| Susceptibility of the albina mutant of Einkorn
wheat to leaf and stem rusts, Puccinia triticina and P. graminis K . KATSUYA National Institute of Genetics, Misima, Japan The susceptibility of the albina mutant of Triticum monococcum flavescens to stem and leaf rusts was tested in the phytotron (20C in daytime, 15C at night) at the second leaf stage with Puccinia triticina 21 B and P. graminis f. sp. tritici 21. At first albina seedlings were kept in a sowing box and then they were placed in water culture with WHITE's nutrient medium (1943) to which 3 percent sucrose was added. They were inoculated by brushing. Rust readings were made 7 to 16 days after inoculation. The degree of susceptibility was determined by the types of lesions formed on the leaves. The tests were repeated 2 to 3 times. Albina exhibited susceptibility to leaf and stem rusts, while the normals were resistant to the former and susceptible to the latter. The uredosori of stem rust on albina were much larger than those on normal plants. Thus, susceptibility of host plants to leaf and stem rusts belonging to obligate parasites is not necessarily connected with quantitative differences in chlorophyll. A difference in another component may be the cause of a higher susceptibility of albina to leaf rust. Studies concerning amino acids await further experiments. |