In situ evaluation of fruit yield and estimation of repeatability coefficient for major fruit traits of umbu tree [Spondias tuberosa (Anacardiaceae)] in the semi-arid region of Brazil

The umbu tree (Spondias tuberosa) is a xerophytic woody species endemic to the northeast of Brazil. The present work reports a three-year in situ evaluation of major yield components in a random set of trees in Petrolina city, Pernambuco State, Brazil and the application of repeatability coefficient in the context of genetic resources utilization. Five traits were assessed: total fruit yield per plant (FY); total number of fruits per plant (NF); average fruit weight (FW); average pulp weight (PW) and average fruit diameter (FD). The values observed for FY ranged from 4.2–184 kg with mean of 61.5 kg. The values for NF ranged from 257 to 12,981 fruits/tree with mean 3,993 fruits. For FW, the range was from 10.82–23.36 g with mean of 16.03 g. The values for PW ranged from 7 to 17 g with mean of 11.2 g, while FD values varied from 2.5 to 3.5 cm with mean of 3.0 cm. Six methods were employed to estimate repeatability coefficient (r) for all parameters. The r ranged from 0.68–0.76 for NF; 0.87–0.89 for FW; 0.65–0.75 for FY; 0.64–0.78 for PW and 0.70–0.84 for FD. Narrower ranges across methods were observed to r-values greater than 0.80, as observed for FW and FD. Three to four years of measurements will be necessary for FY, NF, and PW and one year for FW to obtain a precision of 90% to provide a reliable identification of individuals for in situ or ex situ conservation.     

Ecogeographic and genetic diversity based on morphological characters of indigenous rice (Oryza sativa L.) in Yunnan, China

Yunnan is one of the largest centres of genetic ecological diversity and the richest area for elite germplasm of rice (O. sativa L.) resources in the world. Its indigenous rice average diversity index of six ecological groups are, in turn, javanica (1.2319) > aman (1.1738) > communis (1.1726) > nuda (1.1618) > aus (1.1371) > boro (0.9889), and there are great differences between indica (1.1454) and japonica (1.2081). The indigenous rice in Yunnan can be divided into 58 varieties, almost the total number found in China, and the cultivars account for 8.6% of the total cultivars in China. A great difference in ecological diversity index of rice resources between prefectures or counties in Yunnan province also exists, with the southwest part (Lincang, Xishuangbanna, Dehong, Simao) and southeast part (Wenshan) having been found to be the largest centre of genetic diversity, as their average genetic diversity index ranges from 1.2735 to 1.2036, especially. The average diversity index of the Cangyuan, Gengma, Zhenkang, Yongde, Yingjiang, Jinghong, Menghai, Shuangjiang, Ruili, Longchuan, Mojiang, Wenshan and Guangnan counties, in particular, have an average diversity index ranging from 0.8 to1.0. On the contrary, in Diqing, Dongchuan, Kunming, Lijiang, Qujing, Chuxiong, it is comparatively low, i.e., 0.7843–1.1075. Differences in the ecological diversity index of rice resources between rice regions are small, only 1.1322 to 1.2849.     

Determination of genetic diversity in european cranberrybush (Viburnum opulus L.) genotypes based on morphological,phytochemical and ISSR markers

Genetic Resources and Crop Evolution - Turkey has a high diversity of native and commercially grown plants. European cranberrybush, a fruit species grown commercially in the country, is of interest...     

湖南典型茶树地理种群遗传多样性研究

本文利用RAPD分子标记技术，对4个湖南典型茶树地理种群的240个单株的遗传多样性、种群内和种群间的遗传变异进行研究，结果表明：21个10碱基随机引物共检测到226条谱带，其中多态性谱带为201条，占88.9%。遗传多样性分析结果显示：Shannon's多样性指数为0.43，74.7%的变异分布于群体内，而种群间变异占了25.3%；Nei's指数群体总基因多样度(HT)为0.37，群体内平均基因多样度(HS)0.28，群体间的基因多样度(HST)0.09，群体Nei's基因分化系数（GST）为0.23，说明76.7%的变异存在于种群间，群体内的变异占了总变异的23.3%，与Shannon's多样性指数相比基本一致，均表明种群内有较丰富的遗传变异；种群间的基因流（Nm）为0.74，显示种群间的基因交流有限。     

ISSR analysis shows low genetic diversity versus high genetic differentiation for giant bamboo, Dendrocalamus giganteus (Poaceae: Bambusoideae), in China populations

