*Variation in seed germination traits of three wild populations of* Entandrophragma bussei *in Tanzania.*

**Table 2.**


#### **Table 3.**

*Pearson correlation coefficients for seed germination traits of three wild populations of* Entandrophragma bussei *in Tanzania.*

#### **Figure 3.**

*Nursery growth trends of three wild populations of* Entandrophragma bussei *in Tanzania. Vertical bars are Standard Errors.*

observed between shoot dry weight and root collar diameter (*r* = 0.35, *P* < 0.05) while the highest was between root fresh weight and root dry weight (*r* = 97, *P* < 0.001) (**Table 6**).

*Germination and Seedling Growth of* Entandrophragma bussei *Harms ex Engl. from Wild… DOI: http://dx.doi.org/10.5772/intechopen.97489*


*Means followed by a common letter(s) in the same column are not significantly different at P < 0.05, Tukey's HSD Test; Means are followed by the Standard Deviation (SD) of the mean.*

#### **Table 4.**

*Evolution of seedling growth traits of three wild populations of* Entandrophragma bussei *in Tanzania.*


*Means followed by a common letter(s) in the same column are not significantly different at P < 0.05, Tukey's HSD Test; Means are followed by the Standard Deviation (SD) of the mean.*

#### **Table 5.**

*Variations in seedling growth traits of three wild populations of* Entandrophragma bussei *at 105 days in Tanzania.*


*\*\*\*Significant at 0.001 probability level.*

#### **Table 6.**

*Pearson correlation coefficients for the seedling growth traits of three wild populations of* Entandrophragma bussei *at 303 days in Tanzania.*


*Means followed by a common letter(s) in the same column are not significantly different at P < 0.05, Tukey's HSD Test; Means are followed by the Standard Deviation (SD) of the mean.*

#### **Table 7.**

*Variation in seedling growth traits of three wild populations of* Entandrophragma bussei *at 303 days in Tanzania.*

Most of the evaluated seedling growth traits did not differ significantly (*P* > 0.05) between the three populations on harvesting at 303 days (**Table 7**). However, the number of course roots differed significantly (*P* < 0.05) between the three populations with Tarangire (13) and Ruaha (12) having the higher number of roots per seedling than Kigwe (10). Similarly, Tarangire (28.8 g) and Ruaha (26.9 g) populations had significantly (*P* < 0.05) higher shoot fresh weight than Kigwe (22.9 g) (**Table 4**). In terms of survival in the nursery, Ruaha had the highest seedling survival (56%) followed by Kigwe (41%) and Tarangire (36%) being the last.

#### **4. Discussion**

#### **4.1 Variation in germination**

This study has demonstrated the differences in germination traits in three populations of *E*. *bussei* found in three agroecological zones of Tanzania. Germination of less than 100% may indicate dormancy or non-viability of the un-germinated seeds. The rapid germination observed in this species may indicate that this species establishes itself in the environment as quickly as possible to take advantage of the favourable conditions and to give it competitive advantage. All of the three populations germinated well within 34 days which is ideal for nursery production.

The study species *E*. *bussei* is a native species which is recommended for restoration and conservation strategies since it is adapted to local habitat conditions. So germination studies facilitate better understanding of optimal conditions for germination and influence of seed populations. The observed variation in germination among populations emphasizes the need for proper seed source selection to minimize waiting time and cost of nursery operations [18]. Commercial nurseries are often established to produce large number of high quality planting stocks in the possible shortest time. This study has shown that all the *E*. *bussei* populations can be produced under nursery conditions to supply strong materials for planting out in agroforestry and plantation forestry. Our study has shown that *E*. *bussei* can germinate well within reasonable time of five weeks.

