Germination and seedling growth of ornamental species of Passiflora under artificial shade

Abstract

Passiflora morifolia, P. suberosa litoralis, and P. palmeri var. sublanceolata are three wild species with ornamental potential that occur in Brazil. These species were evaluated with the purpose of determining the effects of different shade levels on seedling emergence and initial growth. Treatment with 50% shade resulted in the highest percentage of seedling emergence and the highest emergence speed index for all three species. The 50% shade level was the best condition for growth of P. morifolia and P. palmeri var. sublanceolata seedlings because in this condition, they presented higher growth in relation to control and the other treatments. However, P. suberosa litoralis can be considered a sun species because it grew better in full sunlight and 25% shade, but its growth was stunted at 75% shade. Increased leaf area and specific leaf area were due to changes in leaf dimension and shape in response to an increase in shade levels. These observations related to the initial growth reflect the development and adaptation of adult plants to heterogeneous environments. Therefore, P. morifolia and P. palmeri var. sublanceolata seedlings adapted better to moderate shade conditions, and P. suberosa litoralis seedlings should be cultivated in full sunlight.Germinação e crescimento inicial de espécies ornamentais de Passiflora sob sombreamento artificial RESUMO. Passiflora morifolia, P. suberosa litoralis e P. palmeri var. sublanceolata são espécies silvestres com potencial ornamental, que ocorrem no Brasil. Foram avaliadas com o objetivo de verificar os efeitos de diferentes níveis de sombreamento na germinação e no crescimento inicial de plântulas. O tratamento com 50% de sombreamento apresentou os maiores valores de percentagem de germinação e de índice de velocidade de emergência para as três espécies. Esse tratamento foi o mais indicado para a formação de plântulas de P. morifolia e P. palmeri var. sublanceolata, pois nessa condição elas apresentaram maior crescimento em altura e incremento de biomassa. Por outro lado, P. suberosa litoralis apresentou maior incremento de biomassa a pleno sol e a 25% de sombreamento, com redução a 75% de sombreamento. O incremento da área foliar e da área foliar específica foi devido às alterações na dimensão e na forma das folhas em resposta ao sombreamento. Essas observações demonstram que o crescimento inicial de plântulas reflete o desenvolvimento e a adaptação de plantas adultas à ambientes heterogêneos. Por fim, plântulas de P. morifolia e P. palmeri var. sublanceolata mostraram-se mais adaptadas às condições de sombra moderada ao passo que plântulas de P. suberosa litoralis podem ser cultivadas à pleno sol.Palavras-chave: Passifloraceae, flor-da-paixão, índice de velocidade de emergência, desenvolvimento, irradiância.

Effects of Biotic and Abiotic Environmental Stimuli on the Morphology and Biomass Allocation of Mimosa pigra L.

“…Plasticity enables M. pigra to increase resource uptake to improve survivability and this situation might arise quite commonly for competing plants such as weeds (Ballare et al 1988). It is suggested that the ability to grow quickly in height is an important adaptation mechanism when plants are deprived of ample resources (Pires et al 2012). The development of the stem diameter was inversely proportional to the plant height, and it is believed that height growth convergence was slowing down the stem development.…”

Tissue culture and biotechnological techniques applied to passion fruit with ornamental potential: an overview

“…EX DC (Peixoto, 2005), Passiflora caerulea (Conceição et al, 2011), Passiflora cincinnata ( Figure 2B) (Oliveira and Ruggiero, 2005); Passiflora mucronata (Meletti et al, 2011), Passiflora morifolia, Passiflora suberosa litoralis, Passiflora palmeri var. sublanceolata (Pires et al, 2012), Passiflora capsularis, Passiflora rubra (Amorim et al, 2011). Other species stand out for the beauty and exuberance of their flowers showing a great ornamental potential to be explored, such as; Passiflora nitida ( Figure 2C), Passiflora capparidifolia ( Figure 2D), Passiflora miniata ( Figure 2E) Passiflora cristalina ( Figure 2F).…”

Morphometry, in vitro-ex vitro germination and tetrazolium testing of stinking passionflower [Passiflora foetida var. glaziovii Killip] (Passifloraceae) seeds

“…The establishment of quality patterns requires an understanding of viable propagation methods and is dependent on information regarding the propagation and physiological potential of P. foetida var. glaziovii (Pires et al, 2012). Germination and tetrazolium (TZ) tests are among the main methods for evaluating the physiological potential of seeds, and the correct application of these methods is very important for generating satisfactory results for this species.…”