Variability of Baobab (Adansonia digitata L.) fruits’ physical characteristics and nutrient content in the West African Sahel

The present study was carried out to evaluate variability in fruit characteristics and nutritional quality of Baobab fruits with the aim of providing the background to select trees bearing fruit with desirable characteristics for further utilisation. Vitamin C, total sugar and ash contents were assessed in 178 Baobab fruit samples from 11 sites in Burkina Faso, Mali and Niger. Furthermore the following tree and fruit physical characteristics were recorded: tree height, bark colour, fruit size, pulp weight, seed weight, seed size and pulp colour. The content (mean?±?SD) of vitamin C was 4.78?±?1.02?g?kg^?1, sugar 514?±?72?g?kg^?1 and fruit weight 293?±?96?g. There was a significant correlation between annual precipitation of the tree population site and vitamin C content but not with sugar content. For sugar, there were significant positive correlations with latitude and longitude. Negative correlations were found between fruit size and both longitude and latitude with smaller fruits generally being found to the north/east. No relation was found between pulp or bark colour and the sugar or vitamin C content. The contents of protein, lipid, carbohydrates, ash and moisture in the seeds ranged from 156 to 159, 143 to 150, 641 to 652, 44 to 49 and 50 to 55.7?g?kg^?1 respectively. The variation for vitamin C and sugar found within populations is a first indication that valuable gains could be made by selection of superior trees.     

Phenotypic variation in fruit and seed morphology of Adansonia digitata L. (baobab) in five selected wild populations in Malawi

Adansonia digitata L. (Baobab) is widely distributed throughout Sub-Saharan Africa stretching from Senegal to Sudan, and from Ethiopia to Natal. Information of phenotypic and genetic variation is a prerequisite for the domestication and improvement of baobab fruits from the wild. A study was done to determine within and between provenance variability in fruit and seed characteristics of five populations selected from four silvicultural zones and assess whether morphometric traits could delineate populations from different zones into land races. Fruits were characterized from 55 trees representing a wide geographical range. Six fruit traits and three individual seed traits were assessed. Results showed highly significant differences (P????0.001) in fruit, pulp, and seed weight, fruit length and width, number of seed, individual seed weight, seed length and width within and between populations. Mean fruit weight ranged from 125.8?±?3.25 to 162.9?±?3.25?g, seed weight ranged from 38.6?±?2.5 to 66?±?2.01?g and pulp weight ranged from 28.7?±?1.33 to 41.4?±?1.33?g. Single seed weight showed pronounced evidence of divergence of populations into ecotypes. The rich diversity found between and within populations is important for domestication purposes and tree improvement through selection and breeding. All populations could be used for seed source but distribution should be consciously done recognizing existence of races.     

Phenotypic variation of baobab (<Emphasis Type="Italic">Adansonia digitata</Emphasis> L.) fruit traits in Mali

We analyzed the phenotypic variation of baobab (Adansonia digitata L.) fruits from Mali to define the domestication potential of this species. 269 trees, selected from 10 provenances distributed along a rainfall gradient, were characterized. Five fruits were sampled from each tree. Total individual fruit weight was partitioned into shell, pulp, and seed weight. Ratios were calculated between pulp + seed and total weight, and between pulp and seed weight. For all the measured fruit traits, we detected significant differences between provenances, as well as between trees from the same provenance. Assuming that the measured traits are under genetic control, the latter facts indicate that there are considerable opportunities for tree selection on a local scale. However, candidate plus trees with specific properties, e.g., extremely high pulp or seed weight, were found only in some locations. Mean pulp yield per fruit might be considerably increased by selecting the 5% trees with the highest pulp weight (mean: 45 ± 1 g, best 5%: >100 g). The same might be true for seed production (mean: 71 ± 2 g, best 5%: >150 g). Also the ratio between pulp and seed weight can be an important fruit characteristic for selection: in fruits with a low ratio, relatively more pulp sticks to the seeds when separating the two fruit parts by grinding, and thus more pulp will be lost for further processing. We identified several trees with a high pulp weight combined with a high ratio between pulp and seed weight. It is concluded that there is considerable phenotypic variability in traits of baobab fruit in Mali, offering opportunities for cultivar selection.     

