Degree Type

Dissertation

Date of Award

1988

Degree Name

Doctor of Philosophy

Department

Horticulture

First Advisor

William L. Summers

Abstract

In vitro anther culture is a promising tool for the obtention of haploid or dihaploid plants. In some crops, it has been useful for plant breeding purposes, but not in the tomato. For this study we chose the anther-to-plantlet pathway which apparently is the best way of obtaining the desired plants;There are different approaches for the obtention of calluses and the possibility of improving the response is high when results from other species are taken into account. The objective of the work reported in this dissertation was to evaluate a series of factors influencing the production and regeneration of calluses. With this we wished to define a protocol that could be used with a wide range of genotypes with good results;For the development of the protocol we evaluated factors such as media, media components, growth regulators, genotypes, anther development stage, temperature, pretreatments, and dark-light pretreatments. Results indicated that there are suitable media, as in the case of DBM[subscript]1, that can be improved further with the use of filtered thiamine and pyridoxine and the selection and proper concentration of the agar type. The use of dark treatment for incubation increased not only the number but the diameter of calluses. The most striking effect on number of callus was related to the development of the anther. When plated at the beginning of prophase I the more the anthers produced calluses. On the other hand it was possible to induce callus, although in lower numbers, at any stage of anther development including the first mitosis;Genotypic differences were very stable across the different treatments evaluated, however, growth regulators, vitamins, and agar type among others may increase the response in low callus yielding cultivars;Regeneration results were low but promising. The medium MS developed by Murashige and Skoog in 1962 plus zeatin and IAA induced formation of plantlets probably originating from the sporogenous tissue. No ploidy level was confirmed.

DOI

https://doi.org/10.31274/rtd-180813-11563

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Juan Jaramillo

Language

en

Proquest ID

AAI8825928

File Format

application/pdf

File Size

230 pages

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