Abstract

VELASCO HERNANDEZ, Sara Irene  and  MUNOZ GUTIERREZ, Liliana. Phenological observations on Pinus patula Schltdl. & Cham. clones. Rev. mex. de cienc. forestales [online]. 2024, vol.15, n.86, pp.144-166.  Epub Mar 03, 2025. ISSN 2007-1132.  https://doi.org/10.29298/rmcf.v15i86.1482.

The lack of floral synchronization in a seed orchard favors a decrease in the genetic diversity of the seed lot, increases the percentage of abortive ovules and empty seeds. Therefore, it is necessary to determine the phenological stages and the degree of synchronization between pollen dispersal and female receptivity. In a 1.5 generation Pinus patula clonal seed orchard, the start, end and duration dates of each phenological stage of the male and female reproductive structures were estimated by macro-SYNCHRO. The female receptivity period lasted 13 days average, and the pollen dispersal period, 27.5 days. Pollen dispersal and female receptivity occurred when 370.5 and 440 degree-days accumulated, respectively. The general synchronization index of the orchard is considered low (PO=0.24) so there is no total synchronization between clone pairs. A positive correlation was found between the onset and duration of both phenological events (r=0.41) with a synchrony of seven days; therefore, it is possible that pollination between clones in the orchard with moderate synchronization indexes (PO between 0.30 to 0.60) can take place, but it is necessary to determine the variability and genetic control of the clones in subsequent evaluations.

Keywords : Pollen dispersal; degree-day; ramets; feminine receptiveness; seeds; phenological synchronization.

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