Biotechnological Applications for Improvement of the Pearl Millet Crop

Pearl millet [Pennisetum glaucum (L.) R. Br.] is the chief staple crop cultivated on approximately 26 mha under arid and semi-arid tropical regions of Africa, Latin America and Asia. In India, it is the fourth most commonly cultivated crop, with an average production of 9.73 million tons. It has high nutritional value and is rightly termed as a nutri-cereal, as it is rich in protein, dietary fiber, essential fatty acids, vitamins and minerals. In this context, it is important to raise awareness of its nutritional value and reorient the efforts to improve its yield and quality. Various biotechnological techniques, such as transgenic approaches, molecular tools, genomic studies and genetic modifications, can be helpful in its genetic improvement, along with conventional approaches. These modern approaches are promising techniques and are gaining a lot of momentum these days as they have high chances to increase the efficiency and accuracy of conventional breeding. Using marker assisted selection (MAS) strategies and genomics tools, Fe–Zn QTL have been identified and improved HHB 67 has been released. Further, efforts are being made to identify genomic loci for tightly linked SSR markers for iron and zinc content within a consensus map and research is in progress towards mapping QTL for flour rancidity. Detection and gene tagging of specific traits in the genome is now possible, due to a lot of progress in next-generation sequencing (NGS) and several other molecular profiling techniques. Recently, the whole genome sequencing of pearl millet has been carried out and the draft genome and re-sequencing data will help researchers in understanding the trait variation in a better way and, thus, will ultimately help in advancing genetic improvement of the crop. The huge amount of polymorphism in pearl millet which has been detected by genome mapping will stimulate the tagging and mapping of specific genomic loci or specific genes controlling various significant traits, including grain, fodder yield, drought tolerance, etc. In addition, gene introgression and MAS into enviable genetic backgrounds can provide many opportunities to assist crop improvement by reducing lengthy phenotypic selection and evaluation. Thus, the development and application of novel biotechnological approaches such as genomic selection tools, development of marker–trait associations, NGS and genotyping-by-sequencing (GBS) need to be intensified to accelerate the genetic gains targets and enhance the efficiency of breeding in pearl millet to mitigate the effects of a changing climate.