02011naa a2200241 a 450000100080000000500110000800800410001910000230006024500980008326000090018152012210019065000140141165000130142565000170143865300280145570000290148370000260151270000260153870000200156470000240158470000210160877301400162914523502005-04-27       2003    bl uuuu     u00u1 u    #d1 aOLIVEIRA, M. F. de  aMutation breeding in sunflower (Helianthus annuus L.) for disease resistance and oil content.  c2003  aGenetic variability for resistance to Alternaria disease (Alternaria helianthi) can be induced in cultivated sunflower by radiation or chemical mutagens. The objectives of this study were to develop sunflower germplasm resistant to Alternaria with good oil content. In the first experiment, sunflower seeds of the genotype HA BR 104 were irradiated with 150 and 165 Gy of gamma rays. Seeds were sown in the field at the Embrapa Soja experimental station, in Londrina, PR and M1 plants were harvested in bulk. M2 M3 and M4 plants were screened for disease resistance, under natural infection in the field. Self-pollinated plants and open pollinated plants from the 150 Gy and 165 Gy populations with no or mild disease symptoms were selected. Regrettably, all the selections proved susceptible in M4 and were discarded. In the second experiment, sunflower seeds of the genotypes HA 300 and HA BR 104, were treated with ethyl methanesulfonate (EMS) at 0.015 M and the M1 and selected M2 and M3 were grown and screened at the above Station. From the EMS treatment 300 M3 plants were recovered. Their agronomic characteristics, oil content, disease resistance and combining ability are under evaluation in the offspring.  aGenética  aGirassol  aMelhoramento  aResistência á doença1 aLEITE, R. M. V. B. de C.1 aCASTIGLIONI, V. B. R.1 aFARIAS NETO, A. L. de1 aARIAS, C. A. A.1 aMANDARINO, J. M. G.1 aTULMANN NETO, A.  tIn: IMPROVEMENT of new and traditional industrial crops by induced mutations and related biotechnology. Vienna: IAEA, 2003. p. 153-159.