A "single cross" is another name for
an F1 hybrid. When two IBLs are crossed the F1 hybrid,
or single cross, is the result. This type of cross has
the most uniformity and
which makes it the best choice for the home
A "double cross" is made by crossing
two single crosses which come from four separate IBLs. A
double cross will be somewhat more variable than a
single cross, but will have a wider range of
adaptability. This adaptability makes the double cross
good for diverse indoor environments.
cross" and the "three way cross" are used as testers. A
top cross is an IBL crossed with a variety, and it is
used to test for general combining ability.(Ed.note:Only
GCA can be found in a topcross.SCA is not sought because
one half of the topcross is from a single genotype and
the other half is from mixed gametes,therefore,one gene
donor is unspecified.) A three way cross is an IBL
crossed with an F1. The result of this cross will be one
of the parents of the double-cross, and it is used to
test for specific combining ability.
"backcross" is crossing the progeny back to one of its
parents,and on another level, to any plant with the same
genotype as a Parent. It is designed to improve the
parent by retaining most of its qualities and adding a
new one. After a series of backcrosses,some degree of
uniformity is realized as a result of increased gene
frequencies,fixing of some loci through selection and
some incidental homozygosity. However, the offspring can
only become completely homozygous if the recurrent
parent was completely homozygous,and will remain
heterozygous for the loci that were heterozygous in the
" is the result of a female Cannabis plant
pollinating herself, whether by artificial induction or
natural hermaphrodite tendencies. A female that has
produced seed from its own pollen is said to be the S0
generation and the resulting seeds are the S1 progeny.
A "full sib" cross is a straight male-female
cross between brothers and sisters.
A "half sib"
cross uses sister females and unrelated males.