KELLY CRISTINA CANCELA INFLUÊNCIA DA FAMÍLIA E DO ...

ABSTRACT
Little attention has been reported over the variation in seed size of different mother
trees of Pinus taeda and the implication of this variation in nursery and field
performances. This work made a comparison among clones of a clonal seed orchard
(CSO) and mother trees of a seed production area (SPA) in relation to the
productivity of cones and seeds, seed size and seed technological properties of the
seed lot. In a seed lot constituted by different families were evaluated the effect of
seed size classification in technological properties and in the genetic value of the lot.
The effect of the family and of the seed size was evaluated in nursery development
and in survival and initial growing in field. Clonal seed orchard ramets have
demonstrated an advantage in cones productivity compared to mother trees from the
seed production area in both of years evaluated, but seed productivity was
significantly greater just in the former year. Seeds from the clonal seed orchard were
bigger than seeds from the seed production area. The germination percentage was
higher in seeds from the seed production area and the number of seeds per kilo was
higher in the clonal orchard lot. There were significant differences among clones from
the CSO and mothers trees from the SPA for seed productivity, number of seeds per
kilo, germination velocity index (GVI) and germination percentage. Seed size didn’t
affect the emergence velocity and emergence percentage in nursery. Those
characteristics were affected by the original family. After six months in nursery with or
without fertilization there was a significant difference in the stem diameter and height
of seedlings from different families and different seed sizes. Bigger seeds had a
better performance than smaller ones, but the differences even significant, were
minimal. The dried biomass wasn’t affected by the seed size. Nine months after
planting, the survival and growing wasn’t influenced by seed size but was by the
family. In conclusion, it is recommended the sowing of families separately in order of
to uniform the growing and get the nursery operations facilitated, as well considering
the potential growing of the each family before the outdoor planting, increasing the
uniformity in field, without care about the seed size.
Key-words: Pinus taeda; Forest nurseries; Seed-quality; Seed tecnology.
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