Alexandre Pio Viana

Diversidade genética entre genótipos comerciais de maracujazeiro-amarelo (Passiflora edulis f. flavicarpa) e entre espécies de passifloras nativas determinada por marcadores rapd

The genetic variability among yellow passion fruit genotypes was evaluated using RAPD as genetic markers of DNA. For that, genetic materials were collected in commercial populations from traditional production fields of the North Fluminense (Itaperuna, Sao Francisco do Itabapoana, Campos of Goytacazes, RJ-Brazil). The diversity among the cultivated species Passiflora edulis f. flavicarpa Deg. and species related P. alata, P. giberti, P. cincinnata, P. foetida, P. edulis. P. maliformis, P. mucronata, P. suberosa, P. malacophylla, was also estimated. For the study on yellow passion fruit, expressive genetic diversity was not verified; the populations were distributed according to its origin, and the individuals collected in Sao Francisco do Itabapoana presented major consistency in its grouping, once the formation of the groups a larger number of those individuals were allocated among the same group. For the interspecific study, it was verified that P. maliformis was in a different, but close group to P. mucronata. P. alata was allocated in an isolated group as well as P. giberti. For P. cincinnata and P. edulis (purple passion fruit), both were allocated in the same group, evidencing proximity between the same ones while P. foetida and P. suberosa formed a single group.

Seleção recorrente intrapopulacional no maracujazeiro amarelo: alternativa de capitalização de ganhos genéticos

Objetivou-se, neste trabalho, estimar parâmetros geneticos e correlacoes associadas a caracteristicas agronomicas do maracujazeiro amarelo (Passiflora edulis Sims), predizer o progresso genetico esperado com a selecao direta e baseado em indice de selecao, bem como sugerir uma estrategia de capitalizacao de ganhos geneticos nos ciclos de selecao recorrente. Foram avaliadas 26 progenies de meio-irmaos provenientes da recombinacao de genotipos selecionados do primeiro ciclo de selecao via Delineamento I, as quais representam a populacao melhorada, UENF/MA1. O delineamento estatistico utilizado foi blocos casualizados com duas repeticoes e parcelas constituidas de cinco plantas. Foram avaliadas cinco caracteristicas relacionadas ao fruto, no periodo de fevereiro a julho de 2007, utilizando dados de media de parcelas. As estimativas dos parâmetros geneticos e das correlacoes, bem como a selecao baseada no indice de selecao possibilitaram a identificacao de progenies com desempenhos agronomicos superiores para varios caracteres, simultaneamente. Alem disso, a presente estrategia pode constituir alternativa de capitalizacao de ganhos geneticos na selecao recorrente, aumentando a eficiencia do processo seletivo e potencializando a sua utilizacao em programas de melhoramento de fruteiras, uma vez que permite ganho genetico em duas (geracao e teste de progenies) das tres etapas de selecao recorrente.

Influência dos estádios de maturação na qualidade do suco do maracujá-amarelo

This work evaluated the influence of the ripening stages on the chemical characteristics of the yellow passion fruit juice (Passiflora edulis f. flavicarpa Degener.), during the period that precedes the peel color change until the period of fruits abscission, when they show the peel totally yellowish. During the ripening of the fruits was observed a progressive increase in the Hunter L and b parameter, in a way that the lower area of the fruit presented higher brightness and yellowing indexes than the upper area. The content of SST showed a progressive increase from an immature condition of the fruits (52 DAA) until a ripening stage with 65% of yellowish peel, in 76 DAA, staying constant after this period. The measures of total acidity and pH indicated a small accumulation of organic acids in the immature fruits (60 DAA) and, later, it occurred a partial consumption of these acids, as showed by the decreasing of titrable acidity and the increasing of pH during the ripening of the yellow passion fruit. The TSS/TA ratio also increased progressively in this period.

Meiotic irregularities and pollen viability in Passiflora edmundoi Sacco (Passifloraceae)

Abstract Meiotic and pollen viability studies were conducted in Passiflora edmundoi Sacco (n = x = 9). For meiotic studies anthers were squashed in a drop of 1% acetic carmine. For analysis of pollen viability, pollen grains of flowers at anthesis were stained with two stains, lugol and Alexander stain. At diakinesis frequency of bivalents was high (86% of pollen mother cell observed) and it was observed other pairing patterns (7 II + 1 IV; 5 II + 2 IV; and 18 I). The average number of chiasmata per cell was 9.3, in concordance with high frequency of bivalents. Meiotic phases showed the presence of spindle irregularities, asynchrony, and other abnormalities as laggard chromosomes and anaphase bridges. Different post‐meiotic products were observed and the frequency of triads was higher than monads, dyads, and polyads; however the meiotic index was 97.2% and the pollen viability was 97.9% suggesting meiotic stability. Sterile pollen was sorted in two categories: empty (60.3%) and shrunken (contracted cytoplasm) grains. The high meiotic index, pollen viability, frequency of chiasmata and bivalent pairing indicate that the species is meiotic stable and can be used in selection programs and intra and inter‐specific crosses beyond the meiotic irregularities observed.

