In order to better plan controlled pollination conducted by the shea tree improvement program of C?te d’Ivoire hosted at Peleforo Gon Coulibaly University (UPGC, Korhogo), a study was carried out to optimize the in vitro germination tests of shea tree pollen. Two successive experiments were conducted at the UPGC laboratory of the African Centre for Shea Research and Applications (CRAK). The first experiment aimed to determine the most suitable culture medium composition for optimal in vitro germination of shea pollen. Four media coded as M1 (10 g sucrose, 1.5 g agar, 100 ml distilled water), M2 (10 g sucrose, 0.6 g agar, 100 ml distilled water), M3 (20 g sucrose, 0.6 g agar, 100 ml distilled water), and M4 (9 g sucrose, 0 g agar, 100 ml distilled water) commonly used for forest tree species were tested with four incubation durations (5, 10, 30, and 48 hours) at 30?C. The second experiment aimed to identify the optimal temperature for pollen germination. Five temperature conditions were tested: 25?C, 30?C, 35?C, 40?C, and ambient temperature (29?C - 37?C). The results showed culture media M1 (10 g sucrose, 1.5 g agar) and M2 (10 g sucrose, 0.6 g agar) gave the highest in vitro pollen germination rate (75.73%) after 30 hours of incubation. Heat significantly influenced the in vitro germination capacity of shea pollen. Based on these findings, the Shea Tree Improvement Program of C?te d’Ivoire can now assess pollen viability using a gel-based medium with 10 g sucrose and either 0.6 g or 1.5 g agar, incubated for 30 hours at a temperature ranging from 25?C to ambient conditions (29?C - 37?C).
References
[1]
Diarrassouba, N., Jesus, F.I., Emmanuel, I.A. and Divine, B.N. (2009) Typology of Shea Trees (Vitellaria paradoxa) Using Qualitative Morphological Traits in Côte d’Ivoire. Gene Conserve, 8, 752-780.
[2]
Naughton, C.C., Lovett, P.N. and Mihelcic, J.R. (2015) Land Suitability Modeling of Shea (Vitellaria paradoxa) Distribution across Sub-Saharan Africa. AppliedGeography, 58, 217-227. https://doi.org/10.1016/j.apgeog.2015.02.007
[3]
Christophe, D., Diaga, D., Seyni, S. and Kandioura, N. (2014) Morphological Characterization of Shea Tree (Vitellaria paradoxa subsp. Paradoxa) Populations in the Region of Mandoul in Chad. InternationalJournalofBiodiversityandConservation, 6, 184-193. https://doi.org/10.5897/ijbc2013.0662
[4]
Soro, D., Traore, K. and Kassi, N. (2011) Variabilité des caractères morphologiques chez le karité (Vitellaria paradoxa), dans le Nord de la Côte d’Ivoire. InternationalJournalofBiologicalandChemicalSciences, 5, 1201-1214 https://doi.org/10.4314/ijbcs.v5i3.72263
[5]
Yé, S., Lebeau, F., Wathelet, J.P., Leemans, V. and Destain, M.F. (2007) Étude des paramètres opératoires de pressage mécanique des amandes de Vitellaria paradoxa Gaertn CF (karité). Biotechnology, Agronomy, Society and Environment, 11, 267-273.
[6]
Diarassouba, N., Koffi, K.E., N’Guessan, K.A., Van Damme, P. and Sangare, A. (2008) Connaissances locales et leur utilization dans la gestion des parcs à karaté en Côte d’Ivoire. AfrikaFocus, 21, 77-96. https://doi.org/10.1163/2031356x-02101007
[7]
Lamien, N. (2006) Fructification du karité (Vitellaria paradoxa CF Gaertn. Sapotaceae): Facteurs de déperdition, amélioration et prévision des rendements à Bondoukuy, Ouest Burkina Faso. Master’s Thesis, Université de Ouagadougou.
[8]
Diallo, R., Saraka, D.M.Y., Wentoin, A.M.P.D., Zadjehi Koffi, E.B. and Diarrassouba, N. (2025) Flowering and Fruiting Phenology of Shea (Vitellaria paradoxa C.F. Gaertn.) for Optimized Controlled Pollination. Ecologia, 15, 1-14.
[9]
Jourda, J.P., Saley, M.B., Kouamé, K.J., Kouadio, B.H., Biémi, J. and Razack, M. (2005) Gestion et protection des ressources en eaux souterraines: Contribution d’un SIG à la réalisation de la carte de vulnérabilité à la pollution des aquifères fissures de Korhogo (Nord de la Côte d’Ivoire) selon la méthode DRASTIC. Les Actes de la Conférence francophone SIG, Paris, 5-6 October 2005, 16.
[10]
Albergel, J. (2007) Le nord de la Côte d’Ivoire, un milieu approprié aux aménagements de petite et moyenne hydraulique. In: Cecchi, P., Ed., L’eau En Partage: Les Petits Barrages de Côte d’Ivoire, IRD, 45-57.
[11]
Agarwal, S. and Govila, R. (1982) Effect of Light Spectra on Pollen Germination and Pollen Tube Growth in Cicer Arietinum cv. BG 209. Acta Botanica Indica, 10, 311-312.
[12]
Colas, F. and Mercier, S. (2000) Évaluation et maintien de la viabilité des pollens utilisés dans le programme d’amélioration des arbres. Gouvernement du Québec, Ministère des ressources naturelles, Forêt Québec.
[13]
Li, M., Jiang, F., Huang, L., Wang, H., Song, W., Zhang, X., et al. (2023) Optimization of in Vitro Germination, Viability Tests and Storage of Paeonia ostii Pollen. Plants, 12, Article 2460. https://doi.org/10.3390/plants12132460
[14]
Mondo, J.M., Agre, P.A., Asiedu, R., Akoroda, M.O. and Asfaw, A. (2021) Optimized Protocol for in Vitro Pollen Germination in Yam (Dioscorea spp.). Plants, 10, Article 795. https://doi.org/10.3390/plants10040795
[15]
Silva, D.M., Zambon, C.R., Techio, V.H. and Pio, R. (2020) Floral Characterization and Pollen Germination Protocol for Castanea crenata Siebold & Zucc. SouthAfricanJournalofBotany, 130, 389-395. https://doi.org/10.1016/j.sajb.2020.01.027
[16]
Siham, K. And Hadjer, L. (2021) L’étude de la germination des grains du pollen du Pin d’Alep (Pinus halepensis Mill.). Ph.D. Thesis, Université Ziane Achour.
[17]
Youmbi, E., Tamnet, R and Ndzomo, G.T. (2011) Conservation des pollens de deux plantes mel-lifères (Vitellaria paradoxa et Steganotaeniaaraliacea) de la région de l’adamaoua (cameroun). Tropicultura, 29, 153-160.
[18]
Latruffe, N. (2017) Effets de la température et du pH sur l’activité enzymatique. In: Biochimie: 200 fiches de cours, 155 QCM, sujets de synthèse et ressources en ligne, 118-119.