PHYSIOLOGICAL ACTIVITIES OF HELMINTHOSPOROL AND HELMINTHOSPORIC ACID: I. EFFECTS ON GROWTH OF INTACT PLANTS

Helminthosporol (H-ol) and helminthosporic acid (H-acid) wereeffective in promoting elongation of leaf sheaths of rice, Japanesebarnyard grass and dwarf maize (d-2 and d-5) and of hypocotylsof taisai (Brassica chinensis), but inactive in leaf sheathsof oat and wheat, hypocotyls of sesame and morning glory (Pharbitisnil) and epicotyls of Pharbitis and dwarf and tall peas. Onthe elongation of the leaf sheath of maize d-1, H-ol was promotivebut the activity of H-acid was doubtful. On hypocotyls of lettuceand daikon (Raphanus sativus), only H-acid was active. Multiplicationrate and size of fronds of Lemna perpusila were not affectedby either of the substances. Compared with gibberellic acid for the effect on the shoot growth,H-ol and H-acid were weak in activity and narrower in the scopeof plants that responded. H-ol and H-acid characteristicallypromoted the elongation of the primary root. Comparative effectivenessof H-ol and H-acid varied with plant species or parts examined. ¹ This study was supported in part by grant-in aid of the Ministryof Education (No. 0417). The results reported here were presentedat the Annual Meeting of the Botanical Society of Japan at Kanazawain 1964 (S).     

Stomatogenesis and Formation of Cirri in Fragments of Oxytricha fallax Stein

Of fragments involving a partial removal of the original adoral zone of membranelles (AZM), the monomacro-nucleate ones become reorganized monostomes resulting from a simple fusion of the remnant AZM to the oral primordium induced, and the binucleate ones become dividers by initiation of the oral primordium posteriorly from the posterior terminal of the remnant AZM. The cirral primordium in any fragment arises alongside its corresponding oral area. Weisz's idea of the dominance and inhibition of the original oral system extending over the oral primordium site is applicable in stomatogenesis of the present species. This application is found also in cirral formation.
In fragments from early stage dividers, a formed oral primordium is easily absorbed by influence of the intact original AZM. This event also occurs after complete removal of the AZM. Such results led to the hypothesis that the oral primordium in the normal divider may be formed under some stoma-togenic activation of the AZM followed by escape from inhibition also arising from the same source. Irrevocable furrow formation and irreversibility of the oral primordium in stomatogenesis occur in later stages of division. Nevertheless division in these stages is blocked when certain operations are performed, forming monsters possessing the AZM of the opisthe translocated to the side opposite to that of the proter. In other monsters obtained from a fusion of the AZM of the proter to that of the opisthe, division occurs belatedly, prior to which secondary oral and cirral primordia are produced.     

Morphology of sternum V glands in three caddisfly species, Stenopsyche marmorata, Eubasilissa regina and Nemotaulius admorsus (Insecta: Trichoptera)

The present study describes the morphology of the sternum V gland of three caddisfly species, Stenopsyche marmorata Navas, Eubasilissa regina (McLachlan) and Nemotaulius admorsus (McLachlan), each of which belongs to a different family of the order Trichoptera, using light and scanning electron microscopy. In both sexes of these three species, the gland orifices are located on the sides of the sternum V as crescent-shaped slits, and are connected with the glandular tissue via cuticular gland ducts. The shapes of glands differ greatly among species; a slender ampullar form in S. marmorata , a flattened saccular form (horseshoe shape) in E. regina and a kidney shape in N. admorsus . The glands are composed of four essential components: large secretory cells, small reservoir cells, the lining of the reservoir and the gland duct. In S. marmorata and E. regina , additional components, muscle fibers, are present around the small reservoir cells. The secretory cells covering the whole outer surface of the gland are very large, and form many bunches in S. marmorata and E. regina , but do not form them in N. admorsus . The small reservoir cells lie inside the layer of the secretory cells and are tightly connected with the cuticular lining of the reservoir. The linings become thick cuticular ducts near the gland orifices. Histological features suggest that the secretory cells of the sternum V gland of Trichoptera belong to the type of class 3 cells in insect epidermal glands.     

Wolbachia‐induced feminisation newly found in Eurema hecabe,a sibling species of Eurema mandarina (Lepidoptera: Pieridae)

1. Complete feminisation of genetic males into functional females, a unique case among insects, is known in Eurema mandarina (former Eurema hecabe Y type) that are infected with two strains of Wolbachia, wCI^Em and wFem^Em. 2. Here, we newly found that a proportion of wild‐caught E. hecabe (former E. hecabe B type) produced only female offspring. Cytogenetic observations indicated that individuals of E. hecabe displaying the all‐female trait were genetically male (i.e. feminisation). 3. Multilocus sequence typing analyses demonstrated that the feminised individuals of E. hecabe were infected with two Wolbachia strains, wCI^Eh and wFem^Eh, that were indistinguishable from wCI^Em and wFem^Em, respectively. 4. Even identical strains of Wolbachia can be regulated differently depending on the host genetic background. Therefore, we compared the infection densities and vertical transmission efficiencies of Wolbachia between feminised E. mandarina and E. hecabe, but detected no significant differences in these traits. 5. The possible routes by which the two Wolbachia strains have transferred between E. mandarina and E. hecabe are discussed.