The Association of Semisterile-1 in Maize with Two Linkage Groups.
In 1925 there appeared in one of the senior writer’s cultures of maize a few plants producing 50 percent aborted pollen. Subsequent examination of the ears borne by these individuals revealed that they likewise developed only one-half the normal number of seeds. Following BELLING’S (1914) application of the term to a similar condition in Stizolobium, the phenomenon was called semisterility. The pedigreed line to which the
Cytogenetics of Hybrids between Zea Mays and Euchlaena Mexicana.
NDOUBTEDLY specific and generic as well as lesser differences may U be largely attributed to differences in the chromosomes. Detailed analysis of gene and chromosome differences between related genera is seldom possible because of sterility and lack of genetical or cytological information. A striking exception is provided by Zea mays L. and Euchlaena mexicana Schrad. Between these distinct species highly fertile hybrids are easily obtained. Genetic and cytological work with maize is sufficiently advanced to make analysis of hybrids profitable. Linkage groups as well as cytological markers have been established for all 10 chromosomes in Zea mays. In some cases the approximate position of genes on a chromosome has been determined. Some of the most useful chromosome markers have been obtained as a result of the recent work with segmental interchange strains. The meiotic prophase crosses and rings which appear in maize heterozygous for an interchange make identification of the chromosomes concerned relatively easy. A consideration of these facts led to the belief that hybrids of maize and annual teosinte would be exceptionally favorable material for cytogenetical studies. From the study of hybrids it was hoped that a clearer knowledge of the similarities and differences of the chromosomes of maize and its relative, annual teosinte, would be obtained. Knowledge of this kind is useful in estimating the evolutionary processes which have been effective in the differentiation of the two forms studied. Three varieties of annual teosinte are recognized : Florida, Durango, and Chalco. The latter two varieties have been found growing wild in Mexico (Collins, 1921), whereas the cultivated Florida variety is thought to have come originally from Guatemala. Recently, Collins (1932) has reported that an annual teosinte resembling the Florida variety has been discovered which is native to that region.
THE CHALLENGES IN IDENTIFICATION OF ARTISTS-MANAGERS: CONSEQUENCES FOR CREATIVITY
Research on identity, its tensions and paradoxes have extensive literature and a large number of scientists exploring the subject. Our own experiences in the fields of art and management were the main arguments for the introduce of the concept of “artists-managers” and to undertake research in the area of artists-managers’ identity to find the conclusions for creativity. This article aims to describe the challenges in the identification of artists-managers, who can be crucial in understanding the creativity factor. To reach our goal, we run empirical qualitative research based on in-depth interviews with key-informants from Europe, Africa and North America as well as auto-analysis of an artist-manager identity. We answer the research question “Who is the artist-manager?”. We present our “creativity development model” on the base of artists-managers’ characteristics and we describe what kind of challenges should be considered in the empirical research of artists-managers. These challenges may be used as guidelines for artists-managers: for those who discover an artist-manager in their personality, for defined artists-managers to help to better understand their features, and for artists-managers’ followers to be more sensitive for their leaders’ characteristics. Our model may help to understand and develop the creativity of society.