Domestication potential of Marula (<Emphasis Type="Italic">Sclerocarya birrea</Emphasis> subsp. <Emphasis Type="Italic">caffra</Emphasis>) in South Africa and Namibia: 3. Multiple trait selection

An understanding of the inter-relationships between the traits characterising tree-to-tree variation in fruits and kernels is fundamental to the development of selected cultivars based on multiple trait selection. Using data from previously characterised marula (Sclerocarya birrea) trees in Bushbuckridge, South Africa and North Central Region of Namibia, this study examines the relationships between the different traits (fruit pulp, flesh/juice mass, and nut shell and kernel mass) as a means to determine the opportunities to develop cultivars. Strong and highly significant relationships were found between fruit mass and pulp mass in trees from South Africa and Namibia, indicating that size is a good predictor of fruit pulp production. However, fruit size is not a good predictor of nut or kernel production, as there were weak relationships between fruit and nut and/or kernel mass, which varied between sites and landuses. Generally, the relationships between fruit mass and kernel mass were weaker than between fruit mass and nut mass. Relationships between kernel mass and shell mass were generally weak. The lack of strong relationships between fruit and kernel mass does, however, imply that there are opportunities to identify trees with either big fruits/small nuts for pulp production, or trees with large kernels in relatively small fruits for kernel oil production. However, within fruits from the same tree, nuts could contain 0–4 kernels, indicating that even in trees with an inherent propensity for large kernels, improved pollination may be required to maximise kernel mass through an increase in kernel number. Finally, the relationships between percentage kernel oil content and the measured morphological traits were also very weak. The conclusions of these results are that there is merit in identifying different combinations of traits for the selection of trees producing either pulp or kernels. Consequently, fruit and kernel ‘ideotypes’ are presented as guides to the selection of elite trees for cultivar development. These results have important implications for the domestication of the species as a producer of fruits or kernels for food/beverages or cosmetic oils.     

Genetic differentiation and diversity of Adansonia digitata L (baobab) in Malawi using microsatellite markers

Baobab (Adansonia digitata L) belonging to Bombacaceae family, is one of the most widely used indigenous priority tree species in sub-Saharan Africa, valued in the cosmetic industry for its seed oil, and powdery fruit pulp for juice making. Baobab has high potential for domestication in southern Africa, therefore understanding its genetic diversity and population structuring is warranted. The study investigated the level of genetic diversity and differentiation of five populations of A. digitata L. sampled from four diverse silvicultural zones in Malawi. Variation at nine microsatellite loci were examined in 150 individual trees. Low mean genetic diversity was expressed through genetic diversity indices: Nei’s genetic diversity (h, 0.18 ± 0.03), Shannon Information Index (I, 0.21 ± 0.07), observed number of alleles (na, 1.47 ± 0.10), effective number of alleles (ne, 1.23 ± 0.04) and percentage polymorphic loci (pp, 48 %). The low genetic variation found is attributed to the population growing in marginal areas of genetic centre of diversity of the species, anthropogenic factors and founder effects. Moderate genetic differentiation was observed among populations (Gst = 0.13) indicating the presence of a large number of common alleles resulting in a homogenisation effect. Clustering of individual trees by genetic similarity coefficients indicated that mainland trees were genetically closer than the trees on Likoma Island. Mantel’s test showed a weak positive insignificant correlation (Z = 0.12; P = 0.64) between genetic distance among populations and actual distance on the ground implying that geneflow was not directly influenced by isolation by distance. The results suggest that seed distribution and tree improvement should recognise the presence of ecotypes and conservation measures should protect all the populations due to existence of private alleles which are of adaptive importance.     

