The narrow genetic base of existing commercial oil palm cultivars has prompted oil palm breeders to give increased importance to augmenting these genetic resources because the sustainable development of the crop depends largely on the availability of genetic diversity and its use. Therefore, the purpose of this study was to conduct a molecular characterization of an ex situ collection of oil palm Elaeis guineensis Jacq. populations from the Republic of Cameroon using microsatellite molecular markers. Overall, 31 simple sequence repeats were polymorphic, with a total of 223 alleles, 78.4% of which were found at low frequency. The total genetic diversity was relatively high (HT= 0.673). The genetic differentiation between geographical regions was low (GST= 0.023, P= 0.001), and between families it was high (GST= 0.166, P= 0.001), showing greater variation between families than among geographical regions. The molecular data indicate that genetic diversity among the genotypes evaluated is mainly distributed within regions, suggesting that there is no isolation by geographical distance and that all the sampled individuals form a single diverse population. Therefore, it was concluded that a relatively low number of accessions (120 in the analysed case) that includes at least one representative of each family would allow us to efficiently collect almost the entire genetic diversity of Cameroon within the collection studied. This will allow for the efficient use of genetic resources and a reduction in morpho-agronomic characterization costs.

Substantial variation in phenotypic traits and ISSR fingerprinting was observed among twenty populations of Achillea fragrantissima (Forssk.) Sch. Bip. in Egypt. Such variation was reflected in the clustering of the examined populations into two major groups: one representing populations in the mountainous area of South Sinai and the other comprising populations growing at low elevations in the middle of Sinai and the desert west of the Suez Canal from Suez in the east to Cairo in the west. Five populations in the eastern part of Sinai near Nuwieba and Taba on the Gulf of Aqaba were loosely assigned to the first group. The populations growing at high elevations in South Sinai, under lower temperature and higher humidity, were characterized by a higher number of total and polymorphic ISSR markers compared with other populations. Unique ISSR markers were more often observed in the fingerprinting of seven populations including five populations growing in the high mountains of Saint Catherine in South Sinai and two populations growing at low elevations but at Wadi Hof south-east of Cairo. Interestingly, unique bands were found in the populations that possessed traits associated with larger plant size and seed yield as well as better vigour. These are important criteria for the selection of A. fragrantissima populations for conservation and sustainable commercial use.

Castor is an industrially important oilseed crop. Vascular wilt caused by the soil borne fungus Fusarium oxysporum f. sp. ricini is a serious disease of castor. Use of resistant cultivars is the only viable option for management of wilt disease problem in castor production. Excellent sources of resistance to wilt have been found in castor germplasm. In this study, a set of four castor inbred lines (48–1, CI-1, AP42 and AP48) was characterized for inheritance of resistance to wilt by studying segregating populations generated by crossing these inbred lines with eight different susceptible genotypes. An artificial screening method (sick pot) with a new scoring system (days to wilt) was used for evaluation of plant progenies for reaction to the pathogen infection. The reaction of F1s indicated that the nature of resistance in 48–1, CI-1 and AP48 is recessive whereas it was dominant in AP42. Inheritance results from eight F2 populations showed that resistance to wilt is conferred by a single locus in one population and at least two loci, which interact in complementary way, in other seven populations. Different modes of inheritance were also observed when the same resistant source was crossed with different susceptible parents, indicating the possible role of genetic backgrounds in determining resistance. Overall, the results suggested that Mendelian resistance to wilt is predominant in the castor genotypes, which can be exploited for breeding cultivars. Particularly, AP42 with dominant nature of resistance will be of great interest to hybrid breeding.

Drought stress ‘particularly at seedling stage’ causes morpho-physiological differences in wheat which are crucial for its survival and adaptability. In the present study, 209 recombinant inbred lines (RILs) from synthetic wheat (W7984)× ‘Opata’ (also known as SynOpRIL) population were investigated under well-watered and water-limited conditions to identify quantitative trait loci (QTL) for morphological traits at seedling stage. Analysis of variance revealed significant differences (P < 0.01) among RILs, and water treatments for all traits with moderate to high broad sense heritability. Pearson's coefficient of correlation revealed positive correlation among all traits except dry root weight that showed poor correlation with fresh shoot weight (FSW) under water-limited conditions. A high-density linkage map was constructed with 2639 genotyping-by-sequencing markers and covering 5047 cM with an average marker density of 2 markers/cM. Composite interval mapping identified 16 QTL distributed over nine chromosomes, of which six were identified under well-watered and 10 in water-limited conditions. These QTL explained from 4 to 59% of the phenotypic variance. Six QTL were identified on chromosome 7B; three for shoot length under water-limited conditions (QSL.nust-7B) at 64, 104 and 221 cM, two for fresh root weight (QFRW.nust-7B) at 124 and 128 cM, and one for root length (QRL.nust-7B) at 122 cM positions. QFSW.nust-7B appeared to be the most significant QTL explaining 59% of the phenotypic variance and also associated with FSW at well-watered conditions. These QTL could serve as target regions for candidate gene discovery and marker-assisted selection in wheat breeding.

