Genetics of Choanephora cucurbitarum

Date

1996

Contributor

Advisor

Department

Instructor

Depositor

Speaker

Researcher

Consultant

Interviewer

Narrator

Transcriber

Annotator

Journal Title

Journal ISSN

Volume Title

Publisher

Volume

Number/Issue

Starting Page

Ending Page

Alternative Title

Abstract

Zygospores of Choanephora cucurbitarum (Berkeley et Ravevel) Thaxter germinated by producing germ tubes with terminal germsporangia, germsporangioles on vesicles or germ tubes which continued to grow without producing germsporangia. Zygospores have a light requirement for germination and were stimulated by KMnO4, NaClO and H2O2. Zygospore progeny from crosses between (+) and (-) isolates of g. cucurbitarum consisted of (+), (-) and (+,-) mating types. Mating types of germsporangiospores in each germsporangium were either all (+), or all (-) from respective (+) or (-) zygospore cultures and, all (+,-), or (+) and/or (-) plus (+,-) types from (+,-) zygospore cultures. Mating type heterokaryons (+,-) obtained from zygospore and germsporangiospore cultures in all crosses produced azygospores and zygospores which segregated into (+) and (-) during asexual propagation. All the zygospore and germsporangiospore progenies from the cross between two fast growing isolates were of fast growing type, while all those from the crosses between two slow growing isolates were of slow growing type. The crosses between fast and slow growing isolates gave rise to progeny with both fast and slow growing types. Mating types of zygospore isolates from crosses between two near identical isolates followed 1(+):1(-):2(+,-) ratio. The distribution of mating types (+) and (-), and growth types F and S fit a 1:1 ratio in zygospore progeny in all crosses. Results suggest that mating type as well as growth type are each controlled by a gene with a pair of alleles, and that these two genes are linked to each other with a distance of about 33 cM. The heterokaryotic zygospore progeny from the crosses between F and S types consisted of F(+,-), S(+,-), F,S(+,-), S,F(+,-), F,S(+) and F,S(-). Each of them segregated into two types during sporangiospore formation, suggesting that only two of the four nuclei resulted from meiosis move into the germ tube of a germinating zygospore. Mating type heterokaryons (+,-) formed through fusion of (+) and (-) protoplasts. The (+,-) colonies from protoplast fusion also produced azygospores and zygospores which segregated into (+) and (-) mating types during sporangiospore formation.

Description

Thesis (Ph. D.)--University of Hawaii at Manoa, 1996.
Includes bibliographical references (leaves 103-104).
Microfiche.
xi, 104 leaves, bound photos. (some col.) 29 cm

Keywords

Choanephora cucurbitarum -- Genetics

Citation

Extent

Format

Geographic Location

Time Period

Related To

Theses for the degree of Doctor of Philosophy (University of Hawaii at Manoa). Botanical Sciences (Plant Pathology); no. 3348

Related To (URI)

Table of Contents

Rights

All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.

Rights Holder

Local Contexts

Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.