Seed germination responses of Cereus jamacaru DC. ssp. jamacaru (Cactaceae) to environmental factors

Abstract

In the present study, we assessed the seed germination responses of Cereus jamacaru DC. ssp. jamacaru (Cactaceae) to environmental factors. The seeds were collected from an area within Caatinga, a semiarid vegetation area located in north-eastern Brazil. We determined the optimal temperature for germination of C. jamacaru seeds and evaluated the effect of temperature, light intensity, light quality, water and saline stress on seed germination. Cereus jamacaru was classified as a positive photoblastic species. Maximum germination (95.8 Ϯ 2.6%) was found under white light, and seed germination was not observed in darkness in any of the temperature, water or saline stress treatments. The optimum temperature for seed germination was 30°C because this temperature favored most of the parameters evaluated. Seed germinability responded positively to a wide range of temperatures, but was affected neither by light intensity nor by light quality. A reduction in water availability and an increase in saline concentration affected germinability and promoted slower, unsynchronized germination. The positive response of C. jamacaru seed germination to the environmental factors investigated may account for the abundant occurrence and wide distribution of the species in the Caatinga area.

Cereus jamacaru seed germination and initial seedling establishment as a function of light and temperature conditions

“…Conversely, seeds of C. jamacaru, Microchanthus flaviflorus and Pilosocereus gounelli had high germination percentages when incubated at 20-30 °C and 25-35 °C in photoperiod conditions, whereas -and in agreement with this study -seeds under the darkness condition showed inhibited germination (Veiga-Barbosa et al, 2010). In a recent study of C. jamacaru germination under different environmental conditions, no germination in darkness was observed, suggesting that these seeds are positively photoblastic (Meiado et al, 2010). On the other hand, in this study, seeds germinated in darkness, just as other columnar cacti such as Pachycereus pringlei (Nolasco et al, 1997).…”

“…This result demonstrates that C.jamacaru seeds are indifferent to light quality, by the fact that germina- tion occurred similarly for white and red light at 25 °C. In another study with C. jamacaru, the maximum germination for this species was observed at 30 °C in white light, corresponding to 95.8 % of germination (Meiado et al, 2010). Additionally, for globose cactus Melocactus bahiensis, the highest germination percentage and germination speed index were detected at 25 °C (Lone et al, 2007).…”

The effect of temperature on the germination of Melocactus violaceus Pfeiff. (Cactaceae), a threatened species in restinga sandy coastal plain of Brazil

“…In a study with four Brazilian cacti species, Almeida et al (2009) observed that seeds of these species did not require the alternating temperature regime and constant temperatures were more favorable to germination. Constant temperatures, ranging from 25 to 30°C, also seem to be efficient to the germination of Cereus jamacaru in areas of Caatinga in the Northeast of Brazil (Meiado et al 2010).…”

Seed reserve composition and mobilization during germination and early seedling establishment of Cereus jamacaru D.C. ssp. jamacaru (Cactaceae)

“…Farmers also use their fruit as food, and infusions of their stems and roots are professed to be efficient for treating respiratory diseases (Mors et al 2000, Lorenzi andMatos 2002). Recently, Meiado et al (2010) classified C. jamacaru as a positive photoblastic species and showed that saline and water stresses negatively affected its germination. They also reported that the high seed germination capacity of C. jamacaru while under the influence of different environmental factors was associated with high fruit production per individual and the high seed production per fruit.…”