无患子果实发育动态及内含物含量变化

对无患子果实生长发育动态及果肉内含物含量变化进行研究,结果表明,无患子果实纵径、横径、侧径、鲜质量等性状发育进程呈现明显的S型生长曲线特征;以果实生长发育时期为横轴(x),分别以果实纵径、横径、侧径、鲜质量的均值为纵轴(y),构建的果实生长发育数学模型表明,无患子果实生长各性状与果实发育时期高度相关,数学模型可以正确地反映无患子果实生长发育动态变化规律。对无患子果实脱落规律、果肉含水量、可溶性糖含量、皂苷含量变化规律等综合分析表明,10月下旬,无患子果实发育成熟,生长性状趋于稳定,果肉含水量和可溶性糖含量从峰值下降至相对较低水平,而果肉皂苷含量相对较高,因此提出该时期为无患子果实采摘的适宜时期。     

Seed Maturation Indicators in Pyracantha crenulata Roxb. in Kumaun Central Himalaya

Fruits of Pyracantha crenulata were collected from two locations varying by approximately 550 m in elevation from south aspect for assessing seed maturation indicators. The mean seed size (length×diameter) across the collection dates varied between 1.61 ± 0.7 and 4.93 ± 0.06 mm² across both the locations. The seed moisture content negatively correlated with germination. The change in fruit colour from dark green to light orange, the range of fruit moisture content (30.43% ± 0.06 to 36.10% ± 0.25) and the seed moisture content between 68.8% ± 0.68 and 71.6 ± 0.62 coincided with maximum germination and appear to be major indicators of seed maturation in Pyracantha crenulata.     

Domestication of Irvingia gabonensis: 3. Phenotypic variation of fruits andkernels in a Nigerian village

Domestication of Irvingia gabonensis, a fruit tree grown in agroforestry systems in West and Central Africa, offers considerable scope for enhancing the nutritional and economic security of subsistence farmers in the region. Assessments of phenotypic variation in ten fruit, nut and kernel traits were made on twenty-four ripe fruits from 100 Irvingia gabonensis trees in Ugwuaji village in southeast Nigeria, a center of genetic diversity for this species. There were important differences between the young planted trees of this study and the older unplanted trees of a similar study in Cameroon. Significant and continuous tree-to-tree variation was found in fruit mass(69.0–419.8 g), flesh mass (59.5–388.8 g), nut mass (9.5–40.6 g), shell mass (4.9–30.9 g) and kernel mass (0.41–7.58 g); fruit length (49.2–89.3 mm) and width (46.2–100.5 mm) and flesh depth (12.9–31.4 mm), as well as considerable variation in flesh colour, skin colour, fruit taste and fibrosity. Some fruits were considerably bigger than those found in Cameroon. These quantitative results will help in the development of cultivars within participatory approaches to agroforestry tree domestication, and so promote poverty alleviation and sustainable agriculture. This revised version was published online in June 2006 with corrections to the Cover Date.     

Cacao-fruit tree intercropping effects on cocoa yield, plant vigour and light interception in Côte d’Ivoire

A major challenge for cocoa producers in Côte d’Ivoire is to seek alternative shade trees or crop associations to adapt their planting devices and techniques to the shortage of forests. The recent tendency developed by farmers is to plant simplified orchards combining cacao and fruit trees. An on-farm trial was set up in a 5-year-old cocoa farm to compare a cacao monocrop planted at densities of 1,115 trees ha^?1 with cacao intercropped with orange or avocado trees, both at 44 trees ha^?1. Observations were done on incident light received by the cacao, vigour, growth and cocoa yields. On average, the cacaos received 100 % light in the monocrop, 89.6 % under orange trees and 80.6 % of incident light under avocado trees. They yielded 64.0 pods tree^?1 year^?1 in the monocrop (equivalent to 2.54 kg dry cocoa beans tree^?1), 30.3 pods tree^?1 when combined with orange trees and 28.3 pods tree^?1 with avocado trees. The two combinations allowed cocoa yields equivalent to those observed in the region (0.58 kg dry cocoa beans tree^?1). Vigour and yield were very highly correlated with the incident light received. Both the yield and the incident light are a logistic function of the planting distance from the shade tree. The inflexion point of the logistic functions corresponds to the minimum planting distance between the cacao and the intercropped fruit trees. On this basis, we suggest that the cacaos should not be planted closer than 6.50 ± 0.2 m to the orange or avocado trees.     

