34 research outputs found
Relative Tolerances of Wild and Cultivated Barleys to Infection by Blumeria graminis f.sp. hordei (Syn. Erysiphe graminis f.sp. hordei)
The relative tolerances of two lines of wild barley (Hordeum spontaneum), B19909 and I-17-40 and one cultivated barley (Hordeum vulgare), cv. Prisma infected by Blumeria graminis f.sp. hordei (syn. Erysiphe graminis f.sp. hordei) were investigated by growth analysis. Mildew development was assessed as percentage leaf area colonised, and by numbers of conidia produced. At all stages of plant growth, the percentage leaf area colonised by the mildew was slightly higher on the wild line B19909 than on cv. Prisma and much more than on the wild line I-17-40. When mildew was measured as conidial production, line B19909 was found to support more fungal biomass than cv. Prisma and cv. Prisma much more than line I-17-40
Hydrogen production through oxygenic photosynthesis using the cyanobacterium Synechocystis sp. PCC 6803 in a bio-photoelectrolysis cell (BPE) system
Effects of drought stress on fluorescence characteristics of photosystem II in leaves of Plectranthus scutellarioides
Relative tolerances of wild and cultivated barley to infection by Blumeria graminis f.sp hordei (Syn. Erysiphe graminis f.sp hordei). II - the effects of infection on photosynthesis and respiration
Photosynthetic light response curves determined with the leaf oxygen electrode: minimisation of errors and significance of the convexity term
From photosynthetic studies on a range of monocotyledonous (C-3 and C-4) and dicotyledonous (C-3) plants using a leaf oxygen electrode, we conclude the following. (i) A non-linear model [J.H.M.Thornley (1976) Mathematical models in plant physiology, Academic Press, London; B. Marshall and P.V. Biscoe (1980) J Exp Bot 31:29-39] significantly better describes the photosynthetic light response curve [rate of photosynthesis (P) versus incident photosynthetic photon flux density (I)] than the frequently used linear hyperbolic model [E.I. Rabinowich (1951) Photosynthesis and related processes, vol 2, Wiley, New York]. (ii) When used at the recommended CO2 partial pressures (Ca=1-5 kPa), CO2 supply saturates the photosynthesis rate in the C-3 dicot Phaseolus coccineus L. but not in the C-3 monocot Hordeum vulgare L.. (iii) Fits using a linear hyperbolic model for P versus I produce relatively large and statistically significant errors (,60%) in the estimation of Pmax and quantum efficiency (!) if Ca is not >5 kPa. (iv) The convexity term, Š, incorporated into the non-linear models for P versus I appears to reflect the limitation placed on the carboxylation processes by the supply of CO2 to the chloroplast stroma. Therefore, the use of a non-linear model providing an estimate of Š should be encouraged, as it is likely to provide information on the physiological status of plants
The potential signalling pathways which regulate surface changes induced by phytohormones in the potato cyst nematode (Globodera rostochiensis)
The influence of phosphite treatments on oak leaves and damage caused by powdery mildew Erysiphe alphitoides
The aim of the project was to check the influence of ammonium phosphite preparation − Actifos on the physiology of leaves and a possible reduction of infection by the fungus a year after the application of fertilizer. Three observation plots were selected in Karczma Borowa, Krotoszyn and Piaski Forest Districts (FD). In each of these observation plots, trees were chosen randomly. In Karczma Borowa FD, the trees were treated by watering them with a 3% solution of Actifos. In Krotoszyn FD, the leaves of trees were sprayed twice (in July and September) from the plane using a 50% solution of Actifos; and in Piaski FD, only the trunks of tress were sprayed twice the same way, but in July 2012 and September 2013. In October 2013, from each tested tree, ten leaves were selected randomly from the upper, well-lit parts of their crowns. The assessment of leaf surface damaged by mycelium and chlorophyll a fluorescence was performed. After the application of the phosphite, no negative physiological consequences for the treated trees were noticed − neither concerning the average leaf area nor the fluorescence of chlorophyll. The manner of phosphite application (leaves, trunks or roots) did not cause any negative consequences for the vitality/health of the treated trees as compared to the control trees. A certain tendency in the reduction of oak mildew on the treated leaves with phosphite was observed, however these observations should be continued in the next years
The relationship among children’s arithmetic problem solving, working memory, and planning ability.
本研究は小学生における算数問題解決,ワーキングメモリ(WM),プランニング能力の関連を検討した。小学6 年生48 名(12 歳)が調査に参加した。算数問題解決,WM 容量,プランニング能力の測度として,全国学力・学習状況調査に基づいた算数文章題(基礎問題,応用問題),リーディングスパンテスト,Porteus 迷路課題がそれぞれ用いられた。その結果,基礎的な文章題の遂行,WM,プランニング能力は応用的な文章題の遂行に有意に関連すること,そして,月齢と基礎的文章題の遂行を統制した場合でさえ,WM やプランニング能力の寄与が持続することが示された。また,WM の相対的に小さい児童は問題文の誤読や計算ミスをなす傾向があった。本データは,算数文章題の遂行におけるWM とプランニング能力の重要性を示している。This study examined the relationship among elementary student’s arithmetic problem solving, working memory (WM), and planning ability. Forty-eight 6th graders (12-year-olds) participated in this study. Arithmetic word problem based on national achievement test (basic problems and practical problems), reading span test, and Porteus maze test were used as the measures of arithmetic problem solving, WM capacity, and planning ability, respectively. The results showed that the achievement on basic word problem, WM, and planning ability were significantly related to the achievement on practical word problem, and that the contribution of WM and planning ability persisted even month old and the basic problem achievement were partialled out. Also, the results showed that the children with low WM tended to misread a problem statement and to mistake in calculation. The data showed the importance of WM and planning ability in the achievement on arithmetic word problems