Speed Breeding : Accelerated Plant Breeding

Abstract

Burgeoning population, ever changing lifestyles and advancing climate change has made it mandatory to revamp the currently available crop cultivars so as to secure food & nutritional security worldwide and accomplish other market driven traits. Although a lot of appreciable work has been done to produce high yielding and nutrient-rich strains of panoply of food and fiber crops, the pace of breeding superior varieties is yet to match the demand for the same. The duration of the seed-to-seed cycle, which is 10-12 years in case of conventional approaches, is one of the crucial bottlenecks in the progress of modern plant breeding ventures. The concept of Speed Breeding serves as a saviour here by drastically reducing the time required for cultivar development, release and commercialization to nearly half. It is a suite of techniques that involves the manipulation of environmental conditions under which crops are grown, aiming to accelerate flowering & seed set and advance to the next breeding generation as quickly as possible. It encompasses manipulation of day/night temperature, available light spectrum & intensity, photoperiod duration, soil moisture, use of PGRs, adjusting CO2 & O2 levels in air and high-density plantings in order to reduce time to floral initiation, hasten embryo development and seed maturity. Recent research has shown the power of combining emerging techniques, such as gene editing using CRISPR/Cas9, high-throughput phenotyping and genotyping, genomic selection, and MAS, with SB for boosting genetic gain. There are few key challenges limiting the deployment of speed breeding techniques in developing countries, including the high costs of infrastructure, required expertise & skill set and continuous financial support for research and development to maintain this as a sustainable operation. However, the existing constraints can be resolved by further optimization of the SB protocols for critical food crops and their efficient integration in plant breeding pipelines. Collaborative international research endeavours involving multi-disciplinary teams are needed to encourage the integration of SB systems in basic and applied research. Nonetheless the technique of Speed breeding will come out as the next breakthrough of the century and become the part and parcel of modern breeding manoeuvres.