Hordeum chilense Roem. et Schultz. is a diploid wild barley native to Chile and Argentina. The high crossability of this species with other members of the Triticeae tribe promoted the development of the new species × Tritordeum Ascherson et Graebner. Hexaploid tritordeum was developed from the hybrid derived from the cross between H. chilense (used as female parent) and durum wheat. The interest of H. chilense is based on the presence of traits potentially useful for wheat breeding, including high endosperm carotenoid content, septoria tritici blotch resistance and abiotic stress tolerance. Besides, the variability at cytoplasm level is also important in this species. The development of common wheat–H. chilense alloplasmic lines (nucleus from wheat and cytoplasm from H. chilense) results in fertile or male sterile genotypes, depending on the accession donating the cytoplasm. Furthermore, these alloplasmic lines constitute an ideal system for deepening our knowledge on nuclear–cytoplasm interactions. In conclusion, H. chilense is an interesting source of variability for wheat breeding.

The Drake Passage arises as a likely route for gene flow into Antarctica, as it is the shortest path between this continent and the rest of the world. Despite this, long-distance dispersion into Antarctica could be particularly complex for terrestrial biota. To compare the levels of genetic diversity between Antarctic and South American populations of the Antarctic pearlwort, Colobanthus quitensis, we conducted the first estimation of genetic diversity in this species using amplified fragment length polymorphism. Four populations across the Drake Passage were selected and their genetic composition was characterized. Differences among the levels of genetic diversity were found between the populations analysed as well as between their allelic identities. However, interestingly, their spatial distribution across the Drake Passage suggests a north-to-south gradient of increasing genetic diversity.

South American tomato moth, Tuta absoluta, a serious pest of tomato (Solanum lycopersicum) in tropics and subtropics, is rapidly spreading world over. Twenty one wild/cultivated/advanced breeding lines of tomato were screened for resistance to T. absoluta under greenhouse conditions (choice bioassay) and promising genotypes were evaluated further for their antibiosis activity through no choice bioassay under in-vitro conditions. From 21 genotypes screened, six wild accessions viz., S. pennellii (LA 1940); S. chilense (LA 1963); S. arcanum (LA 2157); S. lycopersicum (LA1257) and S. corneliomulleri (LA 1292, LA1274) were relatively resistant to T. absoluta based on mean percent damage and were further studied under in-vitro conditions. These genotypes recorded relatively more larval mortality, prolonged larval and pupal duration with reduced adult emergence of T. absoluta. Among these six genotypes, S. pennellii (LA-1940) showed resistance both under choice and no choice bioassays with higher number of type IV trichomes, highest total flavonoids and phenols. In general, glandular trichomes (GTs) (type I, IV, VII) showed negative correlation in different genotypes of tomato with reference to larval number/plant, percent damage and adult activity, whereas type V (non-GTs) showed negative correlation with number of larvae/plant.

Crop wild relatives (CWR) are valuable gene pools for crop improvement and offer unique potential and opportunity for enhancing food security and adaptation to climate change. However, current actions towards conservation of plant genetic resources in Zambia do not adequately cover CWR occurring in the country. The article describes the process leading to the development of a national strategic action plan (NSAP) for the conservation and sustainable use of priority CWR in Zambia. Based on 59 prioritized crops, a partial checklist of 459 CWR taxa was generated from the national flora checklist of 6305 taxa. The generated CWR taxa were prioritized based on the socio-economic value of the related crop, their utilization potential in crop improvement, relative distribution and threat status to produce 30 prioritized CWR taxa. Occurrence data were compiled for all CWR inventory taxa and used in spatial analyses to establish species distribution, species richness, gaps in in situ conservation and genebank collections, and to identify priority sites for in situ conservation and ex situ collecting. Consistent with the national developmental agenda, along with the contribution of national stakeholders, spatial analyses of occurrence data of priority CWR taxa are valuable input for the development of the NSAP for the conservation and sustainable use of the priority CWR.

