Muppala P. Reddy

Isolation of novel microsatellites using FIASCO by dual probe enrichment from Jatropha curcas L. and study on genetic equilibrium and diversity of Indian population revealed by isolated microsatellites.

Jatropha curcas L. belongs to family Euphorbiaceae, native to South America attained significant importance for its seed oil which can be converted to biodiesel, a renewable energy source alternative to conventional petrodiesel. Very few attempts were made to isolate novel microsatellite markers and assessment of the extent of genetic equilibrium and diversity that exists in J. curcas. Therefore, the present investigation was undertaken to isolate the novel microsatellites and access genetic equilibrium, diversity that exists among 44 diverse germplasm collected from distinct geographical areas in India using isolated microsatellites. The overall efficiency of the enrichment of microsatellite by dual probe in the present study found to be 54% and among the sequences obtained the percentage of sequences having suitable flanking regions for the primer designing was found to be 89.58%. The mean co-efficient of genetic similarity (CGS) was found to be 0.97. The overall diversity obtained by microsatellites was found to be low in comparison with the diversity reported by multilocus markers systems observed in earlier studies; however, the good allele polymorphism was observed. The overall dendrogram of microsatellite analysis resulted in random clustering of germplasm and not in accordance to geographical area of collection. The present study, diversity analysis using microsatellite markers concludes the low genetic diversity and genetic disequlibrium of J. curcas in India and will provide pavement for further intra-population studies on narrow geographical areas to understand the population genetic structure, phylogeography and molecular ecological studies. The germplasm characterized, and the microsatellite markers isolated and characterized in the present study can be employed efficiently in breeding programs for genetic improvement of the species through marker assisted selection and QTL analysis, for further genetic resource management and help in making the J. curcas as potential crop with superior agronomical traits.

Cross species amplification ability of novel microsatellites isolated from Jatropha curcas and genetic relationship with sister taxa : Cross species amplification and genetic relationship of Jatropha using novel microsatellites ()

The present investigation was undertaken with an aim to check the ability of cross species amplification of microsatellite markers isolated from Jatropha curcas—a renewable source of biodiesel to deduce the generic relationship with its six sister taxa (J. glandulifera, J. gossypifolia, J. integerrima, J. multifida, J. podagrica, and J. tanjorensis). Out of the 49 markers checked 31 markers showed cross species amplification in all the species studied. JCDS-30, JCDS-69, JCDS-26, JCMS-13 and JCMS-21 amplified in J. curcas. However, these markers did not show any cross species amplification. Overall percentage of polymorphism (PP) among the species studied was 38% and the mean genetic similarity (GS) was found to be 0.86. The highest PP (24) and least GS (0.76) was found between J. curcas/J. podagrica and J. curcas/J. multifida and least PP (4.44) and highest GS (0.96) was found between J. integerrima/J. tanjorensis. Dendrogram analysis showed good congruence to RAPD and AFLP than nrDNA ITS data reported earlier. The characterized microsatellites will pave way for intraspecies molecular characterization which can be further utilized in species differentiation, molecular identification, characterization of interspecific hybrids, exploitation of genetic resource management and genetic improvement of the species through marker assisted breeding for economically important traits.

Phylogeography and molecular diversity analysis of Jatropha curcas L. and the dispersal route revealed by RAPD, AFLP and nrDNA-ITS analysis

Jatropha curcas L. (Euphorbiaceae) has acquired a great importance as a renewable source of energy with a number of environmental benefits. Very few attempts were made to understand the extent of genetic diversity and its distribution. This study was aimed to study the diversity and deduce the phylogeography of Jatropha curcas L. which is said to be the most primitive species of the genus Jatropha. Here we studied the intraspecific genetic diversity of the species distributed in different parts of the globe. The study also focused to understand the molecular diversity at reported probable center of origin (Mexico), and to reveal the dispersal route to other regions based on random amplified polymorphic DNA, amplified fragment length polymorphism and nrDNA-ITS sequences data. The overall genetic diversity of J. curcas found in the present study was narrow. The highest genetic diversity was observed in the germplasm collected from Mexico and supports the earlier hypothesis based on morphological data and natural distribution, it is the center for origin of the species. Least genetic diversity found in the Indian germplasm and clustering results revealed that the species was introduced simultaneously by two distinct germplasm and subsequently distributed in different parts of India. The present molecular data further revealed that J. curcas might have spread from the center of the origin to Cape Verde, than to Spain, Portuguese to other neighboring countries and simultaneously to Africa. The molecular evidence supports the Burkill et al. (A dictionary of the economic products of the Malay Peninsula, Governments of Malaysia and Singapore by the Ministry of Agriculture and Co-operatives. Kuala Lumpur, Malaysia, 1966) view of Portuguese might have introduced the species to India. The clustering pattern suggests that the distribution was interfered by human activity.

