Biotech Updates

Maize Plus Hybrids Can Improve Grain Yields and Pollen Containment of Transgenic Maize

May 13, 2010

In the production of maize or corn (Zea mays L.) Plus-Hybrids, cytoplasmic male-sterile (CMS) hybrids, are combined with male-fertile hybrids which act as the pollinator of the whole stand. CMS hybrids are plants that do not produce functional male reproductive parts due to specific nuclear and mitochondrial interactions. This combination often outproduces the male-fertile self-pollinated hybrids.

A study was conducted by a team of scientists led by Magali A. Munsch of the Institute of Plant, Animal and Agroecosystem Sciences (IPAS) in Switzerland to investigate the combining abilities of five CMS hybrids and eight pollinators in 12 environments, in four countries, for two years. Results showed that Plus-Hybrids increased grain yield by 10-20% in particular environments. There were three highly responsive CMS hybrids and four generally favorable pollinators. The CMS effect brought about increase in the number of kernels depending on the environment, while the allo-pollination effect increased the thousand kernel weight in all environments. Aside from yield increase, the Plus Hybrids could also aid in the safe coexistence of transgenic and conventional maize in the laboratory by eliminating the contamination of transgenic pollens.

Subscribers of Crop Science Journal can download the full research article at