Variability in reproductive traits in Jatropha curcas L. accessions during early developmental stages under warm subtropical conditions

Variability in floral, fruit, and seed characteristics, and oil content of 15 accession of Jatropha curcas during early development were assessed during two flowering periods in south Florida subtropical climate. The two flowering periods had leaf flushing in March. Field evaluation using 18 quantitative traits showed significant variation among accessions. The number of female flowers and female : male flower ratio ranged from 1 to 15 and 1 : 8.8 to 1 : 67.8, respectively. Fruit set by natural pollination was 89 and 66% during the first (1st) and second (2nd) flowering periods, respectively. A higher number of female‐type inflorescences were observed during summer. There were significant differences in seed traits, except for number of seeds per fruit. Accession TREC 31 had the highest individual seed dry weight and 100‐seed weight (0.83 g and 79.7 g, respectively). The oil content varied from 19.30% to 35.62%. Seed dry weight had positive correlation with seed fresh weight, seed length, seed thickness, seed width, and 100‐seed weight, but negative correlation with oil content. Based on the cluster analysis using 15 morphological traits, jatropha accessions were grouped into five main clusters and accessions from different geographic regions grouped together in a cluster. Principal component analyses (PCA) revealed morphological variation. The first three components explained 73.5% of the total variation and seed dry weight, 100‐seed weight, total flowers per inflorescence, male flowers per inflorescence and fruit set can be used to distinguish accessions. The PCA also indicated that flowering traits were more influenced by seed origin while seed traits were affected by flowering spans. Although evaluations were performed in plants during the juvenile phase, accessions TREC 31 and TREC 55 had superior averages for almost all characters evaluated. These results provide a preliminary assessment of the high variability in jatropha accessions evaluated and their potential for use in breeding and genetic improvement programs.     

Genetic diversity and relationships among germplasm of Jatropha curcas L. revealed by RAPDs

Variation is the phenomenon where individuals of a population differ from each other. The variation or diversity can have morphological manifestation or genetic basis. Individual identification based on morphological record is the most common practice in Jatropha. Therefore, in order to find a proper method for estimation of genetic diversity and genetic relationships among different germplasm of Jatropha curcas L., random amplified polymorphic DNA (RAPD) technique based on polymerase chain reaction (PCR) was used for described purpose. Out of 55 decamer primers tested, 26 primers produced good amplification products. A total of 6,011 amplification products were scored from which only 1,859 bands (30.92%) were found to be polymorphic and the size of bands ranged from 300 to 2,500 bp. Unweighted pair group method using arithmetic average cluster analysis revealed clear genetic difference among J. curcas germplasm. The scientific data presented in this study suggests that RAPD-PCR could be used as a valuable tool for estimation of genetic diversity and genetic relationship among germplasm of J. curcas L.     

Genetic associations, variability and diversity in seed characters, growth, reproductive phenology and yield in Jatropha curcas (L.) accessions

A thorough and extensive wild germplasm exploration survey was undertaken and 32 high yielding candidate plus trees (CPTs) of Jatropha curcas from different locations from a latitudinal and longitudinal spread between 12°41′ and 22°′E longitude and 77° and 84°40′N latitude covering 11 locations in an area spread of 150,000 km² was collected for evaluating genetic association, and variability in seed and growth characters. Significant trait differences were observed in all the seed characters viz., seed morphology and oil content as were observed in growth characters viz., plant height, and female to male flower ratio and seed yield in the progeny trial. Broad sense heritability was high in general and exceeded 80% for all the seed traits studied. Female to male flower ratio showed near to 100% heritability followed by yield (83.61) and plant height (87.73). The path analysis revealed that female to male flower ratio had highest positive direct relationship with seed yield (0.789), followed by number of branches (0.612) and number of days from fruiting to maturity (0.431). Negative indirect effects were seen in number of days from flowering to fruiting which indirectly and negatively influenced yield through plant height and number of branches. Hierarchical clustering by Ward’s minimum variance cluster analysis showed phylogeographic patterns of genetic diversity. K-means clustering revealed that trees from different geographic regions were grouped together in a cluster and as were trees from the same geographical area placed in different clusters suggesting that geographical diversity did not go hand in hand with genetic diversity. In addition clustering identified promising accession with favourable traits for future establishment of elite seedling seed orchard and clonal seed orchard for varietal and hybridization programmes. For Genetical statistics please contact Arun K. Shanker (e-mail: arunshank@gmail.com).     

