Jatropha curcas L. is a potential bioenergy crop but has a lack of improved cultivars with high yields and oil content. Therefore, increasing our understanding of J. curcas germplasm is important for designing breeding strategies. This study was performed to investigate the genetic diversity and population structure of Indonesian J. curcas populations from six different islands. To construct a reference, we de novo assembled the scaffolds (N50 = 355.5 kb) using 182 Gb Illumina HiSeq sequencing data from Thai J. curcas variety Chai Nat. Genetic diversity analysis among 52 Indonesian J. curcas accessions was conducted based on yield traits and single nucleotide polymorphism (SNP) markers detected by mapping genotyping-by-sequencing reads from Indonesian population to Chai Nat scaffolds. Strong variation in yield traits was detected among accessions. Using J. integerrima as an outgroup, 13,916 SNPs were detected. Among J. curcas accessions, including accessions from other countries (Thailand, the Philippines and China), 856 SNPs were detected, but only 297 SNPs were detected among Indonesian J. curcas populations, representing low genetic diversity. Through phylogenetic and structural analysis, the populations were clustered into two major groups. Group one consists of populations from Bangka and Sulawesi in the northern part of Indonesia, which are located at a distance of 1572.59 km. Group two contains populations from islands in the southern part: Java, Lombok-Sumbawa, Flores and Timor. These results indicate that introduction of diverse J. curcas germplasms is necessary for the improvement of the genetic variation in the Indonesian collections.

The application of novel feedstuffs in poultry diets, especially in developing countries, has received attention in recent years. Jatropha (Jatropha curcas) is a non-edible oil seed, and its meal is a rich in protein. Jatropha meal (JM) has been characterised as a potentially useful animal feedstuff due to its high content of crude protein level (35-50%), essential amino acid and mineral content. However, jatropha kernel contains high amounts of phytate, ranging from 7 to 10%, which would require phytase supplementation for it to be used in feeds. Jatropha contains toxic compounds and anti-nutritional factors, including lectin, tannin, saponin, phorbol esters and trypsin inhibitors, which require different treatments (physical, chemical or biological) to make it suitable for poultry diets. As a result of the presence of detrimental compounds, only low levels of jatropha in feed are recommended from animal trials. It may be used to partially substitute soybean meal, but not maize. It has been suggested in the literature that, after physical or chemical treatment of jatropha seed meal, it may have other benefits, including as an immunomodulant and antioxidant, as well as hypocholestermic, antihypertensive, hepatoprotectant, antiretroviral, anti-inflammatory, analgesic and antibacterial properties. It appears that heat and enzyme treated jatropha could be used in poultry diets without detrimental effects on productive and reproductive performance and may promote health status in poultry.

Spatial distribution studies in pest management identify the locations where pest attacks on crops are most severe, enabling us to understand and predict the movement of such pests. Studies on the spatial distribution of two mite species, however, are rather scarce. The mites Polyphagotarsonemus latus and Tetranychus bastosi are the major pests affecting physic nut plantations (Jatropha curcas). Therefore, the objective of this study was to measure the spatial distributions of P. latus and T. bastosi in the physic nut plantations. Mite densities were monitored over 2 years in two different plantations. Sample locations were georeferenced. The experimental data were analyzed using geostatistical analyses. The total mite density was found to be higher when only one species was present (T. bastosi). When both the mite species were found in the same plantation, their peak densities occurred at different times. These mites, however, exhibited uniform spatial distribution when found at extreme densities (low or high). However, the mites showed an aggregated distribution in intermediate densities. Mite spatial distribution models were isotropic. Mite colonization commenced at the periphery of the areas under study, whereas the high-density patches extended until they reached 30 m in diameter. This has not been reported for J. curcas plants before.

