ys2 a new mutant in the short arm of chromosome 1

A new mutant with yellow striped leaves appeared in the progeny of a colchicine treated plant of inbred B73. For this mutant, whose phenotype recalls iron deficiency similar to ys1 (chromosome 5, The Mutants of Maize, Neuffer et al., 1968), we propose the symbol ys2.

This yellow striped mutant is generally expressed from the third leaf up to maturity. The yellow stripes develop first in the proximal half of the leaf blade, extending later toward the tip. Environmental conditions have been observed to influence the expressivity of ys2. Because of their slower growing habit these mutants reach anthesis 6 to 7 days later than normal sibs, but the plants are fully fertile.

The analysis of segregating progenies of selfed plants indicated for ys2 a recessive Mendelian inheritance (Table 1). The shortage of homozygous types may be due to reduced embryo vitality as suggested by an inverse correlation between chi-square values and germination rates.

Crosses of ys2 plants as female parents were made to a set of TB-A translocations. The results indicated that ys2 is uncovered by TB-1Sb (Table 2). Therefore this mutant appears to be located in the short arm of chromosome 1.

Table 1.

Table 2.

Norberto E. Pogna,* Achille Ghidoni** and Paolo Ranalli**

*S. Angelo Lodigiano; **Milan

Please Note: Notes submitted to the Maize Genetics Cooperation Newsletter may be cited only with consent of the authors.

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