Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 31, 1999
Publication Date: N/A
Technical Abstract: Sunflower (Helianthus spp.) has trinucleate pollen which has been reported to be difficult to germinate. Selection at the gametophytic or pollen (haploid) level would greatly facilitate selection for resistance to many biotic and abiotic stresses such as herbicide, salinity, low temperature, and phytotoxins which are expressed in the pollen. A requisite for employing such a technique is to be able to culture pollen in vitro enabling selection of gametes for selective fertilization. The objective of this study was to develop an optimum pollen germination technique for annual and perennial Helianthus species using fresh and stored pollen. A modified technique using fresh stigma of a cultivated cytoplasmic male sterile line and a germination medium containing polyethylene glycol was most effective for inducing pollen germination. The method was most effective when used on fresh pollen, and much less effective when used on pollen stored for four months in liquid nitrogen. Storage of stigmas at various temperatures or in glycerol significantly reduced their effectiveness in the germination medium.