Red bean, also known as azuki bean [Vigna angularis (Willd.) Ohwi & Ohashi], belongs to a group of legumes (family Fabaceae). The name azuki is a transliteration of the native Japanese name from the Chinese word Shōzu, which means small bean. In Korea, it is known as pat. In total, 178 red bean accessions were taken to analyse the genetic diversity, population structure and gene flow using 39 polymorphic simple sequence repeat markers. A total of 431 alleles were detected, with an average of 11 alleles per locus, among the 178 tested red bean accessions. Forty-six specific alleles were identified with 20 loci. Locus CEDG090 had the highest number (n = 22) of alleles, whereas only two alleles were observed at loci CEDG144 and CEDC018. The proportion of different alleles for microsatellite loci was analysed using a microsatellite toolkit. In locus CEDG029, one allele was shared in all the three groups of varieties and species, and three alleles were shared between the wild ancestors and cultivated varieties, while in locus CEDG090, one allele was shared in all the three groups and 12 alleles were shared between the wild ancestors and cultivated varieties. Our findings describe the genetic relationships and population structure of the red bean in Korea and will be useful for designing effective breeding programmes and broadening the genetic base of commercial varieties. Moreover, the results demonstrate substantial gene flow from the red bean to nearby wild relatives in a given region.

Galantamine (GAL), a morphine-like alkaloid produced by some members of the Amaryllidaceae plant family, is a possible therapeutic agent in Alzheimer's disease because of its central cholinergic effects. GAL has been extracted from the plant sources or produced synthetically for pharmaceutical use. Limited supply of the natural source and high cost of synthetic production has led to a search for alternative sources of this valuable compound. In the present study, a total of six Galanthus nivalis populations (GNPs) and 11 Narcissus tazetta populations (NTPs) were collected across different regions of Iran and were then subjected to the high-performance liquid chromatography analysis for their GAL quantification. The GAL content ranged from 0.05 to 0.36 mg/g dry weight (DW) in the bulbs of GNPs, and from 0.03 to 0.33 mg/g DW in the bulbs of NTPs. Maximum content of GAL (0.36 and 0.33 mg/g DW) was measured in the Zirab population of G. nivalis and Ghaemshahr population of N. tazetta, respectively. Our results provided a suitable material for further agronomical and biotechnological strategies for enhanced production of valuable GAL compound on a large scale.

Indian gooseberry, popularly known as amla, is harvested from two species of Phyllanthus, namely Phyllanthus emblica and Phyllanthus indofischeri. Although these two species are characterized on vegetative and reproductive features, development of reliable and authentic identification based on molecular approaches is necessary for precise identification. Most of the commercial orchards of Indian gooseberry are established with mixture of the two species. Introduction of unauthentic clones and seedlings in the establishment of orchards and differences in the growth of these two species under different elevations are the major constrains in identification. The present work aims to study the changes in vegetative and reproductive features under different elevations and to develop a simple molecular tool for precise identification of these two species based on single nucleotide polymorphisms in trnL (UAA) intron sequences of chloroplast DNA. Genomic DNA of leaf tissues of P. emblica and P. indofischeri, collected from the authentic source, was subjected to polymerase chain reaction amplification using trnL (UAA) intron gene-specific primers. The amplified product with the molecular weight of 540 bp was sequenced and used as reference for identification of these two species. The trnL (UAA) introns sequenced from 60 individual trees in three different orchards were compared with trnL (UAA) intron of authentic samples, and confirmed that these orchards have 76% population of P. indofischeri and remaining 24% is occupied by P. emblica. Thus, trnL (UAA) intron is a potential DNA marker for precise identification of these two species. The importance of the present study and its practical application in genetic improvement of Indian gooseberry are discussed.

