Glossary Plant Breeding

turns of the cycle to metabolise the two acetate molecules that are produced by
glycolysis from one molecule of glucose.
Kurtosis. The excess or deficiency of frequencies in the centre and the two extremes
compared to the flanks of a frequency curve. Higher kurtosis enhances value of
selection intensity; the reverse is true for low kurtic traits compared to normal
distribution. (Also see skewness).
Laggards. Chromosomes or pairing configurations that show slow movement or no
movement at all during nuclear division (anaphase). Such chromosomes may not be
included in one of the daughter nuclei giving rise to aneuploidy.
Lagging Strand. The strand of the DNA double helix that is synthesized by the ligation
of short fragments synthesized individually in the 5 to 3 direction during DNA
replication.
Lamarckism. An invalid concept of organic evolution, advocated by Lamarck. It states
that adaptive changes induced by the environment within an individual is transmitted
to its progeny. Also see inheritance of acquired characters.
Land Race. A line/strain/group of individuals evolved directly under influence of natural
selection; the earliest cultivated types; the old-established local stocks of a crop
species; any distinctive race of a cultivated species that has become genetically
differentiated as a result of natural and/or human selection operating in ecologically
different circumstances in various regions to which cultivated species have been
introduced; a heterogeneous mixture of genotypes having mutually beneficial
associations with each other and with environmental conditions. One of the most
important uses of such land race is to provide genetic resources for improvement of
our present-day varieties. They are usually tolerant to any pests or diseases probably
because they have had co-evolved at a given point of time. A series of local land races
is collectively called square heads.
Lateral Inhibition. The signal produced by one cell that prevents adjacent cells from
acquiring its fate.
Latin Square Design. An experimental design known for its capacity to handle
simultaneously two known sources of variation among experimental units. It makes it
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