Investigating the wood production and adaptability potential of Corymbia hybrid progeny in northern coastal Zululand, South Africa

Aim of the study: The research was aimed to design microsatellite markers for genotyping and differentiation of trees from the walnut hybrid progeny Mj209×Ra. As a secondary objective, the transferability and classificatory capacity of some of these loci were assessed for Juglans genus.Area of study: The most widely spread walnut hybrid progeny used in Europe for wood production was used. Pure species from Juglans genus as Arizona black walnut (J. major (Torrey) Heller) and European or common walnut (J. regia L.), as well as a different hybrid Mj209xRa lots, were also included.Materials and methods: Genomic DNA from a hybrid tree was used for the construction of libraries enriched with dinucleotides repeats (CA/GA). From approximately 700 fragments containing SSR regions, 18 loci were finally selected for the genetic characterization. Eight of these genomic microsatellite markers were used to assess their transferability into Juglans genus. Main results: Despite the high degree of kinship of the hybrid progeny, it was possible to differentiate random trees with a low probability of error. Markers also allowed to differentiate unambiguously between Arizona black walnut and European walnut. They were even able to discriminate two hybrid Mj209×Ra lots with a high degree of certainty.Research highlights: This new set of microsatellites might be considered a complement for the markers published up to date to perform studies into Juglandaceae family.Keywords: Juglandaceae; wood production; genotyping; genotype identification; simple sequence repeats; SSR.

Download Full-text

Time and Latitude in South Africa

International Astronomical Union Colloquium ◽

10.1017/s0252921100026816 ◽

1972 ◽

Vol 1 ◽

pp. 27-38

Author(s):

J. Hers

Keyword(s):

South Africa ◽

Cape Town ◽

Astronomical Observations ◽

Royal Observatory ◽

The Republic ◽

Astronomical Determination ◽

Limited Accuracy ◽

Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Download Full-text

The Microscopy of Compatibility and Incompatibility in Ulmus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010011934x ◽

1985 ◽

Vol 43 ◽

pp. 504-505

Author(s):

B. L. Redmond ◽

Christopher F. Bob

Keyword(s):

Dutch Elm Disease ◽

Economic Losses ◽

Hybrid Progeny ◽

Ulmus Pumila ◽

Ulmus Americana ◽

American Elm ◽

Asian Species ◽

Ulmus Parvifolia ◽

Initial Appearance ◽

Chinese Elm

The American Elm (Ulmus americana L.) has been plagued by Dutch Elm Disease (DED), a lethal disease caused by the fungus Ceratocystis ulmi (Buisman) c. Moreau. Since its initial appearance in North America around 1930, DED has wrought inexorable devastation on the American elm population, triggering both environmental and economic losses. In response to the havoc caused by the disease, many attempts have been made to hybridize U. americana with a few ornamentally less desirable, though highly DED resistant, Asian species (mainly the Siberian elm, Ulmus pumila L., and the Chinese elm Ulmus parvifolia Jacq.). The goal is to develop, through breeding efforts, hybrid progeny that display the ornamentally desirable characteristics of U. americana with the disease resistance of the Asian species. Unfortunately, however, all attempts to hybridize U. americana have been prevented by incompatibility. Only through a firm understanding of both compatibility and incompatibility will it be possible to circumvent the incompatibility and hence achieve hybridization.

Download Full-text

Indirect Rule in South Africa

10.1017/upo9781580467421 ◽

2009 ◽

Author(s):

J. C. Myers

Keyword(s):

South Africa ◽

Indirect Rule

Download Full-text

Combining Professional Interests and Travel: People to People Citizen Ambassador Program

Perspectives on Global Issues in Communication Sciences and Related Disorders ◽

10.1044/gics1.2.47 ◽

2011 ◽

Vol 1 (2) ◽

pp. 47-54

Author(s):

Alex Johnson ◽

Amanda Hitchins

Keyword(s):

South Africa ◽

Health Education ◽

Communication Disorders ◽

Social Conditions ◽

Speech Language Pathologists ◽

Exchange Program

Abstract This article summarizes a series of trips sponsored by People to People, a professional exchange program. The trips described in this report were led by the first author of this article and include trips to South Africa, Russia, Vietnam and Cambodia, and Israel. Each of these trips included delegations of 25 to 50 speech-language pathologists and audiologists who participated in professional visits to learn of the health, education, and social conditions in each country. Additionally, opportunities to meet with communication disorders professionals, students, and persons with speech, language, or hearing disabilities were included. People to People, partnered with the American Speech-Language-Hearing Association (ASHA), provides a meaningful and interesting way to learn and travel with colleagues.

Download Full-text