An analysis was made of information provided by farmers about products and services of tree species, and the preferred tree species for agroforestry systems in the Yurimaguas, Pucallpa and Iquitos areas of Peru. The methodology of the study was based on a process developed by the International Centre for Research in Agroforestry (ICRAF) and the International Service for National Agricultural Research (ISNAR), with modifications to adapt it to the study area. Farmers selected 58 species in Yurimaguas, 62 in Pucallpa and 100 in Iquitos; the selections included 41 plant families. Considering the number of species preferred by farmers and the number of people surveyed, farmers in the Yurimaguas area appeared to have greater knowledge about trees than farmers in the other 2 areas. Some 23 priory species in 17 families were selected for the development of agroforestry systems for this tropical humid lowland zone. The priority products of these 23 species are wood, energy and food. The highest-priority species for genetic improvement research for agroforestry systems are Bactris gasipaes, Cedrelinga catenaeformis, Inga edulis, Calycophyllum spruceanum and Guazuma crinita.
Tag: guazuma crinita
Genetic diversity in Guazuma crinita from eleven provenances in the peruvian amazon revealed by ISSR markers [Diversidad genética de Guazuma crinita en once procedencias de la Amazonía Peruana revelada por marcadores ISSR]
Guazuma crinita is an important fast-growing timber tree species widely used in agroforestry systems in the Peruvian Amazon. The objectives of our research were (i) to assess genetic diversity of G. crinita using inter-simple sequence repeat (ISSR) markers and (ii) estimate correlation between genetic and geographic distances among provenances. The sample included 44 genotypes from 11 provenances in the Aguaytia and neighboring Pachitea watersheds in the Peruvian Amazon. Ten ISSR primers amplified a total of 65 bands of which 61 were polymorphic (93.8%). The range of DNA amplification varied from 260 to 2,200 bp. Among the provenances, Macuya exhibited the highest percentage of polymorphic bands (PPB) with 67.7%, 0.21 Nei’s gene diversity (He) and 0.33 Shannon index (I). Overall genetic differentiation (Gst) was 0.03, indicating 97% of genetic diversity within provenances. Gene flow (Nm) was 12.9 alleles per generation. Cluster analysis was not related to geographic origin, suggesting a common gene pool. However a weak positive correlation (r = 0.27, P < 0.05) was found between genetic and geographic distance. This is the first study of genetic diversity and structure of G. crinita. We recommend in situ conservation strategies for populations with high levels of genetic diversity. © 2016, Universidad Austral de Chile. All rights reserved.
Variation in wood physical properties within stems of Guazuma crinita, a timber tree species in the Peruvian Amazon
An understanding of wood physical properties and the interrelationships that govern them is required for efficient utilization of timber tree species. Guazuma crinita is a fast-growing timber tree of agroforestry systems in the Peruvian Amazon. The aim of this study was to assess variation in wood physical properties within the G. crinita stem. Wood samples were obtained from the base, middle and top of the stem of 12 randomly selected eight-year-old trees from six provenances in order to determine wood moisture content, density, specific gravity, radial, tangential and volumetric shrinkage and the coefficient of anisotropy. Pearson correlations between physical properties were also determined. The highest basic density was 459 kg/m3 from Tournavista provenance. Mean basic density and specific gravity were 430 kg/m3 and 0.45 respectively. There was statistically significant variation (p 0.05), due to stem level within the trees. The moderate values of density and anisotropy coefficient (1.56) suggest that G. crinita is a stable wood; these are important advantages in terms of costs of the processes of transport and transformation. Given the variation found in the limited tree samples of this study, we recommend further analysis with larger samples from different provenances and planting zones.