Introduction[ edit ] The volumes of Allanblackia seeds, and hence seed oil, produced until now very low. The volume of allanblackia seed oil is in the range of metric tonnes per annum only. When initial studies on the potential of wild-harvesting were done in the early s, the expectations were very high predicting annual production of up to 40, tonnes of seeds. In reality only a few tonnes of seeds were harvested in the first year as the number of wild Allanblackia trees that could actually be harvested had severely been overestimated. Through the plantation of the tree with local farmers in Tanzania, Ghana and Nigeria, the production volumes are expected to increase in the coming decade, once these trees are old enough to starting producing fruits and big enough to carry more of the large fruit pods.
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Hamadina, Joseph A. Agriculture, Forestry and Fisheries. Introduction 2. Materials and Methods 2. Collection of Immature Allanblackia Fruits 2. Fruit and Seed Assessment for Maturity 2.
Chemicals Used 2. Fruit and Seed Preparation 2. Experimental Treatments 2. Seed Incubation and Incubation Conditions 2. Data Collection 2. Experimental Design and Data Analysis 3. Results 3. Fruit and Seed Assessment for Maturity 3. Percentage Shoot Emergence 3. Effects of Treatments on Time Taken to Germinate 3. Effect of Treatments on Seedling Growth 4. Discussion 5. Conclusion 1. Introduction Allanblackia trees produce large berry-like fruits that contain seeds 30 to 50 of high food, cosmetic and pharmaceutical importance Foma and Abdala, , Bonanome and Grundy, Allanblackia seeds are mainly obtained from collections of wild mature fruits that drop off the tree.
Oleic and stearic acids are reported to lower plasma cholesterol levels Bonanome and Grundy, Also, the fat from Allanblackia seeds has a relatively high melting point 35oC , which makes it more valuable than other fats because it can be used without the need to transform its consistency for margarines and similar products Nkengfack et al.
These characteristics make Allanblackia seeds extremely valuable to food and cosmetic industries. To produce large number of Allanblackia trees, the seeds must be domesticated Munjuga et al. Unfortunately, efforts to domesticate Allanblackia through seed propagation is hindered by the lack of a method to induce spontaneous and high rate of seed germination Atangana et al.
Allanblackia seeds could remain dormant for as long as 2 years, and only one in ten seeds eventually germinates Ofori et al. The need to increase the rate of Allanblackia seed germination, and possible methods to stimulate early germination, is the drive behind research aimed to understand the contol of Allanblackia seed dormancy.
Seed rot is however high under these methods. The response of the seeds soaked in fluridone and water suggests that young scarified seeds still exhibit dormancy. We propose that this may be caused by the presence of growth inhibitor s , perhaps abscisic acid, and that the effect of the inhibitor is related to the duration of soak in water or ABA inhibitor.
Fluridone is a plant growth regulator that is known to induce germination in many plant parts that exhibit dormancy by competitively inhibiting C40 carotenoid, which is the precursor of abscisic acid ABA biosynthesis Fong et al. However, the most effective soak duration in fluridone or water on germination of scarified seeds from immature fruits is not known.
Also, information on the effects of such approach on seedling establishment and growth is hard to come by. In this study, all the fruits were plucked by detaching from the tree either at the point of attachment of the fruit stalk pedicel to the stem or along the stalk. Allanblackia floribunda was choosen because it is the dorminant Allanblackia species found in Nigeria. Fruit and Seed Assessment for Maturity The plucked fruits were assessed for maturity using the indices detailed by Bewley and Black , even when the plucked fruits were expected to be immature.
The rationale for collecting immature fruits in this study relates to the hypothesis that dormancy may be avoided by collecting seeds before the desiccation and hardening of the seed coat, and that recalcitrant seeds, when collected before the hardening of the seed coat are germinable and may require no pretreatment to germinate Bewley and Black, Fluridone was purchased from Chem Services Inc. Fluridone was chosen because it is known to inhibit ABA biosynthesis and induce germination.
