To meet the challenge of feeding a growing population, breeders and scientists are continuously looking for ways to increase genetic gain in crop breeding. One way this can be achieved is through 'speed breeding' (SB), which shortens the breeding cycle and accelerates research studies through rapid generation advancement. The SB method can be carried out in a number of ways, one of which involves extending the duration of a plant's daily exposure to light (photoperiod) combined with early seed harvest in order to cycle quickly from seed to seed, thereby reducing the generation times for some long-day (LD) or day-neutral crops. Here we present glasshouse and growth chamber-based SB protocols with supporting data from experimentation with several crop species. These protocols describe the growing conditions, including soil media composition, lighting, temperature and spacing, which promote rapid growth of spring and winter bread wheat, durum wheat, barley, oat, various members of the Brassica family, chickpea, pea, grasspea, quinoa and the model grass Brachypodium distachyon. Points of flexibility within the protocols are highlighted, including how plant density can be increased to efficiently scale-up plant numbers for single seed descent (SSD) purposes. Conversely, instructions on how to perform SB on a small-scale by creating a benchtop SB growth cabinet that enables optimization of parameters at a low cost are provided. We also outline the procedure for harvesting and germinating premature wheat, barley and pea seed to reduce generation time. Finally, we provide troubleshooting suggestions to avoid potential pitfalls.

piggyBac is a short inverted-repeat-type DNA transposable element originally isolated from the genome of the moth Trichoplusia ni. It is currently the gene vector of choice for the transformation of various insect species. A few sequences with similarity to piggyBac have previously been identified from organisms such as humans ( Looper), the pufferfish Takifugu rubripes ( Pigibaku), Xenopus ( Tx), Daphnia ( Pokey), and the Oriental fruit fly Bactrocera dorsalis. We have now identified 50 piggyBac-like sequences from publicly available genome sequences and expressed sequence tags (ESTs). This survey allows the first comparative examination of the distinctive piggyBac transposase, suggesting that it might contain a highly divergent DDD domain, comparable to the widespread DDE domain found in many DNA transposases and retroviral integrases which consists of two absolutely conserved aspartic acids separated by about 70 amino acids with a highly conserved glutamic acid about 35 amino acids further away. Many piggyBac-like sequences were found in the genomes of a phylogenetically diverse range of organisms including fungi, plants, insects, crustaceans, urochordates, amphibians, fishes and mammals. Also, several instances of "domestication" of the piggyBac transposase sequence by the host genome for cellular functions were identified. Novel members of the piggyBac family may be useful in genetic engineering of many organisms.

10To meet the challenge of feeding a growing population, breeders and scientists are continuously 11 looking for ways to increase genetic gain in crop breeding. One way this can be achieved is through 12'speed breeding' (SB), which shortens the breeding cycle and accelerates research studies through