Germination and emergence of passion fruit obtidos por polinizacao aberta e autopolinizacao

• Published in: Acta scientiarum. Agronomy Vol. 37; no. 4; p. 489
• Main Authors: dos Santos, Carlos Eduardo Magalhaes, Morgado, Marcos Antonio Dell'Orto, Matias, Rosana Goncalves Pires, Wagner, Americo, Jr, Bruckner, Claudio Horst
• Format: Journal Article
• Language: Spanish
• Published: Universidade Estadual de Maringa 01-10-2015
• ISSN: 1679-9275
• DOI: 10.4025/actasciagron.v37i4.19616

Seed dormancy is an important adaptive mechanism in many species and is generally lost during plant domestication because of selection that occurs through the collection and planting of seeds. We compared germination and seedling emergence in selfed and open-pollinated progenies obtained from eight passion fruit vines (genotypes). Self-pollination was performed at the button stage to overcome self- incompatibility. The experiment was a randomized block design in a factorial scheme (2 x 8; type of progeny x genotypes) with four replicates and 50 seeds per experimental unit. At 14, 21 and 28 days after sowing, the germination percentage and the emergence speed index were analyzed. The total length of seedlings (cm), shoot length (cm), radicle length (cm) and total dry matter of seedlings (g) were evaluated 28 days after sowing. The mass of 100 seeds (g) was determined before sowing. Differences were noted between genotypes and progeny types with respect to germination and emergence speed. In general, seeds obtained by selfing exhibited earlier germination and a higher emergence speed. It was concluded that seed dormancy is associated with the genotype of the embryo and is most likely conditioned by a dominant genetic effect. Keywork: Passiflora edulis, dormancy, selection, dominance. A dormencia de sementes e um importante mecanismo de adaptacao das especies e, geralmente, perdida durante a domesticacao de plantas, devido a selecao atraves da coleta e plantio de sementes. Objetivou comparar a germinacao e emergencia de plantulas provenientes de sementes originadas de progenies autofecundadas e de polinizacao aberta de oito genotipos de maracujazeiro. As autopolinizacoes foram realizadas na fase de botao com intuito de superar a auto-incompatibilidade, e progenies de polinizacao aberta originadas do cruzamento natural com controle somente do genitor feminino. O experimento foi instalado no delineamento em blocos casualizados, em esquema fatorial 2 x 8 (tipo de progenies x genotipos), com quatro repeticoes e 50 sementes por unidade experimental. Aos 14, 21 e 28 dias da semeadura foram analisadas a porcentagem de germinacao e o indice de velocidade de emergencia. O comprimento total das plantulas (cm), comprimento da parte aerea (cm), comprimento da raiz (cm) e materia seca total de plantulas (g) foram avaliados aos 28 dias de semeadura. A massa de 100 sementes (g) foi avaliada antes da semeadura. Ha diferencas entre genotipo e tipo de progenie na germinacao e velocidade de emergencia. Verificou-se inicio de germinacao adiantado e maior velocidade de emergencia em sementes obtidas por autopolinizacao. Conclui-se que a dormencia da semente esta associada com o genotipo do embriao e que provavelmente e condicionado por um efeito genetico dominante. Palavras-chave: Passiflora edulis, dormencia, selecao, dominancia.