Genetic studies among Ramgarhias and Ramdasias of Punjab, North India

This study reports results of investigations on ABO, Rh, haptoglobin and transferrin types in the two hitherto uninvestigated endogamous groups of Punjab, North India. Frequencies for the A, B, and O genes were found to be 0.1711, 0.2566, and 0.5723 in Ramdasias, and 0.1737, 0.2960, and 0.5303 in Ramgarhias. In all 13 Rhesus-negative individuals were encountered. The Hp2 allele shows a high frequency of 0.8060 for Ramdasias, and 0.7860 for Ramgarhias.     

Genetic variability, heritability and genetic advance of growth and yield components of Jatropha (Jatropha curcas Linn.) genotypes

A total of 113 Jatropha curcas clonal accessions collected from different regions of India were studied to quantify the magnitude of genetic variability present in the test population and to identify important yield-attributing characters useful for developing high-yielding Jatropha cultivars. High heritability was observed for fruits per plant, seeds per plant, 100-seed weight, seed/kernel (S/K) ratio and kernel oil percentage coupled with high genetic advance suggesting that the accessions can be considered improvement. The significant positive association of seed oil content (%) with 100-seed weight suggested the effectiveness of indirect selection for seed oil content through 100-seed weight. Accessions 76, 120, 29, 86 and 84 showed above average higher values for all yield attributes (viz. fruit and seed yield, 100-seed weight, S/K ratio and oil content) suggesting these as best out of the test accessions. Accessions showing higher values for one or the other yield attributes could be selected as parents for further improvement.     

Genetic diversity analysis of Jatropha curcas L. (Euphorbiaceae) based on methylation-sensitive amplification polymorphism

Genetic analysis of 56 samples of Jatropha curcas L. collected from Thailand and other countries was performed using the methylation-sensitive amplification polymorphism (MSAP) technique. Nine primer combinations were used to generate MSAP fingerprints. When the data were interpreted as amplified fragment length polymorphism (AFLP) markers, 471 markers were scored. All 56 samples were classified into three major groups: γ-irradiated, non-toxic and toxic accessions. Genetic similarity among the samples was extremely high, ranging from 0.95 to 1.00, which indicated very low genetic diversity in this species. The MSAP fingerprint was further analyzed for DNA methylation polymorphisms. The results revealed differences in the DNA methylation level among the samples. However, the samples collected from saline areas and some species hybrids showed specific DNA methylation patterns. AFLP data were used, together with methylation-sensitive AFLP (MS-AFLP) data, to construct a phylogenetic tree, resulting in higher efficiency to distinguish the samples. This combined analysis separated samples previously grouped in the AFLP analysis. This analysis also distinguished some hybrids. Principal component analysis was also performed; the results confirmed the separation in the phylogenetic tree. Some polymorphic bands, involving both nucleotide and DNA methylation polymorphism, that differed between toxic and non-toxic samples were identified, cloned and sequenced. BLAST analysis of these fragments revealed differences in DNA methylation in some known genes and nucleotide polymorphism in chloroplast DNA. We conclude that MSAP is a powerful technique for the study of genetic diversity for organisms that have a narrow genetic base.     

Occurrence of Arbuscular Mycorrhizal Fungi in Rhizosphere of Jatropha curcas L. in Arid and Semi Arid Regions of India

A study was conducted to identify common arbuscular mycorrhizal (AM) fungi present in rhizosphere of Jatropha curcas L., an important bio-diesel crop, from different arid and semi arid regions of India viz., Jodhpur (Rajasthan), Hissar (Haryana), Jhansi and Lalitpur (Uttar Pradesh) and Hyderabad (Andhra Pradesh). A total of 20 AM species were recorded, which consisted of two species of Acaulospora and 18 species of Glomus. The highest frequency of occurrence was recorded for Glomus intraradix (100%), followed by Acaulospora scrobiculata (83%), G. etunicatum (50%) and Glomus 1 (50%). Maximum species richness was recorded at Jodhpur, followed by Jhansi, Hissar, Hyderabad and Lalitpur. The results seem to suggest that species richness was more in arid regions as compared to semi arid areas.     

Evaluation of Multispecies Plant-Growth-Promoting Consortia for the Growth Promotion of Jatropha curcas L.

Direct interactions that occur between members of different microbial types often result in the promotion of key processes that benefit plant growth and health. In the present study, four isolates, Brevibacillus brevis (MS1), Bacillus licheniformis (MS3), Micrococcus sp. (MS4), and Acinetobacter calcoaceticus (MS5), were used to develop multispecies consortia. They have the ability to produce IAA, solubilize inorganic P, and produce ACC deaminase and siderophore. The growth profile of MS1 was similar in monospecies and mixed-species cultures, but about a 24?% increase in mean growth rate was recorded for MS5. They enhanced the growth of Jatropha curcas in individual trials. Plant growth further improved maximally when the three were applied together. All four strains enhanced Jatropha growth in greenhouse and field experiments. Co-inoculation provides the largest and most consistent increases in shoot weight, root weight, total biomass, shoot and root length, total chlorophyll, shoot width, and grain yield.     

