Efficiencies of Mass Encapsulation in Alginate of Vegetative Explants

Author

Laurie J. George, Southern Illinois University CarbondaleFollow

Date of Award

12-1-2015

Degree Name

Doctor of Philosophy

Department

Agricultural Sciences

First Advisor

Preece, John

Second Advisor

Walters, Stuart

Abstract

‘Lord Baltimore’ hardy hibiscus (Hibiscus moscheutos L.) was used in the mass encapsulation protocol, rinsing effects on bulk encapsulation, growth comparisons using K-NAA, acclimatization to greenhouse environment, and leaf anatomy comparisons. Nodal segments, each containing a single axillary bud, were harvested and cut to 4mm prior to mass encapsulation. Results showed that using 2.75% alginate with a concentration of 60 or 80 mM calcium chloride produced an alginate mass, or “cookie”, which was able to hold together during rinsing protocols. The rinsing study resulted with the potential to reduce rinse times from 2 three-minute rinses to 1 one-minute rinse. After 4 weeks under mist, ~58% of root growth was generated when using 1 one-minute rinse. After 8 weeks under mist, the greatest percentage of shoot and root growth occurred when using 1 one-minute rinse. The use of K-NAA in the gel matrix, after four weeks, resulted in no discernable differences. Concentrations of 0 or 0.1 µM will generate a greater percentage of shoot and root growth. Using 1.0 µM K-NAA, and extending the time under mist to 8 weeks, will result in a greater percentage of shoots and roots generated. Acclimatization study investigated the survival rates on mass encapsulated nodal segments, looking at different media, depth of planting and humidity. Increases in shoot lengths can be expected up to 8 weeks under mist and planted either on top or 1 cm deep. A reduction in root growth was seen when placed on top of the medium after 4 weeks. The anatomical study found differences in the leaf cell lengths based on the stage of leaf development. However, there was no indication of a gradual change in anatomy as they adapted from in vitro to greenhouse environment. The best results were found when comparing epidermal, palisade and spongy mesophyll cells on the fourth fully expanded leaf under mist. Hydrangea quercifolia ‘Snow Queen’ was used to test the effects of tissue culture media and plant growth regulators. Research found that using dichloroisocyanuric acid (NaDCC) resulted in a decrease of contamination on explants without a reduction in the number of shoots produced. This would reduce the amount of time and labor on the encapsulation procedure, as no rinsing is required. The best result, looking a nutrient formulation, was found to be WPM with 1 µM BA added.