Breeding controlled crosses

There are three general approaches used in Jerusalem artichoke breeding (1) controlled crosses conducted under greenhouse conditions, (2) natural open-pollinated crosses using polycross nurseries, and (3) a variation of the latter where isolated pairs are allowed to cross in the field. Each method has its advantages and disadvantages. 

Further information concerning heritability of traits of interest (e.g., mussels selected to be less affected or unaffected by toxic blooms, mussels with a specific commercial characteristic) is needed to assess the potential of breeding programmes. It is really only possible to undertake artificial selection for useful traits in mussels when there are large-scale hatchery facilities routinely available to carry out controlled crosses and to maintain mussel broodstock with clearly identified pedigrees based on DNA analysis. Such facilities are already available for oysters, and increased commercial... 

The RACB does not give information on specific male and female reproductive effects unless cross-breeding of control and treated males and females is done following the 14-week mating trial. It also does... 

Based on genetic studies (cross-breeding) with Portulaca grandma, Trezzini and Zryd (1990) postulated that only three loci are responsible for betalain biosynthesis. While two loci control the bios)mthesis of q/do-Dopa and betalamic acid, the third controls the transport of betalamic acid into the vacuole. They proposed that the formation of betanidin (condensation of cydo-Dopa with betalamic acid) proceeds in the cytoplasm and the formation of betaxan-thins (condensation of betalamic acid with an amino acid/amine) takes place spontaneously in the plant vacuole (Trezzini, 1990). 

Breeding a mid-oleic sunflower requires at least one oleic parent. The USDA/ ARS Northern Crop Science Laboratory in Fargo, North Dakota, provided private companies with crossing lines of mid-oleic sunflower. Hybrid seeds were developed by traditional crossing methods no hybrids of transgenic sunflower were used. The mid-oleic concentration appears to be controlled by a partially dominant major gene and one or more dominant minor modifier genes (46, 47). 

Not only by crossing with mice which egress Cre, but also by infection with Cre-adenovirus vectors the tissue-specific control of the knockout event can be achieved. This is a simple and attractive approach which reduces time, labour, and the number of animals needed for breeding. Adenoviral delivery of Cre in adult ventricular cardiomy-ocytes in vivo has been shown effective. ... 

Spermatozoa Requires mature broodstock /reproduction control +++ in fish, mollusc +/- in cmstacean Fertilization Cross breeding, requires females from close strains... 

The composition of boron carbide is approximately 80 atomic percent boron. The material is often considered as a source of boron, without the high reactivity of the latter. Like boron, B4C has a high neutron capture cross-section for thermal neutrons and a low secondary gamma radiation. As such, it provides an excellent neutron absorber and is used extensively to control the neutron flux in nuclear fission reactors, such as the boiling water, pressurized water, and fast breeding reactors. It is also used for the compact storage of spent fuel rods.l l... 

In the early 1900 s, apiology researchers had perfected the technique of instrumental insemination of the queen bee. This method made it possible to control the breeding process and has allowed for dramatic advances in the crossing of bees. The practical outcome of this science for the beekeeper is a well-tempered and productive bee. 

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