Dendrocalamus giganteus Munro is a high-value woody bamboo widely grown in Southeast Asia and China’s Yunnan Province. We investigated its genetic diversity in Yunnan as a prelude to considering effective breeding programs and the protection of germplasm resources. Inter-simple sequence repeat (ISSR) markers were used to assess the genetic structure and differentiation of seven populations. Seven ISSR primers generated 140 bands, of which 124 were polymorphic (88.57%). Genetic diversity within populations was relatively low, averaging 11.33% polymorphic bands (PPB), while diversity was considerably higher among populations, with PPB = 88.57%. Greater genetic differentiation was detected among populations (G _ST = 0.8474). We grouped these seven populations into two clusters within an UPGMA dendrogram—one comprised the Xinping and Shiping populations from central Yunnan, the other included the remaining five populations. Mantel tests indicated no significant correlation between genetic and geographic distances among populations. Breeding system characteristics, genetic drift, and limited gene flow (N _m = 0.0901) might be important factors for explaining this differentiation. Based on the overall high genetic diversity and differentiation among D. giganteus populations in Yunnan, we suggest the implementation of in situ conservation measures for all populations and sufficient sampling for ex situ conservation collections.     

Variation of morphological and adaptive traits in subterranean clover populations from Sardinia (Italy)

Variation was studied in subterranean clover for two morphological and four adaptive characters on genetically complex populations from Sardinia. The aim was to assess the population genetic structure in this almost completely inbred species, and to verify whether or not similar levels of diversity occurred at distinct sites of origin. Differences were found among populations for the class frequencies of the two morphological characters and for the subsequent level of intrinsic diversity measured by the Shannon-Weaver index. The variation among and within populations found for the other four characters suggested thatpopulations adjust in the long term their adaptive features to the environmental conditions but maintain contextually high levels of intra-population variation, which, in turn, is a primary factor of adaptation in environments that are seldom uniformspatially and temporally. A principal component analysis executed on the important traits for adaptation showed that these features could be combined, on the average, in different ways in the genetically complex populations here examined. Similarities or differences among populations were not necessarily related to geographic distances ofthe respective collection sites.     

Traditional seed management and genetic diversity in barley varieties in high-hill agro-ecosystems of Nepal

Chawali and Lekali are two common farmer’s barley varieties or landraces in Jumla, Nepal (2,240–3,000 m) with small to bold grains and wide adaptation from irrigated low lands to high hills. This study was undertaken to test whether features of the traditional seed system can significantly influence the diversity of a crop and its conservation on-farm. In Jumla (high-hill), the barley seed system is completely informal and is mainly from farmer to farmer. In the present study, the seed flows and the pattern of genetic diversity in barley were investigated to detect differences between the two varieties and test the divergence among populations of each variety These data suggested that Chawali, the more common variety, was less subject to homogenising gene flow between farms than was Lekali. A total of 128 farming households were surveyed for seed supply information and 128 populations for each landrace from two villages: Kartikswami and Talium were collected for SSR diversity analysis. Some 92 SSRs were screened in an initial sample of 20 barley populations of both landraces and 2 improved varieties (LG-51 and Soluwa). Of the 81 SSRs that consistently amplified, only 15 SSRs (19%) were polymorphic with gene diversity values ranging from 0.09 to 0.71. A medium to low diversity was detected among the landrace populations of barley varieties. Chawali populations were less polymorphic within ecological groups, and more divergent between than were Lekail populations. This result accords with Chawali having a more conservative local seed system.     

Analysis of genetic diversity in Turkish sesame (Sesamum indicum L.) populations using RAPD markers⋆

The genetic diversity of 38 cultivated populations of Sesamum indicum L. from four different regions of Turkey was estimated at the DNA level with the random amplified polymorphic DNA (RAPD) technique. Sixty-one bands were obtained for all populations 78% of which were polymorphic. Analysis of molecular variance (AMOVA) was used to investigate the genetic diversity of the populations which yielded highly significant differences among populations within regions (91.9% of the total genetic diversity). According to AMOVA and Shannon's index that were performed separately for each region, the highest value of genetic variation was observed among Northwest region populations (CV = 7.7; H₀ = 0.304) and lowest in the Southeast regions' populations (CV = 2.6; H₀ = 0.068). Nei and Li's similarity index was calculated and phylogenetic tree was established using the neighbor-joining algorithm. This phenetic analysis grouped 35 of 38 accessions in six groups leaving three highly diverse accessions outside. Wagner phylogenetic method was used to assess the phylogenetic relationships among the populations. In the majority-rule consensus tree, only 7 of the 32 forks showed above 60% occurrence. Using Principal Coordinate Analysis (PCO) of the RAPD data set, the groups were clearly separated along the first three axis. These results indicate that RAPD technique is useful for sesame systematics, and should be valuable for the maintenance of germplasm banks and the efficient choice of parents in breeding programs.     

