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progression revealed normal, though accelerated, generation. Therefore, integrating speed breeding
development for all species compared to the and SSD techniques can effectively accelerate the
day-neutral conditions. Wheat plants produced generation of inbred lines for research and plant
significantly more spikes than those in day-neutral breeding programs.
conditions and grain number was unaffected by Speed Breeding III
the rapid development in both wheat and barley. In an additional protocol, which successfully
Notably, time to anthesis was more uniform within implemented a low-cost speed breeding growth
each species under speed breeding conditions - room design, lit exclusively by LEDs to reduce
an important feature, as synchronous flowering the operational cost of lighting and cooling, which
across genotypes is desirable for crossing. permits 4-5 generations a year, depending on
Additionally, wheat seed was harvested before genotype and crossing plans. These results
maturity: 14 days post anthesis in speed breeding highlight the flexibility of tailoring the speed
conditions, and following a 4-day cold treatment breeding 'recipe1 to suit the local purpose and
seed viability was high, indicating that generation resources.
time can be further reduced by harvesting
immature seed without the need for labour- Speed Breeding's applications in various
intensive embryo rescue. Seed viability of all research frontiers
other species under Speed breeding II conditions 1. Mutation studies
was either unaffected or improved compared We observed that phenotypes associated with
with day neutral conditions. Since temperature the ethyl methane sulfonate-induced mutation
greatly influences the rate of plant development, of the awn suppressor B1 locus and the Green
generation time may be further accelerated Revolution Reduced height (Rht) genes in wheat
by elevating temperature. This may, however, could be accurately recapitulated in the controlled-
induce stress and affect plant performance. Seed environment room conditions.
production (g per plant) of canola and chickpea 2. Disease resistance studies
was similar between speed breeding and day-
neutral conditions. The application of speed Clear signs of FHB progression in the susceptible
breeding conditions in a glasshouse fitted with cultivar, and little to no disease progression in the
supplementary lighting exemplifies the flexibility of resistant cultivar. Previously, it has been shown
the approach and may be preferred over growth that adult plant resistance to wheat leaf rust
chambers if rapid generation advance is to be (caused by Puccinia triticina f. sp. tritici) and wheat
applied to large populations, such as in breeding stripe rust (Puccinia striiformis f.sp. tritici) can
programs. SSD is commonly used in breeding and also be scored accurately under speed breeding
research programs to facilitate development of conditions.
homozygous lines following a cross. This process 3. Cytogenetic studies
only requires one seed per plant to advance each