c-m(r)860904 - a mutant controlled by En-I system, the origin of a receptor allele from c-m655437

--Ch. Jayaram, A. R. Reddy* and Peter A. Peterson

*University of Hyderabad

The mutability at c-m655437 is controlled by an autonomous En transposable element (MNL 1988). Crosses of homozygous spotted round kernels c-m Sh Wx/c-m Sh Wx with c sh wx tester give approximately 87.83% spotted round kernels among progeny ears. However, in one particular instance (86 0904 x-3), the progeny ear exhibited the segregation of spotted round and colorless round kernels in approximately a 1:1 ratio. To determine whether these colorless kernels represent a case of the origin of a receptor element of c from the autonomous En element, these colorless were then crossed with c sh wx En line which has more than two En elements segregating independently in the genome, to find out whether these colorless kernels represent a case of the origin of a receptor element of c from the autonomous En element. Table 1 shows the segregation of spotted round kernels among the progeny ears confirming that these colorless kernels have a receptor element which respond to a trans-active En element.

Table 1. The cross c-m(r)?.Sh Wx/c sh wx x c sh wx En En
 
  Spotted round Colored round Colorless round  Shrunken Total
4601-21 x 2756-3 120 1 5 135 261
-22 x 2753-4 164 0 22 172 358
-23 x 2755-8 92 0 4 106 202
-24 x 2753-3 145 0 12 174 331
-25 x 61 0 10 85 156
-26 x 25 0 2 29 56
4602-21 37 0 1 41 79
-23 138 0 16 160 314
-24 151 0 10 165 326
-25 94 0 8 99 201
-26 x 63 0 7 60 110


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

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