| Negative evidence of the transmission of the cytoplasmic
male sterility in wheat by embryo-endosperm grafting Juan-Ramon LACADENA Department of Cytogenetics and Plant Breeding Estacion Experimental de Aula Dei, Zaragoza, Spain Investigations carried out by FRANKEL (1956, 1962) and Edwardson and Corbett (1961) in Petunia, which demonstrated the asexual transmission of cytoplasmic male sterility by grafting, as well as the negative results obtained by Sand (1960) working with Nicotiana, induced to the present author to test the possible asexual transmission of the cytoplasmic male sterility in wheat. The material used (supplied by Dr. R. W. LIVERS, Hays, Kansas, U. S. A.) was as follows : line B (normal fertile) Bison wheat C. I. 12518 ; line A (cytoplasmic male sterile) : T. timopheevi x Bison10; line R (fertility restorer) : (T. timopheevi x Marquis 3) x Bison F4. Investigation was made by grafting embryos of male sterile plants (A) on endosperms of fertile plants (B) and, reciprocally, B embryos on A endosperms. Selfings and crosses showed the following results: Results of Table 1 show that neither cytoplasmic male sterility nor fertility are asexually transmitted by embryo-endosperm grafting (plants BA and AB respectively). Tables 2 b and 2 c indicate that crossability of male sterile with maintainer lines is not modified by the graft. Progeny obtained from the crossings indicated in Tables 2a, 2b and 2c will be tested the next generation in order to verify whether or not the fertility restoring mechanism has been modified. (Received June 29, 1966) |