ABSTRACT


Ernesto Hacke E.1 y Carmen Sanz de Cortázar2
 
In a previous work with chemical mutagenics three mutants of bread wheat, cultivar Orofen, were obtained by the same authors in the greenhouse. Eight M2 plants descendant from colchicine treatment and one from ethyleneimine were resistant to a biotype of race 15 of Puccinia graminis Pers. f. sp. tritici Eriks and Henn.In the present work, the descendants of the three mutants were studied under field conditions at La Platina Experiment Station for the reaction to the biotype above mentioned and to a mixture of stem rust races. The reaction to a mixture of P. striiformis tritici and P. recondita tritici, agronomical characters and yielding ability were also considered.Only some M3, descendant lines from the colchicine treatment showed resistance to the rusts, and none from ethyleneimine treatment. A great variability was observed on rust resistance as well as on some agronomic characters. All M5 and M6 mutant lines were more resistant than Orofen to the inocolum of the three rusts employed; 10 of these lines showed stability in their precocity and 9 in their height. Mutants mantained in general the Orofen yielding ability and only two M6 lines (25 in total) showed statistical difference to lower yielding ability (Duncan 0.05).
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1Ing. Agr. Programa Cereales, Estación Experimental La Platina, Instituto de Investigacioens Agropecuarias (INIA), Casilla 5427, Santiago, Chile.
2Ing. Agr. M. S., Programa Cereales, Estación Experimental La Platina, Instituto de Investigaciones Agropecuarias (INIA), Casilla 5427, Santiago, Chile.