Study on heterosis of two semi-exotic maize populations constructed with CIMMYT and Reid germplasm.

The heterosis of some maize lines selected from two semi-exotic populations constructed with CIMMYT sub-tropical germplasm and temperate lines was tested to study their improvement effect and cross direction in high latitude area such as Heilongjiang,China.The lines selected from semi-exotic population(B73×Pob45)×B73 had higher heterosis when crossed with the lines in Lvdahonggu group and Lancaster group.The lines selected from semi-exotic population(Ye107×Pob69)×Ye107 had higher heterosis when crossed with the lines in Lancaster group only.Some good lines from both semi-exotic populations were identified.