Donor inbred lines for enhancing the performance of single-cross sunflower hybrids

The performance of single-cross hybrids can only be enhanced by adding favorable alleles from donor inbred lines that are not present in either parent. The public inbred lines of cultivated sunflower (Helianthus annuus L.) have not been systematically screened as a source of new favorable alleles for enhancing hybrid performance. The objective of this study was to assess the merits of a sample of public inbred lines as donors of alleles for increasing 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 statistics 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 hybrids 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 most promising donors for increasing the seed yield of HA383 x RHA373 were HA822, HA851, and HA372. Similarly, the most promising donors: for increasing the seed yield of HA372 x RHA377 were HA821 and HA384, and the most promising donors for increasing the seed yield of HA89 x RHA373 were HA383, HA384, and HA821. The elite gene pool of sunflower seems to be a rich source of favorable alleles for increasing hybrid seed yields.