Variabilidade genética de copaifera multijuga hayne e sua relação com a produção de oleorresina

Abstract

Copaifera spp. Trees, commonly known as copaibeiras, in addition to their economic importance, have economic, ecological and social importance for the traditional peoples of the Amazon. Due to its medicinal properties, copaiba oil is one of the main Non-Timber Forest Products (NTFPs) marketed in the Amazon. However, as production limitations of oleoresin, mainly, does not refer to the variability of production between nodes of the same species and natural population, including non-productive trees, they are still an obstacle to the management of this NTFP. But, what is the reason for this variability in production between individuals? In this context, this research aimed to estimate the genetic variability of Copaifera multijuga Hayne, as well as to verify whether there is genetic differentiation between productive and non-productive oleoresin trees, using heterologous microsatellite markers, in a natural population and in a progeny, plantations with 39 years of age, in the region of Manaus, Amazonas, Brazil. For the genetic study, 27 trees of the Ducke Reserve natural population (2º 57 '43 ”South and 59º 55 '38” West) were sampled, with known phenotypes (productive and non-productive), including as parent trees of the progeny test . In the progeny test, 94 trees from Planting I (daughters from 3 productive mothers) and 86 trees from planting II (daughters from 3 non-productive mothers) were selected, totaling 180 daughter trees. Both plantations are assumed at INPA's Tropical Silviculture Experimental Station (2º 35 ’51, 28 ”South and 60º 02 ’10, 57” West). A phenotypic analysis was also performed within the progeny test. For this, among the 180 daughter trees, were selected as trees with the largest existing diameters (DAP ≥ 20 cm): 44 trees (Planting I) and 31 trees (Planting II). A phenotypic analysis revealed that, in relation to the production of oleoresin in the trunk of C. multijuga trees, productive and non-productive trees can generate offspring with both phenotypes. Six microsatellite loci of C. lagsdorffii were amplified heterologously and successfully characterized for C. multijuga. Six microsatellite loci of C. lagsdorffii were amplified heterologous and successfully characterized for C. multijuga. The genotype analysis of C. multijuga trees in the natural population (Ducke Reserve) showed levels of variability from low to moderate, a total of 39 alleles, with an average of 6.5 alleles per locus and the expected average heterozygosity of 0.692. The PIC proved to be very informative for all loci used (> 50%), except for CL02 (48%). Only one locus (CL01) showed heterozygous deficiency (HO < HE), with significant deviation from EWH (FIS < 0.000). In the groups of C. multijuga phenotypically different, productive and non-productive oleoresin trees (Ducke Reserve, Planting 1 e 2 / ESST), a total of 91 alleles were identified and an average of 7.6 alleles per locus. In both groups, the most polymorphic locus was CL32, with 12 and 11 alleles respectively, of which the mean expected heterozygosity values were 0.698 (productive) and 0.713 (non-productive). Despite the low value FST = 0.003 (expected for tropical tree species), DAPC showed that there is a genetic distinction between productive and non-productive trees, forming two well-structured genetic groups and with a low level of mixture for membership probabilities > 90%. The presence of exclusive alleles strengthens the hypothesis that they are genetically different. The results show new useful heterologous markers, available for application in studies of the reproductive system, population genetics and the probable conservation of natural populations of C. multijuga.