Curcas Accessions Research Articles

Impact of Heat Wave on the Plant Architecture of Field Grown Jatropha curcas Accession

Heatwave is one of the common phenomena in the arid and semi-arid regions which greatly hinders crop productivity. Jatropha curcas, which is well known for its medicinal and seed biodiesel uses, is one of the crops that are negatively affected by high temperatures. Therefore, this study was aimed at monitoring the effect of a heat wave on the plant architecture of Jatropha curcas plants grown in the south east of Botswana, a semi-arid region. The field experiment was conducted in 2016 (2016/2017) and 2017 (2017/2018) cropping season using plants that were established in 2011. Data on changes in leaf numbers, changes in leaf areas, photosynthetic rates, leaf temperatures, and soluble sugar levels were measured over the spring, summer, and autumn seasons of 2016 and 2017. In 2016, the general trend of the above measured parameters was that they peaked in summer and declined in autumn. However, in the summer of 2017, the accessions were hit by a heat wave, which depressed the photosynthetic rates, concomitantly decreasing leaf numbers, leaf areas, and leaf area indices. This reduction continued into the autumn of 2017. The plant architecture of the J. curcas accessions differed in the two years, indicating that the accessions responded differently under heat waves. The observations made as the plants recovered was that immediately below the apex, 2–3 leafed lateral shoots developed, which would normally be evident much lower down the stem. This suggests that the effect of the heat wave thus appeared to have impacted the plant architecture in the autumn. Soluble sugar levels were also higher in the autumn leaves of 2017 than in the autumn leaves of 2016.

Comparative Study of Jatropha curcas Accessions Control of Photoinhibition and Photoprotective Mechanisms in Senescing Leaves in a Semi-Arid Region Botswana

Comparative Study of Jatropha curcas Accessions Control of Photoinhibition and Photoprotective Mechanisms in Senescing Leaves in a Semi-Arid Region Botswana

Photosynthetic Characteristics of Younger Leaves (Emerging Leaves) and Older Leaves (Mature Leaves) of Various Field-Grown J. Curcas Accessions

Photosynthetic Characteristics of Younger Leaves (Emerging Leaves) and Older Leaves (Mature Leaves) of Various Field-Grown J. Curcas Accessions

Water Stress Response in Different <i>Jatropha curcas</i> Accessions from Different Geographical Zones of Botswana: Biochemical & Physiological Perceptive

Jatropha curcas L. is one climate smart drought-resistant multipurpose plant with a variety of properties that have conjured interest all over the world due to its potential to produce biofuel. In this study, Jatropha curcas accessions were collected from three different climate zones of Botswana; Northern region (Maun), Central region (Mmadinare) and Southern region (Thamaga). These accessions were subjected to water stress to study their biochemical and physiological responses. Results showed that water stress increased malondialdehyde (MDA) content, electrolyte leakage as well as proline content in all the accessions. It is worth-noting that Maun accession exhibited highest proline content, when subjected to water stress. Maun accession also displayed less MAD and electrolyte leakage than the other two accessions, an indication of less perturbation to membranes under water stress. This could be attributed in part, to its higher catalase and superoxide dismutase contents, which presumably prevented lipid peroxidation by mopping up reactive oxygen species. The slightly higher dry weights exhibited by Mmadinare and Maun accessions could be ascribed to their ability to maintain membrane integrity under water stress conditions. It can therefore be concluded that Maun and Mmadinare accessions can be grown under drought conditions commonly experienced in Botswana.