Genetic analysis of ecologically relevant morphological variability in Plantago lanceolata L.

Summary Morphological variability was studied in two populations of Plantago lanceolata using diallel analysis. In each population, reciprocal crosses between all possible pairs of ten plants were made. In the greenhouse, six members of each family were grown and many characters were measured. Using the model of Cockerham and Weir, the contributions of the different genetic variance components were calculated. From earlier papers it was postulated in advance to what extent and by which effect the characters in both populations were genetically determined. The populations had been differentiated for life history and morphological characters, and varied also in the relative contribution of genetic components to variability. In the Merrevliet (Me) population, where strong biotic selection was assumed, low levels of additive-genetic variability were present and the relative dominance appeared to be high. The contrasting population, Westduinen (Wd), which is abiotically controlled and shows strong environmental variability, possessed higher levels of additive-genetic variability and lower levels of relative dominance. It is possible that differential natural selection has diminished additive-genetic variability to different extents in both populations: plasticity and environmental heterogeneity prevented the loss of additive-genetic variability in Wd, whereas in the stable population, Me, natural selection had the opportunity of not only changing the means of the characters but also of diminishing additive-genetic variability to a great extent.Grassland Species Research Group Publication No. 146     

Genetic analysis of ecological relevant morphological variability in Plantago lanceolata L.

Summary Morphological variability was analysed in an F₂-generation derived from crosses between two ecotypes of Plantago lanceolata L. Six allozyme loci, localised in five linkage groups, were used as markers. For two marker loci, Got-2 and Gpi-1, segregations did not fit monogenic ratios. In the linkage groups to which these two loci belonged, male sterility genes appeared to be present. In these crosses, male sterility (type 3, as described by Van Damme 1983) may be determined by two recessive loci located in the linkage groups of Got-2 and of Gpi-1. Many correlations of morphological and life history characters with allozyme markers were observed. The quantitative trait loci did not appear to be concentrated in major gene complexes. Often many loci were involved, sometimes with effects opposite to those expected from the population values. Main effects of the linkage groups appeared to be more important than interaction effects in determining variability. It also appeared that there is a positive correlation between the number of heterozygous allozyme loci and generative growth.Grassland Species Research Group Publication No. 115     

Genetic analysis of ecological relevant morphological variability in Plantago lanceolata L.

Summary Plants of an F₂ generation derived from crosses between two ecotypes of Plantago lanceolata L. had previously been studied in a greenhouse. In the present experiment, F₂ plants were transplanted into their original habitats (a hayfield and a pasture). Six allozyme loci were used as markers in the analysis of survival and performance of the segregating genotypes. Fitness differences between the plants were large enough to detect natural selection. In both transplantation sites selection appeared to operate, though in different ways. In the hayfield habitat directional selection was hypothesized and both survival and performance of the plants were related to genotype, with the genotypes originating from the hayfield almost always performing better. In the pasture habitat where the habitat is not uniform and unpredictable hazardous droughts occur, survival was nearly genotype independent and environmentally determined, whereas performance of the plants was genotype dependent. The expression of two morphological characteristics, number of leaves and leaf length, was often not in concordance with the greenhouse results and was contradictory in both sites. Expression of both characters in the field, therefore, appeared to be strongly dependent on the general performance and growth conditions of the plant and not on the genotype.Grassland Species Research Group Publication no. 143     

