Abstract
We compared the influence of pollination intensity (PI) on fruit set and seed number per pod in two cacao (Theobroma cacao L.) clones, IFC5 (Forastero Lower-Amazon Amelonado), which is self-compatible and known to produce a high number of seeds per pod under open pollination, and SCA6 (Forastero Upper-Amazon), which is self-incompatible and known to produce a low number of seeds per pod under open pollination. With both clones, PI had a positive effect on fruit set, with the maximum rate requiring more than 150 pollen grains per pod. One-half of the maximum rate of fruit set was reached with 39 pollen grains per pod for SCA6, and 78 for IFC5. With SCA6, a significant positive effect of PI on seed number per pod was also observed, with maximum seed number requiring more than 200 pollen grains per pod. In contrast, seed numbers with IFC5 were approximately equal over the PI range 100–800 pollen grains per pod. Patterns of seed number per pod were compared after: (1) open insect pollination, (2) low-intensity hand pollination and (3) high-intensity hand pollination. The patterns obtained with IFC5 under open pollination showed a peak of 40–50 seeds per pod, whereas the distribution patterns were more even with SCA6. The pattern of seed number under open pollination was similar to that obtained with high-intensity hand pollination for IFC5, and with low-intensity hand pollination for SCA6. We concluded that the high number of seeds per pod observed with IFC5 under natural insect pollination may be explained by a high number of compatible self-pollen grains on the stigma and by a severe drop of low-pollinated flowers eliminating potential lowfilled fruits. With SCA6, however, the number of compatible pollen grains deposited on the stigma was probably low under open pollination, and the flowers required lower pollen quantities to set fruit, which resulted in a high frequency of low seed numbers per fruit. This difference in the capacity to set low-seeded fruits might be considered as an adaptive trait related to the mode of reproduction.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bawa KS (1983) Patterns of flowering in tropical plants. In: Jones CE, Little RJ (eds) Handbook of experimental pollination biology. Van Nostrand Reinhold, New York
Billes DJ (1941) Pollination ofTheobroma cacao L. in Trinidad, BWI. Trop Agric (Trinidad) 28: 151–156
Bouharmont J (1960) Recherches cytologiques sur la fructification et l'incompatibilité chezTheobroma cacao L. (Série scientifique no 89) Institut National pour l'Etude Agronomique du Congo, Brussels
Brew AH, Boorman J (1993) Preliminary observations on the classification ofForcipomyia midges (Diptera, Ceratopogonidae) of Ghana with special reference to species involved in the pollination of cocoa (Theobroma cacao L.). Cafe Cacao The 37: 139–144
Cheesman EE (1944) Notes on the nomenclature, classification and possible relationships of cacao populations. Trop Agric 22:144–159
Cope FW (1962) The mechanism of pollen incompatibility in Theobroma cacao L. Heredity 17: 157–182
De Reffye P, Parvais JP, Mossu G, Lucas P (1978) Influence des aléas de la pollinisation sur les rendements du cacaoyer. Modèle mathématique et simulation. Cafe Cacao The 22: 254–274
Diggle PK (1992) Development and the evolution of plant reproductive characters. In: Wyatt R (ed) Ecology and evolution of plant reproduction. Chapman and Hall, New York, pp 326–355
Falque M (1994) Fécondation et développement des fruits et des graines chez le cacaoyer (Theobroma cacao L.). Influence de l'irradiation du pollen et de l'intensité de la pollinisation. Doctoral dissertation, Institut National Polytechnique de Toulouse, Toulouse
Falque M, Vincent A, Vaissière BE, Eskes AB (1995) Effect of pollination intensity on fruit and seed set in cacao (Theobroma cacao L.). Sex Plant Reprod 8: 354–360