Size, symbiotic effectiveness and genetic diversity of field pea rhizobia (Rhizobium leguminosarum bv. viciae) populations in South Australian soils

Field pea (Pisum sativum L.) is widely grown in South Australia (SA), often without inoculation with commercial rhizobia. To establish if symbiotic factors are limiting the growth of field pea we examined the size, symbiotic effectiveness and diversity of populations of field pea rhizobia (Rhizobium leguminosarum bv. viciae) that have become naturalised in South Australian soils and nodulate many pea crops. Most probable number plant infection tests on 33 soils showed that R. l. bv. viciae populations ranged from undetectable (six soils) to 32×10³ rhizobia g⁻¹ of dry soil. Twenty-four of the 33 soils contained more than 100 rhizobia g⁻¹ soil. Three of the six soils in which no R. l. bv. viciae were detected had not grown a host legume (field pea, faba bean, vetch or lentil). For soils that had grown a host legume, there was no correlation between the size of R. l. bv. viciae populations and either the time since a host legume had been grown or any measured soil factor (pH, inorganic N and organic C). In glasshouse experiments, inoculation of the field pea cultivar Parafield with the commercial Rhizobium strain SU303 resulted in a highly effective symbiosis. The SU303 treatment produced as much shoot dry weight as the mineral N treatment and more than 2.9 times the shoot dry weight of the uninoculated treatment. Twenty-two of the 33 naturalised populations of rhizobia (applied to pea plants as soil suspensions) produced prompt and abundant nodulation. These symbioses were generally effective at N₂ fixation, with shoot dry weight ranging from 98% (soil 21) down to 61% (soil 30) of the SU303 treatment, the least effective population of rhizobia still producing nearly double the growth of the uninoculated treatment. Low shoot dry weights resulting from most of the remaining soil treatments were associated with delayed or erratic nodulation caused by low numbers of rhizobia. Random amplified polymorphic DNA (RAPD) polymerase chain reaction (PCR) fingerprinting of 70 rhizobial isolates recovered from five of the 33 soils (14 isolates from each soil) showed that naturalised populations were composed of multiple (5-9) strain types. There was little evidence of strain dominance, with a single strain type occupying more than 30% of trap host nodules in only two of the five populations. Cluster analysis of RAPD PCR banding patterns showed that strain types in naturalised populations were not closely related to the current commercial inoculant strain for field pea (SU303, ≥75% dissimilarity), six previous field pea inoculant strains (≥55% dissimilarity) or a former commercial inoculant strain for faba bean (WSM1274, ≥66% dissimilarity). Two of the most closely related strain types (≤15% dissimilarity) were found at widely separate locations in SA and may have potential as commercial inoculant strains. Given the size and diversity of the naturalised pea rhizobia populations in SA soils and their relative effectiveness, it is unlikely that inoculation with a commercial strain of rhizobia will improve N₂ fixation in field pea crops, unless the number of rhizobia in the soil is very low or absent (e.g. where a legume host has not been previously grown and for three soils from western Eyre Peninsula). The general effectiveness of the pea rhizobia populations also indicates that reduced N₂ fixation is unlikely to be the major cause of the declining field pea yields observed in recent times.     

Extreme neutral genetic and morphological divergence supports classification of Adriatic three-spined stickleback (Gasterosteus aculeatus) populations as distinct conservation units

The fact that the intraspecific genetic differentiation in neutral genetic markers and genes coding for adaptive traits are not typically correlated has caused a great deal of conceptual and practical trouble in delimitation of conservation units. Although the importance of combining information on adaptive genetic divergence with information on historical and recent gene flow in the delimitation of conservation units has been recognized, integrated empirical studies to this end are still rare. We explored the evidence for the specific conservation status of two freshwater three-spined stickleback (Gasterosteus aculeatus) populations on the Adriatic side of the Balkan Peninsula by comparing their phenotypic and genetic characteristics to those of other representative European populations. Apart from focusing on the neutral genetic divergence in mitochondrial DNA sequences and microsatellite markers, we also compared the patterns of morphological differentiation (i.e. bony armour development) resulting from adaptation to freshwater environments. The Balkanic populations formed two distinct groups with regard to neutral genetic variation and had the least developed bony armour of all the examined populations. All morphometric analyses identified the two Balkanic populations as phenotypically – and hence most likely also ecologically – clearly distinct from other European three-spined stickleback populations. These results suggest that the two Balkanic populations (River Neretva and River Zeta) fulfil the most stringent criteria (i.e. lack of genetic and ecological exchangeability) to be classified as conservation units distinct from other European three-spined stickleback populations.     