麻疯树(Jatropha curcas L.)幼苗生长和光合作用对盐胁迫的响应

为探讨盐胁迫对麻疯树幼苗生长和叶片光合生理的影响,在温室不同浓度NaCl处理下,对生长、光合色素含量、净光合速率Pn等光合参数、叶片MDA含量和电解质相对外渗率EL进行测定.结果表明:① 25～50 mmol·L-1 NaCl处理促进幼苗生长,尤其是50 mmol·L-1 NaCl处理,鲜重较对照显著增加44.3%,100～150 mmol·L-1 NaCl对生长影响不大,200～250 mmol·L-1 NaCl使生长受抑制,鲜重较对照分别显著下降39.3%和70.2%.② 50 mmol·L-1 NaCl时,Pn较对照显著增加17.2%,100～150 mmol·L-1 NaCl时与对照无显著差异,200～250 mmol·L-1 NaCl时分别比对照显著下降73.2%和77.9%,Gs和Tr呈相同趋势,MDA含量、EL则相反.③叶绿素Chl在 25～50 mmol·L-1 NaCl时递增,100～250 mmol·L-1 NaCl时递减,但Chl a/Chl b值变化小;类胡萝卜素Car 在25 mmol·L-1 NaCl时显著增加,100 mmol·L-1 NaCl后缓慢下降,但Car/Chl值呈上升趋势.④ 25～150 mmol·L-1 NaCl时幼苗水分利用效率WUE与对照无显著差异,200～250 mmol·L-1 NaCl时比对照显著下降.综上所述,25～50 mmol·L-1 NaCl时,麻疯树幼苗通过增加气孔开张、增强光合膜等细胞膜稳定性和膜功能,使Pn显著增加,促进植株生长和提高耐盐性,100～150 mmol·L-1 NaCl时,通过稳定的WUE使Pn下降不显著,生长受影响小,具有较好的耐盐性,200～250 mmol·L-1 NaCl时,光合膜等生物膜功能减弱,使Pn显著下降,幼苗诱导活性氧清除系统并通过减小生长来提高耐盐性,具有较好的耐盐适应性.150 mmol·L-1 NaCl以下是麻疯树幼苗生长的适宜浓度.     

麻疯树中ADP核糖基化因子基因的克隆和表达

从麻疯树cDNA文库中筛选到包含完整编码序列的ADP核糖基化因子的cDNA序列,命名为Jc-arf．其长度为887bp,开放阅读框546bp,推测的编码蛋白含181个氨基酸残基,具有典型的GTP结合蛋白家族的特点：P框（GLDAAGKT）、G’框（DVGGQ）和G框（NKQDL）。序列分析显示,Jc-arf矿接近于人类ClassI型arf基因,其蛋白序列与多种植物ARF有很高的同源性。半定量RT-PCR结果显示,Jc-arf的表达具有一定的组织特异性,在花中最丰富。PEG、低温、NaCl胁迫下,Jc-arf的表达受PEG和低温的诱导,而对NaCl胁迫不敏感。     

Isolation of novel microsatellites from Jatropha curcas L. and their cross-species amplification

Jatropha curcas L., a member of the Euphorbiaceae, is widely distributed in different parts of the globe. In the present study, 12 microsatellites were isolated from J. curcas and their cross-species amplification was checked in six species of genus Jatropha. Within J. curcas, observed and expected heterozygosities ranged from 0.94 to 0.54 and from 0.95 to 0.56, respectively. Of the 12 loci, five showed significant deviation from Hardy-Weinberg equilibrium. There was no significant linkage disequilibrium detected between any of the loci. The markers isolated in the present investigation will be useful for assessing the population diversity and genetic structure of J. curcas and also in other species of Jatropha.     

盐胁迫下水、氮对小桐子形态特征与水分利用的影响

为研究盐胁迫下不同水氮对小桐子(Jatropha curcas)形态特征和水分利用的影响,采用3种施盐水平(S1:0 g,S2:3 g,S3:6 g),3种供水水平(W1:12.7 mm,W2:25.4 mm,W3:38.1 mm)和2种施氮水平(N1:0 g,N2:0.4 g)进行盆栽试验。结果表明:随着施盐量的增多,小桐子胡伯尔值显著上升,而总干物质质量、壮苗指数和灌溉水利用效率均显著下降;随着灌水量的增加,小桐子灌溉水利用效率显著下降,而在S2和S3盐分胁迫下,小桐子总干物质质量和壮苗指数均在W2处理时达到最大值,胡伯尔值在W2处理时处于最小值;在每个灌水量与施盐量水平上,施氮处理(N2)的小桐子幼树总干物质质量、壮苗指数和灌溉水利用效率都比对照有显著增加,而胡伯尔值显著下降;在中盐胁迫(S2)条件下,与W3N2相比,W2N2的总干物质质量、壮苗指数和灌溉水利用效率分别显著增加了23.0%、16.6%和84.6%,胡伯尔值显著降低了21.1%,节约灌溉量达33.3%;在高盐胁迫(S3)条件下,与W3N2相比,W2N2的总干物质质量、壮苗指数和灌溉水利用效率分别增加了21.9%、5.6%和81.7%,胡伯尔值降低了7.3%,节约灌溉量达33.3%;在一定盐胁迫下,有利于小桐子生长、形态特征和灌溉水利用效率提高的最佳水氮耦合处理为W2N2处理。     

Transformation of Jatropha curcas L. for production of larger seeds and increased amount of biodiesel

