Hybrid breeding

A search for alternative breeds/hybrids has not yet produced the ideal organic hen . 

In castor growing regions, the castor plants grown vary from semiwild accessions to hybrids bred for specific traits. Each castor raceme bears male (stami-nate) and female (pistillate) flowers, with the male flowers on the lower portion of the raceme and the female flowers above. Proportions of male to female flowers vary and can be affected by a number of conditions (Severino et al., 2012 Tan et al., 2013) including temperature, hormone treatment, or wounding, as well as cnltivar variation. Cultivars that produce only staminate or pistillate flowers are natnrally desired for breeding hybrid castor, and there are several such cultivars (Tan et al., 2013). 

The three approaches to create more allelopathic crops are the traditional breeding the incorporation of allelopathic properties to hybrid crop and genetic engineering. The results indicated that the heterotic effect on allelopathy was positively significant, so hybridization could be a promising method. At present, no commercial... 

For next development of allelopathy utilization, especially such ways as breeding for stronger allelopathic potential is very hopeful. Hybridization could be a promising method of breeding. However, allelopathic activity was identified as a quantitative trait and therefore this characteristic is affected by both genetic effects and environmental conditions. The main disadvantage of the application of allelopathy is considerable variability in the dependence on environment. Therefore all results achieved in laboratory should be compared with effects of allelopathic crops in field conditions. 

Magg T, Melchinger AE, Klein D, Bohn M (2002) Relationship between European com borer resistance and concentration of mycotoxins produced by Fusarium spp. in grains of transgenic Bt maize hybrids, their isogenic counterparts, and commercial varieties. Plant Breed 121 146-154 Maheshwari N, Rajyalakshmi K, Baweja K, Dhir SK, Chowdhry CN, Maheshwari SC (1995) In vitro culture of wheat and genetic transformation - retrospect and prospect. Plant Sci 14 49-178... 

Since time immemorial, animal breeders have had to cross-foster motherless lambs or calves, or had to attach newborn mammals to a mother of a different species. They have been aware of odor barriers and developed methods to overcome them. A ewe will accept a non-related lamb if it has been rubbed with the hide or amniotic fluid of her own, perhaps stillborn, lamb. A classical case of successful cross-fostering between species is a technique employed by Peruvian livestock breeders to produce hybrids between alpacas and vicunas. The cross is called paco-vicuM and combines the large quantity of wool of the alpaca with the fine quality of vicufia hair. To breed an alpaca female with a vicufia male, first a male has to be imprinted on alpacas. A newborn male vicuna is covered with the hide of a newborn alpaca and presented to a lactating female alpaca without young. The young vicuna is accepted and nursed on account of his alpaca odor. Successfully raised by his alpaca mother, he will imprint on, and breed with, alpacas when adult. 

Pierce AC, Rao G, Bemis GW. (2004) BREED Generating novel inhibitors through hybridization of known ligands. Application to CDK2, p38, and HIV protease. /. Med. Chem. 47 2768-2775. 

In plant breeding, obtaining interspecific hybrid is important for introducing desirable genes from wild species to cultivated species. However, it is very difficult to obtain a viable hybrid plant between widely related species. These problems would predominantly come from sexual reproduction such as cross incompatibility, hybrid inviability, etc [118,119]. 

Norbask, R., Christensen, L.P., and Brandt, K., An HPLC investigation of flower color and breeding of anthocyanins in species and hybrids of Alstroemeria, Plant Breed., 117, 63, 1998. 

Jansky, S. (2006). Overcoming hybridization barriers in potato. Plant Breed, 125,1-12. 

Bae, J., Halterman, D., Jansky, S. H. (2008). Identification of a molecular marker associated with Verticillium wilt resistance in diploid interspecific potato hybrids. Molecular Breeding, 22, 61-69. 

Carputo, D., Cardi, T., Palta, J. P, Sirianni, P, Vega, S., Fruseiante, L. (2000b). Toleranee to low temperatures and tuber soft rot in hybrids between Solanum commersonii and Solanum tuberosum obtained through manipulation of ploidy and endosperm balanee number (EBN). Plant Breeding, 119, 127-130. 

De Jong, H., Tai, G. C. C. (1991). Evaluation of potato hybrids obtained from tetraploid-diploid erosses. Plant Breeding, 107, 177-182. 

Johnson, A. A. T., Nault, B. A., Veilleux, R. E. (2003). Transmission of a Bacillus thuringiensis eiy3Aa transgene from diploid to tetraploid potato using 4x-2x hybridization effeet of ploidy inerease on transgene expression and implieations for TPS hybrid produetion. Plant Breeding, 122,223-228. 

Przetakiewicz, J., Nadolska-Orczyk, A. N., Kuc, D., Orczyk, W. (2007). Tetraploid somatic hybrids of potato Solanum tuberosum L.) obtained from diploid breeding lines. Cellular and Molecular Biology Letters, 12, 253-267. 

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