| Chromosome location of a fertility-restoring gene of
a common wheat Chinese Spring for the Aegilops mutica cytoplasm H. TSUJIMOTO and K. TSUNEWAKI Laboratory of Genetics, Faculty of Agriculture, Kyoto University, Kyoto 606, Japan At present, two sources of Aegilops mutica cytoplasm are available in our laboratory, the cytoplasms introduced into the common wheat Triticum aestivum cv. Selkirk by MAAN (1977) and that introduced into T. aestivum cv. Penjamo 62 by PANAYOTOV (1980). These two cytoplasms have been introduced into 12 common wheats by repeated backcrosses (TSUNEWAKI & TSUJIMOTO 1984). The cytoplasm obtained from MAAN's line induces complete male sterility in three of the 12 common wheats, while the cytoplasm obtained from PANAYOTOV's line causes complete sterility in all 12 common wheats. The chromosomal location of the fertility-restoring gene of Chinese Spring wheat for the first mutica cytoplasm was determined in the present work. Materials and Methods The two alloplasmic lines with Aegilops mutica cytoplasm were kindly provided by Drs. S.S. MAAN (North Dakota State University, USA) and I. PANAYOTOV (Institute for Wheat and Sunflower, Bulgaria), and were used as the cytoplasm donors to the following 12 common wheats ; T. aestivum var. erythrospermum (abbrev. Tve), strain P168 (P168), cv. Chinese Spring (CS), cv. Norin 26 (N26), strain Salmon (Slm or Salmon), cv. Jones Fife (JF), cv. Selkirk (Sk or Selkirk), and cv. S-615 (S615), T. sphaerococcum var. rotundatum (Sphr), T. compactum cv. No. 44 (Cmp), T. spelta var. duhamelianum (Splt or Spelta) and T. macha var. subletschchumicum (Mch or Macha). Ditelocentric 1BL and 1BS lines of Chinese Spring which were produced by SEARS & SEARS (1978), were used to locate a fertility-restoring gene in Chinese Spring for MAAN's mutica cytoplasm. Pollen fertility indicates here the percentage of normal pollen grains with a vegetative and two wedge-shape male nuclei. Acetocarmine staining was used for this observation. Selfed seed fertility indicates the percentage of the seed setting in the first and second florets of an ear bagged before anthesis. Results and Discussion Fig. 1 illustrates the selfed seed fertilities of the 12 alloplasmic lines of common wheat with two mutica cytoplams used in this study. Three common wheats, i.e., Salmon, Spelta and Macha, showed almost complete sterility to MAAN's mutica (abbrev. mutica M) cytoplasm, whereas the other nine wheats had almost normal fertility. This fertility spectrum is the same as those produced by Ae. kotschyi, Ae. variabilis and Ae. uniaristata cytoplasms, which are classified as type II fertility spectrum by TSUNEWAKI & TSUJIMOTO (1984). PANAYOTOV's mutica (abbrev. mutica P) cytoplasm caused complete male sterility in all 12 common wheats, of which fertility spectrum is similar to those produced by T. boeoticum, Ae. comosa and Ae. heldreichii cytoplasms, and is classified as type VIII fertility spectrum. Two mutica cytoplasms are known to have identical chloroplast DNAs so far as the restriction fragment patterns produced by eight restriction enzymes are concerned (TERACHI et al. 1984) |
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