RNA-Seq transcriptome analysis of Jatropha curcas L. accessions after salt stimulus and unigene-derived microsatellite mining

The small oleaginous tree of Jatropha curcas L. (physic nut) is an excellent biodiesel source whose crop could represent a good income source for farmers in tropical and semi-arid zones. However, in some areas in particular, salinity, such as many other abiotic stresses, can compromise productivity. We analyzed the root RNA-Seq transcriptome of two Brazilian J. curcas accessions after a three-hour NaCl exposition (150 mM) aiming at identifying differentially expressed genes (DEGs) useful for breeding programs. The de novo transcriptome covered 145,422 assembled transcripts (126,343 unigenes), out of which 84,589 showed at least one significant alignment to the GenBank reference genome. Differentially expressed unigenes (DEGs) of the salt-sensitive Jc171 accession (4,646) suppressed those of the salt-tolerant Jc183 (57) one. A MapMan analysis of the DEGs using Manihot esculenta Crantz genes as reference (Euphorbiaceae family) highlighted the metabolism of phytohormone, carbohydrate (CHO), lipid, amino acid, redox, and secondary metabolite in the salt-responses. RT-qPCR results of nine selected Jc183 DEGs [phenylalanine ammonia-lyase (PAL), S-adenosylmethionine-dependent methyltransferase (SAMe), S-adenosylmethionine synthase (SAM), carboxylesterase (CXE), homeobox-leucine zipper gene (HD-Zip), NAC transcription factor gene (NAC), methionine-gamma lyase (MGL), peroxidase (PX), and xyloglucan endotransglucosylase (XTH)] evaluated in 36 combinations accession/treatments validated 86.11 % of the in silico results. The data generated improved the J. curcas transcriptome based on Illumina-21 bp tags as reported before, which can benefit breeders in the improvement of salt-tolerance in J. curcas. Additionally, primer pairs successfully designed for 1,423 DEGs presenting microsatellite motifs can contribute to the development of co-dominant molecular markers, a very useful marker applied to genetic analysis.

English

Jatropha curcas L. is an undomesticated plant species that has recently received great attention for its utilization in biofuel production in many countries including Botswana. The experiment investigated 30 J. curcas accessions, and the results revealed high significant differences (P<0.01) among accessions for peduncle length, number of seed per fruit, length of fruit stalk, fruit length, fruit width, seed length, seed width, seed weight, leaf length, leaf width, petiole length, total flower per cluster, female and male flower per cluster, and number of fruit per cluster. The qualitative characters revealed substantial amount of variability among the accessions except in fruit shape, stem color and flower color. Multivariate cluster analysis based on morphological characters and molecular characterization grouped the accessions into four clusters at dissimilarity coefficient of 1.37 and 0.85, respectively. The clustering based on morphological characters slightly matched that of groupings derived through molecular analysis with group A and B having some similar accessions. One Ghana accession used as reference was clearly separated from other accessions by both morphological and molecular markers, and also by seed weight and inflorescence compactness. Eight morphological characters and six molecular markers correlated positively with correlation coefficient values ranging from 0.56 to 0.66. Key words: Characterization, genetic diversity, Jatropha curcas, molecular markers, morphological markers

Diversity between Jatropha curcas L. accessions based on oil traits and X-ray digital images analysis from it seeds

Jatropha curcas L. is a species with high potential for the biodiesel production. Therefore, the oil yield and quality from it seeds should be known. This study aimed to estimate the correlation between morphological traits, yield and oil quality evaluated in the seeds, to know the genetic diversity between J. curcas accessions and it behavior regarding to three harvest seasons. For this purpose, X-ray digital images from seeds of 18 accessions were obtained, and the seeds analyzed for external and internal morphological aspects. The same seeds were analyzed for oil yield and quality. In general, the results concerning diversity indicated a narrow genetic base. More rounded and very long seeds had lower oil yield. Larger seeds presented higher oil yield only when their internal cavity was filled by their endosperm. Most of the accessions showed variation regarding the size of the endosperm, yield and oil quality between harvest seasons.