Ganho genético avaliado com índices de seleção e com REML/Blup em milho-pipoca

The objective of this work was to compare four selection indices and the REML/Blup method in the evaluation of the predicted genetic gains for the characteristics of interest to the breeding program of the UENF 14 popcorn. Two hundred full-sib progenies were evaluated in one season, in two locations (North and Northwest Regions of the state of Rio de Janeiro, Brazil), with two replicates, totaling 800 observations. The characteristics evaluated were average plant height, average height of first ear insertion, final stand, tipping, stem diameter, prolificacy, grain yield and popping expansion. Among the selection indices tested, Mulamba & Mocks provided the best results for selection of full-sib progenies. The REML/Blup method proved to be very efficient, selecting progenies with high relative performance and better predicted genetic gains than those of the selection indices tested. The progenies selected using the REML/Blup method, for highest grain yield, are not the same as those selected for higher popping expansion. The Mulamba & Mock index and the REML/Blup method provide the best predicted gains for the UENF 14 population.

Produtividade e qualidade de frutos de cultivares de maracujazeiro‑amarelo com ou sem polinização artificial

The objective of this work was to evaluate the influence of artificial pollination on productivity and fruit quality of yellow passion fruit cultivars. Seven commercial cultivars of yellow passion fruit were evaluated in two experiments carried out in Tangara da Serra, MT, Brazil, in a randomized block design with five replicates and plots consisting of two rows of four plants. In the first experiment, pollination was natural, whereas in the second it was artificial, performed twice a week. Planting was done on January 11, 2010, and harvests occured from July 2010 to March 2011. Artificial pollination increase the productivity of all cultivars, but their response to the technique varied. When artificial pollination was used, the cultivars FB 100, FB 200 and BRS Ouro Vermelho had a higher productivity than IAC 275, IAC 277, BRS Sol do Cerrado e BRS Gigante Amarelo. Artificial pollination increases productivity, fruit mass, diameter and length of fruit, and pulp percentage, and it reduces peel thickness. Strong genotype by environment interaction may be occurring, as for the productivity of the evaluated cultivars.

Artificial neural network analysis of genetic diversity in Carica papaya L.

The study of genetic diversity is fundamental in the preliminary selection of accessions with superior characteristics and for a successful use of these genotypes in breeding programs. The purpose of this study was to evaluate, as a strategy for genetic diversity analysis, the bioinformatics approach called artificial neural network. Based on the average of three growing seasons, eight quantitative traits and thirty-seven papaya accessions were evaluated in a randomized complete block design, with two replications. By Andersons discriminant analysis, 91.90 % of the accessions were correctly classified in the groups previously defined by artificial neural network. It was concluded that the technique of artificial neural network is feasible to classify the accessions. The presence of significant genetic diversity among accessions was observed.

Diversidade genética em seleção recorrente de maracujazeiro-amarelo detectada por marcadores microssatélites

The objective of this work was to estimate the genetic variability in two recurrent selection cycles of the yellow passion flower (Passiflora edulis), and to evaluate the impact of selection on the progenies selected via changes in allele frequency, detected by microsatellite markers. Twenty-three microsatellites were used for genotyping 66 full-siblings. Allele frequency, expected (He) and observed (Ho) heterozygosity, polymorphic information content (PIC) and inbreeding coefficient (f) were estimated. Thirty-two alleles were found in these populations, of which only two were lost during selection. The average number of alleles per locus was 2.46 in the first cycle, and 2.30 in the second. The differences in allele frequencies in the two cycles were not significant. The mean He in the first cycle was 0.20 per locus, slightly higher than Ho (0.15). In the second selection cycle, the mean value of Ho was lower than of He, with an average of 0.12. The mean values of f increased in the second selection cycle, from 0.26 to 0.32. Most of the loci showed negative values of f, which suggests high levels of heterozygosity. The mean value of PIC decreased from 0.18 to 0.16 in the second cycle. There were small losses of variability and changes in allele frequencies; however, these variations can be considered normal when selection is practiced.

Qualidade do suco de maracujá-amarelo em diferentes épocas de colheita

Yellow passion fruit presents seasonal production and occurs in the winter and summer harvest seasons. The aim of this work was to evaluate the influence of two different harvest seasons on the quality of yellow passion fruit (Passiflora edulis f. flavicarpa Degener) juice, in seven maturation stages. The experiments were constituted of two harvest seasons (EP 1 and EP 2) and seven maturation stages, with 10 repetitions. The results were evaluated through the Tukey test at a 5% probability level. In EP 1, characterized by lower temperatures and lower total precipitation, the fruits presented higher Total Titratable Acidity (TTA), total soluble solids content (TSS), dry matter and TSS/TTA ratio, and lower pH, until the ripening stage of 65% yellow color of the peel, when compared with EP 2. After this stage no difference in TSS content between harvest seasons was found. However, the juice of totally mature fruits presented lower contents of dry matter and TSS/TTA ratio in the EP 1 season, as well as higher acidity. It was concluded that yellow passion fruit can be harvested with 65% yellow color of the peel in harvest season EP 1, due to the maintenance of chemical quality; however, in harvest season EP 2, the fruits showed an increase in the TSS/TTA ratio until the mature stage.

Influência do tipo de fruto, peso específico das sementes e período de armazenamento na qualidade fisiológica de sementes de mamão do grupo formosa

The present study evaluated the influence of the fruit type, specific seed weight and storage on the germination and vigor of papaya seeds of the Solo group. After harvest the fruits were classified as small, medium or large. The seeds were extracted manually, washed and placed to dry in the shade. After drying, the seeds were processed in a pneumatic machine to separate light materials and also through a gravity table machine, where the seeds were separated into three classes: light, intermediate and heavy. The seeds were placed in paper bags, stored in a cold chamber and evaluated for germination and vigor (First Count of GT, Seedling Size and Accelerated Aging test) at the start of the experiment and after 3 and 6 months of storage. The best germination and vigor results were found when heavy seeds were used. High seed quality was preserved until the third month of storage.