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.     

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.     

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.     

Evidence that subsistence farmers have domesticated indigenous fruits (Dacryodes edulis and Irvingia gabonensis) in Cameroon and Nigeria

Ten fruit and kernel traits were measured in 152 Irvingia gabonensis and 293 Dacryodes edulis trees from 6 villages in Cameroon and Nigeria. Frequency distribution curves were used to examine the range of variation of each trait of each species in each village and aggregated into national and regional populations. There were differences between the village sub-populations, with regard to the normality (e.g., mean kernel mass of D. edulis) or skewness (e.g., mean flesh depth of D. edulis) of the distribution curves and in the degree of separation between the individual village populations along the x axis, resulting in the development of a bimodal distribution in the regional population. For all traits, populations of both species differed significantly between countries, but only in D. edulis were there significant differences between the Cameroon populations. On the basis of the results of this study, D. edulis can be said to be virtually wild in Nigeria but semi-domesticated in Cameroon, while I. gabonensis is wild in Cameroon and semi-domesticated in Nigeria. These results are discussed with regard to a hypothesis that the range and frequency of variation in the different populations can be used to identify five stages of domestication. From a comparison of the frequency distribution curves of desirable versus undesirable traits, and statistically identifyable changes in skewness and kurtosis, it is concluded that as a result of the farmers’ own efforts by truncated selection, D. edulis is between Stages 2 and 3 of domestication (with a 67% relative gain in flesh depth) in Cameroon, while I. gabonensis in Nigeria is at Stage 2 (with a 44% relative gain in flesh depth). In this study, genetic diversity seems to have been increased, and not reduced, by domestication. This revised version was published online in June 2006 with corrections to the Cover Date.     

Domestication potential of Marula (Sclerocarya birrea subsp caffra) in South Africa and Namibia: 2. Phenotypic variation in nut and kernel traits

As part of a wider study characterizing tree-to-tree variation in fruit traits as 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 nuts were removed from the fruit flesh, and the kernels extracted, counted and weighed individually to determine the patterns of dry matter partitioning among the nut components (shell and kernel) of different trees. Mean nut, shell and kernel mass were not significantly different between the two countries. Between sites in South Africa there were highly significant differences in mean nut mass, shell mass, kernel mass and kernel number. In Namibia, there were highly significant differences between geographic areas in mean shell mass, kernel mass and kernel number, but not in nut mass. These differences had considerable impacts on shell:kernel ratios (8.0 - 15.4). In South Africa, mean kernel mass was significantly greater in fruits from farmers fields (0.42 g) than from communal land (0.30 g) or natural woodland (0.32 g). Within all sites, in both South Africa and Namibia, there was highly significant and continuous variation between individual trees in nut mass (South Africa = 2.3 - 7.1 g; Namibia = 2.7 - 6.4 g) and kernel mass (South Africa = 0.09 - 0.55 g; Namibia = 0.01 - 0.92 g). The small and valuable kernels constitute a small part of the nut (Namibia = 6.1- 11.1%; South Africa = 7.6 - 10.7%). There can be 4 kernels per nut, but even within the fruits of the same tree, kernel number can vary between 0-4, suggesting variation in pollination success, in addition to genetic variation. The nuts and kernels of the Namibian trees were compared with the fruits from one superior tree (Namibian Wonder: nuts = 10.9 g; kernels = 1.1 g). Oil content (%) and oil yield (g/fruit) also differed significantly between trees (44.7 - 72.3% and 8.0 - 53.0 g/fruit). The percentage frequency distribution of kernel mass was skewed from trees in farmers fields in South Africa and in some sites in Namibia, suggesting a level of anthropogenic selection. It is concluded that there is great potential for the development of cultivars for kernel traits, but there is also a need to determine how to increase the proportion of nuts with four kernels, perhaps through improved pollination success.     