Free JB (1993) Insect pollination of crops. Academic press, New York, pp 505–514
Hernandez BJ (1965) Insect pollination of cacao (Theobroma cacao L.) in Costa Rica. PhD dissertation, University of Wisconsin
Kaufmann T (1975) Cocoa pollination by males ofForcipomyia squamipennis (Diptera: Ceratopogonidae) in Ghana. Trop Agric 52: 71–74
Lachenaud P (1991) Facteurs de la fructification chez le cacaoyer (Theobroma cacao L.). Influence sur le nombre de graines par fruit. Doctoral dissertation, Institut National Agronomique Paris-Grignon, Paris
Lachenaud P (1994) Variations in the number of beans per pod inTheobroma cacao L. in the Ivory Coast. I. The role of pollen. J Hortic Sci 69: 1123–1129
Lachenaud P (1995a) Variations in the number of beans per pod inTheobroma cacao L. in the Ivory Coast. III. Nutritional factors, cropping effects and the role of boron. J Hortic Sci 70: 7–13
Lachenaud P (1995b) Variations in the number of beans per pod in Theobroma cacao L. in the Ivory Coast. II. Pollen germination, fruit setting and ovule development. J Hortic Sci 70: 1–6
Lachenaud P, Mossu G (1985) Etude comparative de l'influence de deux modes de conduite sur les facteurs du rendement d'une cacaoyère. Cafe Cacao The 29: 21–30
Lanaud C (1986) Genetic studies ofTheobroma cacao L. with the help of enzymatic markers. II. Study of polymorphism of six enzymatic systems. Cafe Cacao The 30: 278–280
Lloyd DG (1992) Evolutionarily stable strategies of reproduction in plants: who benefits and how? In: Wyatt R (ed) Ecology and evolution of plant reproduction. Chapman and Hall, New York, pp 137–168
Massaux F, Tchiendji C, Misse C, Decazy B (1976) Etude du transport du pollen de cacaoyer par marquage au32P. Cafe Cacao The 20: 163–170
Mossu G, Paulin D, De Reffye P (1981) Influence de la floraison et de la pollinisation sur les rendements du cacaoyer. Liaisons mathématiques entre les données expérimentales. Equation du rendement. Cafe Cacao The 25: 155–168
Parvais JP, De Reffye P, Lucas P (1977) Observations sur la pollinisation libre chezTheobroma cacao: analyse mathématique des données et modélisation. Cafe Cacao The 21: 253–262
Paulin D (1981) Contribution à l'étude de la biologic florale du cacaoyer. Bilan de pollinisations artificielles. Cafe Cacao The 25:105–112
Paulin D, Decazy B, Coulibaly N (1983) Etude des variations saisonnières des conditions de pollinisation et de fructification dans une cacaoyère. Cafe Cacao The 27: 165–176
SAS Institute, Inc. (1985) SAS user's guide: statistics. SAS Institute, Cary, NC
Seavey SR, Bawa KS (1986) Late-acting self-incompatibility in angiosperms. Bot Rev 52: 195–219
Soria SJ, Wirth WW (1974) Identidade e caracterizacao taxonomica preliminar das mosquinhasForcipomyia (Diptera, Ceratopogonidae) associadas com a polinizacao do cacaueiro na Bahia. Rev Theobroma 4: 3–12
Tovar G, Ortiz M (1991) Evaluación de algunos componentes del rendimiento en una plantación de hibridos de cacao de 5 años de edad en la región de Granada (Meta). Agron Colombiana 8: 105–115
Valle RR, De Almeida AAF, Leite RMO (1990) Energy costs of flowering, fruiting and cherelle wilt in cacao. Tree Physiol 6: 329–336
Wood GAR, Lass RA (1985) Cocoa, 4th edn. (Tropical agriculture series) Longman, London
Young A (1986) Cocoa pollination. Cocoa Growers Bull 37: 5–23
Young AM, Erickson EH, Strand MA, Erickson BJ (1987) Pollination biology ofTheobroma andHerrania (Sterculiaceae) I. Floral biology. Insect Sci Appl 8: 151–164
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Falque, M., Lesdalons, C. & Eskes, A.B. Comparison of two cacao (Theobroma cacao L.) clones for the effect of pollination intensity on fruit set and seed content. Sexual Plant Reprod 9, 221–227 (1996). https://doi.org/10.1007/BF02173102
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02173102