Heidrun Bückmann and Katja Thiele
Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Germany
Alexandra Hüsken
Max-Rubner-Institut (MRI), Federal Research Institute of Nutrition and Food, Germany
Joachim Schiemann
Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Germany

Cytoplasmic male sterility (CMS) is a maternally inherited trait that suppresses the production of viable pollen. CMS is a useful biological tool for containment strategies to reduce or prevent gene flow and cross-pollination to facilitate coexistence of genetically modified (GM) and non GM-crops in cases where it is required. CMS is reversible and can restore to fertility in the presence of nuclear restorer genes (Rf-genes) and by environmental impacts. The aim of this study was to investigate the influence of air temperature on the stability of CMS maize hybrids under defined greenhouse conditions. Three CMS maize hybrids were grown in three different temperature regimes. Tassel characteristics, pollen production, and fertility were studied. The CMS stability was high in hot air temperatures and decreased in lower temperatures. The extent of these phenomena was dependent on the CMS maize genotype and should be known before using CMS for coexistence purposes.

Key words: Air temperature, biological containment, coexistence, cytoplasmic male sterility (CMS), genetically modified (GM) maize (Zea mays L.), restoration of fertility.