TRANSFER OF PH(I) GENES PROMOTING HOMOEOLOGOUS PAIRING FROM TRITICUM SPELTOIDES TO COMMON WHEAT

Diploid-like chromosome pairing in polyploid wheat is controlled by se veral Ph (pairing homoeologous) genes with major and minor effects. Ho moeologous pairing occurs in either the absence of these genes or thei r inhibition by genes from other species (Ph(I) genes). We transferred Ph(I) genes from Triticurn speltoides (syn Aegilops speltoides) to T. aestivum, and on the basis of further analysis it appears that two du plicate and independent Ph(I) genes were transferred. Since Ph(I) gene s are epistatic to the Ph genes of wheat, homoeologous pairing between the wheat and alien chromosomes occurs in the F-1 hybrids. Using the Ph(I) gene stock, we could demonstrate homoeologous pairing between th e wheat and Haynaldia villosa chromosomes. Since homoeologous pairing occurs in F-1 hybrids and no cytogenetic manipulation is needed, the P h(I) gene stock may be a versatile tool for effecting rapid and effici ent alien genetic transfers to wheat.