Jean Pierre Henri Joseph Ducroquet

Efeito de anos e determinação do coeficiente de repetibilidade de características de frutos de goiabeira-serrana

The environmental variance is quite significant in production and fruits traits, most of quantitative inheritance nature. This study evaluated the effect of years and the determination of the minimum number of necessary years for evaluation one needs for fruit weight, peel weight, length, diameter, relationship length/diameter, pulp revenue and soluble solids contents of fruits of feijoa (Acca sellowiana). Except for soluble solids contents, the effect of years represented great part of the total variance. Based on the repeatability coefficient, it was determined that it would be necessary at least four to six years of evaluation for selection of plants, with accuracy ofxa080%.

Qualidade de goiaba-serrana em resposta à temperatura de armazenamento e ao tratamento com 1-metilciclopropeno

The objectives of this work were to characterize the postharvest physiology and to evaluate the effects of temperature and treatment with 1-methylcyclopropene (1-MCP) on the postharvest quality of fruits of feijoa (Acca selowiana) accessions from the germplasm bank of Empresa de Pesquisa Agropecuaria e Extensao Rural de Santa Catarina. Fruits were harvested at commercial maturity. The genotypes Brasil (accession no. 387) and Uruguai (accession no. 454) were evaluated for respiration and ethylene production at 20oC, and respiration rates and skin color alterations at 0, 5, 10, 20, 30oC. The genotype Brasil (accession no. 242) was evaluated for ripening at 4oC, after treatment with 1-MCP (0, 500 and 1,500 ppb). Brasil (accession no. 387) and Uruguai (accession no. 454) exhibited a climacteric pattern, with a peak of ethylene evolution and respiration rate at the 8 and 12 days of storage at 20C, respectively. There was no signifi cant difference for respiration rates and ethylene evolution between these genotypes at this temperature. There was a substantial increase of respiration rate in both genotypes with the increase in temperature from 0 to 30oC, with a metabolic coeffi cient of approximately 3.5. With the increase in temperature, fruits of the genotype Brasil showed the greatest change of skin green color, while fruits of the genotype Uruguai exhibited the greatest darkening of skin. Feijoa fruits of genotype Brasil (accession no. 242) had delayed ripening when treated with 1-MCP and stored at 4C.The objectives of this work were to characterize the postharvest physiology and to evaluate the effects of temperature and treatment with 1-methylcyclopropene (1-MCP) on the postharvest quality of fruits of feijoa (Acca selowiana) accessions from the germplasm bank of Empresa de Pesquisa Agropecuaria e Extensao Rural de Santa Catarina. Fruits were harvested at commercial maturity. The genotypes Brasil (accession no. 387) and Uruguai (accession no. 454) were evaluated for respiration and ethylene production at 20oC, and respiration rates and skin color alterations at 0, 5, 10, 20, 30oC. The genotype Brasil (accession no. 242) was evaluated for ripening at 4oC, after treatment with 1-MCP (0, 500 and 1,500 ppb). Brasil (accession no. 387) and Uruguai (accession no. 454) exhibited a climacteric pattern, with a peak of ethylene evolution and respiration rate at the 8th and 12th days of storage at 20oC, respectively. There was no significant difference for respiration rates and ethylene evolution between these genotypes at this temperature. There was a substantial increase of respiration rate in both genotypes with the increase in temperature from 0 to 30oC, with a metabolic coefficient of approximately 3.5. With the increase in temperature, fruits of the genotype Brasil showed the greatest change of skin green color, while fruits of the genotype Uruguai exhibited the greatest darkening of skin. Feijoa fruits of genotype Brasil (accession no. 242) had delayed ripening when treated with 1-MCP and stored at 4oC.

Transference of microsatellite markers from Eucalyptus spp to Acca sellowiana and the successful use of this technique in genetic characterization

Abstract The pineapple guava (Acca sellowiana), known in portuguese as the goiabeira-serrana or “Feijoa”, is a native fruittree from southern Brazil and northern Uruguay that has commercial potential due to the quality and unique flavor ofitsfruits.Knowledgeofgeneticvariabilityisanimportanttoolinvariousstepsofabreedingprogram,whichcanbefa-cilitated by the use of molecular markers. The conservation of repeated sequences among related species permitsthe transferability of microsatellite markers from Eucalyptusspp.to A. sellowianafor testing. We used primers devel-oped for Eucalyptusto characterize A. sellowianaaccessions. Out of 404 primers tested, 180 amplified visible prod-ucts and 38 were polymorphic. A total of 48 alleles were detected with ten Eucalyptusprimer pairs against DNA from119 A. sellowianaaccessions. The mean expected heterozygosity among accessions was 0.64 and the mean ob-served heterozygosity 0.55. A high level of genetic diversity was also observed in the dendrogram, where the degreeofgeneticdissimilarityrangedfrom0to65%amongthe119genotypestested.Thisstudydemonstratesthepossibil-ity of transferring microsatellite markers between species of different genera in addition to evaluating the extent ofgenetic variability among plant accessions.