Domestication potential of Marula (Sclerocarya birrea subsp caffra)in South Africa and Namibia: 1. Phenotypic variation in fruit traits

Studies of tree-to-tree variation in fruit traits are a pre-requisite for cultivar development. Fruits were collected from each of 63 marula (Sclerocarya birrea) trees in Bushbuckridge, South Africa and from 55 trees from the North Central Region of Namibia. The South African trees were in farmers fields, communal land and natural woodland, at three sites: Acornhoek road, Allandale/Green Valley and Andover/Wits Rural Facility. The Namibian trees were all from farmers fields in three areas: North east, North west and West. The fruits were partitioned into skin and flesh/juice to examine the extent of the variation found in different components of marula fruits from different trees. Namibian fruits were significantly larger than those from South Africa (26.7 vs 20.1 g), due to their greater pulp mass (22.2 vs 16.2 g), especially the flesh/juice component. In South African fruits, those from farmers fields were significantly larger in all components (Fruit mass = 23.6 vs 19.3 and 18.0 g in natural woodland and communal land respectively). In Namibia, mean fruit mass did not differ significantly across sites (25.5 − 27.0 g). However, within each sample there was highly significant and continuous variation between trees in the pulp (S Africa = 7.5 − 31.3 g; Namibia = 8.3 − 36.0 g) and flesh/juice mass (S Africa = 2.2 − 7.6g; Namibia = 3.8 − 22. 6g), indicating the potential for selection of trees producing superior products. The fruits of the Namibian trees were compared with the fruits from one superior tree (‘Namibian Wonder) with a mean fruit mass of 69.9 g The percentage frequency distribution of fruit mass from trees in farmers fields in South Africa was skewed, while being bimodal in North east and North west populations from Namibia, suggesting that at these sites farmers are engaged in domestication through truncated selection of the best mother trees. It is concluded that there are trees in on-farm populations that have great potential to be propagated vegetatively as selected cultivars.     

Variability in pod and seed traits of <Emphasis Type="Italic">Pongamia pinnata</Emphasis> Pierre ecotypes in North Karnataka,India

An evaluation of 30 naturally available candidate-plus trees (CPTs) of Pongamia pinnata was carried out to elucidate the genetic variability and relationship of pod and seed traits and progeny growth traits to select the best planting material with higher productivity. Significant variations were observed in pod and seed characteristics, oil content, and during the progeny trial studies. The highest values were found in 100-pod weight (410.4 gm) and 100-seed weight (195.92 gm) and the phenotypic and genotypic variance was found maximum in 100 pod weight (4364.71 and 4289.93) and 100 seed weight (813.8 and 768.93), respectively. Estimates of the phenotypic coefficient of variance were higher than the genotypic coefficient of variance for all the pod and seed traits and progeny growth traits, which depict the predominant role of the environment. Approximately 99 % of broad-sense heritability was revealed in oil content, followed by 100-pod weight (98.28 %), and canopy growth (96.93 %). Pod thickness shows the highest genetic advance of 56.61 %, followed by pod width (53.43 %) and canopy growth (49.3 %). Pod and seed traits have proven a positive correlation between each other and with progeny growth traits, except a few negative values. Hierarchical clustering by Ward’s minimum variance cluster analysis showed phylogeographical patterns of genetic diversity. K-means clustering revealed that trees from different geographical regions were grouped together in a cluster where as trees from the same geographical area are placed in a different cluster. Seven Pongamia ecotypes (GRP-8, 9, 13, 14, 18, 28, and 29) are found superior in traits, namely 100-pod weight, 100-seed weight, oil content, germination rate, plant height, canopy growth, and collar diameter. The traits 100-pod weight and 100-seed weight are highly correlated with the progeny growth traits and even have higher heritability and genetic advantages.     