#### *Germination and Seedling Growth of* Entandrophragma bussei *Harms ex Engl. from Wild… DOI: http://dx.doi.org/10.5772/intechopen.97489*

Germination is an important factor in assessing the quality of any seed and determines early seedling performance and end products standard. In this study, seed cumulative germination percentage ranged from 63.4% to 81.4% indicating that the three populations possess quality seeds that can be used during domestication and tree improvement processes. The observed variation in germination percentage among the provenances is not attributed to differences in altitudes, environmental factors (day length, temperature, light quality, water availability and altitude), and climatic conditions of particular population, since this study was undertaken in one geographic location [19]. The results overall indicate that, maternal factors associated with individual seeds from each population could explain the observed variations [20]. It has been reported that position of seed in the fruit or tree and the age of the mother plant influence seed germination ability [21]. However in this study, such effects were not studied.

In this experiment no treatment was undertaken for germination of *E*. *bussei* but the overall germinations for all populations were good as opposed to other species in the genus *Entandrophragma*. For example, it has been reported that *E*. *cylindricum* needs pre-sowing to attain higher germination while *E*. *angolense* requires certain substrate type for germination in West Africa [22]. In order to support establishment of a nursery for *E. bussei* domestication, genotypes with superior germination traits are favoured [23]. Kigwe provenance had significantly higher values for most of the germination traits (i.e. germination percentage, mean germination rate and germination index) as compared to the other two populations. These observed results could be attributed to by the fact that Kigwe source had heavier seeds than the other two sources (Andrew et al., *in press*). Studying variation in *Uapaca kirkiana*, Mwase et al. [24] pointed out that seeds with heavy weight were producing higher cumulative germination percentages. High nutrients reserved in seeds from Kigwe have a chance of germinating at 81.4% within 16 days (**Figure 3**). The selection of seeds from this population would be appropriate during nursery development in tree domestication, agroforestry and plantation forestry.

#### **4.2 Variation in seedling growth**

Seedling traits including shoot height, root collar diameter, number of leaves, tap root length, total number of course roots per seedling, fresh and dry weights of all course roots and shoots variations are important determinants of seedlings to be planted in the field. This study has demonstrated that there are degrees of variation among various seedling growth traits suggesting that selection of any trait for improvement would be effective [18]. Number of leaves differed significantly among the three populations, with Kigwe and Tarangire having higher number of leaves than Ruaha, at 105 days (**Table 5**). Ruaha and Tarangire had higher number of course roots and shoot fresh weight than Kigwe population at 303 days (**Table 7**). Parker et al. [25] and Assogbadjo et al. [26] reported a positive influence of large seed size and seed reserve on the establishment and early growth of seedlings. So, higher seed width, weight and length might have contributed to the observed variation of *E*. *bussei* populations in this study. It is known that roots support plants growth by absorbing nutrients and water so presence of higher number of course roots contributed to the higher survival of Ruaha population. It has been reported that traits displayed by seedlings in the nursery are influenced by mostly genetic rather than phenotypic origin. This experiment was set at the DTSP nursery in Morogoro for all the three provenances. It is obvious that the observed results have been influenced mostly by seed genetic makeup (which were not tested in this study though) from each individual population rather than variation of environmental factors between the populations as reported by Freigoun et al. [20] on *Balanite aegyptiaca*. During

the study period of ten months, some seedling growth traits were not significantly different but showed a positive and strong correlation among them (**Table 6**). Despite such observations, it is important to consider raising the seedlings in the nursery until plantable size when seedlings are at least 25–30 cm high and with root collar diameter of 3–4 mm to allow seedling maturation and biomass increase [27].

#### **5. Conclusion**

*E*. *bussei* is threatened by recent intensified utilization pressure, deforestation and high mortality rate of seedlings and hence in situ and ex situ conservation measures are urgently needed to restore and preserve genetic diversity. On site measures can include wide planting, extension services and enforcement of laws governing forestry-agriculture interphase. Domestication of *E. bussei* from the wild should consider collection of seeds that possess swift germination and seedling growth under managed nurseries. Establishment and/or incorporation of the tree into farms or agroforestry systems would help to reduce the pressure on the remaining natural populations. In this study, Kigwe had the best germination traits with high germination percentage, mean germination rate and germination index. However, a different trend was observed during the nursery experiment where Tarangire and Ruaha performed well in number of course roots and shoot fresh weight. Ruaha had the highest survival rate at the age of 10 months. The difference observed for the two experiments could have resulted from variations in genetic factors. Results of this study pave a way for further studies to confirm the best performing population(s) for in situ and ex situ conservation and tree improvement. It is therefore recommended that seedlings in the nursery are monitored until when they reach plantable size (i.e. height of 25–30 cm and root collar diameter of 3–4 mm).

