Caracterização das fenofases reprodutivas e viabilidade de pólens e sementes de cactáceas

Abstract

Regarding the diversity of cacti in the country, the use of these species for animal feed can have consequences for their survival. The objective of this work was to monitor the reproductive phenophases of cacti, the biometry of flower buds and ripe fruits, evaluate the pollen viability of stored pollens, and perform the seed germination test. The study area is a Caatinga forest fragment, located in the municipality of Bananeiras, Paraíba. In the study area, 30 individuals of each species were selected, the phenological follow-up was fortnightly, setting up a phenological calendar of the reproductive phenophases of the species: Cereus jamacaru, Pilosocereus pachycladus, Xiquexique gounellei and Tacinga inamoena. Floral buds and ripe fruits were collected for biometry, pollen and seed viability. Four eppendorf tubes were used for each species and environment, containing 40 anthers each tube and stored in a natural environment and in a refrigerator at 8°C. The count of pollen grains took place on the first day, with period 0 being the control, the counts took place between 30, 60 and 90 days, using Alexander's dye. In the germination test, the seeds were distributed in Gerbox, placed in BOD at a temperature of 25ºC and with a photo period of 12 hours, 100 fruit seeds stored in a freezer at -12°C for 20 days were used, 100 seeds stored for 2 years in paper bags and 100 fresh fruit seeds. C. jamacaru showed seasonal flowering and fruiting, the flowering and fruiting of P. pachycladus and T. inamoena in the studied population was continuous and persistent. X. gounellei presented only continuous fruiting. Both species, flowering and fruiting occur in the dry and rainy season. The species showed high pollen viability, above 91% of viable pollens. Storage did not affect the viability of pollen grains, for a period of up to 90 days. Only the seeds of P. pachycladus, C. jamacaru and X. gounellei from the natural treatment germinated, the storage methods did not prove to be effective. T. inamoena did not germinate in any treatment, which highlights the need for further studies on this species.