Orbit Graphing by Iteration: A Simple Laboratory Exercise

1965 ◽  
Vol 33 (8) ◽  
pp. 605-612
Author(s):  
Leo Lavatelli
Keyword(s):  
Laboratory Exercise

Laboratory Exercise on the Segregation of Flower Color and Related Genes Using Salpiglossis sinuata

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 555b-555
Author(s):  
Chiwon W. Lee
Keyword(s):  
Phenotypic Expression ◽  
Pollen Grains ◽  
Flower Color ◽  
Segregation Ratio ◽  
Crop Breeding ◽  
Flower Opening ◽  
Pigmentation Pattern ◽  
Laboratory Exercise ◽  
Demonstration Plant ◽  
Corolla Color

Velvet flower (Salpiglossis sinuata, Solanaceae) can be used as an excellent demonstration plant for horticultural crop breeding classes. Salpiglossis produces large trumpet-like flowers exhibiting an assortment of corolla color and pigmentation pattern. The pistil is large (3 to 4 cm long) with a sticky stigmatal tip and anthers can be easily emasculated prior to anthesis. The large pollen grains are shed in tetrads, which can be separated and individually placed on the stigma. It takes 8 to 9 weeks from seeding to blooming, with a prolific flowering cycle repeated in flushes. Numerous seeds (about 750/capsule) are obtained in 3 weeks after self- or cross-pollination. The influences of three genes that control flower color and pigmentation pattern can be conveniently demonstrated with their dominant and recessive alleles. The R gene controls flower color with red (RR or Rr) being dominant over yellow (rr) flower color. The D gene controls the density of pigmentation with solid (DD or Dd) color being dominant over dilute (dd) color. Corolla color striping is controlled by the St gene with striped (stst) being recessive to non-striped (StSt or Stst) pattern. For example, by using diploid lines of genotypes RRDD (red, solid), RRdd (red, dilute), or rrdd (yellow, dilute) and their crosses, students can easily learn a dominant phenotypic expression in the F1 hybrid and the digenic 9:3:3:1 segregation ratio in the F2 progeny. Another gene (C) that controls flower opening can also be used to show its influence on cleistogamous (closed, self-pollinated, CC or Cc) versus normal chasmogamous (open-pollinated, cc) corolla development. In addition, the induction and use of polyploid (4X, 3X) plants in plant breeding can be effectively demonstrated using this species.

A laboratory exercise using the microcomputer to determine nutrient recommendations and least-cost fertilizer blends

1984 ◽  
Vol 13 (1) ◽  
pp. 50-53
Author(s):  
Kenneth M. Oates ◽  
James Camberato ◽  
M. J. Vepraskas
Keyword(s):  
Laboratory Exercise

Laboratory Simulation of Induction Tube Welding

1986 ◽  
Vol 23 (2) ◽  
pp. 159-165
Author(s):  
L. Hobson ◽  
A. Taylor ◽  
A. H. Woodcock
Keyword(s):  
Electrical Engineering ◽  
Measurement Techniques ◽  
Laboratory Scale ◽  
Laboratory Simulation ◽  
Laboratory Exercise ◽  
Tube Welding

An advanced laboratory exercise is outlined in which the industrial technique of induction tube welding is simulated on a laboratory scale. Details are given of the different measurement techniques used. This experiment may be used to introduce basic electrical engineering topics into engineering disciplines of all types.

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