High
frequency of parthenogenesis in a cross of tetraploid X diploid
--Ting, YC, Tran, L
In order to produce a triploid perennial maize, several crosses between
a tetraploid(Clg clg clg clg) and a diploid (clg clg) were
attempted. In one of the crosses, the F0 progeny kernels were of predominantly
defective endosperm, which was unexpected. According to previous observations,
pentaploid maize endosperms had normal growth and were like the triploid
type. However, in this particular cross, 99 percent of the progeny kernels
were defective. It appears that the ovules were not fertilized or fertilizations
had occurred without union of the parental gametes. In consequence, the
progeny kernels were not fully developed. With the objective of testing
this explanation, 10 defective kernels, together with the same number of
their normal sibs, were grown in the greenhouse. It was interesting to
note that the viability of these two types was surprisingly high, approximately
99 percent. As soon as their root-tips, as well as their male inflorescences,
become available for cytological investigations, their chromosome constitutions
will be examined.
Please Note: Notes submitted to the Maize Genetics Cooperation Newsletter may be cited only with consent of the authors.
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