[Molecular proof of wheat transformed by total DNA of Leymus racemosus]

Four repetitive DNA sequences (pHv7161, pHv7179, pHv7191 and pHv7293) cloned from barley (Hordeum vulgare) genome were used for a molecular hybridization in the genome of Leymus racemosus (donor), Spring wheat 761 (receptor) and the wheat transformed by total DNA of Leymus racemosus (donor) through pollen tube pathway. Our results indicate that some bands are common in Leymus racemosus and the transformed wheat but absent in Spring wheat 761. The HindIII fragments which are common in Leymus racemosus and the transformed wheat have been cloned. The clone of Leymus racemosus was nominated as pLR980. pLR980 contains the homologous sequences to the four repetitive sequences of barley. The pLR980 cloned from Leymus racemosus was used as probe to study Leymus racemosus, Spring wheat 761 and the transformed wheat. This study demonstrate that pLR980 is homologous in both genome of Leymus racemosus and wheat. Common bands absent in the Spring wheat 761 were also showed in Leymus racemosus and the transformed wheat. pLR980 was proved to be associated with the transform of wheat by total DNA of Leymus racemosus through pollen tube pathway. This provides a direct witness to the exogenous DNA introduction.