Morphological variation in <Emphasis Type="Italic">Balanites aegyptiaca</Emphasis> fruits and seeds within and among parkland agroforests in eastern Niger

Balanites aegyptiaca (L.) Delile. is one of the priority indigenous fruit trees for rural communities in the West African Sahel. As part of a participatory tree domestication program in Niger, phenotypic variation in fruit and seed morphology was assessed in four natural populations in eastern Niger. Measured variables were weight of the fruit, seed coat and kernel; length and width of the fruit and seed (25 trees per population, 30 fruits per tree). Derived variables were the tree’s coefficient of variation (CVs) for each measured variable, and two sets of factor scores from principal components analysis of tree means and CVs. ANOVA indicated significant variation in all measured variables due to trees nested in populations. ANOVA and simple linear regression indicated significant geographic variation in some variables: the drier parts of the sample region tended to have heavier fruits and kernels, longer/narrower seeds, and lower within-tree variability in fruit and seed width. Length and width were strongly correlated between fruits and seeds, fruit weight was moderately correlated with seed dimensions, and CVs of fruit weight and width were moderately correlated with the CV of seed width. Some hypotheses for the geographic variation are presented, and some practical implications of the correlations for tree domestication programs are discussed.     

Domestication of Irvingia gabonensis: 2. The selection of multiple traits for potential cultivars from Cameroon and Nigeria.

Ten fruit and kernel traits were assessed in 24 fruits of each of 152Irvingia gabonensis trees in three distinct populations in west and central Africa [2 populations of non-planted trees in Cameroon: Nko'ovos II (21 trees) and Elig-Nkouma (31 trees) and 1 population of planted trees in Nigeria: Ugwuaji (100 trees)]. Strong relationships were found between fruit weight and other fruit traits (e.g. flesh weight[r ² = 0.99: P < 0.001],fruit length [r ² = 0.74–0.83:P < 0.001], fruit width[r ² = 0.77–0.88: P< 0.001]). In contrast, relationships between kernel weight and other kernel/nut traits (e.g. shell weight and nut weight) were found to be weak[r ² = 0.009–0.37, P =0.058–0.001], with the exception of nut weight at Nko'ovos II(r ² = 0.65, P < 0.001).Relations hips between fruit and kernel traits (fruit massv. kernel mass, fruit mass v. shell mass, flesh mass v. kernel mass, nut massv. fruit mass and flesh depth v.kernel mass) were found to be very weak. This indicates that domestication through the selection and vegetative propagation of multiple-trait superior phenotypes is unlikely to be able to combine good fruit characteristics and good kernel characteristics within cultivars. Consequently, domestication activities should independently focus on ideotypes representing: 'fresh fruit' traits, and 'kernel' traits, that combine high values of the different fruit and kernel characteristics respectively. Evidence from this study indicates that selection of the three trees closest to the fruit ideotype per village as the mother plants for vegetative propagation and cultivar development, should give village level gains of 1.3 – 2-fold in fruit mass, and up to 1.5-fold in taste. Similarly for the kernel ideotype, selection of the three trees with the best fit would give potential gains in kernel mass of 1.4 – 1.6-fold. This revised version was published online in June 2006 with corrections to the Cover Date.     

Variation of pomelo (Citrus grandis (L.) Osbeck) in Nepal and participatory selection of strains for further improvement

A farmers’ participatory survey was carried out in the mid-hill and plain (Terai) regions of Nepal to assess the diversity, consumers’ preference for fruit quality and potential for selection of elite pomelo clones. A wide variation of morphological characters of tree, fruit, leaf and seed was identified from information gathered and from laboratory analysis. Multivariate analysis of the data produced five discrete groups, which were represented by plants from different agro-ecological regions and soil types. The groups differed significantly in yield efficiency, fruit shape and size, pulp, juice, total soluble solids and acid content, seed number, leaf shape and size. Some fruit characters, such as yield, size and acid content were found to be affected by environment and genotype, whereas others, such as fruit shape, pulp colour, seed number, bitterness were not affected by environment. Leaf shape and petiole wing shape were also not affected by the environment. Farmers were more interested in quality characteristics rather than to aspects of yield. Six superior types were identified.     