Seed oil of Jatropha curcas L. germplasm: Analysis of oil quality and fatty acid composition

Jatropha curcas L. is recognized as one of the important non-edible tree borne oilseeds (TBOs) in India and many other tropical countries. J. curcas is a promising bioenergy crop as its seed oil is a suitable feedstock for biodiesel production. This study focused on a total of 19 J. curcas accessions for seed oil extraction, oil quality analysis and fatty acid composition. Most of the accessions showed more than 30% oil content with free fatty acid content ranging from 0.21 to 1.82%. The oil samples were transesterified efficiently to fatty acid methyl esters as evident from proton nuclear magnetic resonance (1H NMR) spectra. As revealed by gas chromatography, the contents of the four major fatty acids were found to significantly vary in the seed oils viz Palmitic acid (8.64–17.05%), stearic acid (4.34–7.94%), oleic acid (26.26–46.36%) and linoleic acid (28.72–53.78%). A number of seed oils showed high level of oleic acid (40.02–46.36%), and some other oil samples were rich in linoleic acid (∼45%). These J. curcas accessions appeared to be promising with regard to clonal propagation, field trials, large-scale plantations for biodiesel feedstocks, other industrial applications, and also as prebreeding materials in crop improvement programs.

Survey and selection of Jatropha curcas L. germplasm: Assessment of genetic variability and divergence studies on the seed traits and oil content

Jatropha curcas L., member of the Euphorbiaceae family, is widely recognized as a promising bioenergy crop. Its seed oil is used particularly for eco-friendly biodiesel production. A thorough survey led to select a total of 31 morphologically superior candidate plus trees (CPTs) of J. curcas from different locations of Punjab, a North-Western state of India. The seed samples showed considerable variation with regard to shape, size and color of the seed coats. 100-seed weight ranged from 35.10–77.34 g. Seed oil content was found to vary from 13.74% to 54.37%. Most of the accessions showed 30–40% oil content, and a few accessions showed more than 40% oil content. Both genotypic and phenotypic variances were highest and comparable for 100-seed weight followed by seed oil content. Genotypic coefficient of variation and phenotypic coefficient of variation also showed similar pattern. The highest heritability of 99% was recorded for 100-seed weight followed by oil content (97%) and seed length (81%). Positive and significant correlation was observed between 100-seed weight and oil content (r = 0.517). The J. curcas accessions were distinctly grouped into 6 clusters on the basis of non-hierarchical K-Means cluster analysis. Some of these accessions will be useful in terms of germplasm exchange, mass propagation, multi-location trials, feedstocks for biodiesel and as prebreeding materials for genetic improvement.

Photosynthetic performance of contrasting Jatropha curcas genotypes during the flowering and fruiting stages

Abstract: The objective of this work was to evaluate physiological processes in contrasting physic nut (Jatropha curcas) genotypes during the flowering and fruiting stages. Gas exchange parameters were measured using an infrared gas analyzer, and morphological traits were evaluated during each stage under natural conditions, in a randomized complete block design with five replicates. Differences in yield between J. curcas accessions were not related to photosynthetic performance, but rather to the number of inflorescences and female flowers, which are genetically determined. Moreover, the net CO2 assimilation was equivalent in both genotypes, although they produced different amount of fruit. The genotypes differed consistently in terms of carboxylation efficiency and ribulose bisphosphate regeneration. Finally, J. curcas branch growth is not impaired by the increased sink strength during fruiting, and fruit may have been actually exerting a positive effect on the net CO2 assimilation, which may have enabled plants to maintain growth while producing flowers and fruits.

Characterization of Jatropha curcas accessions based in plant growth traits and oil quality

Variability in growth and reproductive characteristics, seed traits, quality and oil content of six accessions of Jatropha curcas growing in Murcia (Spain) under greenhouse conditions were analysed. Differences were found among accessions in branch length, ratio female to male flowers (F/M), productions, seed weight, endosperm weight, percentage of endosperm and percentage of aborted seeds oil contents, fatty acids composition and quality indexes of the biodiesel. Two genotypes (8-8 and 6-3) have shown a good vigor plant, the best F/M ratio, and appropriate average productions. In addition, these accessions showed the highest average single seed weights, and the best average endosperm weights. The highest total seed oil percentages were observed in the accessions 4-5 (42.42±0.26), 6-3 (41.51±0.20), and 8-8 (40.41±0.73), whereas percentages lower than 30% were recorded in the others. The percentage of endosperm oil ranged from 42.72±0.98% to 65.71±0.36%. In relation to the fatty acids composition, the highest monounsaturated fatty acids percentages with the highest concentration of oleic acid and the lowest concentration of linolenic acid were observed in three genotypes (4-5, 8-8 and 6-3). The biodiesel obtained from these accessions presented high cetane number and low iodine value, which indicates the good ignition quality and stability of the oil.The knowledge of plant growth parameters and oil quality of the studied genotypes could be useful to choose the appropriate ones to be grown under subtropical climatic conditions or to be used as parents in a breeding program.

