| Epicuticular wax of wheat. Alkane composition of 29
ditelosomic lines. G. BIANCHI & E. LUPOTTO Istituto di Chimica Organica, Viale Taramelli 10, 27100 pavia, Italy and M. CORBELLINI & B. BORGHI Istituto Sperimentale per la Cerealicoltura - Sezione di S. Angelo Lodigiano. 20079, Italy JENSEN and DRISCOLL (1962) report the results of a number of investigators who as early as in the thirties studied some phenotipic aspects of wax production in wheat. These studies dealt mainly with inheritance patterns of the waxiness character in segregating generations derived from interpsecific crosses (e.g. Triticum vulgare x T. compactum ; T. turgidum x T. vulgare ; T. pyramidale x T. durum ; T. dicoccoides x T. persicum). These early genetic studies gave results difficult to interpret owing to the complexity of the various levels of ploidy present in that material. JENSEN and DRISCOLL (1962) made use of the glaucous line 5075, a 42 chromosomes strain derived from a series of interspecific crosses involving tetraploid Long Kernel which in turn arose from a cross of T. dicoccoides and T. polonicum. The character glaucous appeared dominant in the F1 generation with a typical mono-mendelian 3 : 1 segregation in F2. In another paper DRISCOLL and JENSEN (1964) were able to localize a gene affecting wax production (decrease) on the short arm of chromosome 2A. By means of ditelosomic lines DRISCOLL (1966) localized the gene inhibiting wax production at 42-50 map units from the centromer. Furthermore, DRISCOLL and JENSEN (1964) cited a studies by Muramatsu on nullisomics of Chinese Spring from which the investigator localized genes controlling wax production on chromosomes 2A, 4B and 6B. Further results by other Authors are worth being cited : ALLAN and VOGEL (1960) located on chromosome 2A a gene responsable of the large wax production of a durum wheat; an inhibitor, on the contrary, was found by TSUNEWAKI (1962) on chromosome 2D of a synthesized hexaploid wheat. Furthermore TSUNEWAKI (1964) confirmed MURAMATSU and DRISCOLL and JENSEN findings that a gene associated with waxiness is located on chromosome 2A of Chinese Spring. It is clear from the foregoing literature survey on studies concerning the identification of chromosomes or genes associated with wax (glaucousness) character that the limiting factor of such studies was the difficulty of a proper evaluation of the amount and the chemical composition of wax. |
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