Estimativas de parâmetros genéticos e a variabilidade em procedências e progênies de Handroanthus vellosoi

Abstract

The present study aimed at estimating genetic parameters and variability among and within provenances for silvicultural traits of Handroanthus vellosoi (Toledo) Mattos, in provenances and progenies test stands, located at the Luiz Antônio Experimental Station (São Paulo State, Brazil). The test was established in the compact family block design, with two provenances (allocated in the plots), six replicates and sub-linear plots of five plants, totalizing 35 progenies. Diameter at breast height (DBH), plant height, cylindrical volume, stem form and survival at 24 years of age were evaluated. Significant differences among the provenances were observed only to the trait stem form. The analysis of deviance showed significant differences among progenies for the joint analysis of the provenances (experimental population), suggesting that the population has high genetic variation and indicating the possibility of genetic improvement by selection of the best progenies. Heritability estimates in individual and family level ranged from low to moderate (26% for DBH, 32% for plant height, 24% for cylindrical volume, 27% for form and 36% for survival), confirming the possibility of genetic improvement by selection and that the provenances have potential to respond to the pressure of natural selection.

Keywords

• Ex situ conservation
• Tropical tree species
• Population genetics
• Quantitative genetics