Non-toxic Jatropha Research Articles

Effects of soil texture on germination and survival of non-toxic Jatropha curcas seeds

Toxic oil seeds of Jatropha curcas have been widely propagated in tropical and subtropical regions for biofuel production. However, very little is known about the non-toxic seeds of J. curcas and their germination. This paper describes the germination and survival of non-toxic J. curcas seeds over two consecutive years. Non-toxic seeds native from southeastern Mexico (600–800 mg weight) were sown in three soils with different texture (sandy; sandy-loam and clay-loam) in order to assess germination, speed of germination and survival rates of the emerged seedlings. Sandy soil had the lowest organic matter (OM) content with 1.68 g-kg−1 of dry soil, followed by sandy-loam soil (39 g-kg−1) and clay-loam soil with the highest OM (72.63 g-kg−1). The highest germination rate was obtained in sandy-loam (76%), followed by sandy (75%) and clay-loam soil (24%). The highest survival rates were obtained in sandy (99%) and sandy-loam (99%) soils followed by clay-loam soil (87%). The highest average speed of germination index was recorded in sandy (155), followed by sandy-loam (125) and clay-loam soil (23). It can be concluded that sandy and sandy-loam soil textures, with bigger pore size and low organic matter content, were the more suitable substrates to germinate non-toxic J. curcas seeds; clay loam as substrate was not suitable for non-toxic J. curcas seeds due to the low germination rate and speed.

Non-toxic jatropha plants as a potential multipurpose multi-use oilseed crop

Jatropha curcas has been intensively investigated recently as a biodiesel feedstock producer because of its adaptability to adverse soil and climatic conditions. It has been seen that increasing value from by-products of oil production is important for the viability of the crop for the farmers. The seed kernel meal left after oil extraction is potentially of high market value as an animal feed ingredient. Every kilogram of oil produced from jatropha seeds generates about 0.75kg of high quality seed kernel meal. It has a high protein content (65% on a dry matter basis) with a favourable amino acid composition, but is toxic because of the presence of compounds called phorbol esters. We introduce a non-toxic jatropha variety where phorbol esters are absent in the seeds and hence, the kernel meal can be included in animal feeds after conventional heat treatment similar to that done for soybean meal. Preliminary observations in a field trial indicates that there are non-toxic jatropha provenances that are similar to or better than the conventional toxic jatropha varieties in seed yield per plant and seed oil content. Non-toxic jatropha has potential as a viable bio-oil crop if high quality seeds are used for developing the plantation.

Localisation of antinutrients and qualitative identification of toxic components in Jatropha curcas seed

Jatropha curcas seed oil is a promising feedstock for biodiesel production. The seeds contain major toxic (phorbol esters, PEs) and antinutritional (phytate and trypsin inhibitor) factors. In the present study the localisation of antinutrients and a rapid qualitative method for detecting the presence of PEs were investigated. Kernels were separated into cotyledon, hypocotyl, kernel coat and endosperm. The majority of phytate (96.5%), trypsin inhibitor (95.3%) and PEs (85.7%) were localised in the endosperm. Based on PEs, a qualitative method was developed to differentiate between toxic and non-toxic Jatropha genotypes. In this method, PEs were easily detected by passing methanol extracts of kernels (Jatropha toxic and non-toxic genotypes) through a solid phase extraction (SPE) column and measuring the absorption of the resulting eluates at 280 nm. For raw kernels, SPE eluates with absorbance ≥ 0.056 were considered as toxic and those with absorbance ≤0.032 as non-toxic. For defatted kernel meals, SPE eluates with absorbance ≥ 0.059 were considered as toxic and those with absorbance ≤0.043 as non-toxic. The majority of antinutrients/toxic compounds are localised in the endosperm of the kernel. The qualitative method developed for rapid identification of toxic PEs could be useful in screening the toxicity of Jatropha-based products in the biodiesel industry. Further confirmation of PEs should be established by high-performance liquid chromatography.

Development of SCAR Marker Specific to Non-Toxic Jatropha curcas L. and Designing a Novel Multiplexing PCR Along with nrDNA ITS Primers to Circumvent the False Negative Detection