Biotechnology Advances in Jojoba (Simmondsia chinensis)

Wax esters have important applications in medicine, and in the cosmetics and food industries, besides their more traditional usage as lubricants. The value of the wax from sperm whales was one of the factors responsible for this animals being hunted to near extinction, which prompted the eventual ban on harvesting and the search for alternative sources. Recognition of jojoba oil as an alternative to sperm whale oil has led to a surge of interest in jojoba across the globe. The hardiness of this plant, which is amenable to cultivation even on water-deficient wastelands, has led to it being cultivated as a crop in several semi-arid and arid regions of the world. In addition, oil from the seed de-oiled cake is rich in protein and can be used as livestock feed and as a source of commercial enzymes. The plant is dioecious, and exhibits tremendous variability in male:female ratio in a given population, with male plants generally outnumbering female plants, leading to low yields as expected due to heterogeneity in the population. High yielding genotypes have been selected from experimental plantations, and vegetative propagation methods have been developed to provide genetically uniform, known sex plants to boost yields. Due to limited production, jojoba waxes are not available for a number of applications in spite of high demand. The advent of genetic engineering has provided novel opportunities to tailor the composition of plant lipids and also engineer agronomically suitable oilseed crops to produce high levels of wax esters in the seed oil. This chapter discusses efforts made towards the domestication, genetic improvements for yield and oil content, detoxification of cake for use as a live stock feed, and aspects of micropropagation of this species.

Genetic Transformation of Jatropha curcas: Current Status and Future Prospects

Energy production systems of the future must depend less on petroleum based resources and more on alternative sources, as it is essential for the well being of mankind on the planet. Bioenergy holds the greatest promise to contribute significantly to reduce the petroleum dependency and protect the environment. Jatropha curcas, a drought tolerant oil yielding perennial plant has received much attention as a potential source for biodiesel production. Despite the potential of J. curcas, the crop productivity is far too low to be commercialized. Very limited information is available on genetic variability and availability of superior genotypes for commercial cultivation. The traditional way to improve the desired traits is by breeding techniques, but these techniques have limitations as they depend on sexual compatibility, and takes considerable time (10–15 years) to release a new variety. Alternatively, genetic manipulation tools, such as, genetic transformation methods are urgently required for rapid improvement of the species. The most widely used methods of genetic transformation are Agrobacterium-mediated and direct gene transfer using particle gun A very limited progress is made on genetic transformation for different traits in J. curcas. In this review, we attempt to address the currently available literature and discuss about improvement of the species through genetic transformation.

Salicornia strobilacea (Synonym of Halocnemum strobilaceum) Grown under Different Tidal Regimes Selects Rhizosphere Bacteria Capable of Promoting Plant Growth

Halophytes classified under the common name of salicornia colonize salty and coastal environments across tidal inundation gradients. To unravel the role of tide-related regimes on the structure and functionality of root associated bacteria, the rhizospheric soil of Salicornia strobilacea (synonym of Halocnemum strobilaceum) plants was studied in a tidal zone of the coastline of Southern Tunisia. Although total counts of cultivable bacteria did not change in the rhizosphere of plants grown along a tidal gradient, significant differences were observed in the diversity of both the cultivable and uncultivable bacterial communities. This observation indicates that the tidal regime is contributing to the bacterial species selection in the rhizosphere. Despite the observed diversity in the bacterial community structure, the plant growth promoting (PGP) potential of cultivable rhizospheric bacteria, assessed through in vitro and in vivo tests, was equally distributed along the tidal gradient. Root colonization tests with selected strains proved that halophyte rhizospheric bacteria (i) stably colonize S. strobilacea rhizoplane and the plant shoot suggesting that they move from the root to the shoot and (ii) are capable of improving plant growth. The versatility in the root colonization, the overall PGP traits and the in vivo plant growth promotion under saline condition suggest that such beneficial activities likely take place naturally under a range of tidal regimes.

