| Recovery of chlorophyll content in some mutants in
Einkorn wheat, Triticum monococcum flavescens T. FUJII National Institute of Genetics, Misima, Japan Viability of the virido-albina mutant is poor, but the chlorophyll content becomes almost normal when the plants are placed in the phytotron. On the other hand, double recessive plants virido-albina - basi-viridis II look like albina and, even in the phytotron died without developing chlorophyll, while both parents have the ability to recover. Moreover, the new chlorophyll mutants, basi-viridis III, virido-albina II, and xantha-alba I, obtained from irradiation experiments, which have little chlorophyll at the seedling stage, also have shown the ability to develop almost normal chlorophyll content. From these findings, it appears that in certain chlorophyll mutants the recovery of chlorophyll content might be initiated in the presence of a small amount of chlorophyll in the leaf tips. In an experiment, the green tips of the leaves were cut off and the plants were placed in the greenhouse and in the phytotron at seedling stage or later, when the young plants had developed 5-6 leaves. The batch in which the green parts were removed did not grow, and the plants died after about 2 weeks, while the batch containing uncut plants continued to develop. On the other hand, recovery of the chlorophyll content in the virido-albina mutant in agar culture with WHITE's solution to which 3 percent sucrose was added was faster than in soil culture. After 20 days in agar culture the plants recovered to normal green, while it took about one month for the recovery in soil in the phytotron. Thus, it seems that agar culture is more suitable for increasing the chlorophyll content than soil culture. But, the cut batches of virido-albina died also in agar culture. Albina mutants and albina like plants obtained from tne cross between virido-albina and basi-viridis II were also sown on agar, but they never developed any chlorophyll. It is well known that chlorophyll and radiant energy are the essentials of photosynthesis, the most important process for plant growth. The virido-albina mutant, mentioned above, could not survive when the green parts of the leaves were cut off. A small amount of chlorophyll was necessary for priming the process of further chlorophyll development (cf. Fujii 1959: Jap. Jour. Genet. 34). |