The aim of this work was to analyse : a) the phenotypic and cytogenetic differences of
Zea mays and
Zea perennis hybrids 2n=30 and 40; b) the effect of colchicine on their chromosomes pairing in meiosis. The plant materials used for these studies were
Z. mays (Zm20) 2n=20,
Z. mays (Zm40) 2n=40 and
Z. perennis (Zp) 2n=40 and the hybrids Zm20 ×Zp (MP30) 2n=30 and Zm40 × Zp (MP40) 2n=40. Some characteristics of
Z. perennis such as rhizomes, distic ears, perennially and profuse tillering were only observed in MP40 plants. In the other hand, MP30 plants had maize like phenotype; they were annual, with 4 round ears and low tillering. Therefore, phenotypic expression of several traits depends upon the dose of genes from each parent in the hybrid. The genomic formulae proposed for these species and hybrids were Zm20 : AmAm BmBm; Zm40 : AmAmAmAm BmBmBmBm; Zp : ApApApAp Bp
1Bp
1 Bp
2Bp
2; MP30 : AmApAp Bp
1Bp
2 Bm; MP40 : AmAmApAp BmBm Bp
1Bp
2. Prezigotene colchicine treatment increased the frequency of quadrivalents in Zm20, Zp and Mp40 and trivalents in MP30. These results suggest homoeology between Bm and Bp
1Bp
2 genomes from maize and Zp, respectively.
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