Biology and Biotechnological Advances in Jatropha curcas – a Biodiesel Plant

Increasing global demand for energy, the impending depletion of fossil fuels, and concern over global climate change have lead to a resurgence in the development of alternative energy sources. Bio-fuels and bio-energy encompass a wide range of alternative sources of energy of biological origin, and offer excellent, environmentally friendly opportunities to address these issues. The recognition that Jatropha oil can yield high quality biodiesel has led to a surge of interest in Jatropha across the globe, more so in view of the potential for avoiding the dilemma of “food vs fuel”. Hardiness, rapid growth, easy propagation, short gestation period, wide adaptation, and optimum plant size combine to make this species suitable for sustainable cultivation on wastelands. Besides biodiesel from the seed, the plant produces several useful products that also have commercial value. Large scale cultivation remains the single most important factor that will ultimately determine the success of Jatropha as a source of bio-fuel. The limited knowledge of the genetics of this species, low and inconsistent yields, the narrow genetic variability, and vulnerability to insects and diseases are major constraints in successful cultivation of Jatropha as a bio-fuel crop. Despite the optimal protein content and composition of the pressed cake, the presence of phorbol esters makes it unsuitable for consumption by livestock. A non-toxic variety with low or no phorbol ester content has been identified from Mexico, and the utility of pressed cake from this variety as livestock feed has been demonstrated successfully. In the absence of any morphological differences, identification of linked markers for toxic/non-toxic varieties will add value to the crop and facilitate further improvement. This chapter discusses current efforts towards assessing the diversity and phylogeny of Jatropha, identification of specific markers for toxic and non-toxic varieties, and aspects of micropropagation and genetic transformation.

Karyology and Genomics of Jatropha: Current Status and Future Prospects

Global warming, population, environmental degradation and food production are serious concerns to the well being of mankind. Development of sustainable energy resources is an essential component to many of these problems. Bioenergy holds great promise to contribute significantly to reduce petroleum consumption and emission of green house gases. Biodiesel derived from the oil of Jatropha curcas seed is emerging as an alternative to fossil fuel, since it has the desirable physiochemical characteristics and performance even superior to conventional petroleum diesel. In addition, the plant is able to grow on marginal lands, which eliminates the “food versus fuel” dilemma. However, large scale cultivation of J. curcas remains the single most important issue that will ultimately decide of its success. Despite the availability of a vast germplasm with wide variability, not much progress has been made in developing varieties or hybrids for higher oil yield, better agricultural and economic features. Additional information about the karyology, genetic diversity and genomics is necessary to generate mapping populations, marker assisted selection and to develop superior genotypes. In this review, we discuss the state of the art of genetic improvement research for J. curcas.

Jatropha Tissue Culture: A Critical Review on Present Scenario and Future Prospects

Ever increasing fuel prices and depletion of fossil reserves have ignited worldwide search for alternative renewable energy sources. Development of biofuels as an alternative and renewable source of energy has become critical in the national efforts towards maximum self-reliance, the corner stone of our energy security strategy. Ever since it was established that Jatropha methyl esters yields biodiesel of an exceptional quality and easy adaptation to semi-arid marginal lands, there has been a surge of interest in biodiesel “miracle tree”. Large scale cultivation remains the single most important factor that will ultimately determine the success of Jatropha curcas as a source of biofuel. Non-availability of superior clones/varieties, shortage of cuttings, low multiplication rate, gaps in knowledge of clonal technology, higher cost of clonal plantation, etc. are the major factors that limit large-scale cultivation. Recent advances in DNA technology and genetic transformation offer a credible approach for the genetic improvement of the species. The last decade witnessed a blooming interest in the development of micropropagation and transformation techniques for this energy crop. In this review, the achievements made during the last three decades in J. curcas micropropagation are presented.

Plant Regeneration and Genetic Transformation in Jatropha

Jatropha curcas, a non-edible oil bearing species with multiple uses, and considerable economic potential is emerging as a potential biofuel plant. The limited knowledge of this species, low and inconsistent yields, the narrow genetic variability, and vulnerability to insects and diseases are major constraints in successful cultivation of Jatropha as a biofuel crop. Hence, genetic improvement of Jatropha is essential by conventional and modern biotechnological tools to use as a viable alternative source of bio-diesel. Realising its potential as a bio-energy crop, in vitro regeneration methods have been established to meet the demand of large scale supply of superior clones, and also as a prelude for genetic improvement of the species through transgenic approaches. In this chapter, an overview of in vitro tissue culture and genetic transformation of Jatropha is discussed.