#### **Acknowledgements**

G. Ngatena, M. Said, R. Khalfani, P. Mmanda and J. Mtika assisted during fieldwork. Tanzania Forest Services Agency (TFS) supported data collection.

#### **Conflict of interest**

None.

*Germination and Seedling Growth of* Entandrophragma bussei *Harms ex Engl. from Wild… DOI: http://dx.doi.org/10.5772/intechopen.97489*

## **Author details**

Samora M. Andrew1 \*, Siwa A. Kombo1,2 and Shabani A.O. Chamshama1

1 Department of Ecosystems and Conservation, Sokoine University of Agriculture, Morogoro, Tanzania

2 Directorate of Tree Seed Production, Tanzania Forest Services Agency, Morogoro, Tanzania

\*Address all correspondence to: smacrice@sua.ac.tz

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

#### **References**

[1] Kideghesho J, Rija A.A., Mwamende K.A. and Selemani I.S. (2013). Emerging issues and challenges in conservation of biodiversity in the rangelands of Tanzania. Nature Conservation 6:1-29

[2] Msanga, H. P. (1998). Seed Germination of Indigenous Trees in Tanzania, Including Note on Seed Processing, Storage and Plant Uses. University of British Columbia Press, Vancouver. 292 pp.

[3] Styles, B.T. and White, F. (1991). Meliaceae Flora of Tropical East Africa. Meliaceae, 67 pp.

[4] Hall, J. S. (2008). Seed and seedling survival of African mahogany (*Entandrophragma* spp.) in the Central African Republic: Implications for forest management. Forest Ecology and Management 255: 292-299

[5] Makonda, F.B.S. and Batiho, T.A. (2018). Benchmarking Current Status of *Entandrophragma bussei* an Endemic Species of Tanzania. Final KiLi meeting Moshi, Tanzania 2nd – 4th October 2018, 6 pp.

[6] Dery, B. B. (1999). Indigenous Knowledge of Medicinal Trees and Setting Priorities for Their Domestication in Shinyanga Region, Tanzania. World Agroforestry Centre, Nairobi, Kenya.

[7] Monela, G. C., Chamshama, S. A. O., Mwaipopo, R. and Gamassa, D. M. (2005). A study on the Social, Economic and Environmental Impacts of Forest Landscape Restoration in Shinyanga Region, Tanzania. Ministry Natural Resource and Tourisms, Dar es Salaam, Tanzania 223pp.

[8] Mouthé-Happi, G., Tchaleu Ngadjui, B., Green, I. R. and Fogué Kouam, S. (2018). Phytochemistry and

pharmacology of the genus Entandrophragma over the 50 years from 1967 to 2018: A golden' overview. Journal of Pharmacy and Pharmacology 70(11): 1431 – 1460.

[9] Nibret, E., Ashour, M. L., Rubanza, C. D. and Wink, M. (2010). Screening of some Tanzanian medicinal plants for their trypanocidal and cytotoxic activities. Phytotherapy Research 24(6): 945 – 947.

[10] Rao, M.R., Palada, M.C. and Becker, B.N. (2004). Medicinal and aromatic plants in agroforestry systems. Agroforestry Systems 61:107-122.

[11] Dery, B. B. and Otsyina, R. (2000). The 10 priority medicinal trees of Shinyanga, Tanzania. *Agroforestry Today*12(1):5 – 8.

