Chromosome-mosaics Observed in a Variety of Wheat, “Shirahada”

Abstract

When the meiotic indices of wheat varieties were examined to serve the breeding program of the future, the author's attention was attracted to a variety called "Shirahada ", since it shows a very low meiotic index (56.55%). With the aim of making clear this cause, a cytological study was carried out on this variety.This paper deals briefly with the results obtained. Material and MethodsThe seeds of a variety of common wheat, " Shirahada " (Triticum vulgare Vill. 2n=42), used in this experiment, were presented by Mr. Ootani, the Head of the Wheat Breeding Laboratory, Tohoku National Agricultural Experiment Station. These had been preserved for a long time in the experimental field of his laboratory.The author wishes to express his sincere thanks to Mr. Ootani for his kindness.In the first year of this experiment, a population of 50 plants were grown in the field in the usual way, and after harvest the seed-fertility and the morphological characters were measured for all plants.On the basis of this result, five plants altogether, one with the highest fertility, two with low (including one with the lowest fertility), and two with pubescent hairs on the glumes, were selected for the cytological studies of the following year. The latter two plants with pubescent hairs on the glumes belonged to the intermediate class of fertility. Thus, the self-pollinated seeds of these five plants respectively were sown in the field, and from the plants which matured, 25 plants altogether, five plants from each one, were selected at random and from each plant the young anthers, which attained to the meiotic stage, were collected and fixed by acetic-alcohol

Cytology of Monosomic Rye (<i>Secale Cereale</i> L.) Substitutions in Wheat (<i>Triticum Aestivum</i> L.) with Reference to Univalent Behaviour

“…The chromosome mosaics like those reported here were also observed by Watanabe (1961Watanabe ( , 1962 casionally 4 univalents were observed. The rye univalent divided more often than the wheat univalent at anaphase I, as a result of which the rye chro mosome lagged more frequently at anaphase II.…”

Genetic control of chromosomal chimerism found in a regenerate from tobacco callus.

“…Among the various studies on chromosomal chimerism in intact higher plants, some suggested the existence of a gene controlling spindle abnormalities which lead to abnormal cell division in Ribes nigrum (Vaarama 1949), in a variety of common wheat (Watanabe 1962), in diploid hybrids of Solanum tuberosum (Mok and Peloquin 1975a, b) and in Lolium perenne (Omara 1976). For the colchicine-treated Ribes plants, Vaarama (1949) ascribed "chromosomal mosaics" to the altered genic control induced by the permanent effect of colchicine.…”

The Cytological Chimeras in Original Regenerates From Tobacco Tissue Cultures and in Their Offsprings

“…There have been numerous reports on the chromosomal chimerism in higher plants (Hollingshead 1932;Love 1938;Vaarama 1949;Watanabe 1962;Kessel and Rowe 1974). Limiting to the studies on the genus Nicotiana, a great number of investigations have been made on cytological chimeras in cultured tissues (Fox 1963;Cooper et al 1964;Shimada and Tabata 1967;Murashige and Nakano 1967) and in the regenerated plants (Sacristan and Melchers 1969;Ogura 1975;Niizeki and Kita 1975), as well as in intact plants or hybrids (Moav 1957;Yang 1964Yang , 1965Gerstel and Burns 1966).…”

“…Among various studies on chromosomal chimerism in intact higher plants (mainly hybrids), several studies suggested the existence of a gene controlling spindle abnormalities which lead to abnormal cell division in Ribes nigrum (Vaarama 1949), in a variety of common wheat (Watanabe 1962) and in diploid hybrids of Solanum tuberosum (Mok and Peloquin 1975b). In the case of colchicine-treated Ribes plants described by Vaarama (1949), he ascribed "chromosomal mosaics" to the altered genic control induced by a permanent effect of colchicine.…”

“…In the case of colchicine-treated Ribes plants described by Vaarama (1949), he ascribed "chromosomal mosaics" to the altered genic control induced by a permanent effect of colchicine. Watanabe (1962) assumed a gene inducing spindle abnormalities, although he added that a detailed study on the processes in early stages before diakinesis is required to determine the existence of a gene with certainty. Mok and Peloquin (1975a, b) The morphactin was supplied through the generosity of Kyowa Hakko Kogyo Co.…”