Forced Pollen Shedding Effects on Pollen Diameter and Early Seedling Growth in Maize

Abstract

In those crops such as maize, which have been improved for many generations by man, the effectiveness of pollen genotype selection would be decreased each generation because the usual improvement procedure involves pollination with excess quantities of fresh pollen released normally under field conditions. In these crops, variation in this standard pollination scheme may amplify existing pollen transmission differences so that the effectiveness of pollen genotype selection would be enhanced. In maize, such changes as extended pre-pollination mature pollen storage at 2°C and pre-pollination sty1ar treatments with various chemicals increased pollen transmission differences at both qualitative and quantitative loci (Pfahler 1974b, 1986, Pfahler et a1. 1986a,b). Under field conditions, attached maize tassels usually shed pollen daily between 800-1200 h, with all or most of the pollen grains in the tassel released in 7-10 days. Detached tassels with their cut ends submerged in water and exposed to low light intensity high humidity, and 25–30°C, shed pollen continuously, with all or most of the pollen grains in the tassel released in three days.