Genetic Diversity of Indonesian Physic Nut (J. curcas) Based on Molecular Marker

Various reports of molecular genetic diversity evaluation of physic nut ( J. curcas ) have given inconsistent results. Part of the reasons were because of the used of unrealiable markers. This study was conducted to evaluate genetic diversity of Indonesian physic nut germplasm using four types of molecular markers (RAPD, ISSR, SSR and SCAR markers). Twenty four J. curcas accessions planted in Pakuwon, Sukabumi, with various phenotypes were evaluated. Twenty eight SSR marker loci yielded monomorphic allele pattern and indicated that the evaluated accessions probably were all genetically homogeneous for the respective loci. Eight RAPD and 4 ISSR primers out of the total 31 tested primers produced scoreable markers and some (i.e. UBC 873, OPG 17, OPP 03 and OPQ 11 primers) generated polymorphics markers. Genetic similarity coefficiens among evaluated accessions ranged from 0.6 to 1.0 with a population mean of 0.9 indicating low diversity and narrow genetic background among accessions in all populations. Therefore, breeding program utilizing such population would only result in low genetic gain. Based on the evaluated SCAR markers, all accessions belonged to the non-toxic Mexican type of physic nut. This information is important inputs for designing future physic nut breeding strategies in Indonesia.

High genetic diversity of Jatropha curcas assessed by ISSR.

Jatropha curcas L. is a highly promising oilseed for sustainable production of biofuels and bio-kerosene due to its high oil content and excellent quality. However, it is a perennial and incipiently domesticated species with none stable cultivar created until now despite genetic breeding programs in progress in several countries. Knowledge of the genetic structure and diversity of the species is a necessary step for breeding programs. The molecular marker can be used as a tool for speed up the process. This study was carried out to assess genetic diversity of a germplasm bank represented by J. curcas accessions from different provenance beside interspecific hybrid and backcrosses generated by IAC breeding programs using inter-simple sequence repeat markers. The molecular study revealed 271 bands of which 98.9% were polymorphic with an average of 22.7 polymorphic bands per primer. Genetic diversity of the germplasm evaluated was slightly higher than other germplasm around the world and ranged from 0.55 to 0.86 with an average of 0.59 (Jaccard index). Cluster analysis (UPGMA) revealed no clear grouping as to the geographical origin of accessions, consistent with genetic structure analysis using the Structure software. For diversity analysis between groups, accessions were divided into eight groups by origin. Nei's genetic distance between groups was 0.14. The results showed the importance of Mexican accessions, congeneric wild species, and interspecific hybrids for conservation and development of new genotypes in breeding programs.

Genetic variation and phylogenetic relationship analysis of Jatropha curcas L. inferred from nrDNA ITS sequences

Genetic variation and phylogenetic relationships among 102 Jatropha curcas accessions from Asia, Africa, and the Americas were assessed using the internal transcribed spacer region of nuclear ribosomal DNA (nrDNA ITS). The average G+C content (65.04%) was considerably higher than the A+T (34.96%) content. The estimated genetic diversity revealed moderate genetic variation. The pairwise genetic divergences (GD) between haplotypes were evaluated and ranged from 0.000 to 0.017, suggesting a higher level of genetic differentiation in Mexican accessions than those of other regions. Phylogenetic relationships and intraspecific divergence were inferred by Bayesian inference (BI), maximum parsimony (MP), and median joining (MJ) network analysis and were generally resolved. The J. curcas accessions were consistently divided into three lineages, groups A, B, and C, which demonstrated distant geographical isolation and genetic divergence between American accessions and those from other regions. The MJ network analysis confirmed that Central America was the possible center of origin. The putative migration route suggested that J. curcas was distributed from Mexico or Brazil, via Cape Verde and then split into two routes. One route was dispersed to Spain, then migrated to China, eventually spreading to southeastern Asia, while the other route was dispersed to Africa, via Madagascar and migrated to China, later spreading to southeastern Asia.