Domestication of Dacryodes edulis: 1. Phenotypic variation of fruit traits from 100 trees in southeast Nigeria

A participatory approach to tree domestication is being pioneered by ICRAF and international partners in Cameroon and Nigeria. The domestication of Dacryodes edulis offers opportunities to improve the livelihoods of subsistence farmers and to diversify farming systems, such as cocoa farms. The trees produce marketable fruits as well as shade for cocoa and coffee. Twenty-four ripe fruits were collected from each of 100 D. edulis trees in Mgbuisi, southeast Nigeria by subsistence farmers. There was continuous and significant tree-to-tree variation in fruit mass (10.2±0.5–71.4±1.3 g), flesh mass (6.8±0.3– 62.2±1.2 g) and kernel mass (1.3±0.5–15.1±0.4 g). Mean fruit mass did not differ significantly between different land uses. Flesh mass:kernel mass ratio varied from 0.79 to 29.0. Two trees had fruits without kernels. There was also continuous and significant tree-to-tree variation in fruit length (39.0±0.6– 95.1±1.2 mm), fruit width (21.82±0.16–43.75±0.33 mm) and flesh thickness (1.82±0.1–6.39± 0.1 mm). Fruit length:width ratio varied from 1.35 to 3.18. Cooked fruits varied in taste with only 14% of trees getting the highest score. Similarly, fruits varied in oiliness with only 3% of trees getting the highest score. Thirteen skin colours were recorded, with the most common being dark blue (31%), greyish violet (29%) and deep blue (9%). Ninety-nine percent of the trees had been planted, with 57% in homegardens, 22% in crop fields, 17% in fallow land and 4% in cocoa. Tree height ranged from 4 to 22m, and DBH from 9.55 to 63.65 cm. Tree age ranged from 5 to 64 years. Farmers reported first fruiting from age 3 up to 22 years (average of 9.4 years). Most trees originated from seeds bought in markets (63%). Market prices of fruits from different trees, ranged from 2 to 12 fruits for 10 Naira (US0.07). These quantitative results will help in the identification of elite trees of D. edulis for cultivar development through clonal propagation.     

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.     

楚雄地区漾濞泡核桃果实性状研究

对云南省楚雄地区海拔1346~2200 m区域栽培的漾濞泡核桃果实性状进行观测分析。结果表明,其感官性状:核桃取仁容易,仁色以黄白色或黄色为主,食味香甜或香纯,无涩或微涩;经济性状:坚果三径均值为3.32~3.51 cm,果形指数为1.14~1.20,果壳为1.27~1.37 mm,单果质量为1.27~1.37 g,出仁率为46.21%~51%,单果质量、果壳厚具有相对较高的变异系数,分别为13.26、8.35,果形指数变异系数最低,为4.19。在不同海区间段三径均值、果形指数、果壳厚差异极显著,单果质量及出仁率差异不显著。海拔与果形指数呈显著的负相关,单果质量与出仁率呈极显著的正相关,出仁率与果壳厚、果形指数呈显著的负相关。在海拔1800~2100 m区域果实性状各项指标最优。     

同一区域不同分布高度葛萝槭表型性状变异分析

为了解同一区域不同分布高度葛萝槭种群表型变异程度及变异规律,对来自河北省灵寿县五岳寨地区3个分布高度葛萝槭种群进行单果质量、单果皮质量、果长、果宽、果厚、果实长宽比、单种质量、种长、种宽、种厚、种子长宽比及种子千粒质量等12个表型性状进行观测,采用平均值、变异系数、方差分析及相关性分析等方法进行分析.结果 表明:同一区...     

长柄扁桃坚果表型多样性及其相关关系研究

正长柄扁桃(Amygdalus pedunculata Pall.)属蔷薇科,桃属,扁桃亚属,有柄组落叶灌木,又名野樱桃、毛樱桃等,在我国主要分布于内蒙古中部和陕西北部的山坡或沙地[1-2],具有抗寒[3]、抗旱[4]、耐盐和耐贫瘠[5]等特性。长柄扁桃种仁富含油脂和蛋白,种仁含油率达55%[6]以上,蛋白质达15%30%[7]。油以油酸和亚油酸为主,脂溶性维生素含     

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.     

