| Abstracts from the PROCEEDINGS OF THE SECOND WHEAT
GENETICS SYMPOSIUM, JAPAN (Seiken Ziho, No. 13, 1962) Commemorating its 20th Anniversary, the Kihara Institute for Biological Research has sponsored the 2nd Wheat Genetics Symposium (Japan) on April 8-9, 1962, under the auspices of the National Institute of Genetics. 54 wheat specialists from 24 different institutions attended the symposium. Dr. H. KIHARA, the general chairman, pointed out the following accomplishments, as epoc - making events in wheat genetics; (1) discovery of the right chromosome numbers, (2) completion of the genome analysis, (3) discovery of D - genome species and the synthesis of 6x wheat, (4) establishment of the aneuploid series, and (5) discovery of the most probable progenitor of B - genome species. He asked all attendants to make use of this occasion for exchanging and creating new ideas in order to promote wheat genetics and, especially, to prepare for the 2nd International Wheat Genetics Symposium held in 1963. Biochemical mechanism of pollen abortion and other alterations in cytoplasmic male-sterile wheat H. FUKASAWA Biological Institute, Faculty of Science, Kobe University, Japan In the male - sterile strain, already described, plants with 14 bivalents from Triticum durum and one extra - chromosome from ovata genome (abbreviation, 14II + 1I - plant) produce good pollen grains, showing nearly normal pollen - fertility, like that of normal fertile durum plants. Accordingly, all 14 - or 15- chromosome pollen grains are functional, irrespective of the presence or absence of an extra - chromosome. Therefore, it may be said that the extra - chromosome exerts its effect only in the sporophyte - not in the male - gametophyte. Further, male - sterile durum plants grown in a glass - house in winter give much smaller anthers than in the field in a normal season. From these findings, it is considered that the cytoplasmic effect on pollen degeneration exists also in the sporophyte including the tapetum, in the first place, --- not in the gametophyte, although GABELMAN (1949) described in his study of cytoplasmic partial male - sterility in maize that a cytoplasmic particle exerts its effect only in the developing gametophyte. Thus, it is assumed in male - sterile wheat that some nutritive substances of microspores fail to be produced in the vegetative tissue or that no transmission from the tapetum to microspores takes place in the anthers (FUKASAWA 1959). |
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