Study on the Photosynthetic Characteristics of Two Cultivars Prunus Humilis Bge. in Shandong Province / 世界科学技术-中医药现代化

To study the photosynthetic physiological characteristics of Cultivars Prunus Humilis bge. in the region of shandong, analyze on the relationship between the quality of seeds and photosynthesis, In order to formulate reasonable cultivation measures and improve the yield quality of seed production. LI-6400 portable photosynthesis apparatus was used to determine light response curve, diurnal change of photosynthetic parameters of Huadong 1 and Huadong 2. Using vernier caliper and electronic balance to measure the quality data of two varieties of eucalypis, the quality difference was analyzed. Two kinds of Prunus Humilis bge, cultivating in Shandong, had higher photosynthetic rate and higher light saturation point, and the photosynthetic rate were "unimodal" type curve. The change of the two peaks all appeared at11: 00, and had no obvious "lunch break" phenomenon. The photosynthetic rate, the utilization of strong and weak light, and the efficiency of absorption and conversion of light energy of Huadong 2, were all higher than that of Huadong 1, which had better quality. The quality of seed of Prunus Humilis bge is related to its photosynthetic capacity. When planting Prunus Humilis bge., we should formulate reasonable cultivation measures according to its features such as photosynthesis, transpiration, water use efficiency.

Photosynthetic production of wheat under precision planting patterns in northern china / Produção fotossintética de trigo através de padrões de plantação de precisão no norte da china

Winter wheat (Triticum aestivum) is cultivated across a wide region; however, water is scarce during the growing season of wheat in the Northern Plain of China. Therefore, winter wheat should be irrigated to maintain a stable and high grain yield. The aim of this field study was to develop a water-conserving precision planting pattern for winter wheat that is grown in the Northern China Plain with the purpose of exploring the benefits in maintaining water and effects on wheat productivity. To accomplish this, several production variables and photosynthetic indexes were measured, including the number of stems, the leaf area index (LAI), photosynthetically available radiation (PAR), net photosynthetic rate, and grain yield. The study was carried out during the 2011­2012 and 2012­2013 winter wheat growing seasons. The experiment included a double-row planting pattern (DRPP) and a single-row planting pattern (SRPP), both of which were either irrigated or rainfed. The area of each plot was 9 m2, and the experimental design was a randomized blocks design with three replicates. All results were analyzed with an ANOVA, the F test, and the LSD (p 0.05) for means comparison. PAR capture ratios in the DRPP were higher than those in the SRPP at 50­120 cm above the ground. The photosynthetic traits of flag leaves under irrigated conditions were not significantly influenced by the respective planting pattern. However, at a growth stage of 80 under the rainfed conditions, the mean photosynthetic rate within flag leaves in the DRPP was higher than that in the SRPP. Furthermore, the DRPP under rainfed conditions was more likely to increase the apparent quantum yield (AQY) of flag leaves than the yield obtained under irrigation. These results suggest that DRPP optimizes the canopy PAR distribution in winter wheat and contributes to the maintenance of a higher photosynthetic capacity in the flag leaves under water stress (the rainfed condition). This relationship may be applied in demonstration trials to encourage winter wheat farmers to incorporate the use of DRPP in the drought-prone areas, which are subjected to insufficient precipitation during the growing stage of wheat in Northern China.

O trigo de inverno (Triticum aestivum) é cultivado em uma vasta região; no entanto, a água é escassa durante a estação de crescimento do trigo na Planície do Norte da China. Assim, o trigo de inverno deve ser irrigado para manter um rendimento de grãos estável e elevado. O objetivo deste trabalho de campo foi o de desenvolver um padrão de plantação de precisão que conserve a água para o trigo de inverno que é cultivado na Planície do Norte da China com o propósito de explorar os benefícios da retenção de água e os efeitos na produtividade do trigo. Para isso, diversas variáveis de produção e índices fotossintéticos foram medidos, incluindo o número de hastes, o índice de área da folha (do inglês, LAI - leaf area index), a radiação fotossinteticamente disponível (do inglês, PAR - photosynthetically available radiation), taxa fotossintética líquida e o rendimento de grãos. O estudo foi conduzido durante as estações de crescimento do trigo de inverno em 2011-2012 e 2012-2013. O experimento incluiu um padrão de plantação em fila dupla (do inglês, DRPP - double-row planting pattern) e um padrão de plantação em fila única (do inglês, SRPP - single-row planting pattern), em ambos os casos ou foram irrigados artificialmente ou através da chuva (regadio e sequeiro). A área de cada lote de terra foi de 9 m2, e o delineamento experimental foi um de blocos aleatórios com três repetições. Todos os resultados foram analisados com uma ANOVA, um teste F, e um LSD (p 0.05) para a comparação das médias. As taxas de captura de PAR no DRPP foram maiores do que aquelas no SRPP a 50-120 cm acima do solo. As características fotossintéticas das folhas-bandeira (do inglês, flag leaves) sob condições de irrigação artificial não foram significativamente influenciadas pelo respectivo padrão de plantação. No entanto, num estágio de crescimento de 80% abaixo das condições de irrigação pela chuva, a taxa fotossintética média dentre as folhas-bandeira no DRPP foi maior que aquela observada no SRPP. Além disso, o DRPP sob condições de irrigação pela chuva foi mais suscetível ao aumento do rendimento quântico aparente (do inglês, AQY - apparent quantum yield) das folhas-bandeira do que o rendimento obtido através da irrigação artificial. Estes resultados sugerem que o DRPP otimiza a distribuição PAR do dossel no trigo de inverno e contribui para a manutenção de uma maior capacidade fotossintética nas folhas bandeira sob estresse hídrico (a condição de sequeiro). Esta relação pode ser aplicada em ensaios de demonstração para encorajar os agricultores de trigo de inverno a incorporar o uso do DRPP em áreas propensas à seca, que estão submetidas a precipitação insuficiente durante a fase de crescimento do trigo no Norte da China.