Characterization of tree-to-tree variation in morphological,nutritional and medicinal properties of <Emphasis Type="Italic">Canarium indicum</Emphasis> nuts

As part of a feasibility study of the commercialization potential of C. indicum nuts as Agroforestry Tree Products in Papua New Guinea, preliminary characterization studies have examined the tree-to-tree variation in morphological traits (nut and kernel mass and kernel:nut ratio), as well as nutritional (carbohydrate, fat, protein, sodium, vitamin E) and medicinal traits (anti-oxidant activity, anti-inflammatory activity and phenolic content) of kernels from 18 to 72 trees in a small number of different villages of Papua New Guinea (East New Britain Province). There was continuous variation in these traits indicating opportunities for multiple trait cultivar development targeted at food and pharmaceutical markets. Certain traits, for example anti-inflammatory activity, in which tree-to-tree variation was highly significant, present greater opportunities than others, such as saturated:unsaturated fatty acid ratio. This intraspecific variation was greater within populations than between populations. The data presented has allowed the development of a strategy to domesticate C. indicum for cultivation in homegardens and cocoa–coconut agroforests, using a participatory approach aimed at the production of agroforestry tree products (AFTPs) to empower small-holders and enhance their livelihoods and income.     

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.     

辽西高产山杏间接选种数量性状指标的确定

通过统计理论和SPSS软件对辽西山杏实生群体29个数量性状相关性、变异性和分布特征的研究表明:与经济性状核、仁相关的数量性状有嫩枝长、叶柄长、叶柄宽、叶形指数、果体、果皮厚、果重、核体、核皮厚;变异系数以雌蕊发育程度最大,高达86.5%,其次变异系数>20%的依次为果重、出核率、嫩枝长、核重、果皮厚、仁重、出仁率、仁形指数;所测性状均呈正态分布。将相关性、变异性相结合,确定雌蕊发育程度、嫩枝长度、叶形指数、果体、果重作为高产山杏间接选种的主要数量性状指标。     

Genetic variability and divergence studies in pod and seed traits of Pongamia pinnata （L.） Pierre., accessions in Bay Islands

In this study, we assessed the variability in pod, seed traits and oil content of 24 accessions of Pongamia pinnata collected from different parts of the Andaman and Nicobar Islands, India. The experiment was conducted at the Central Agricultural Research Institute, Port Blair during 2010 to 2011. The variability studies for pod and seed traits revealed that, the accession CPT-6 collected from New Wandoor in South Andaman recorded the maximum values for eight traits viz. pod length （75.51 mm）, pod width （34.62 mm）, pod thickness （17.55 mm）, 100 pod weight （770.33 g）, seed width （21.23 mm）, 100 seed weight （377.00 g）, oil percentage （43.92%） and germination percentage （94.7%）. However, the maximum seed length （26.46 mm） was recorded from CPT 2 and the maximum pod-seed ratio was obtained from CPT 13 and CPT 4 （2.50 and 2.44 respectively）. The phenotypic and genotypic coefficients of variations were also close to each other for all traits, but the 100 pod and seed weight exhibited higher phenotypic and genotypic coefficient of variation than the other traits. Estimates of broad sense heritability ranged from 0.30 （for seed length） to 0.95 （pod length） and genetic ad- vance as percent of the mean ranged between 11.66% and 57.40% with seed length giving the lowest value and 100 pod weight giving the high- est value. Both the phenotypic and genotypic correlation between pod length, pod width, pod thickness, 100 pod weight, seed width and 100 seed weight and between pod thickness, 100 pod weight, seed width, 100 seed weight and germination percentage were found to be strong. On the basis of non hierarchical Euclidian cluster analysis, 24 accessions were grouped into six clusters. The maximum numbers of seven accessions were included in cluster VI. The maximum intra cluster distance （10.238）shown by cluster VI and the maximum inter cluster distance （17.021） between V and HI followed by III and II （15.942）. Among the six clus- ters formed the cluster III recorded maximum oil percentage, 100 pod weight, 100 seed ,weight, pod length, pod thickness, pod width, seed width and. germination percentage, while cluster V recorded maximum pod seed ratio and germination percentage. The present findings suggest that the crossing between accessions of cluster V and cluster III will result in a wide spectrum of variability in subsequent generations.     

