| Susceptibility of chlorophyll mutants of Einkorn wheat
to stem and leaf rusts, Puccinia graminis and P. triticina
K. KATSUYA National Institute of Genetics, Misima, Japan In order to examine the susceptibility of chlorophyll mutants of Triticum monococcum flavescens to stem and leaf rusts, the mutants chlorina, basi-viridis II, virido-albina and albina were tested in the phytotron (20C in daytime, 15C at night) at the first leaf stage with Puccinia graminis f. sp. tritici 17 and P. triticina 21 B. Both filter paper and brushing inoculation methods were used. 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. These tests were repeated 2 or 3 times. Susceptibility of chlorophyll mutants to stem and leaf rusts is shown in Table 1. The mutant strain "chlorina" whose chlorophyll content amounted to about 50% of that of the normal plants was not much different from the normal plants in susceptibility to both rusts. However it showed a tendency to earlier formation of uredosori. The mutant strain "albina", exhibiting resistance, differed from the normal plants in susceptibility to both rusts. No uredosori were found, since albina dies from 7 to 12 days after inoculation. Both kinds of rusts formed uredosori on the white parts, having no chlorophyll, and also on the green parts of the leaves of virido-albina, having chlorophyll. The susceptibility of this mutant to leaf rust was higher than that of normal plants. The mutant strain "basi-viridis II" was susceptible to stem rust. |