Genetic Parameters for Fruits, Seeds and Oil Content Traits of Jatropha curcas L. in a Semi-arid Region of Senegal

Aim: The aim of this work was to study the genetic parameters of fruits, seeds and oil content of Jatropha curcas accessions in a semi-arid region of Senegal. Methodology: The study was conducted on 35 accessions of J. curcas planted at the research station of National School of Agriculture located in Thies, Senegal. Fruits were collected from 1-4 years old plantations. Then, for each accession, 30 dry fruits were randomly selected and were Original Research Article

De novo Transcriptome Analysis of Apical Meristem of Jatropha spp. Using 454 Pyrosequencing Platform, and Identification of SNP and EST-SSR Markers

A high-throughput sequencing by 454 pyrosequencing was performed on the transcriptomes of apical meristem tissue of two Jatropha curcas accessions and four jatropha-related species. J. curcas accession (acc.) CN produced 45.61 Mb data from 127,094 reads with 11,579 contigs and 15,645 singletons, while acc. M10 produced 54.52 Mb data from 142,447 reads with 10,964 contigs and 12,069 singletons. J. integerrima acc. KL gave 20.91 Mb from 71,541 reads with 4,551 contigs and 5,144 singletons, while acc. KY gave 48.74 Mb from 149,392 reads with 8,440 contigs and 8,299 singletons. J. multifida (acc. JM) gave 66.72 Mb from 191,654 reads with 17,444 contigs and 13,965 singletons, and J. podagrica (acc. JP) gave 73.28 Mb from 165,228 reads with 14,070 contigs and 16,572 singletons. BLASTX search of all contigs revealed that 1,683 unique proteins were orthologous across all four Jatropha spp. From 432 EST-SSR primer pairs designed and tested on these six accessions, 269 markers showed polymorphism and produced a total of 862 alleles. Based on sequence alignments between J. curcas accessions with low and high phorbol esters (PEs), 20 candidate SNPs were identified in four coding sequences including one gene relating to biosynthesis pathways of PEs. These expressed sequence tag-sample sequence repeat (EST-SSR) markers and candidate single nucleotide polymorphisms (SNPs) will be useful for jatropha breeding in the future.

Analysis of genetic diversity and fatty acid composition in a prebreeding material of Jatropha

Genetic and fatty acid variability in four datasets of accessions and prebreeding lines of Jatropha curcas was analyzed. The datasets were comprised of J. curcas accessions (13), BC1 (28), BC1F2 (12) and single seeds (12). The BC1, BC1F2 and single seed dataset were derived from an interspecific cross between J. curcas and J. integerrima. The average within-group (within dataset) polymorphism revealed by AFLP markers was 28.5 %. The average genetic similarity within the four datasets, namely, J. curcas accessions, BC1, BC1F2 and single seeds was 0.92, 0.82, 0.90 and 0.92 respectively with an overall average genetic similarity of 0.80. The values of percent polymorphism, Shannon’s information index and expected heterozygosity were highest for BC1 dataset. The total unsaturated fatty acids in the oil varied from 63.64 to 89.10 %. Levene’s test showed that within-group variance was significantly different for three fatty acids, namely, palmitic acid, oleic acid and linoleic acid. BC1F2 dataset had the highest variance for palmitic and oleic acid, whereas BC1 dataset had the highest variance for linoleic acid. The results revealed that both genetic as well as fatty acid variability was significantly higher in the newly created prebreeding lines and the level of fatty acid variability in these datasets was different and highly correlated to the level of their genetic variability as revealed by AFLP markers. This new prebreeding material, especially, the BC1 and BC1F2 lines, will be useful for development of Jatropha varieties with specific fatty acid composition for specific industrial applications.