Evaluating quality traits is important to the selection of elite lines in Brassica napus L. In this study, the quality traits of 488 global collections of B. napus L were evaluated for two consecutive years under central Chinese growing conditions, and a series of phenotypic data was obtained. The measured total glucosinolate content (GLC) and erucic acid content (ERU) values for 95.5% of the accessions were consistent with the original values, and large variations in quality traits were found among these accessions, thus enabling selection for these characters. In general, Chinese accessions tended to have a higher oil content (OC) than foreign accessions, while compared with winter and spring accessions, semi-winter accessions tended to have the highest OC. The mean GLC and ERU of Chinese rapeseed accessions showed gradual downward trends over time, and the genotypic variation in ERU accounted for 98.44% of the total variation, which was the highest among all 10 of the quality traits. Additionally, the heritability for ERU was largest among all 10 of the quality traits. Significant correlations were observed between different traits; OC had significantly (P < 0.01) negative correlation coefficients with oleic acid content, whereas OC had significantly (P < 0.01) positive correlation coefficients with ERU. Principal component analysis revealed that there was no clear boundary among materials of different geographic origins and different ecotypes according to the first two principal coordinates, respectively. This information about variations in quality traits revealed in this study could identify parents for improved rapeseed breeding.

DNA profiles of 92 banana and plantain cultivars were generated with 12 amplified fragment length polymorphism (AFLP) primer pairs. The average polymorphism information content (PIC) values of the polymorphic AFLP markers varied from 0.270 to 0.341, and the profiles could distinguish all the 92 cultivars analysed. It was possible to identify differences between two accessions of the AAB genome cultivar Rasthali, indicating the presence of intra-cultivar genetic variation. A UPGMA (unweighted pair group method of arithmetical means) dendrogram generated with 1581 AFLP products identified four major clusters, each comprising cultivars of similar genomic constitution. All the ABB cultivars grouped in a single cluster, which was well separated from the rest. The within-group similarity coefficients indicated that the most diverse group was AAB, followed by AAA. However, significant genetic diversity was also present among AA, AB and ABB Indian banana cultivars, supporting the notion that India, along with other neighbouring south-eastern Asian countries, is the centre of diversity for cultivars of banana and plantain. The presence of substantial diversity among the banana and plantain landrace cultivars could be exploited in varietal improvement programmes.

The fatty acid composition of peanut seed oil from a range of samples included in the core of the core or the ‘mini core’ of the US peanut germplasm collection was determined using gas chromatography. Oil contents of the seeds ranged from 31.4 to 47.9%. Very long-chain fatty acids are defined as those having more than 22 carbons in chain length. Although it has been reported in peanuts seed previously, the presence of hexacosanoic acid (C26:0) was quantified in a large variety of samples here for the first time along with docosanoic (C22:0) and tetracosanoic acids (C24:0) to demonstrate the potential of peanut seed as a source of very long-chain fatty acids that have been associated with widely varying effects such as the metabolism of the dietary fatty acids and physical properties of the oils themselves. Use of representative samples from the peanut germplasm collection allowed for comparison of very long-chain fatty acid content among seeds of different origins, and showed, although values overlapped, the seeds did cluster according to area of origin.

This paper reviews marker methods based on retrotransposons and illustrates examples from oil palm. Prior to this study, very little had been known about the repetitive DNA present in oil palm and no marker systems based on retrotransposons had been developed. Firstly, copia like retrotransposons of Elaeis oleifera, Elaeis guineensis and Cocos nucifera were characterized by performing phylogenetic analyses on a portion of the reverse transcriptase (RT) gene of copia-like retrotransposons. The results identified three classes of copia-like retrotransposons in the three species studied. While the C-class RT sequences seemed to have amplified preferentially only in Elaeis guineensis, the classes A and B were present in Elaeis guineensis and Cocos nucifera as well. Secondly, long terminal repeats (LTRs) from these retrotransposon classes were isolated as a prelude to developing a marker system in palm based on retrotransposons. The B- and C-class LTRs were isolated by primer walking from the RT region and the B-class from Elaeis oleifera and Cocos nucifera with the use of oil palm-specific RnaseH primers. The method has been developed and applied for breeding purposes in oil palm, hybrids between E. oleifera and E. guineensis and within the tribe Cocoeae. There is scope for the method to be used in the isolation of new retrotransposon families endogenous for each palm species and as an alternative to amplified fragment length polymorphism (AFLP) in diversity studies within the Palmae.