安徽地区华东野核桃果实特征和坚果品质的初步评价

[目的]探究华东野核桃果实性状、核仁成分及其相关性,为其资源的开发和综合利用提供依据。[方法]本研究以皖南华东野核桃资源为对象,测定其鲜果单果质量、果皮厚度与坚果单果质量、壳厚度、出仁率等果实性状及坚果核仁成分,分析其相关性。[结果]华东野核桃果实性状具有丰富的变异,大部分变异系数大于10%,其中,坚果壳厚度变异系数最大为43.92%。对坚果核仁成分的测定表明:核仁中脂肪含量最高,蛋白质次之,总糖含量较低;对脂肪组分的进一步分析可知,其不饱和脂肪酸含量较高,达92.68%。利用相关性分析,发现坚果单果质量与核仁脂肪含量呈显著正相关。利用主成分分析对华东野核桃果实性状及核仁成分的综合分析及评价发现,单株编号10和8的鲜果大小及不饱和脂肪酸含量在所受试单株中综合表现最好,可作为进一步育种的遗传资源。[结论]本研究首次报道华东野核桃果实核仁成分,发现其核仁脂肪酸含量高于薄壳山核桃、山核桃,且不饱和脂肪酸含量也高,表明其核仁是值得开发的一种新食品资源。该研究结果为华东野核桃资源的综合开发与利用提供了数据支持。     

Agroecological variation in the fruits and nuts of shea butter tree (<Emphasis Type="Italic">Vitellaria paradoxa</Emphasis> C. F. Gaertn.) in Nigeria

A basic understanding of the relationships between key phenotypic characters of the shea butter tree is considered a crucial step to its genetic improvement. As such fruit samples of the shea butter tree, Vitellaria paradoxa, were collected from nine locations in July, 2006, to determine the fruit and nut characteristics of the species. The choice of the locations was informed by the need to have as broad a picture of the trait diversity as possible. The nine locations covered were Akwanga, Ilorin, Lokoja, Makurdi, Minna (in the Southern Guinea Savanna), Jalingo, Kachia (in the Northern Guinea Savanna), Kano and Yola (in the Sudan Savanna), recognized as the main shea butter tree belt in Nigeria. Analysis of variance indicated significant (P < 0.05) variations in fruit and nut traits across agro-ecologies and specific locations (representing individual accessions). The Northern Guinea Savanna accessions had higher values for nut weight, nut length kernel weight and fruit weight. The Southern Guinea Savanna fruits were, however, superior in percent pulp weight. Nuts sourced from Akwanga were comparatively heavier and longer, had wider diameters, heavier kernels and higher percent testa weights which did not differ from those of Minna. Also fruits from Akwanga had significantly (P < 0.05) higher values for fruit length, fruit diameter, fruit weight and pulp weight. The Lokoja accession was superior to the rest in percent pulp weight, but it recorded least nut weight and nut length values. Nut shape index varied from 2.3 (Makurdi) to 1.5 (Jalingo). Nuts from Akwanga, Jalingo and Kachia had wide variation in nut weight in contrast to those from Lokoja, Makurdi and Yola (that were relatively similar). Fruit length had significantly (P < 0.05) positive relationship with pulp weight, fruit weight and fruit diameter. Nut diameter, however, had a negative relationship with percent pulp weight. A strong influence of some environmental variables on certain phenotypic traits was detected. Principal components analysis indicated nut weight, nut shape index, percent pulp weight and fruit shape index as the key discriminant variables for grouping shea butter fruit and nut in Nigeria. Results of this study indicated considerable diversity in fruit and nut traits of the shea butter tree in Nigeria, suggesting the possibility of selection for desirable traits.     

