaci resistance were determined in 62 half-sibs progenies of onion ValeOuro IPA-11 cultivar. The experiment was conducted under field conditions in Juazeiro, Bahia State, Brazil, with evaluations at 48; 69 and 93 days after transplant (DAT). Commercial bulb yield (PBC) presented genotypic correlation with leaf length (CF) (0,63**); leaf number (NTF) (0,74**); damaged leaf number (NFD) (0,74**); commercial bulb average weight (PMBC) (0,54**); commercial bulb yield (%BC) (0,61**); and non-commercial bulb yield (%BNC) (-0,63**). Genotypic correlations were observed in the number of ninfas of T. tabaci between two fully developed central leaves (NINFA), at 69 DAT and central leaf angle (ANG) (-0,76**); NTF (0,46**); %BC (-0,35**); and yield of unproductive plants (%I) (0,39**). These correlations indicate that lower NINFA numbers occur in plants with lower NTF and higher ANG. Lower NTF plants, on the other hand, have higher ANG (-0,92**). Never thelessNTF correlated positively with PBC, PMBC (0,45**) and %BC (0,43**). Positive genotypic correlations between NFD and PBC, PMBC (0,40**) and %BC (0,51**), imply that this population presents resistance through tolerance.

Physical and production characteristics of acerola fruit from active germplasm bank in Pernambuco

The objective of this research was to evaluate the physical and production characteristics of fruits from twelve acerola genotypes cultivated at the Active Germplasm Bank in Federal Rural University of Pernambuco. The average weight and size of fruits from the Winter/1999, Summer/2000 and Summer/2001 seasons as well as plant yield and average number of fruits/genotype were assessed. Results from the joint analysis of all harvests presented average variation on fruit weight of 3.88 to 7.11g; fruit height of 1.74 to 2.07cm and fruit diameter of 1.94 to 2.46cm. The annual production variation of 12 genotypes during 1999 was of 3.23 to 10.31 Kg of fruit/plant; meanwhile during 2000 this variation was of 6.73 to.44.70 Kg of fruit/plant. In 1999 and 2000, approximately, 50% of the annual production occurred in October, November and December. The genotypes 012-CPA, 013-CPA and 014-CPA are potentially promising because they were considered the most productive and showed the physical characteristics (weight and diameter) demanded by transformation industry.

Avaliação de dez linhagens e seus híbridos de milho superdoce em um dialelo completo

In 1996/97, 45 single cross supersweet maize hybrids, from a complete diallel cross involving ten inbred lines (S4) and their parents, were evaluated at Pesqueira and Vitoria de Santo Antao, Brazil. A latice 7 x 8 design was used with two replications for each location. The general (GCA) and specific (SCA) combining ability effects and heterosis value were estimated for husked ear weight (HEW), unhusked ear weight (UEW) and ear rate (ER = UEW/HEW x 100). The general and specific combining ability effects were significant (P<0.01) for all characteristics. Inbreds L5 = 76.5%; L7 = 71.2% and L4 = 69.6% (Pesqueira); L4 = 70.8%; L5 = 69.4% and L7 = 65.3% (Vitoria de Santo Antao) showed the highest (ER), and the highest GCA effects at both locations. The best crosses for ER were: L4 x L8 = 74.9% (Pesqueira) and L7 x L8 = 70.3% (Vitoria de Santo Antao), with the highest SCA effects at both locations. For ER, heterosis values related to parental mean ranged from -20.19 to 24.01% (Pesqueira) and -18.02 to 16.76% (Vitoria de Santo Antao). Heterosis values related to the higher yielding parent ranged from -23.52 to 22.99% (Pesqueira) and -22.05 to 12.03% (Vitoria de Santo Antao).

Caracteres de produção da cebola associados à resistência a tripes

The variability of yield characters associated to Thrips tabaci (Thysanoptera: Thripidae) resistance was estimated in 62 half-sib progenies of onion cv. ValeOuro IPA-11. The controls were the cvs. ValeOuro IPA-11 and the parentals Roxa IPA-3 and Belem IPA-9. The experiment was conducted in field conditions, in Juazeiro, Bahia State, Brazil, following a complete randomized block design, with three replications. The estimates of the parameters from the population of ValeOuro IPA-11 demonstrated high enviromental influence for all characters. The highest estimates of herdability and expected gain with 20% of selection pressure were, respectively, 35.74% and 10.39% for the production of commercial bulbs (PBC), 31.33% and -24.48% for percentage of unproductive plants (%I), 33.92% and -16.80% for production of non commercial bulbs (PBNC) and 30.31% and 13.18% for percentage of non commercial bulbs (%BNC). These characters seem to indicate better possibility of genetic progress with the selection. The characters mean infestation of immature T. tabaci on the two completely developed inner leaves (NINFA) present herdability of 18.24 and 21.34% and expected gain with 20% of selection pressure of 18.24 and -11.22% at 48 and 69 days after transplanting (DAT), respectively, indicating superior gains in selections at 69 DAT. Although NINFA were 31.96 insects, 45.16% of ValeOuro IPA-11 progenies demonstrated PBC values above the average, suggesting that tolerance may be the resistance mechanism.

Emergência em campo de híbridos simples de milho superdoce de um cruzamento dialélico

To identify single crosses hybrids of supersweet maize of high seed germination in 1996/97, 45 single crosses and 10 inbred lines were evaluated (S4), from a complete diallel cross, at Pesqueira and Vitoria de Santo Antao, Brazil. A lattice 7 x 8 design was used with two replications, per each location. The general (GCA) and specific (SCA) combining ability effects were estimated for the trait stand. In the combined analysis of variance, lines, hybrids and both GCA and SCA effects were significant (P<0.01). The interactions of GCA and SCA (P<0.01) were significant with the locations. For the individual analysis, the mean squares estimates for lines, hybrids, GCA and SCA were also significant (P<0.01). The relative magnitude of GCA and SCA mean squares indicated predominance of additive gene effects. The average mean seed germination were of 40.4% and 56.5% at Pesqueira and Vitoria de Santo Antao, respectively. The hybrids L3 x L6 and L3 x L7 at Pesqueira and L1 x L10 and L3 x L5 at Vitoria de Santo Antao, were the most favorable single crosses of high quality seed having good field emergence potential.