We report on identification of core collection from 192 accessions collected from 12 Indian states and five other countries based on 109 polymorphic amplified fragment length polymorphism (AFLP) markers. Pairwise Jaccard's similarity coefficient for accessions varied from 0.25 to 1 with a maximum genetic distance of 0.75 obtained between accessions Jc428 (from Mexico) and J204 (from Madurai, Tamil Nadu). Both UPGMA (Unweighted Pair Group Method of Arithmetic Averages) clustering and principal coordinate analyses showed similar grouping of accessions in three major clusters in which Mexican accessions clustered separately from Indian, Chinese and African accessions. Results obtained from analysis of molecular variance indicated that 59% of the genetic variation was distributed among the populations, while 41% of variation was within the populations. A total of 16 (8.3% of the entire collection) core accessions were identified, which contained the entire allelic diversity of 192 accessions with respect to the sampled AFLP loci. The core accessions would be highly useful for future genetic improvement of Jatropha. To the best of our knowledge, this is the first report on identification of core accessions in Jatropha.

Jatropha curcas (jatropha) is an important non-edible oilseed crop with potential as a raw material for biofuel production. Although J. curcas has 30–35% oil content in its seeds, it has low seed yield ( < 2 ton/ha) and thus cannot become an economically viable crop. However, jatropha has many related species and genera such as J. integerrima, J. multifida, J. podagrica and Ricinus communis that are suitable for interspecific and intergeneric hybridization. The desirable features that can be obtained from these species are high number of inflorescences from J.integerrima, large fruit size from J. multifida, high oil content from J. podagrica and raceme-type inflorescence from R. communis. We were initially successful in producing hybrids between J. curcas and these related species. Hybridity was confirmed using expressed sequence tag (EST)–simple sequence repeat markers developed from the J. curcas EST database.

Aqueous extracts of Tephrosia vogelii and Hyptis suaveolens, and of oils of Azadirachta indica and Jatropha curcas, as well as the pesticide Furadan 5G were evaluated for their insecticidal activity against the maize cob borer Mussidia nigrivenella Ragonot in laboratory and field experiments. In general, treated plants had a strong deterrent effect on ovipositing M. nigrivenella. The oviposition deterrence index was highest with neem oil at both concentrations, J. curcas at 5% and H. suaveolens at 20%. In addition, neem and Jatropha oils adversely affected egg hatch; it decreased with an increase in concentrations of oil emulsions and varied between 3 and 25.5% for neem and 6 and 16% for J. curcas. The lethal concentration 50 values calculated were 1.3 and 0.8%, respectively, for neem and J. curcas. By contrast, larval survival was not affected by the oil treatments. In the field, Furadan, neem and J. curcas oils significantly reduced the number of M. nigrivenella larvae by 16–49.2%, while aqueous extracts of T. vogelii and H. suaveolens were similar to the emulsified water control. The treatments did not significantly influence cob weight, and only neem oil at both concentrations and Furadan significantly reduced cob damage and consequently grain losses. These results showed that oil emulsions of A. indica and J. curcas oils act not only as an oviposition deterrent but also as ovicides. The prospects for possible inclusion of botanicals into integrated M. nigrivenella control in maize cropping systems are discussed.

Studies were conducted from 1993–1995 at Samanko, Mali, on rearing and pheromone trapping of Busseola fusca Fuller (Lepidoptera: Noctuidae), and on the insecticidal effect of extracts of Jatropha curcas (Euphorbiaceae) on B. fusca and Sesamia calamistis Hampson (Lepidoptera: Noctuidae). A technique for mass rearingof B.fusca larvae on a chickpea and sorghum leaf-based meridic diet was developed, requiring about 10 g of diet per larva. An average of 7.3 successive generations were obtained per year. Pupal and larval mortalities were less than 15%. Oviposition was obtained on artificial substrates, with a fecundity of 300–500 eggs per female. Laboratory tests were conducted with diets in which extracts of nuts of J. curcas had been added. A 100% larvicidal effect was obtained with B. fusca and S. calamistis at 0.01% and 1% crude oil concentration respectively, and with 0.025% of the phorbol ester fraction on S. cahmistis. Trapping experiments using traps made of aluminum trays baited with synthetic pheromone showed that B. fusca male moths flights could be satisfactorily monitored. An improvement of traps and/or pheromone effectiveness is, however, necessary before their use as a control method.