Plus-hybrid effect refers to a combined effect of cytoplasmic male sterility (CMS) and xenia in maize (
Zea mays
L.) It could
be used in commercial production by growing a mixture of 80% CMS hybrid and 20% of another fertile hybrid. The aim
of this research was to examine individual and combined CMS and xenia effects on two hybrids widely grown in Serbia.
Sterile and fertile versions of ZP 1 and ZP 2 hybrids (three-way; Iodent × Lancaster dents) were used as females, while ZP
1, ZP 2, ZP 3, ZP 4, and ZP 5 (three-way or single cross; Iodent (BSSS) × Lancaster dents) were used as pollinators. All
of them belong to medium maturity group. The trial was set up at one location in Serbia (Zemun Polje) in 2009, 2010, and
2011. Molecular analysis of the five genotypes was done using simple sequence repeat (SSR) primers. Plus-hybrid effect
on grain yield ranged from -6.2% to 6.2%; on thousand kernel weight from -1.7% to 5.2%; on number of kernels per area
from -1.0% to 8.0%. The poor response could be due to a use of three-way instead of single cross hybrids in S type of
sterility. Modified Rogers’ distance between hybrids was in the range 0.211 to 0.378 and was not relevant for the effect,
which depended mostly on the sterile hybrid genotype and the fertile hybrid pollinator ability. This approach should be
more suitable for female hybrids with slightly poorer performance, already being produced on a sterile base.
