Relationship between the Genetic Distances Based on Molecular Markers and Heterosis in Hybrid Wheat

Heterosis is an important approaches to increase crop yield and improve quality,and the quick and accurate method to predict heterosis is helpful to select good hybrids with strong heterosis.Eight wheat parents with different characters were crossed in 2003 and 2004 in an incomplete dialed mating system in order to evaluate the heterosis of the 9 characters.The molecular genetic distances of 8 parents were estimated by 287 pairs of SSR and 33 ISSR primers.The relationship between the genetic distances based on SSR and ISSR markers and heterosis of wheat was investigated.The results showed that there was very significant correlation between the two kinds of genetic distances.Except for plant height,no significant correlation was found between genetic distances and heterosis of other agronomic traits in all the 28 crosses.For the 12 extreme crosses,the correlation was improved,correlations between genetic distances and heterosis of agronomic traits were significant or very significant in plant height,1000-grain weight of the culm ear and 1000-grain weight.The results in the two years were similar.Therefore,the correlation was affected by the parents used,and more studies should be carried for the relationship between the SSR and ISSR genetic distance and heterosis of wheat.