Genetic variation for floral traits among teak (Tectona grandis Linn. f.) clones: Implications to seed orchard fertility

Variations for floral traits among constituent clones can potentially influence the pollination success in a clonal seed orchard. A study was undertaken in a nineteen -year-old Clonal Seed Orchard of teak (Tectona grandis Linn. f.) to assess the nature/extent of variation for floral traits among clones d erived from diverse provenances. Inter-clonal variation was significant for all the eight floral traits, while within the clone variation was negligible. Pollen grains per stigma varied to a large extent (CV = 42.24%) and the remaining traits exhibited very low levels of vari ation. The association of length and diameter of stigma with number of pollen grains captured per stigma was positive and significant (r = 0.64 and 0.76 respectively), however, the association of anther filament length with length of stigma was negative (r = – 0.46), suggesting a possibility of conflict between male and female function. Teak clones with larger corolla tube diameter showed a higher fruit set as shown by their positive correlation (r = 0.55). The broad sense heritabilities estimated based on clonal means were higher, suggesting a strong genetic control, hence selection could yield beneficial results. The implications of the results to genetic improvement of teak are discussed in the light of poor fertility among teak clones in seed orchards.