Research on photosynthetic and eco-physiological characteristics of Epimedium pseudowushannense in different growing age / 中国中药杂志

Epimedium is a widely used medicinal plants. Due to excessive use of wild resources and resource constraints, artificial cultivation is the only way to achieve sustainable use of resources. E. pseudowushannense is intended to achieve the first cultivated species, but plant production technology is not yet fully mature.The diurnal variation of photosynthetic and eco-physiological characteristics of E. pseudowushannense in different growing age was studied by the CI-340 Portable Photosynthesis System under natural conditions. The net photosynthetic rate (Pn), stomatal conductance (C), intercellular CO2 concentration (Ci), photosynthetically active radiation (PAR), relative humidity (RH), air temperature (Ta), apparent mesophyll conductance (ALMC), transpiration rate (E), leaf temperature (Tl), water use efficiency (WUE) and other photosynthetic physiological factors and environmental factors were measured. The obtained data was analyzed by correlation analysis, path analysis and stepwise multiple-regression analysis to explore the relationship between net photosynthetic rate and physiological and ecological factors. The results show that： ①The daily variation of the Pn, E, ALMC, C of E. pseudowushannense in different growing age took on"two peak type", the Pn was with an obvious midday depression phenomenon at noon.②The Pn, ALMC and C of annuals' were significantly higher than biennial or three-year; but the Ci was basically a three-year > biennial> annual.③The correlation analysis, path analysis and stepwise regression analysis showed that ALMC, Ci, Ta might played important role in the Pn and ranked as ALMC>Ci>Ta.

Study on leaf transpiration and stomatal structure of medicinal plant Tetrastigma hemsleyanum / 中草药

Objective: Taking annual Tetrastigma hemsleyanum (Tetrastigma Radix) from three habitats, Taizhou, Minhou, and Shunchang, as materials to study the effects of different light intensity stress on the stomatal shape and leaf transpiration. Methods: The stomata, leaf transpiration rate, net photosynthetic rate, and stomal structure of T. hemsleyanum were observed using a scanning [0-2000 μmol/(m2·s)] to explore the optimal light intensity. Results: The stomata with surround and parallel distribution types were only distributed in the lower epidermis in the leaves of T. hemsleyanum; The transpiration rate, stomatal conductance, and net photosynthetic rate of T. hemsleyanum from the two habitat regions (Minhou and Taizhou) by rising after falling with the 30℃ stress, which suggested the stress could make the light intensity heavier. At the same time, the transpiration rate, stomatal conductance, and net photosynthetic rate of T. hemsleyanum from the habitat region Shunchang were rising. The stomatal type of leaves was 600 μmol/(m2·s) in Minhou, and 1900 μmol/(m2·s) in Shunchang, when the water utilization ratio of T. hemsleyanum leaves from the three habitats was higher. Conclusion: Different habitats and light intensity are the important factors of leaves transpiration in natural world, which is more beneficial to the growth of the root crops and suitable for the accumulation of flavonoids in plants.

Cadmium: Toxicity and tolerance in plants.

Of all the non-essential heavy metals, cadmium (Cd) is perhaps the metal which has attracted the most attention in soil science and plant nutrition due to its potential toxicity to humans, and also its relative mobility in the soil-plant system. This review summarizes the toxic symptoms of Cd in plants (i.e. growth retardation, alterations of photosynthesis, stomatal movement, enzymatic activities, water relations, interferences with mineral uptake, protein metabolism, membrane functioning, etc.) but also includes the mechanisms of cadmium uptake, translocation and deposition. Moreover, it also throws light on chelation, including identification of Cd ligands present in cytosol and vascular tissue. Cadmium-induced oxidative stress is also considered as one of the most widely studied topics in this review.

Characteristics of photosynthesis in three Dendrobium species / 中草药

Object To determine the diumal changes of photosynthesis, its relationships with light intensities and temperatures, and the contents of chloroophyll in leaves of Dendrobium candidum Wall. ex. Lindl., D. wilsonii Rolfe and D. hercoglossum Reichb. f. Methods The net photosynthetic rate (NPR) was measured at intervals of 1.5 h during daytimes 7:30—16:30, under the photosynthetic affective rates 0—140 mmol/(m 2?s), and under the temperatures 29.6—38.2 ℃; contents of chlorophyll a and b in leaves were measured. Results NPR, light saturation point and compensation point were low in each of the three Dendrobium L. species. The NPR peaked during 8:00 and 10:00 am, and thereafter decreased rapidly as the temperature and light intensity increased. Content of chlorophyll b was high in the leaves. Conclusion These results indicated that the Dendrobium L. species, which are sciophyte plants, have great adaptations to their growing habitats.