2011 - 20th Annual NC State Undergraduate Research Spring Symposium

Session Time : 4/12/11 12:15 PM - 4/12/11 1:30 PM

Content Area : Horticultural Science

Student Presenters :
Anna Leigh Sauls Horticultural Science

Mentors and/or Co-Authors :
Dennis Werner Horticultural Science

Abstract Title : The Effect of Pollen Irradiation on Pollen Tube Growth, Seed Set, and Offspring Vigor in Controlled Hybridizations of Buddleja (Butterfly Bush)

Abstract :
A study was conducted to investigate the effect of pollen irradiation on pollen tube growth, seed set, and offspring vigor in controlled hybridizations of Buddleja. This information is vital to developing a pollen mutagenesis technique for development of compact and sterile forms of this excessively vigorous and potentially invasive plant. Pollen of the cultivar 'Miss Molly' was irradiated at 0 (control), 20, 40, 80, 160, and 320 Gy of gamma irradiation derived from Cobalt 60. Treated pollen was then used in controlled hybridizations onto the female parent 'Blue Chip'. Two experiments were conducted. Seed set was not impacted at the 20 and 40 Gy treatments, but was reduced at 80 Gy by 42.07 and 39.95% in experiment 1 and 2, respectively. No seed set was obtained using pollen treated at 160 Gy and 320 Gy. No clear trend was observed between pollen irradiation treatment and seedling vigor in experiment 1, as measured by dry weight after about 40 days growth, except that seedlings derived from the 80 Gy treatment showed a 38.9% decrease in dry weight as compared to the control. In experiment 2, percent dry weight reduction of seedlings in the 20 Gy, 40 Gy, and 80 Gy treatments was 0, 10.1, and 29% compared to the control. Only a slight reduction in pollen tube length was observed in the 160 Gy treatment, No clear trend was observed between pollen irradiation level and in vitro pollen germination for treatments between 0 and 160 Gy.