[12] Adewunmi, A. O., Bolanle–Ojo, O. T. and Oladejo, A. O. (2014). Seedling growth performance of *Entandrophragma angolense* (Welw.) CDC as influenced by different light intensities. *Journal of Agriculture, Forestry and the Social Sciences* 12(2): 197 – 206.

[13] Hall, J. S., Medjibe, V., Berlyn, G. P. and Ashton, P. M. S. (2003). Seedling growth of three co-occurring *Entandrophragma* species (Meliaceae) under simulated light environments: implications for forest management in central Africa. Forest Ecology and Management 179 (3): 135 – 144.

[14] Hamasha HR, Hensen I (2009). Seed germination of four *Jordanian Stipa* spp.: differences in temperature regimes and seed provenances. Plant Species Biology 24:127-132.

[15] Asiedu, J. B. K., Van Der Puije, G. C., Taah, K. J. and Dovlo, V. (2012). Effect of some presowing treatments on germination of *Bauhinia rufescens* seeds. *Germination and Seedling Growth of* Entandrophragma bussei *Harms ex Engl. from Wild… DOI: http://dx.doi.org/10.5772/intechopen.97489*

International Journal of Agricultural Research 7(4): 195 – 204.

[16] Djavanshir, K. and Pourbeik, H. (1976). Germination value: a new formula. Silvae Genetic 25: 79-83.

[17] R Development Core Team (2020). R: a language and environment for statistical computing. R Foundation for 343 Statistical Computing, Vienna.

[18] Ngulube, M. R., Hall, J. B. and Maghembe, J. A. (1997). Fruit, seed and seedling variation in Uapaca kirkiana from natural provenances in Malawi. Forest Ecology and Management 98(3): 209 – 219.

[19] Vazquez-yanes, A. C., Rincón, E., Toledo, J. R. and Barradas, V. L. (1990). Light beneath the litter in a tropical forest: Effect on seed germination*.* Ecology 71(5):1952 –1958.

[20] Freigoun, S. A., Raddad, E. Y. and Elagib, T. Y. (2019). Provenance variation in seed morphological traits and early seedling growth of *Balanites aegyptiaca* Del. Sudan Journal of Agricultural Research 27(2): 93 – 108.

[21] Gutterman Y (2000). Maternal effects on seeds during development. In: Fenner M (ed) Seeds: the ecology of regeneration in plant communities, 2nd edn. CABI Publishing, Wallingford, pp 59-84.

[22] Ambebe, T. F. and Achankeng, N. (2019). Influence of pre-sowing treatment and substrate on germination and seedling vigour of *Acacia angustissima* (Mill.) Kuntze, *Entandrophragma angolense* (Welw) CDC and *Newtonia camerunensis* Villiers. *Journal of Agriculture and* Forestry Sciences 7(2): 25 – 35.

[23] Mkwezalamba, I., Munthali, C. R. and Missanjo, E. (2015). Phenotypic Variation in Fruit Morphology among Provenances of *Sclerocarya birrea*

(A. Rich.) Hochst. International Journal of Forestry Research 2015: 1 – 8.

[24] Mwase, W. F., Bjørnstad, Å., Ntupanyama, Y. M., Kwapata, M. B. and Bokosi, J. M. (2006). Phenotypic variation in fruit, seed and seedling traits of nine *Uapaca kirkiana* provenances found in Malawi. Southern African Forestry Journal 208(1): 15 – 21.

[25] Parker W.C., Noland T.L. and Morneault A.E. (2006). The effects of seed mass on germination, seedling emergence, and early seedling growth of eastern white pine (*Pinus strobus* L.). New Forests 32:33-49

[26] Assogbadjo, A. E., Glèlè Kakaï, R., Edon, S., Kyndt, T., & Sinsin, B. (2010). Natural variation in fruit characteristics, seed germination and seedling growth of *Adansonia digitata L.* in Benin*.* New Forests 41(1), 113-125.

[27] United Republic of Tanzania (URT) (2021). Technical Order No. 1 of 2021. Forestry and Beekeeping Division, Ministry of Natural Resources and Tourism.

#### **Chapter 11**