Also, if dormancy in immature Allanblackia seeds resulted from ABA concentration then, inhibiting ABA biosynthesis should induce early germination. Fruit and Seed Preparation Allanblackia floribunda fruits were wrapped in plantain leaves for two weeks to soften them prior to seed extraction.
The seeds were extracted from the fruits, cleaned, weighed, scarified and weighed again. Scarification was done because seeds tend to germinate faster when the hard seed coat is removed or thinned down. The seeds were observed weekly for germination. A one-hour soak duration was considered the maximum duration it could take to wash and surface-sterilizes seeds in a routine seed preparation activity.
Seed Incubation and Incubation Conditions Scarified, treated seeds were placed in sterile transparent plastic containers. The containers were kept moist by spraying some distilled water on the inner part of the cover. Each container was then wrapped in a black polythene bag and placed in a warm screen house.
Temperature and relative humidity, inside the seed storage containers, and screen house were monitored using a MHZ cable free Oregon scientific sensor model BTHR One seedling was transplanted into a polypot filled with 3 kg top soil. The height of each plant was measured weekly for eight weeks.
The number of leaves per plant was counted weekly. Experimental Design and Data Analysis This experiment was a 3 x 3 factorial experiment arranged as a Completely Randomized Design; with three fluridone concentrations and three soak durations. Data was analyses using GenStat Release Rate of germination was determined using percentages. Data on duration from treatment date to germination was analyzed using survival data analysis. Survival data analysis is a statistical tool for analyzing data where the outcome variable is time until the occurrence of an event, which in this study was shoot emergence.
This program is most suitable in the analysis of data on duration from a defined time to the occurrences of a named event, and where some elements in the study survive i. Thus for such seeds, the duration to germination is unknown but at least as long as the duration of the study and so, it is censored and used in the model. Censoring is important in survival analysis, representing a particular type of missing data.
Also, because the distribution of this type of data is usually not a normal distribution, the regular Analysis of Variance ANOVA cannot be used in this analysis. Plant height data was analyzed using two-way analysis of variance. Means were separated using standard error of difference SED. The seeds on the other hand were germinable; they appeared well filled, embryo was present, they sunk in floating tests for germinability, the endosperm was slightly hard and the seed coat was easy to cut through.
Average seed fresh and dry weights were 6. By 7 WAT, shoot emergence was observed in many treatments and shoots were up to 2 mm. Figure 1. Effect of fluridone concentration and soak duration on rate and percentage shoot emergence Thus, prolonging the soak duration in water to 12 h increased the percentage seed germination.
Figure 2. Kaplan-Meier log cumulative hazard germination curve for the effect of treatment on time taken to germinate for Allanblackia seeds. These treatments clearly stimulated germination in more seeds and shortened the duration to germination compared to the control.
However, the effects of these treatments were comparable to that of a prolonged 12 h soak in water. Prolonging the soak duration did not hasten the duration to germination. Effect of Treatments on Seedling Growth 3. The mean number of leaves square root transformed was 1. Table 1.
Seedling plant height at transplant as affected by treatments.
Abstract The consumption and commercial exploitation of Allanblackia Clusiaceae seed oils is of current interest. The favorable physicochemical characteristics of Allanblackia oil solid at room temperature; high stearic acid content lend food products that contain it i. Such considerations are important for individuals prone to cardiovascular disease or with hypercholesterolemia. Domestication projects of several Allanblackia species in tropical Africa are underway, but wildcrafting of fruits to meet the seed demand still occurs. Proper species authentication is important, since only authenticated oil can be deemed safe for human consumption. The chemical constituency of Allanblackia seed oils, and potential roles of these phytochemicals in preventive strategies e. The primary and secondary metabolite constituency of the seed oils of nearly all Allanblackia species is still poorly known.
The medium-sized tree up to 30 meters tall is evergreen and dioecious male and female flowers on different plants. The wood is said to be resistant to termites but is not particularly durable. In Ghana small trees are cut for poles and find use as mine pit-props and bridge-piles. The twigs are used in Ghana as candlesticks, and the smaller ones as chew-sticks and tooth-picks in Ghana and Gabon. The bark has anodynal properties. In the Region it is pounded and rubbed on the body to relieve painful conditions.