Glossary Plant Breeding

S. Svedberg unit; a unit of sedimentation velocity that is commonly used to describe
molecular units of various sizes as sedimentation velocity is proportional to the size.
S 0 . Symbol used to designate the original selfed plant.
S-allele. Any allele of those genes which control incompatibility in plants. The various
alleles of the incompatibility may be represented by S 1 , S 2 , S 3 , etc. S F -alleles belong
to the same allelic series but which control self-fertility.
SPhase.The part of interphase of the cell cycle in which DNA synthesis occurs.
S 1 , S 2 , S 3 … Symbols used to designate first, second, etc. generations after selfing an
ancestral plant (S 0t ).
Sample. A finite series of observations taken from a population. Since it is not feasible to
study all the individuals of a population owing to its large size and hypothetical
nature, samples are almost always taken to represent the entire population.
Sampling. The process of selecting a part of the population to represent it as a whole.
Sampling Distribution. A process through which different sample values are put
together for further study.
Sampling Error. Deviation of a sample value from the true value owing to the limited
size of sample.
Sampling Variance (of mean). The square of the standard deviation of the sample means
(that is, standard error).
Satellite. A terminal section of a chromosome that is separated from the main body of the
chromosome by a narrow constriction.
Satellite Chromosome. A chromosome that seems to be an addition to the normal
genome.
Satellite DNA. Any type of DNA having highly repetitive nucleotide sequence. It was
formerly defined as the DNA forming a satellite band after cesium chloride density
gradient centrifugation.
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