Morphological and genetic diversity of Momordica cochinchinenesis (Cucurbitaceae) in Vietnam and Thailand

Momordica cochinchinensis (Cucurbitaceae) is native to South East Asia and is important for its nutritional and medicinal properties. There is little information available on morphological and genetic diversity, crop selection and strategic germplasm collection for M. cochinchinensis. In this study, 42 accessions of M. cochinchinensis collected from Vietnam, Thailand and Australia were analysed for diversity study both at a morphological and molecular level. Both morphological and molecular analyses were in agreement and clustered the accessions based on the country of origin. The markers investigated in this study could be used for future applications with samples from unknown origins or for gene tracking for important cultivars. The Momordica accessions were highly polymorphic based on the markers suggesting high genetic diversity. Therefore the results from this study will be important in future strategic germplasm collection, conservation, horticultural development and commercial propagation of M. cochinchinensis.     

Assessing genetic diversity in 23 early Polish oat cultivars based on molecular and morphological studies

In Poland oat breeding began at the late nineteenth century. During the World War II almost all of Polish breeding materials were lost, and then were replaced by German cultivars. The main aim of this paper was to show the level of genetic diversity of Polish oat cultivars which were bred before 1939. Simultaneously usefulness and informativeness of molecular and morphological methods were tested and compared. This study involved 23 cultivars, which were described by 25 morphological traits and three types of molecular markers (AFLP, ISSR and RAPD). Based on Dice coefficient, genetic distance between cultivars ranged from 0.17 to 0.44. The degree of morphological differentiation within the collection varied depending on trait. Nei’s genetic diversity for the combined results for the whole collection was equal to 0.202. Neither unweighted pair group method with arithmetic mean nor principal coordinate analysis showed any discrimination of cultivars according to breeding period and morphological trait. Part of morphological diversity has been preserved in the Polish early oat cultivars, do not exist anymore in contemporary cultivars, and also in landraces. The interest of breeders in early cultivars germplasm stored in genebank was and still is negligible. Breeding is confined to a few preferred by market morphotypes. So, it is very probable that the gene pools of early and contemporary cultivars could be separable.     

Preliminary study of genetic diversity in Swedish flax (Linum usitatissimum)

To investigate the genetic diversity of Linum usitatissimumL. in Sweden, 18 accessions, including 13 cultivars and five landraces, were analysed. This study was based on genetic variation in three enzyme systems (i.e., PGD, GPI and MDH) by using horizontal starch gel electrophoresis. The total genetic diversity of the studied flax material was very high (H _T= 0.62). Even though the highest genetic diversity lies within the accessions (G _ST= 0.07), a clear differentiation between fibre and oil flax was found with respect to three polymorphic loci (Pgd-1, Gpi-2 and Mdh-1). A phenogram, based on Nei's genetic distances between the accessions studied, showed five clearly defined groups but with low variation within the groups. The unexpected high genetic diversity found within accessions in the studied flax material may indicate that flax is more outbreeding than earlier believed.     

Relationship between population size and genetic diversity in endangered populations of the European bullhead (Cottus gobio): implications for conservation

This study investigated the relationship between the current size of endangered bullhead (Cottus gobio) populations and microsatellite genetic variability. Additionally, the microsatellite data were used to evaluate whether a genetic test for population bottlenecks was able to provide evidence of recent severe population declines. Finally, our results were used to develop conservation priorities and measures. Population size appears to be a crucial parameter in determining the amount of genetic diversity that can be preserved in bullheads, since a significant positive correlation was observed between both variables. Furthermore, in some populations we were able to detect genetic signatures of the documented decline in population size. We suggest that the most immediate goal for bullhead conservation should be to increase the size and the range of the populations, and in doing so minimise or even reverse further genetic erosion. Potential management actions like habitat quality improvement, reduction of river fragmentation and supplementation programmes (translocation, supportive breeding) are discussed.     

