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Wheat carrying Ph1 and wheat-rye hybrids and grain dormancy.
either carrying or lacking Ph1 in speed breeding Alternatively, speed
and control conditions, and observed no breeding could be used
major differences in chromosome pairing and to rapidly generate
recombination in meiocytes at metaphase I. The fixed populations
chromosome behaviour suggests that both wheat through SSD, which
and wheat-rye hybrids are cytologically stable in some species
under speed breeding conditions. In summary, may be cheaper
all the above adult plant phenotypes could be than generating
recapitulated accurately and much faster than in double haploids, for
the corresponding glasshouse conditions. subsequent field evaluation and selection, thus
4. Transformation Experiments facilitating genetic gain and production of improved
Seeds of barley (H. vulgare cv. Golden Promise) cultivars. For genetically well-defined traits, speed
were sown and immature embryos harvested breeding could be used to rapidly introgress
and transformed. The transformation efficiency of genes or haplotypes into elite lines using marker-
speed-grown and normal plants was comparable. assisted selection.
Moreover, transformed barley explants could Conclusion
be grown under speed breeding conditions and Recent advances in genomic tools and resources
viable seed obtained > 6 weeks earlier compared and the decreasing cost of sequencing have
to standard control conditions. enabled plant researchers to shift their focus from
Further Implications model to crop plants. Despite such advances,
Speed breeding is likely to reduce generation time the slow generation times of many crop plants
continue to impose a high entry barrier. Combining
for other crop species, for example, sunflower, these tools and resources with speed breeding will
pepper, and radish, which have been shown to provide a strong incentive for more plant scientists
respond well to extended photoperiod. Speed to perform research on crop plants directly, thus
breeding methods have already been successfully further accelerating crop improvement research.
applied to accelerate breeding objectives for In the context of plant breeding, rapid generation
amaranth, peanut and pea. In a breeding context, advance to homozygosity following crossing will
it should be noted that phenotypes studied under facilitate genetic gain for key traits and allow more
controlled or glasshouse conditions do not always rapid production of improved cultivars by breeding
correlate with field observations: in particular, programs.
complex traits such as yield and abiotic stress 1 2
Dr. Pooja Yadav . Dr. Prem Chand Gyani
tolerance. Yet, phenotypic selection in early 1 Ramakrishna Mission Vivekananda Educational And Research Institute
segregating generations of wheat (F and F ) (RKMVERI). Ranchi, Jharkhand, Rain Forest Research Institute (ICFRE).
2
3
2
has been successfully implemented for some Jorhat, Assam
desirable traits such as stripe rust resistance