In a series of experiments, a total of 95 plants were regenerated from culture of 1416 anthers of a single genotype (PP5) of Solanum phureja that expressed a variable frequency of 2n pollen by the genetic equivalent of first division restitution. The regenerated plants included 29 monoploids (2n = x = 12), 58 diploids (2n = 2x = 24) and 8 tetraploids (2n = 4x = 48). Monoploids carrying the potential for 2n pollen formation are central to the development of a breeding scheme to construct highly heterozygous diplandroids. Segregation of tuber flesh color and tuber protein bands revealed by polyacrylamide gel electrophoresis in first and second generation anther-derived diploid plants provided evidence for both embryogenesis of 2n pollen as well as doubling of monoploid genomes as sources of anther-derived diploids. Because of variation for the same genetic markers in anther-derived tetraploids, sources other than embryogenesis of doubly restituted (4n) pollen grains were implied. An enhanced response to anther culture was noted in some anther-derived dihaploids.Key words: unreduced gametes, potato, anther culture, diplandroid, monoploid.

This book is a complete revision of the first edition with the same title. With a few exceptions, different authors than those of the first edition have written the chapters in this edition. These revisions follow significant changes in the coal mining reclamation requirements as a result of passage and implementation of the Surface Mining Control and Reclamation Act of 1977 (SMCRA, Public Law 95-87). Passage of this law essentially made many chapters of the first edition out of date by the time the book was published in 1978. The first edition (F.W. Schaller and P. Sutton, editors) was largely the result of proceedings from the Wooster, Ohio, symposium. This edition is a cooperative effort of the American Society for Surface Mining and Reclamation (ASSMR) and the American Society of Agronomy as a part of mutual liaison activities between these two societies. Chapters and senior authors were suggested to the editorial committee by action of an ad hoc committee of ASSMR.

Three cultivars and 3 selfed lines of Streptocarpus × hybridus Voss plants proved to be highly variable via cluster analysis. Yet 5 of the 6 populations examined showed a significant, negative, linear correlation between flowering and phyllomorph length at the time of treatment with 25 μg GA4+7. There was no treatment effect on peduncle length or the time span separating flowering of the first and 2nd, 2nd and 3rd, or first and 3rd inflorescences.

California poppy (Eschscholzia californica Cham.) was increasingly sensitive to inductive long day (LD) conditions as the plant aged. A minimum of 10 expanded leaves was required for plants to flower in the shortest time once LD induction began. The amount of photosynthetic leaf area present during LD was not critical for flowering, suggesting specific leaf number to be a dominant factor in the photoperiodic flowering response of California poppy.

The response of cape primrose (Streptocarpus) plants to external N application is dependent on growth media only in terms of response magnitude. A 2.0% to 2.9% tissue N level in either sand or bark media maximized shoot dry weight, the number of potential flowers, and the quantity and quality of plantlets regenerated during subsequent asexual propagation. In sand, 2.9% tissue N was below the level required for maximum leaf elongation and resulted in a desirable restriction of the primary leaf (phyllomorph). Tissue N levels that either exceeded or lagged behind the optima were often detrimental to plant aesthetics, and wasteful where luxuriant tissue levels did not affect the measured characteristics.