Jatropha curcas L., a multipurpose shrub, has acquired significant economic importance for its seed oil which can be converted to biodiesel an emerging alternative to petro-diesel. In addition to the commercial value, it is also having medicinal and even high nutritional value to use as animal fodder which is limited due to the toxicity. Development of molecular marker will enable to differentiate non-toxic from toxic variety of J. curcas in a mixed population and also for quality control since the toxic components of J. curcas has deleterious effect on animals. In the present study, the efforts were made to generate the specific SCAR marker for toxic and/or non-toxic J. curcas from RAPD markers. Among the markers specific for toxic and non-toxic varieties, four were selected, purified, cloned, sequenced, and designed primers out of which one set of primers NT-JC/SCAR I/OPQ15-F and R could able to discriminate the non-toxic with toxic Jatropha by giving expected 430 bp size amplification in non-toxic variety. Furthermore, novel multiplex PCR was designed using the nrDNA ITS primers to overcome the false negatives. Present work also demonstrates utility of the conserved regions of nrDNA coding genes in ruling out the artifacts in PCR-like false negatives frequently occur in SCAR due to various reasons. The specific SCAR markers generated in the present investigation will help to distinguish non-toxic from toxic varieties of J. curcas or vice versa, and isolated marker along with designed multiplex protocol has applications in quality control for selective cultivation of non-toxic variety and will also assist in breeding and molecular mapping studies.

Plant regeneration of non-toxic Jatropha curcas—impacts of plant growth regulators, source and type of explants

Jatropha curcas is an oil bearing species with multiple uses and considerable economic potential as a biofuel plant, however, oil and deoiled cake are toxic. A non-toxic variety of J. curcas is reported from Mexico. The present investigation explores the effects of different plant growth regulators (PGRs) viz. 6-benzyl aminopurine (BAP) or thidiazuron (TDZ) individually and in combination with indole-3-butyric acid (IBA), on regeneration from in vitro and field-grown mature leaf explants, in vitro and glasshouse-grown seedlings cotyledonary leaf explants of non-toxic J. curcas. In all the tested parameters maximum regeneration efficiency (81.07%) and the number of shoot buds per explants (20.17) was observed on 9.08 μM TDZ containing Murashige and Skoog’s (MS) medium from in vitro cotyledonary leaf explants. The regenerated shoot buds were transferred to MS medium containing 10 μM kinetin (Kn), 4.5 μM BAP and 5.5 μM α-naphthaleneacetic acid (NAA) for shoot proliferation. The proliferated shoots could be elongated on MS medium supplemented with 2.25 μM BAP and 8.5 μM IAA. Rooting was achieved when the basal cut end of elongated shoots were dipped in half strength MS liquid medium containing different concentrations and combinations of IBA, IAA and NAA for four days followed by transfer to growth regulators free half strength MS medium supplemented 0.25 mg/l activated charcoal. The rooted plants could be established in soil with more than 90% survival rate.

Jatropha platyphylla, a new non-toxic Jatropha species: Physical properties and chemical constituents including toxic and antinutritional factors of seeds

Local communities in Mexico consume Jatropha platyphylla seeds after roasting. The kernels of J. platyphylla contained ca. 60% oil and were free of phorbol esters. The kernel meal of this Jatropha species contained trypsin inhibitor, lectins and phytate. However, trypsin inhibitor and lectins are heat labile so this explains why the local people can eat roasted seeds without ill effects. Heat-treated J. platyphylla kernel meal (JPKM) was free of trypsin inhibitor and lectin activities. Crude protein content of JPKM was 75%. Heated JPKM and soybean meal were included in a standard diet (crude protein 36%) for Nile tilapia ( Oreochromis niloticus) to replace 50% of the fish meal protein. The growth of fish in all the three groups was statistically similar and the blood biochemical parameters that serve as biomarkers for toxicity were within the normal ranges. This is the first study that confirms the non-toxic nature of J. platyphylla.

Shoot Bud Proliferation from Axillary Nodes and Leaf Sections of Non-toxic Jatropha curcas L.

Protocols for in vitro propagation of non-toxic variety of J. curcas through axillary bud proliferation and direct adventitious shoot bud regeneration from leaf segments have been established. Shoot bud proliferation from axillaries was assessed on an initial basal Murashige and Skoog (MS) salt medium supplemented with different concentrations of benzyladenine (BA), kinetin and thidiazuron (TDZ) followed by subculture to medium with 4.4-8.9 μM BA. Regardless of the concentration of BA in the subculture medium, shoot multiplication rate was optimum (10–12.3) with primary culture on medium supplemented with 2.3–4.5 μM TDZ. Efficient adventitious shoot regeneration from leaf tissues was achieved with culture on medium with 8.9–44.4 μM BA + 4.9 μM indole-3-butyric acid (IBA) followed by transfer to medium supplemented with 8.9 μM BA + 2.5 μM IBA. Similarity index between toxic Indian variety and the non-toxic variety based on 435 RAPD markers was 96.3%. Crossing studies followed by phorbol ester quantitation revealed that outcrosses with toxic J. curcas do not affect the phorbol ester content of seeds borne on the non-toxic variety.