Thirty-eight melon accessions, which are of primary breeding importance in the Ukraine, were analysed for diversity. These collections represent a major non-US and non-western Europe source of melon germplasm that have not yet been subjected to molecular characterization. Molecular diversity was estimated based on a robust set of 465 polymorphisms gathered by amplified fragment length polymorphisms and simple sequence repeats (SSR). In this paper, we report 12 newly developed polymorphic SSR primer pairs, and their use for molecular characterization in the Ukrainian melon collections. Based on these polymorphisms, we estimated similarity indices that ranged from 0.70 to 1.00 among various accessions. The phylogenetic tree based on the similarity indices and a three-dimensional plot of the first three vectors of the principal component analysis corresponded fairly well with the existing three classical morphotypes namely aestivalis, europeus and hiemalis, under the convarEuropeus, which is also known as adana. The polymorphisms generated in the current study, which are specific to the grouping of fruit types and days to maturity will be very useful for further genetic studies and marker-assisted selections.

Water deficit is an environmental factor that constrains crops to express their ecophysiological potential and causes crop yield reduction. Eruca vesicaria has been reported to be one of the most drought-tolerant species in Cruciferae. In this study, polyethylene glycol-simulated drought tolerance was evaluated in one line of Brassica carinata, one line of Brassica napus and 249 Eruca lines based on the principal component analysis (PCA) and unweighted pair-group arithmetic average (UPGMA) cluster analysis. The PCA based on eight drought tolerance indices indicated that the first three components accounted for 85.46% of the total variation, with principal component (PC) 1 accounting for 43.89%, PC2 for 27.85% and PC3 for 13.73% of the total variation. The UPGMA cluster analysis indicated that B. napus cultivar Zhongshuang 9 and Eruca lines could be clustered into five major groups, with group 1 being, in general, drought sensitive, group 2 being slightly–medium drought tolerant, group 3 being drought tolerant, group 4 being highly drought sensitive and group 5 being highly drought tolerant. B. carinata cultivar XB1, as an outstander, showed high drought sensitivity. The UPGMA cluster dendrogram provides a good representation of the similarity matrix (r= 0.68). The drought-tolerant Eruca materials obtained in this study will be valuable for genetic improvement not only in Eruca itself, but also in Brassica crops since they are drought-tolerant lines from a drought-tolerant species.

To assess the genetic diversity among Tunisian local barley, a set of 120 barley accessions representing five distinct geographical regions (North-West, Littoral, South, Jerba and Kerkennah Islands) was characterized with 20 simple sequence repeats (SSR) and 8 expressed sequence tag (EST)-SSR markers. The 28 loci revealed a total of 98 alleles, with an average of 3.76 alleles per locus (range 2–10). Gene diversity averaged 0.50 (range 0.09–0.84). Partitioning analysis of genetic diversity showed that about 95% of the total variation was within regions and no geographical differentiation could be found except for the North-West population. Similarly, neighbour joining clustering of the genotypes did not indicate any clear pattern of division among the barley accessions based on geographical origin. These results may reflect the impact of seed exchange between farmers which is likely to limit highlighting favourable alleles due to local adaptation.

Old germplasm is an important genetic resource for enhancing modern crops with new alleles. In the present study, the genetic diversity of 52 historic varieties and landraces of bread wheat originated from the Western (Bulgaria) and Northeastern (Ukraine, Russia and Georgia) regions of the Black Sea basin was assessed based on microsatellite markers and agronomic characteristics. A set of 24 markers detected a total of 263 alleles at 25 microsatellite loci, with an average number of 10.5 alleles per locus and an average polymorphic information content (PIC) of 0.74. A total of 63 alleles at 22 loci were unique, being specific to a particular accession. Half of the alleles (132) were regionally specific, and the rest were common between the Western and Northeastern accessions. The latter group was characterized with greater total and private allelic richness, a higher number of unique alleles and a higher average PIC. The population was found to be very heterogeneous (average heterogeneity 41%), with the Northeastern pool (52.8%) being more diverse than the Western pool (30.9%). Most of the accessions of the Western group clustered together, and the rest were distributed among the subclusters of the Northeastern germplasm. Large inter-group differences in the frequencies of alleles ranging from 3.1 at Xgwm294-2A to 16.7 at Xgwm333-7B were observed. This variation might partly account for the differences in certain yield-related traits. The Northeastern accessions had significantly longer spikes with more number of spikelets. Some issues related to germplasm preservation in seed genebanks are discussed herein. The large molecular variation observed could be utilized by breeders for the selection of diverse parents, or by researchers for the production of mapping populations.