Fertilization - Part II
The anueploid type of pollen can fertilize the seed
parent in two ways. One way is for the sperm nucleus
with the duplication to fertilize the primary endosperm
nucleus while the sperm nucleus with the deficiency
fertilizes the embryo. The second way is for the sperm
nucleus that is deficient to fertilize the primary endosperm
nucleus and the sperm nucleus with the duplication fertilizes
the embryo nucleus.
Type I
Type II
Type III
Mapping Genes To The Correct Chromosome
Cytogeneticists can use root-tip smears to identify
which chromosome carries the A-B translocation. A-B
translocation genetic stocks are developed for each
of the ten maize chromosomes. The A-B translocation
stock is used as the male parent and carries a dominant
marker allele. The female parent is a normal stock with
ten A-type chromosomes and is homozygous recessive for
the marker locus. A sugary, homozygous recessive corn
kernel is evidence that the male gametic nucleus was
deficient for the portion of the A chromosome (4B)
which contains the su locus. The A-B translocation stock
which results in sugary kernals is the chromosome that
contains the locus.
