Effect of Air or Medium Temperature on Occurrence of Leaf-yellow-spot in Chrysanthemum 'Seikou-no-makoto'

Leaf-yellow-spot, a physiological abnormality occurring in leaves of several chrysanthemum (Chrysanthemum x morifolium) cultivars is a very serious production problem in Japan. High temperature or high irradiation are possible physiological factors, which may lead to leaf-yellow-spot. In the present study, effects of air or medium temperature on the occurrence of leaf-yellow-spot in 'Seikou-nomakoto' were investigated. The nodal position with spotted leaves and rate of leaf-yellow-spot increased with increasing day/night temperature. The nodal position with spotted leaves and rate of leaf-yellow-spot of plants grown on 30°C night air temperature were smaller than those grown on 25°C or ambient night air temperature. The days to first occurrence of leaf-yellow-spot showed no differences among medium temperatures. As occurrence of leaf-yellow-spot was not affected by root zone temperature, we recognized that occurrence of leaf-yellow-spot was promoted by high temperature or solar radiation on shoot, especially leaf. Occurrence of leaf-yellow-spot was reduced by long period high temperature and/or high solar radiation as plant growth reduced. Therefore, we thought that occurrence of leaf-yellow-spot was promoted by environmental condition as plant growth would promote.キク（Chrysanthemum × morifolium）‘精興の誠’の葉身で発生する黄斑に及ぼす気温および培地温度の影響を調査した．昼夜温を40/30℃，35/25℃，なりゆきの3区で栽培した場合，昼夜温が高いほど生育は抑制され，黄斑の発生は早くなったが，黄斑発生度は40/30℃区と比較してなりゆき区で高くなる傾向がみられた．夜温を30℃，25℃となりゆき区で栽培した場合，黄斑発生度は30℃区と比較してなりゆき区で有意な差がみられた．生育が抑制されるほどの長期間の強光や高温は黄斑発生を抑制させたことから，生育が旺盛な環境条件における外的要因により黄斑発生は助長されると考えられた．地下部の温度は黄斑発生に影響しなかったことから黄斑発生は地上部，特に葉身部位の高温により助長されることが明らかになった

Bacterial and fungal bioburden reduction on material surfaces using various sterilization techniques suitable for spacecraft decontamination

Planetary protection is a guiding principle aiming to prevent microbial contamination of the solar system by spacecraft (forward contamination) and extraterrestrial contamination of the Earth (backward contamination). Bioburden reduction on spacecraft, including cruise and landing systems, is required to prevent microbial contamination from Earth during space exploration missions. Several sterilization methods are available; however, selecting appropriate methods is essential to eliminate a broad spectrum of microorganisms without damaging spacecraft components during manufacturing and assembly. Here, we compared the effects of different bioburden reduction techniques, including dry heat, UV light, isopropyl alcohol (IPA), hydrogen peroxide (H2O2), vaporized hydrogen peroxide (VHP), and oxygen and argon plasma on microorganisms with different resistance capacities. These microorganisms included Bacillus atrophaeus spores and Aspergillus niger spores, Deinococcus radiodurans, and Brevundimonas diminuta, all important microorganisms for considering planetary protection. Bacillus atrophaeus spores showed the highest resistance to dry heat but could be reliably sterilized (i.e., under detection limit) through extended time or increased temperature. Aspergillus niger spores and D. radiodurans were highly resistant to UV light. Seventy percent of IPA and 7.5% of H2O2 treatments effectively sterilized D. radiodurans and B. diminuta but showed no immediate bactericidal effect against B. atrophaeus spores. IPA immediately sterilized A. niger spores, but H2O2 did not. During VHP treatment under reduced pressure, viable B. atrophaeus spores and A. niger spores were quickly reduced by approximately two log orders. Oxygen plasma sterilized D. radiodurans but did not eliminate B. atrophaeus spores. In contrast, argon plasma sterilized B. atrophaeus but not D. radiodurans. Therefore, dry heat could be used for heat-resistant component bioburden reduction, and VHP or plasma for non-heat-resistant components in bulk bioburden reduction. Furthermore, IPA, H2O2, or UV could be used for additional surface bioburden reduction during assembly and testing. The systemic comparison of sterilization efficiencies under identical experimental conditions in this study provides basic criteria for determining which sterilization techniques should be selected during bioburden reduction for forward planetary protection

The Learning and Change of Teacher Trainees during Japanese Language Education Training : Toward Improving the Teacher Training Program

In this report we discuss the Japanese language education training which was offered as a new course for undergraduates of the Faculty of Letters and explore what the Japanese teacher trainees learned and how they changed through taking this course. The results of our research showed that trainees learned a wide range of knowledge necessary for the teaching of Japanese and that they became more deeply interested in Japanese language teaching through their participation in the course. It was also shown that they became more cooperative, more communicative, and showed more initiative through taking the course. On the other hand, it was revealed that at the beginning of the course, trainees lacked sufficient knowledge to prepare for the teaching of Japanese, which appears to indicate a potential problem existing in the present curriculum of the teacher training program.2019～2020 年度関西大学教育研究高度化促進費研究課題「日本語教師養成講座の教育実習プログラムの構築 : 全学連携を目指した取組