Document Type

Dissertation - University Access Only

Award Date

1994

Degree Name

Doctor of Philosophy (PhD)

Department / School

Biology and Microbiology

First Advisor

C.H. Chen

Abstract

The use of doubled haploid plants in a wheat cross-breeding program requires an efficient regeneration system. The objective of this research was to develop a simple but efficient anther culture method for regenerating dihaploid pollen plants. The techniques may be supplemented to the conventional breeding procedures of rapid genetic fixation and selection for economically desirable plants. Pre-cool treated anthers containing uninucleate pollen grains of spring wheat F1 hybrids were plated on W14 medium and placed under 33°C for three days as a heat shock. Incubation temperature was then reduced to 27°c for callus induction. Androgenesis of pollen grains in cultured anthers followed both asymmetrical and symmetrical pathways. The frequency of occurrence of multicellular grains was different among genotypes tested. Anthers plated at the density of 15 per mL medium yielded high callus initiation regardless of genotypes. Plant regenerability in callus on 190-2 medium was greatly influenced by genotypes and growth conditions of anther donor plants. prolonged subcultivation of calli on maintenance medium weakened plant regenerability. Calli newly initiated from Fl hybrids of three crosses were grown on 190-2 medium containing Oto 200 mg/L of colchicine and incubated at 4°C and 27°C for two days before being transferred onto colchicine-free 190-2 medium for plant regeneration. Although toxicity of colchicine significantly reduced the plant regenerability, calli treated with colchicine at 50-100 mg/Lat 4°C initiated more dihaploid than haploid plants. Colchicine toxicity to calli decreased if the calli were treated under cool temperature, thereby more dihaploid plants were regenerated. The protocol for dihaploid regeneration in spring wheat anther culture is described.

Library of Congress Subject Headings

Wheat -- Breeding -- South Dakota
Wheat -- Genetics
Regeneration (Botany)

Format

application/pdf

Publisher

South Dakota State University

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Rights Statement

In Copyright