梅州不同区域油茶表型性状分析

对梅州地区梅江区(MJ)、梅县区(MX)和平远县(PY)、大埔县(DB)、丰顺县(FS)、五华县(WH)等6个不同区域的油茶花、叶及果3种器官的17个表型性状进行差异性分析。结果表明:梅州地区油茶的表型性状多样性均较丰富,其中花的表型多样性最为丰富。6个不同区域之间油茶的花、叶、果的17个表型性状的差异均达到极显著。表型性状最优的2个居群是FS和PY,其中FS的花冠直径最大,达59.16mm;柱头裂数最多,约8个;油茶鲜籽质量最大,达8.71 g;鲜果出籽率最高,达40.85%。PY的萼片数最多,约4片;花瓣数最多,约4片;叶宽最大,达27.79 mm;侧脉对数最多,约8对;单果质量最大,达22.22 g;平均果径最大,达33.76 mm;籽数最多,约5粒。聚类分析将梅州地区油茶表型性状分为大叶、小花、大果及出籽率低与小叶、大花、小果及出籽率高2种类型。     

6个栓皮栎种源种子形态及其幼苗生长的比较

[Objective]To compare the differences of seed morphological characters among provinces of Quercus variabilis Bl.,and explore the adaptive growth status of seedlings growing in the central distribution area. [Method]The seeds of 6 Q. variabilis provenances from six provinceswerecollected, and the seedlings were cultivated and transplanted to experimental field in the centre of natural distribution range (Wuhan Jiufeng National Forest Park), then the seed morphology and one-year seedling growth traitswere surveyed. [Result](1)There were significantor extremely significantdifferences among provenances in seed length, seed width, seed length/width ratio and 100-seed mass, the order of seed length among provenances was Beijing Provenance (22.28 mm),Hubei Provenance (22.10 mm), He'nan Provenance (20.80 mm), Shaanxi Provenance (19.57 mm), Yunnan Provenance (18.93 mm)and Liaoning Provenance (18.81 mm), the seed width of Beijing Provenance (19.71 mm) and Hubei Provenance (19.16 mm) was higher than that of the others, the seed length/width ratio of He'nan Provenance (1.38) was extremely significantly higher than that of the others; (2)There were significant or extremely significant differences among provenances in seedling height, ground diameter, leaf number, branching number and seedling height/ground diameter, the Beijing Provenance and Hubei Provenance were better in seedling height and leaf number, which were respectively 19.54 cm and 20.26 cm, 8.32 leaves and 9.50 leaves; (3)A decreasing trend with time for seedling growth traits among provenances was found; (4)There was a positive relationship between seed morphological characters and seedling growth traits except seed length/width ratio; the leaf number was significantly related to ground diameter and branching number and the seedling height and leaf number were closely related to the seed morphological characters; (5)It showed a decreasing trend with the growth time in the relationship between seedling growth traits and 100-seed mass. [Conclusion]The seedlings of Beijing Provenance and Hubei Provenance grew better in the experimental field which might be related to their larger seed mass, and the Yunnan Provenance in the south margin and the Liaoning Provenance in the north margin of distribution area of Q. variabilis grew weaker than the provenances in the centre of distribution area.With the effect of climate change, provenances in the margin of distribution area may lose in the community competition in the seedling stage if it cannot take advantage of its dispersal and settlement and affected by the disadvantage of growth and competition, so that the distribution and population renewal would surely be affected.     

大别山山核桃天然群体种实性状表型多样性

在大别山山核桃天然分布区选择3个有代表性的居群,对当年生大别山山核桃的果长、果宽、果形比、壳厚及单果重5个表型性状进行了测定和分析。结果显示,大别山山核桃果实的表型性状在居群间和居群内存在着广泛变异。经显著性检验,5个性状在居群内F值为0.48~2.12,居群间F值为41.64~76.02,差异均达到显著或极显著水平。表型性状中变异系数最大的是壳厚,最小的为果形比。