Late-acting self-incompatibility in Acca sellowiana (Myrtaceae) 1

Acca sellowiana (Berg) Burret is a predominantly allogamous species with hermaphrodite flowers that has barriers to self-fertilisation such as dichogamy by protogyny and self-incompatibility. This study aimed to identify when self-incompatibility occurs in A. sellowiana flowers submitted to self-pollinations. Pollinations were made using nine known self-incompatible accessions in several treatments including manual cross-pollination, manual self-pollination, no pollination and natural pollination. Flowers were pollinated and pistils collected at times ranging from 1 to 30 days after pollination (DAP). In both cross- and self-pollinations the fertilisation occurred from 18 DAP and the zygote was visualised at 24 and 26 DAP, respectively. The abscission of the self-pollinated flowers increased from 26 DAP onwards, when significant differences (Pu2009<u20090.05) were found for the percentage of abscission among self-pollinated and cross-pollinated flowers. At 30 DAP, 72% of self-pollinated flowers were abscised. The size of ovules and ovaries of self-pollinated flowers showed no significant difference from those of non-pollinated flowers throughout 30 DAP, while those from cross-pollinated flowers were significantly larger (Pu2009<u20090.05) than the other treatments from 22 and 24 DAP, respectively. After 40 DAP, there was no fruit development in self-pollination and non-pollination treatments. Our study brings greater clarity to the mechanism of self-incompatibility in A. sellowiana, indicating late-acting self-incompatibility occurring through the rejection/abscission of self-pollinated flowers precisely after syngamy and zygote formation.

Estudo anatômico do crescimento do fruto em Acca sellowiana Berg.

Acca sellowiana Berg. (Myrtaceae) is a fruit-bearing treelet or shrub native from the highlands of South Brazil. The plant is currently in the domestication process. Its fruit is sweet-acidified and can be consumed raw or be used for the preparation of juice and jam. Thus, information on the development, morphology and anatomy of the fruit is of great interest, and was featured as the objective of this study. The average fruit dimensions (ovary surrounded by the hypanthium) in the bloom stage were 0.6 cm in length and 0.4 cm in diameter, being ten times smaller than the ripe fruit. Longitudinally, three distinct regions were observed: a locular-, a sublocular- and a prolongation region. In a transverse cross-section in the middle of the fruit, three regions were delimited: 1) epidermis (peel) with simple unicellular trichomes. 2) parenchymatous region (flesh) rich in stone cells, isolated or aggregated in small groups of 2-3 cells; with eight radially distributed concentric periphloematic vascular bundles; and with many spherical glands near the epidermis. 3) inner region (pulp) with small cubic cells, organized in 3-4 layers around the locules, various containing druses. The four locules are separated by septa. The numerous ovules originate from axillary placentas, with two rows per locule. No nectaries were observed. As the fruit develops, groups of thin-walled cells appear in the intermediate region. These cells become very large and transform into stone cells. The placentas grow and occupy the whole space within the growing locules, as these locules grow bigger and seeds develop. Thus, the ripee fruit has a peripheral region of firm consistence and astringent taste, and a soft sweet core.

Evidência da atuação do sistema de auto-incompatibilidade tardia em Acca Sellowiana (berg) burret. (Myrtaceae)

Acca sellowiana (Myrtaceae) e uma frutifera nativa da regiao Sul do Brasil e nordeste do Uruguai, que vem despertando grande interesse devido ao alto potencial organoleptico de seus frutos. Neste trabalho, teve-se como objetivo a caracterizacao do tipo de sistema de incompatibilidade atuante em A. sellowiana, atraves da avaliacao do desenvolvimento dos tubos polinicos. Utilizaram-se dois acessos: 458, sendo autocompativel, e 101, auto-incompativel. A maior porcentagem de germinacao de graos de polen foi observada no acesso 101, com 68,8% de graos de polen germinados. Nao foram observadas diferencas no crescimento dos tubos polinicos em pistilos autopolinizados ou de polinizacao cruzada, em ambos os acessos. O crescimento completo do tubo polinico ate o ovario ocorreu em pistilos coletados 96 horas apos a polinizacao, independentemente do tratamento aplicado. Sugere-se a ocorrencia de auto-esterilidade ou auto-incompatibilidade tardia ou pos-zigotica, considerando que o abortamento dos frutos de A. sellowiana e uniforme e ocorre num prazo curto, por volta de 20 a 30 dias apos a fertilizacao das flores.