Degradation of protocatechuic acid in the hypocotyls of mung bean seedlings was studied to elucidate the pathway and intermediates involved. The results indicate that protocatechuic acid is oxidatively degraded by the following route: protocatechuic acid-β-carboxy-cis, cis-muconic acid-β-carboxymuconolactone-β-ketoadipic acid-CO2. It was found that some of the intermediates such as β-carboxy-cis, cis-muconic acid, β-carboxymuconolactone and β-ketoadipic acid had been formed in the reaction mixture.
There are two types of life cycle in Hansenula. The first type is that the vegetative cells undertake meiosis, make four spores, respectively, which germinate and conjugate two by two, becoming the ordinary vegetative cell. So the vegetative cells are always in 2n phase. The another type is that the vegetative cells conjugate two by two, undertake meiosis, make four spores, respectively, which germinate and become the vegetative cell. So the vegetative cells are always in n phase. In Schizosaccharomyces pombe the vegetative cells in haploid phase (n=2) conjugate two by two, after many cell divisions by fission. The zygote (2n=4), thus produced, undertakes meiosis at once and makes four spores (n=2). Each spore germinates and becomes the vegetative cell in haploid phase.
Salvinia natans (2n=18) in the neighborhood of Hiroshima and Matsuyama are cytologically studied. Those having the same chromosomal component had two chromosomes which may be due to the reciprocal translocation. It may have occured between a segment from short arm of one of No. 8 chromosome pair and a segment from long arm of one of No. 9 pair in the standard karyotype as found in S. natans from Okayama (Tatuno and Takei6)), which will build up two new type chromosomes, namely, No. 16 (Tr1) and No. 17 (Tr2) as found in plants from Hiroshima and Matsuyama. At meiotic metaphase I in S. natans from Hiroshima and Matsuyama, tetrapartite ring chromosome was formed by two normal (No. 15 and No. 18) and reciprocally translocated chromosomes. As in the translocation heterozygote of other organisms, the separating form of the tetrapartite ring chromosome at meiotic anaphase I shows two types, i. e., ring and zygzag type, and the rate of the fertilized microspore was fifty perecnt in one microsporangium of the translocation heterozygote on S. natans.
Karyological studies were made on seven Japanese species belonging to two genera of Aspleniaceae, of which the chromosome numbers are as follows: Asplenium varians and Camptosorus sibiricus 2n=72; A. antiquum, A. nidus, A. trichomanes, A. ritoense and A. wilfordii 2n=144. Among these, the chromosome numbers of A. antiquum and A. wilfordii were determined for the first time. The somatic chromosome complements of A. varians and C. sibiricus can be morphologically divided into six types (A-F) and furthermore, each type can be divided into two groups. From this observation, the primary basic chromosome number of the two species can be considerd to be b=12, and therefore, these can be considerd to be hexaploid.