A practical method to improve the efficiency of pollination in maize breeding and genetics research

Seed increase through manual pollination is a critical part of maize breeding and genetics research to advance generations in breeding programs, to create desired research crosses, and produce hybrid seed for trials. Pollination in the field and in controlled environments relies on the availability of high-quality pollen at the time that recipient silks are receptive. Generally, pollinations are made by capturing pollen from the tassel in a paper pollinating bag placed on the tassels one day prior to pollination and newly released pollen is then transferred to silks on the target plant. In the field, maize pollen is only viable for one to four hours following dehiscence and the rate of desiccation is influenced by environmental conditions. We have developed a method which increases the lifespan of pollen and allows pollen from a single tassel to be used to pollinate many ears by mixing fresh pollen with a dilutant that can be stored for multiple days. We identified characteristics of the size of suitable substrates and selected a PEEK based substrate for regular utilization. We evaluated pollen viability and empirically demonstrated the capability to store pollen up to nine days when pollen is mixed with a PEEK substrate and stored at 6{degrees}C. The pollen storage method was used to make successful pollinations across 24 maize inbred lines tested and was generally equivalent to the standard manual pollination process. This method has the potential to increase the efficiency of breeding operations and may be useful in an array of genetic studies. Core Ideas* Manual pollinations in breeding and genetics research requires pollen available when recipient silks are viable. * The method collects and stores maize pollen for at least five days and facilitates efficient pollination. * Pollen is mixed with polyetheretherketone and uses field-collected pollen and simple storage conditions. * The method can increase the number of pollinations per tassel and generates a reasonable number of viable seeds.