The development of green energy is important to mitigate global warming. Jatropha (Jatropha curcas L.) is a promising candidate for the production of alternative biofuel, which could reduce the burden on the Earth’s resources. Jatropha seeds contain a large quantity of lipids that can be used to produce biofuel, and the rest of the plant has many other uses. Currently, techniques for plant genetic transformation are extensively employed to study, create, and improve the specific characteristics of the target plant. Successful transformation involves the alteration of plants and their genetic materials. The aim of this study was to generate Jatropha plants that can support biofuel production by increasing their seed size using genes found via the rice FOX-hunting system. The present study improved previous protocols, enabling the production of transgenic Jatropha in two steps: the first step involved using auxins and dark incubation to promote root formation in excised shoots and the second step involved delaying the timing of antibiotic selection in the cultivation medium. Transgenic plants were subjected to PCR analysis; the transferred gene expression was confirmed via RT-PCR and the ploidy level was investigated. The results suggest that the genes associated with larger seed size in Arabidopsis thaliana, which were found using the rice FOX-hunting system, produce larger seeds in Jatropha.     

Development of EST-SSR markers through data mining and their use for genetic diversity study in Indian accessions of Jatropha curcas L.: a potential energy crop

Jatropha curcas L. is gaining importance as a potential energy crop. However, lack of sufficient numbers of molecular markers hinder current research on crop improvement in Jatropha. The expressed sequences tags (EST) sequences deposited in public databases, offers an excellent opportunity to identify simple sequence repeats (SSRs) through data mining, for further research on molecular breeding. In the present study 42,477 ESTs of J. curcas were screened, out of which 5,673 SSRs were identified with 48.8 % simple (excluding mononucleotide repeats) and 52.2 % compound repeat motifs. Amongst these repeat motifs, dinucleotide repeats were abundant (26.5 %), followed by trinucleotide (23.1 %) and tetranucleotide repeats (0.8 %). From these microsatellites, 32 EST-SSR (genic microsatellite) primer pairs were designed. These primers were used to analyze the genetic diversity among 42 accessions collected from different parts of India. Out of the 32 EST-SSR primers, 24 primer pairs exhibited polymorphism among the genotypes, with amplicons varying from one to eight, giving an average of 2.33 alleles per polymorphic marker. Polymorphic information content value ranged from 0.02 to 0.5 with an average of 0.402 indicating moderate level of informativeness within these EST-SSRs markers. The EST-SSR markers developed here will serve as a valuable resource for genetic studies, like linkage mapping, diversity analysis, quantitative trait locus/association mapping, and molecular breeding. The current study also revealed low diversity in the screened Indian Jatropha germplasm. Therefore, the future efforts must be made to broaden the gene pool of Jatropha for the creation of genetic diversity that can be further used for crop improvement through breeding.     

航天搭载对小桐子种子萌发及幼苗生长的影响

研究了航天搭载对两个种源地小桐子种子萌发及幼苗生长的影响.结果表明:航天搭载降低了种子的活力;在幼苗生长方面,航天搭载对小桐子幼苗的成苗率没有显著影响,航天搭载扩大了版纳种源当代幼苗株高及地径的变异范围,对元阳种当代幼苗的株高及地径影响不明显.这说兑叫不同种源地的植物对太空环境的反应有所不同.本研究为航天技术有效的运用于小桐子诱变育种提供依据.     

Phytochemical analysis of Jatropha curcas L. during different seasons and developmental stages and seedling growth of wheat (Triticum aestivum L) as affected by extracts/leachates of Jatropha curcas L

Jatropha curcas shows invasive characters and is a significant source of many phytochemicals with varying biological activities. Different plant parts of Jatropha curcas L exhibited variation in their phytochemical constituents. Leaves and ovary walls were found to contain higher contents of total phenols, tannins and phytic acid whereas free amino acids were greater in leaves. Young leaves of Jatropha show greater contents of all these metabolites. Further, plants exhibit seasonal differences as leaves collected during summer (May-June) have greater accumulation of total phenols, tannins and free amino acids however, phytic acid was more during rainy season. Leachates and extracts in their higher concentrations adversely affected the germination and growth of wheat seedlings however, lower concentrations were more or less stimulatory. These treatments not only decreased the length, fresh and dry weight of seedlings but also affected the chlorophyll contents and activity of enzymes such as nitrate reductase, aminotransferases in wheat seedlings however, the activity of superoxide dismutase and ascorbate peroxidases increased. Experiments indicate harmful allelopathic effects of Jatropha leachates /extracts on wheat seedlings, hence further experimentation and analysis is recommended before continued plantation of Jatropha particularly on fertile soils. However. Growth of Jatropha plants on saline soils and their potential for accumulating sodium, potassium and chloride are the attributes suggesting the possibility of use of Jatropha plants in improving saline soils.