Genome editing for vegetatively propagated crops improvement: a new horizon of possibilities

The world population is expected to reach more than nine billion in 2050. Food requirements are also predicted to increase by 70% to feed the ever-growing population. In addition, several constraints such as climate change, limited resources and globalization have threatened food security and are increasing the hunger index and malnutrition. Vegetatively propagated crops provide a potential option to fulfil food and nutrition demands. Further, they have several commercial applications in the food and fibre industries. Advancements in breeding tools such as CRISPR/Cas based genome editing can help to enhance the nutrition, agronomic performance and industrial values of vegetatively propagated crops. Significant barriers to genome editing in these crops include polyploidy, low transformation efficiency, and a lack of high throughput screening tools. Moreover, due to their sterile nature, generation of transgene-free edited lines is of utmost challenge. Here, we have reviewed some important CRISPR/Cas delivery methods to eliminate the incorporation of a transgene into the host plant, which may help to overcome government acceptance barriers of these genetically improved crops. We have also explored the latest advancements in CRISPR/Cas methods that can be implemented for nutritional and agronomic traits improvement in clonally propagated crops in the future.