Geographical distribution and morphological diversity of red-fleshed kiwifruit germplasm (Actinidia chinensis Planchon) in China

The fruit flesh color of kiwifruit (Actinidia chinensis) is generally green or yellow when ripened. Developing kiwifruit cultivars with new fruit flesh color such as red-fleshed color has stimulated much interest for kiwifruit breeders and researchers recently due to its potentially importance for meeting the increasing and changing markets and consumers. In the present study, the whole geographical distribution and morphological variation of wild red-fleshed kiwifruit in China were investigated. In total of 56 accessions of red-fleshed kiwifruit were found across 19 separated localities, representing different ecological and climatic conditions throughout South and Central China. Characterization of nine horticulturally important fruit traits of all accessions showed that there are extensive variations in fruit shape, fruit hairs and as to red intensity, spread of the red pigments and background flesh color. The results presented here have updated the current knowledge on the natural distribution and ecological adaptation of wild red-fleshed kiwifruit resource, which should be valuable for kiwifruit agriculture such as the determination of planting areas of red-fleshed kiwifruit cultivars. The accessions with extensive morphological variation can also contribute to kiwifruit breeding in future such as developing new cultivars with red color flesh.     

Ecological,morphological and genetic diversity in <Emphasis Type="Italic">Oryza rufipogon</Emphasis> Griff. (Poaceae) from Hainan Island,China

In this study, ecological, morphological and genetic diversity in 11 surviving populations of Oryza rufipogon Griff. from Hainan Island, China were investigated. These data served to provide much needed data in support of conservation strategies. The results divided O. rufipogon into six ecotypes. The cluster analysis based on 19 morphological features showed clear differentiation among populations or within populations. The cluster analysis based on SSR also revealed similar results. The ecological, morphological and genetic diversity observed in O. rufipogon resulted in the following conservation recommendations: (1) the four currently protected O. rufipogon localities should be maintained, due to the different ecological communities represented at these sites; (2) some populations, such as HL (Hele county, Hainan Island), should be protected, but some populations, such as FC (Fucheng county, Hainan Island) and DL (Dalu county, Hainan Island), might not be protected. (3) An isolation zone should be established to avoid possible introgression between O. sativa L. and O. rufipogon; and human activities that impact O. rufipogon should be reduced or eliminated.     

Genetic diversity in wild Tunisian populations of Mentha pulegium L. (Lamiaceae)

The allozyme variation of 15 Tunisian wild populations of Mentha pulegium L. threatened by human activities (clearing, hard-grazing, ploughing, traditional uses) was surveyed by the analysis of 14 isozyme loci using horizontal gel starch electrophoresis. The species exhibited a high level of genetic variation within populations (the mean Ap = 2.20, P = 72%, Ho = 0.349 and He = 0.229), which indicates a predominately outcrossing mating system and the recruitment of new genotypes via dispersal seeds. The genetic structure analysis of the populations using F statistics indicates no inbreeding, and showed an excess of heterozygosity for few loci. The moderate differentiation of populations (F_ST = 0.110) and the low rate of gene flow between them (Nm = 2.02) might been caused by recent isolation of the populations through biotope disturbances. The value of Nei's genetic identity varied from 0.839 to 0.999 reflecting a relatively low genetic divergence between populations. Cluster analysis using UPGMA method and Nei's genetic identity values, showed that populations geographically close didn't always cluster together. However, populations within the same bioclimatic stage generally subclustered together indicating that differentiation between bioclimatic regions occurred.     

Traditional medicinal plant knowledge among Albanians, Macedonians and Gorani in the Sharr Mountains (Republic of Macedonia)

A medico-ethnobotanical study was conducted among Albanians, Macedonians, and Gorani in forty-one villages located in the Sharr Mountains in western Macedonia. The survey was conducted by interviewing local people of each community about the medicinal plants and their uses and properties. Seventy-six mainly wild taxa were found to represent the remaining folk medical heritage of the area. The large majority of the recorded plants are used in form of teas, and mainly for minor dysfunctions of the respiratory system. Among the findings, the uncommon uses of Ballota nigra L. (leaves) tea as a digestive, Convolvulus arvensis L. (aerial parts) tea against hypertension, Chenopodium urbicum L. leaves (topically applied) for treating hemorrhoids, and Cornus sanguine L. (leaves and fruits) tea against stomachaches could be of interest for further phytopharmacological studies. A significant portion of study participants raised concerns regarding the possibility of over-exploitation of a few species due to collecting practices serving both local and outside (pharmaceutical) markets. Most of the uses reported by Macedonians and Gorani were also recorded among Albanians, while a significant portion of plants quoted by Orthodox Macedonians showed an idiosyncratic use. This may be explained by the fact that the Gorani lived very close to the Albanian communities in the study area over the last century, with marriages between the two communities being commonplace and facilitated by their shared (Muslim) faith.