Fruits of our labour: contribution of commercial baobab (Adansonia digitata L.) fruit harvesting to the livelihoods of marginalized people in northern Venda, South Africa

Baobabs (Adansonia digitata) provide products, mainly bark, leaves and fruit, which are used for subsistence purposes and traded to generate cash. Recently, demands for baobab fruit derivatives on the global organic market, namely pulp and seed oil, have increased rapidly, leading to concerns that this may have negative impacts on subsistence users, particularly in areas where there is an existing high dependence on these products, such as West Africa. In contrast, in southern Africa baobab fruit are probably ‘underutilized’ and commercialization would help reduce poverty. This study evaluated the direct-use (subsistence) and income (cash) value of baobab fruit on the livelihoods of baobab fruit harvesters in South Africa. Harvesters were mostly women (98 %), many of whom were unemployed (98 %) and uneducated (70 %). The majority (68 %) received social grants and were involved in informal occupations (55 %), which contributed 35 and 18 % to total annual income respectively. The trade and direct-use value of non-timber forest products contributed 14 and 33 % to annual income, of which, baobab fruit made up 38 and 4 % respectively. Baobab fruit was the only non-timber forest product that had a higher income value (4×) than direct-use value. Cash earned was used to buy food (73 %) and invest in small businesses, suggesting a move from subsistence to cash economy. It is suggested that commercialization of baobab fruit will have far-reaching benefits; and that secured access to trees and investment in local beneficiation will further increase the value of the resource for many marginalized people in southern Africa.     

Long-term study of above- and below-ground biomass production in relation to nitrogen and carbon accumulation dynamics in a grey alder (Alnus incana (L.) Moench) plantation on former agricultural land

In the Northern and Baltic countries, grey alder is a prospective tree species for short-rotation forestry. Hence, knowledge about the functioning of such forest ecosystems is critical in order to manage them in a sustainable and environmentally sound way. The 17-year-long continuous time series study is conducted in a grey alder plantation growing on abandoned agricultural land. The results of above- and below-ground biomass and production of the 17-year-old stand are compared to the earlier published respective data from the same stand at the ages of 5 and 10 years. The objectives of the current study were to assess (1) above-ground biomass (AGB) and production; (2) below-ground biomass: coarse root biomass (CRB), fine root biomass (FRB) and fine root production (FRP); (3) carbon (C) and nitrogen (N) accumulation dynamics in grey alder stand growing on former arable land. The main results of the 17-year-old stand were as follows: AGB 120.8 t ha^?1; current annual increment of the stem mass 5.7 t ha year^?1; calculated CRB 22.3 t ha^?1; FRB 81 ± 10 g m^?2; nodule biomass 31 ± 19 g m^?2; fine root necromass 11 ± 2 g m^?2; FRP 53 g DM m^?2 year^?1; fine root turnover rate 0.54 year^?1; and fine root longevity 1.9 years. FRB was strongly correlated with the stand basal area and stem mass. Fine root efficiency was the highest at the age of 10 years; at the age of 17 years, it had slightly reduced. Grey alder stand significantly increased N and C_org content in topsoil. The role of fine roots for the sequestration of C is quite modest compared to leaf litter C flux.     

Distribution of heartwood extractives in hybrid larches and in their related European and Japanese larch parents: relationship with wood colour parameters

Heartwood is the most valuable part of larch timber when either natural durability or aesthetic aspects of the wood are required. Both properties are directly linked to chemical extractives and particularly to phenols. Based on a broad sample of trees (583) from European and Japanese larch and their interspecific hybrid, we investigated the variability in phenolic content, and particularly of two major compounds, Taxifolin (Tax) and Dihydrokaempferol (DHK), and their link with wood colour. At the individual wood sample level, phenolic contents ranged from 6.0 to 55.9 mg eq. Tax/g DW. Taxifolin was the most abundant constituent (range: 1.3–41.7 mg/g DW) compared with DHK (0.5–13.7 mg eq. Tax/g DW). A high variability among taxa, genotypes and individual trees within taxa and within trees was observed. Japanese larch had the highest amount of total phenols and of Taxifolin and European larch the lowest. For DHK, Japanese larch was the poorest compared with European larch. Hybrid larch had both a high content of Taxifolin and of DHK. Variability for colour parameters was on average weaker than for phenolic content but still large enough to show significant differences between taxa. Correlations between colour parameters and extractives were moderate to weak. At the mean genotype level, a good link (r > 0.51, p < 0.001) was found between a* (red–green axis in CIELAB) and total phenols and Taxifolin contents and between L* (Lightness) and DHK content (r > 0.54). The broad variability observed in this study at different levels for phenolics offers opportunities for breeders to genetically improve the quality of larch heartwood, in particular in relation to decay resistance.     

