Donor inbred lines for enhancing the performance of single-cross sunflowerhybrids

The performance of single-cross hybrids can only be enhanced by adding favo rable alleles from donor inbred lines that are not present in either parent . The public inbred lines of cultivated sunflower (Helianthus annuus L.) ha ve not been systematically screened as a source of new favorable alleles fo r enhancing hybrid performance. The objective of this study was to assess t he merits of a sample of public inbred lines as donors of alleles for incre asing the seed yield of three hybrids (HA383 x RHA373, HA372 x RHA377, and HA89 x RHA373). The net gain of favorable alleles and several other statist ics were estimated from the seed yield means of 14 sterility maintainer (B) lines, four fertility restorer (R) lines, 81 B x B hybrids, and 42 B x R h ybrids in field tests at Corvallis, OR and Casselton, ND in 1996 and 1997. HA383 x RHA373, HA372 x RHA377, and HA89 x RHA373 were the highest-yielding hybrids from three heterotic patterns. HA383 x RHA373 had the highest seed yield across years and locations (3285 kg ha(-1)) among all hybrids. The m ost promising donors for increasing the seed yield of HA383 x RHA373 were H A822, HA851, and HA372. Similarly, the most promising donors: for increasin g the seed yield of HA372 x RHA377 were HA821 and HA384, and the most promi sing donors for increasing the seed yield of HA89 x RHA373 were HA383, HA38 4, and HA821. The elite gene pool of sunflower seems to be a rich source of favorable alleles for increasing hybrid seed yields.