Introgression

The value of spruce-oil chemistry in sorting out problems of hybridization and introgression—major factors in Picea taxonomy—was succinctly summarized by von Rudloff who defined three situations (1) Terpene variation is limited such that it is not possible to use these characters in studies of introgression this is the case in eastern North America where the ranges of black spruce and red spruce overlap. (2) Sufficient variation in terpene profiles exists for the compounds to be useful markers in systematic studies as seen in white spruce. Brewer s spruce, and Sitka spruce. (3) Tree-to-tree variation in terpene content is so variable that use in che-mosystematic studies is precluded, or at least requires very large sample sizes for statistical reliability, as seen with Engelmann s spruce. 

Additional evidence indicating a close relationship between G. bracteata and G. peltata came from the observation of apparent natnral hybridization between them in Quebrada Villagra on Masatierra. A comparison of morphological featnres of both parents and putative hybrid individuals taken along two transects showed clear-cut intermediacy in the latter (Pacheco et al., 1991b). In addition, introgressive hybridization was indicated by the presence of individnals with intermediate valnes... 

Wendel, J. F. and Percy, R. G. 1991. Allozyme diversity and introgression in the Galapagos Islands endemic Gossypium darwinii and its relationship to continental G. barbadense. Biochem. Syst. Ecol. 18 517-528. 

QTLs were also detected in tomato introgression lines (domestic tomatoes with single, defined chromosome regions selected from the progeny of a cross with a wild, non-pigmented variety) that correspond to candidate loci for which genes and mutants have been previously characterized. Detected QTLs included the r locus Psy), the Del locus (LcyE), and the B locus. Similar to the tissue-specific expression of maize Yl, the B locus codes a fruit-specific lycopene cyclase associated with higher levels of P-carotene. ... 

Rousseaux, M.C. et al., QTL analysis of fruit antioxidants in tomato nsing Lycoper-sicon pennellii introgression lines, Theoret. Appl. Genet. Ill, 1396, 2005. 

Ellstrand, N.C, Prentice, H.C. and Hancock, J.F. (1999). Gene flow and introgression from the domesticated plants into their wild relatives , Annu Rev Ecol Syst, 30, 539-563. 

Snow, A.A., Andersen, B. and Jorgensen, R.B. (1999). Costs of transgenic herbicide resistance introgressed from Brassica napus into weedy B. rapa. Mol. Ecol., 8, 605-615. 

Schauer N, Semel Y, Roessner U, Gur A, Balbo I, Carrari F, Pleban T, Perez-Melis A, Bruedigam C, Kopka J, Willmitzer L, Zamir D and Fernie AR. 2006. Comprehensive metabolic profiling and phenotyping of interspecific introgression lines for tomato improvement. Nat Biotechnol 24 447 154. 

Brown, C. R., Adiwilaga, K. (1990). Introgression of Solanum acaule germ plasm from the endosperm balanee number 2 gene pool into the eultivated endosperm balanee number 4 potato gene pool via triplandroids. Genome, 33,273-278. 

Hamemik, A. J., Hanneman, R. E. J., Jansky, S. (2009). Introgression of wild species germplasm with extreme resistance to cold sweetening into the cultivated potato. Crop Science, 49, 529-542. 

Hayes, R. J, Thill, C. A. (2002a). Introgression of cold (4 C) chipping from 2x (2 Endosperm Balance Number) potato species into 4x (4EBN) cultivated potato using sexual polyploidization. American Journal of Potato... 

McGrath, J. M. W., Christie E.,Haberlach, Geraldine T., Wielgus, SusanM.,Uchytil, ThomasF.,Helgeson, John R (2002). Introgression and stabilization of Env/ma tuber soft rot resistance into potato after somatic hybridization of Solanum tuberosum and S. brevidens. American Journal of Potato Research 79,19-24. 

Ortega, R, Carraso, A. (2005). Germplasm enhancement with wild tuber-bearing species Introgression of PVY resistance and high dry matter content from Solarium berthaultii, S. gourlayi, S. tarijense, and S. vemei. Potato Research, 48,97-104. 

Naumova, E. S., Naumov, G. I., Michailova, Y. V., Martynenko, N. N., and Masneuf-Pomarede, I. (2011). Genetic diversity study of the yeast Saccharomyces bayanus var. uvarum reveals introgressed subtelomeric Saccharomyces ceremsiae genes. Res. Microbiol. 162, 204-213. 

Quist, D., and I. H. Chapela. 2001. Transgenic DNA introgressed into traditional maize landraces in Oaxaca, Mexico. Nature 414 541—543. 

Lefebvre, T., Chaline, N. Limousin, D., Dupont, S. and Bagneres A.-G. (2008). From speciation to introgressive hybridization the phylogeographic structure of an island subspecies of termite, R. lucifugus corsicus. BMC Evolutionary Biology, 8,38. 

The Jerusalem artichoke and other members of the sunflower family display a profusion of trichomes that often give the plant a very abrasive surface texture (Seiler, 1981). Trichomes are thought to function in part as a component of the herbivore defense system of the plant. In sunflower, introgression of biotic resistance traits is thought to have been important in adaptation (Whitney et al., 2006). The Jerusalem artichoke has at least four types of trichomes that differ in location, size, and density (Figure 4.5). 

Whitney, K.D., Randell, R.A., and Rieseberg, L.H., Adaptive introgression of herbivore resistance traits in the weedy sunflower Helianthus annuus, The American Scientist, 167, 794—807, 2006. 

Majee, M., Maitra, S., Ghosh Dastidar, K., Pattnaik, S., Chatterjee, A., Hait, N.C., Das, K.P., and Majumder, A.L., 2004, A novel salt-tolerant L-myo-inositol 1-phosphate synthase from Porteresia coarctata (Roxb.)Tateoka, a halophytic wild rice. Molecular cloning, bacterial overexpression, characterization and functional introgression into tobacco conferring salt-tolerance phenotype. J. Biol. Chem. 279 28539-28552. 

Recently the PINO l gene of the salt-tolerant wild rice Porteresia coarctata (Roxb.) was found to encode a salt-tolerant MIPS enzyme, as compared with the MIPS encoded by the salt-sensitive cultivated rice (Oryza sativa L.) (Majee et al., 2004). Comparison of MIPS sequences in these species revealed distinct differences in a 37 amino acid stretch, which upon deletion from the salt-tolerant MIPS rendered it salt-sensitive. Introgression of the PINO I gene via transformation rendered tobacco salt-tolerant. The genome of cultivated rice contains one gene encoding MIPS, termed RINOl. In addition to constitutive and... 

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