Quantitative descriptors of variation in the fruits and seeds of Irvingia gabonensis

Methods were developed to quantify variation in the fruit, nut and kernel traits using the fruits from four trees of Irvingia gabonensis, an indigenous fruit tree of west and central Africa. The measurement of 18 characteristics of 16–32 fruits per tree identified significant variation in fruit, nut and kernel size and weight, and flesh depth. Differences were also identified in shell weight and brittleness, fruit taste, fibrosity and flesh colour. Relationships between fruit size and weight with nut and kernel size and weight were found to be very weak, indicating that it is not possible to accurately predict the traits of the commercially-important kernel from fruit traits. Seven key qualitative traits are recommended for future assessments of the levels of genetic variation in fruits and kernels. These traits describe ideotypes for fresh fruit and kernel production.This revised version was published online in November 2005 with corrections to the Cover Date.     

Fruit- and seed-germination characteristics of Strychnos cocculoides an indigenous fruit tree from natural populations in Zambia

Domestication and improvement of traditionally used wild indigenous fruit trees hold great promise in agroforestry development. Strychnos cocculoides is a wild indigenous fruit tree that was ranked third by farmers and is one of the priority species chosen for domestication in southern Africa. This study was conducted with the objective of determining the variability in fruit, seed and germination characteristics of four populations of Strychnos cocculoides collected from Zambia. Results showed significant differences (P < 0.05) between and within provenances in fruit, pericarp and pulp weights. Fruits from Kalulushi provenance were heaviest (296 g) whereas the lightest were Petauke provenance fruits (158 g). The pulp content of heavy and light fruits were 52.8% and 47.6% respectively. There was no significant difference (P > 0.05) in the number of seeds per fruit within and between the provenances. In contrast, the seed weight was significantly different (P < 0.05) within and between provenances. The heaviest seeds were found in the heaviest fruits — Kalulushi while the lightest were found in Serenje provenance. Fruit weight was positively correlated with pulp weight (P < 0.001, r = 0.70), pericarp weight (P < 0.001, r = 0.54) and seed weight (P < 0.001, r = 0.76). The provenances differed significantly (P < 0.05) in cumulative germination percentage, ranging from 56 (Kalulushi) to 83 (Kasama).This revised version was published online in November 2005 with corrections to the Cover Date.     

Selection of promising chestnuts (<Emphasis Type="Italic">Castanea sativa</Emphasis>) among wild growing trees from southern Mediterranean region forests of Turkey

Turkey ranked third place in the world for chestnut production after China and South Korea and the country has unique chestnut forests including valuable and diverse chestnut genotypes. This study was conducted to select superior chestnut genotypes within seedling populations found in natural wild grown chestnut forest located in Isparta province in Turkey during 2010–2011 years. A total of 2500 wild grown chestnut trees were examined on the field first year and among them the most promising 22 genotypes were chosen according to relatively high yield capacity, earliness, tolerance to chestnut blight (Cryphonectria parasitica), ink disease (Phytopthora cambivora), and fruit quality characteristics. The selected 22 genotypes were evaluated for their detailed morphological, phenological and pomological traits in 2010 and 2011. According to average of 2 years, nut weight, the number of nut per kilogram, nut width, nut length, nut height and nut shell thickness of 22 promising genotypes ranged from 10.26 to 22.32 g, 97.47 to 44.80/kg, 26.80 to 42.47, 16.92 to 25.91, 27.74 to 39.73, and 0.26 to 1.01 mm, respectively. The ash, crude protein, and total fat content of kernels were between 0.85 to 1.94, 3.69 to 7.06 and 1.32 to 4.52, respectively. The genotypes were evaluated with weighted ranking method and the highest general quality score was observed in genotypes of IY17, IY01, IY42, IY43 and IY12.