Development of SCAR markers to distinguish male-sterile and normal cytoplasm in bunching onion (Allium fistulosum L.)

Cytoplasmic male sterility (CMS) is one of the most important systems for the production of F-1 hybrid seed. Here, we obtained two sequence-characterised amplified region (SCAR) markers that could distinguish between male-sterile (S) and normal (N) types of cytoplasm in bunching onion (Allium fistulosum L.). A 327-bp S band (designated S327) was amplified in the male sterile line 980238A and a 1,412-bp N band (designated N1412) was amplified in its maintainer line 980238B. Both SCAR markers were verified in five male-sterile lines and their five maintainer lines, in four paternal lines and their self-crossed progenies, and in four cross combinations (one male-sterile line as the female parent and the four male-fertile paternal lines as the male parents). All the results agreed with their corresponding cytoplasmic type (S or N). Our findings suggest that the cytoplasm of A. fistulosum can be identified as male-sterile or normal using these two SCAR markers. These findings are expected to make a significant contribution to breeding F-1 hybrid cultivars of bunching onion.