Dimas Menezes

Role of the Lizard Teira dugesii as a Potential Host for Ixodes ricinus Tick-Borne Pathogens

ABSTRACT PCR screening of ticks and tissue samples collected from 151 Teira dugesii lizards seems to indicate a potential role of this lizard species in the maintenance and transmission cycle of some Ixodes ricinus tick-borne agents, such as Rickettsia monacensis, Rickettsia helvetica, and Borrelia lusitaniae, that are circulating on Madeira Island.

Características vegetativas do coentro submetido a doses do polímero hidroabsorvente e lâminas de irrigação

This study had the objective of evaluating the effect of five doses of the hidratassolo® hydrogel polymer 0, 4, 8, 12 and 16 dg kg-1 of dry soil, and two irrigation water depths, 60 and 120% of the reference evapotranspiration, on the vegetative characteristics of coriander. A completely randomized experimental design was adopted in split-plots, with four replications. At two stages of coriander growth the water use efficiency, the yield of green and dry matter, and the number of plants increased linearly with the elevation of dose of the polymer, when the smallest water depth was applied, except in the prediction of the height of plants at the first stage of planting according to quadratic model. With application of higher water depth (120%), the estimates of the appraised characteristics with significant interaction were maximized with ideal doses in the range of 6 to 11 dg kg-1 , and also the employment of the maximum dose of 16 dg kg-1 provided a fall in relation to the control.

Genetic variability for agronomic characteristics in lettuce progenies with heat tolerance

Lettuce progenies with tolerance to early bolting were evaluated in relation to commercially desirable agronomic characters, as well as to estimate important genetic components for crop breeding. The experimental design was random blocks with three replications and 18 treatments (13 progenies F7, the genitors Verdinha, Regina, and Tinto, and cultivars Luisa and Baba de Verao). The genetic, phenotypic, and environmental variances, the heritability, and the correlation among the characters number of leaves, plant and leaves fresh weight, plant diameter, stem length, and bolting, were estimated. The F test was significant (p<0,01) for all the studied characteristics. In the clustering of means by the Scott-Knott test, at 5% probability, treatments were assembled in two groups, except for plant diameter, in which cultivar Tinto remained isolated in a third group. The genetic variance was higher than the environmental variance for all evaluated characteristics, and the heritability, below 90%, revealed the environmental influence over some characters. When bolting was correlated to the other characteristics, results were positive and significant for most combinations, considering the genetic correlations. Under these experimental conditions, progeny 76 stood out for its low stem length and reduced bolting index, although its commercial performance was inferior to the control cultivars, genitors, and some other progenies.

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.

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.

Caracterização morfológica de genótipos de coentro

Few coriander cultivars (Coriandrum sativum L.) are available to producers and, in some regions, are grown genotypes of unknown origin, kept by the growers themselves. To conserve such traditional crops it is necessary to collect, save, and characterize them. Thus, this study was to determine morphological characters to differentiate coriander genotypes aiming the registration of cultivars. Two trials were carried out, and the experimental design used in both was in completely randomized blocks with five replications. Americano, Asteca, Palmeira, Portugues, Santo, Superia, Tabocas, Tapacura, and Verdao cultivars, and the line HTV-9299 were characterized for seedling, leaflets, leaves, fruits, and flowers. The data were subjected to a univariate ANOVA. The fruits of cv. Palmeira exhibited greater size and mass. As regards the presence of anthocyanins in seedlings and plants, cv. Americano showed the lowest intensity or slight pigmentation while cv. Tabocas had the highest pigmentation. The cultivars Americano, Palmeira, Asteca, Verdao, and Tabocas and the line HTV-9299 displayed higher number of basal leaves, however, the genotypes that produced larger amount of mass per plant were Tabocas, Palmeira, Verdao, HTV-9299, and Tapacura. The green tone of leaflets showed differences among cultivars. So, cv. Americanos leaflets exhibited a light green, slightly yellowish color, HTV-9299 green, and Tabocas dark green. The morphological traits with higher discriminatory power for the group of the ten evaluated cultivars were: size and weight of fruits; presence or absence of anthocyanin in seedlings and plants; number of basal leaves; length of the fifth leaf; size and color of leaflets; number of days to bolting initiation, and opening of the first flower, and plant fresh mass.

Variabilidade genética em progênies de meios-irmãos de coentro

A large number of producers are involved in the cultivation of coriander throughout the year in Brazil, making it a crop of social and economic importance. Throughout nearly the entire Northeast Region, cultivar Verdao is used. Genetic variability studies on coriander are important for the proper planning of genetic improvement programs. The aim of the present study was to quantify the genetic variability for agronomic characteristics in cv. Verdao to contribute information toward genetic improvement. The study was developed at Universidade Federal Rural de Pernambuco, Pernambuco State, Brazil, in a greenhouse, using randomized blocks of 28 plants in two pots and five replications. The treatments were composed of 55 half-sib progenies from cultivar Verdao. The t test detected significance at 1 and 5% likelihood between the genotypic, phenotypic and environmental correlations. Broad sense heritability ranged from 7.19 for average plant weight to 81.09 for number of bolted plants. The ratio between genetic and environmental coefficients of variation (CVg/CVe) ranged from 0.27 (average weight) to 2.07 (number of bolted plants), indicating that selection against bolting presents more favorable conditions in terms of immediate genetic gains. The genotype correlation between height of non-bolted plants and the number of bolted plants was considered strong (0.86) and highly significant (t test), enabling simultaneous gains from selection.

Biologia de Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae) em pimentão

The biology of Polyphagotarsonemuslatus (Banks) was studied in sweet pepper, Capsicum annuum at 20, 25, and 30 oC. An inverse relationship between P. latus developmental period and temperature was observed for all stages of the white mite life cycle. Duration of eggs-adults period was the greatest at 20 oC (5.7 d for males and 6.2 d for females). Oviposition was lower at 20 oC. The most suitable temperature for fertility was 25 °C (27.9 eggs). The parameters obtained from fertility life table were progressively higher with the increase in temperature, but the opposite ocurred with the mean duration of a generation.

Desempenho de cultivares de alface em cultivo hidropônico sob dois níveis de condutividade elétrica

. Os tratamentos foram as cultivares de alface Baba de Verao, Floresta, Luisa, Manoa, Regina 579, Saia Veia e Vitoria Verdinha. O delineamento experimental foi blocos casualizados, com tres repeticoes. A colheita foi feita aos 45 dias apos a semeadura. Nenhuma cultivar se destacou no conjunto das caracteristicas avaliadas, embora a Manoa tenha apresentado o maior indice de queima de bordas das folhas, sem diferir estatisticamente da Saia Veia e Baba de Verao. As cultivares Regina 579 e Vitoria Verdinha sao as preferidas dos produtores hidroponico de Pernambuco, devido a falta de genotipos mais adaptados a essa modalidade de cultivo, e por apresentarem folhas lisas, levemente enrugadas e de textura macia.

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).