著者
Katsuhiko Inamoto Kaori Nagasuga Takayoshi Yano
出版者
The Japanese Society for Horticultural Science
雑誌
The Horticulture Journal (ISSN:21890102)
巻号頁・発行日
pp.UTD-372, (Released:2022-06-25)

We investigated the effects of CO2 enrichment on photosynthesis, growth, and dry matter accumulation in the Oriental hybrid lily ‘Siberia’. The photosynthetic rate increased as the CO2 concentration was elevated compared to the ambient level. The increase in the photosynthetic rate was greater in the low concentration range and lower in the high concentration range. The relationship between the light intensity-photosynthetic rate and temperature-photosynthetic rate was investigated under different CO2 concentrations. The entire light-photosynthesis and temperature-photosynthesis curves moved toward a considerably higher photosynthetic rate when the CO2 concentration was increased from 380 ppm to 1000 ppm. In contrast, when the CO2 concentration was increased from 1000 ppm to 2000 ppm, the increase in the entire light-photosynthesis curve was small. The relationship between the CO2 concentration and the maximum temperature point of the photosynthetic rate was unclear. We also cultured ‘Siberia’ lily plants with and/or without CO2 enrichment (1500 ppm) altered before (the early stage) and after (the late stage) the visible flower bud stage. The CO2 enrichment increased dry weights dry weight/fresh weight ratios of whole plants, and individual parts at flowering, resulting in improved cut flower quality and enlargement of the mother bulb and daughter bulblets. The effective period of CO2 enrichment was after the visible flower bud stage. In cases where CO2 enrichment was effective for dry matter accumulation, the dry matter distribution ratios of the mother bulb and daughter bulblets to the whole plant were high, and those of the leaves, stem, and flower buds were low. The relative growth rate and net assimilation rate from planting to the flowering stage were increased with CO2 enrichment applied after the visible flower bud stage, indicating that the dry matter accumulation and photosynthesis were enhanced. Finally, the issues that need to be addressed for applying practical CO2 enrichment technology to various lilies are discussed.
著者
Hiroki Ueno Takeshi Maeda Naoki Katsuyama Yu Katou Satoshi Matsuo Kanako Yano Akira Ando Kaori Nagasuga Mizuki Yamada Shunsuke Imanishi
出版者
一般社団法人 園芸学会
雑誌
The Horticulture Journal (ISSN:21890102)
巻号頁・発行日
pp.OKD-101, (Released:2017-10-11)
被引用文献数
11

Several Japanese tomato cultivars develop a physiological disorder called leaf marginal necrosis, which occurs in relatively young compound leaves. Although the positions of the observed symptoms differ from those caused by inadequate potassium (K+) supplementation, previous studies have reported a relationship between the reduction of K+ content and the occurrence of this disorder. However, the mechanism of the relationship between K+ deficiency and leaf marginal necrosis remains unstudied. In the present study, the relationship between K+ deficiency in leaflets and leaf marginal necrosis was investigated by cation measurement and gene expression analysis to understand the possible mechanism responsible for the induction of leaf marginal necrosis. First, cation measurement of the two cultivars differing in their symptom intensities showed a trend of K+ reduction in the ‘CF Momotaro J’ cultivar developing leaf marginal necrosis at the tip leaflets positioned under the flowering fruit truss. Next, a comparison between the basal and tip region of the leaflet from four cultivars differing in their symptom intensities revealed that the K+ concentration in tip leaflets was significantly lower in the tip regions compared to the basal region, especially in the two cultivars ‘CF Momotaro J’ and ‘Momotaro grande’, leading to leaf marginal necrosis. The gene expression analysis of the basal and tip regions identified that the expression patterns of jasmonate-related genes were upregulated in the tomato leaflets with low K+ concentration. The gene expression of a leaf senescence marker gene, a homologue of the SAG12 gene of Arabidopsis thaliana, was detected only in the leaf tip region samples with the lowest K+ concentration. Furthermore, ‘CF Momotaro J’ plants cultivated with K+-supplemented medium showed an increase in the K+ concentration, a decrease in the occurrence of leaf marginal necrosis, and down-regulation of the expression of jasmonate-related genes in tip leaflets. These results indicate that tomato leaf marginal necrosis occurs because of K+ starvation in the tip region of leaflets, leading to the activation of jasmonate-induced signal for necrosis.