Studies on a male sterile strain having the Brassica campestris nucleus and the Diplotaxis muralis cytoplasm. I On the breeding procedure and some characteristics of the male sterile strain

Abstract

1. D. muralis was used as a female parent in crosses with B. campestris (a commercial cultivar, Yukina). Successive backcrossing by the pollen of the latter species raised a male sterile strain having Yukina nucleus and D. muralis cytoplasm. 2. Morphological characters 0L this strain were quite alike to cv. Yukina, except flower organs; such as two nectaries, narrow petals and short filaments with stunted anthers in which was observed a small quantity of pollen. Pistils were normal in mor-phology as well as in function. 3. Two types 0L male sterility were recognized in the strain; one was completely male sterile (MS) without anther dehiscence and the other was partially male sterile (PMS), with a little emission of pollen. In order to obtain a family whose plants are all MS, maintainers were made by two methods, from a selfed progeny of the cultivar and from a cross Yukina><PMS. Completely male sterile families could be established by both the methods.