Seed germination and vigor of passion fruit hybrids

Abstract

Most commercial plantations of passion fruit is propagate plants by seed, but germination is irregular, which hinders the growth of seedlings and uniformity, and is connected with the plant genotype. The objective of this study was to evaluate the germination and early growth of passion fruit hybrid seedlings, obtained from different genetic combinations. The hybrids were obtained from the cross between progenies from the breeding program of the Universidade Federal de Viçosa with hybrids of the Empresa Brasileira de Pesquisa Agropecuária and of the Viveiros Flora Brasil. The experimental design was completely randomized with six hybrids, five replicates and fifty seeds per experimental unit. Germination was assessed daily until the 28 days, and at the end of the period it was obtained the mean time germination, emergence speed index, seedling height, the length of shoots and roots, and the individual seedling dry matter (root + shoot)was assessed. Among the passion fruit hybrids evaluated, hybrid HB2 (UFVM0212 × BRS Sol do Cerrado) showed the highest germination and seedling biometric values and might be a genotype with potential for breeding programs for seed quality. The specific combining ability of parents can influence the quality of seeds and the vigor of passion fruit seedlings. A factor must be considered is the correct choice of maternal and paternal parents, since they influence the quality of seeds.Keywords: biometrics, combining ability, emergency, Passiflora edulis Germinação de sementes e vigor de híbridos de maracujazeiro ResumoA maioria das plantações comerciais de maracujazeiro é propagada por sementes, mas a germinação é irregular, o que dificulta o crescimento das mudas e sua uniformidade, e está ligado ao genótipo da planta. Objetivou-se no trabalho, avaliar a germinação e o crescimento inicial em plântulas de híbridos de maracujazeiro, obtidos de diferentes combinações genéticas. Os híbridos foram obtidos do cruzamento de progênies do programa de melhoramento da Universidade Federal de Viçosa com híbridos comerciais da Empresa Brasileira de Pesquisa Agropecuária e do Viveiro Flora Brasil. O delineamento experimental utilizado foi o inteiramente casualizado, com seis híbridos, cinco repetições e cinquenta sementes por unidade experimental. A germinação foi avaliada diariamente até 28 dias, e ao final do período foi obtido o tempo médio de germinação, o índice de velocidade de emergência, a altura da planta, o comprimento da parte aérea e da raiz e massa seca individual das plântulas (raiz + parte aérea). Entre os híbridos de maracujazeiro avaliados, o híbrido HB2 (UFVM0212 × BRS Sol do Cerrado) apresentou os maiores valores de germinação e biométricos de mudas e pode ser um genótipo com potencial para programas de melhoramento para qualidade de semente. A capacidade específica entre os pais pode influenciar a qualidade das sementes e o vigor das mudas de maracujazeiro. Um fator que deve ser considerado é a escolha correta dos pais maternos e paterno, uma vez que eles influenciam a qu...

Contribution of seed traits to the genetic diversity of a segregating population of Passiflora spp.

“…In this way, we selected those that most contributed to the analysis, since the GroundEye equipment provides a high number of variables. Seventeen seed color, geometry, and texture variables that contributed with more than 5% to the importance of traits of each individual group were thus used; color variables below the Otsu threshold: CIELab a, CIELab dispersion, CIELab dispersion of L, and CIELab L, black dominance, hue variance; geometric variables: Feret diameter, number of Harris corners, medium area, larger area, smaller area, and elliptical variation; texture variables: Haralick contrast, Haralick dissimilarity, RunLength HGRE (high gray-level run emphasis), RunLength LRHGE (long-run, high gray-level emphasis) and RunLength SRHGE (short-run, high gray-level emphasis) (Xu et al, 2004).…”

“…edulis, in turn, has a high germination rate, as demonstrated in the study of Santos et al (2015), who obtained percentages higher than 90% in seven genotypes in open and self-pollination, which were carried out in the bud stage aiming to overcome self-incompatibility. In the case of hybrids from passionfruit progeny, the germination percentage ranged from 3% to 84% (Souto et al, 2017).…”

Evidence of maternal effect on germination and vigor of sour passion fruit

“…The greatest numerical value of the emergence speed index among all crosses and structures was obtained by the hybrid of crosses 02 (4.41). The rate obtained by the hybrid crosses 02 was higher than those found by Souto et al (2017b), that studied germination and emergence speed index and found a value of 4.00 for the best treatment (genotype/hybrid 02). The high emergence speed index and quick emergence of the seedlings in a shorter period play an important role in genotype vigor and uniformity in establishing plants and seedlings production.…”

“…Thus, one of the great challenges that breeders faced is to group into a genotype the greatest number of desirable traits and, in the case of SPF, to obtain fruits with high quality, resistance to the main diseases and seeds with high germinative potential. The percentage of germination and vigor of seedlings are factors that must be considered in the genetic breeding of SPF (SOUTO et al, 2017b).…”

Genetic divergence between passion fruit hybrids and reciprocals based on seedling emergence and vigor

“…Recently, passion fruit breeding programs have considered the genetic influence in expressing seed quality, such as germination, emergence and vigor of seedlings (Souto et al, 2017). Alexandre et al (2004) observed that germination and emergence speed in passion fruit are influenced by the seed genotype.…”