Fertility restoration of cytoplasmic male-sterile Emmer wheats

H. FUKASAWA

Biological Institute, Faculty of Science, Kobe University, Kobe, Japan

As already reported (Fukasawa, 1955), F₁ hybrids between male-sterile durum and T. dicoccoides var. Kotschyanum produced about 86% good pollen grains. The hybrid plants were somewhat weak and late maturing. Since some of them died before heading sufficient investigation have not been carried out. Thus, male-sterile dicoccum (Khapli) plants which have earlier maturing were used in the crossing experiment with dicoccoides var. Kotschyanum. The resulting F₁ plants showed vigorous growth habit and high pollen fertility (97%) as expected.

From the selfing or backcrossing with normal dicoccum (Khapli) plants, many offsprings, sterile, semifertile and fertile plants, were obtained. They were divided into five classes according to the degree of their pollen fertilities as shown in the following table.



The pollen fertility of semi-fertile plants seems to be influenced considerably by environmental conditions. From the data obtained, however, it could be suggested that pollen restoring factor derived from dicoccoides is not one simple gene, but two more genes are involved.

(Received, May 10, 1958)