Development of Novel Microsatellite Markers in Jatropha curcas and Evaluation of Their Cross-Species Transferability

Jatropha curcas has been a species of interest all over the world due to its potential as a renewable biodiesel crop. In the present paper, a set of 40 novel genomic microsatellites from Jatropha developed through cloning and sequencing are reported. The microsatellite markers were evaluated at intra-specific, inter-specific and inter-generic levels. All forty markers successfully amplified fragments from J. curcas and J. integerrima showing their potential in linkage mapping using inter-specific breeding populations involving these species. The average number of alleles within 12 core accessions of J. curcas was 3.083. Polymorphic information content ranged from 0.15 to 0.80 within J. curcas accessions and from 0 to 0.37 among different genera. There was no significant deviation from Hardy–Weinberg equilibrium or linkage disequilibrium. Ten of these microsatellites showed polymorphism within Emblica officinalis while thirteen were polymorphic within Phyllanthus niruri and Ricinus communis accessions. These new set of microsatellite markers are expected to be especially useful in future for linkage mapping in J. curcas and for varietal identification and genetic diversity studies in other genera mentioned above.

Genomic-derived microsatellite markers for diversity analysis in Jatropha curcas

New set of 1,122 novel genomic-derived microsatellite markers developed, validated and a set of 447 polymorphic SSR identified for Jatropha curcas. The AMOVA showed that 6 % of the total genetic variation exists among the population and 94 % within the populations. Jatropha curcas L., a non-edible, oil-rich crop has attracted global attention as a promising renewable resource for biodiesel production. Limited numbers of validated and characterized markers such as SSRs are available that could be utilized for molecular breeding in Jatropha. To enrich the marker resources, we have employed next-generation 454 sequencing to develop a large number of microsatellite markers from trinucleotide-enriched genomic libraries. A total of 124,279 raw reads were assembled into 2,845 contigs and 22,650 singletons. We designed 1,122 SSR flanking primer pairs and validated them with a panel of seven accessions of J. curcas and one J. integerrima to identify polymorphic SSRs. Out of these 1,122 SSRs, 447 (39.83 %) were found to be polymorphic among J. curcas accessions. A higher transferability of SSRs (76 %) to J. integerrima was noticed. A subset of randomly selected SSRs (41 SSRs) was amplified across 96 accessions of J. curcas, which detected a total of 152 alleles ranging from 2 to 9 with an average of 4.0 ± 1.9 alleles/SSR. The analysis of molecular variance (AMOVA) showed that 6 % of the total genetic variation exists among the population and 94 % within the populations indicated high genetic variation within population. The neighbor-joining (NJ) tree based on Jaccard’s coefficient grouped the 96 accessions into three major clusters. The non-toxic accessions form a separate cluster and rest of the accessions intermixed irrespective of geographical distribution. STRUCTURE-based clustering also resulted in a similar pattern of grouping.

Geographic origin is not supported by the genetic variability found in a large living collection of Jatropha curcas with accessions from three continents.

Increasing economic interest in Jatropha curcas requires a major research focus on the genetic background and geographic origin of this non-edible biofuel crop. To determine the worldwide genetic structure of this species, amplified fragment length polymorphisms, inter simple sequence repeats, and novel single nucleotide polymorphisms (SNPs) were employed for a large collection of 907 J. curcas accessions and related species (RS) from three continents, 15 countries and 53 regions. PCoA, phenogram, and cophenetic analyses separated RS from two J. curcas groups. Accessions from Mexico, Bolivia, Paraguay, Kenya, and Ethiopia with unknown origins were found in both groups. In general, there was a considerable overlap between individuals from different regions and countries. The Bayesian approach using structure demonstrated two groups with a low genetic variation. Analysis of molecular varience revealed significant variation among individuals within populations. SNPs found by in silico analyses of Δ12 fatty acid desaturase indicated possible changes in gene expression and thus in fatty acid profiles. SNP variation was higher in the curcin gene compared to genes involved in oil production. Novel SNPs allowed separating toxic, non-toxic, and Mexican accessions. The present study confirms that human activities had a major influence on the genetic diversity of J. curcas, not only because of domestication, but also because of biased selection.