Status of molecular breeding for improving Jatropha curcas and biodiesel

Jatropha curcas is believed to be one of the potential biofuel crops, as it does not compete with planting lands for the edible oil plants. However, J. curcas has not been domesticated for producing biodiesel. Conventional breeding to increase the productivity of J. curcas has started since the early 2000s. Although some genetic improvement of oil yield has been made through conventional breeding, oil yield is currently still too low (≤2000 kg/ha/year) to make the biodiesel production from J. curcas sustainable. Due to the enormous potential of marker-assisted selection (MAS) and genomic selection (GS) to speed up genetic gain through early selection, genomic resources such as DNA markers, a linkage map, transcriptome sequences and a draft genome, have been developed and some are being used in genetic improvement for sustainable production of biodiesel. In this review, we present the recent advances in conventional breeding, as well as development and applications of genomic resources to improve the quantity and quality of biodiesel extracted from seeds of J. curcas. We also highlighted the requirement of a well-assembled reference genome of J. curcas and the potentials of next generation sequencing (NGS) for genome-wide association studies (GWAS) and GS to speed up the increase of the yield and quality of biodiesel from J. curcas.