scholarly journals Penyaringan Cepat dan Toleransi Tanaman Jagung terhadap Intensitas Cahaya Rendah

2014 ◽  
Vol 33 (1) ◽  
pp. 36
Author(s):  
Syafruddin Syafruddin ◽  
Suwarti Suwarti ◽  
M. Azrai
Keyword(s):  
Light Intensity ◽  
Physiological Mechanism ◽  
Rapid Screening ◽  
Production Environment ◽  
Low Light ◽  
Maize Production ◽  
Low Light Intensity ◽  
Maize Genotypes ◽  
Intensity Stress ◽  
Dark Room

Maize cropping under plantation tree crop has a potential for increasing the national maize production. Environment under the tree crops has relatively low light intensity, which hinder the leaf photosynthesis. Therefore, research to identify maize genotypes tolerant to low light intensity was conducted. The research was carried out in three stages; stage-1 was to identify the most effective shading method to be used for the rapid screening, consisted of two treatments, namely: 87.5% and 99.9% light interception. Stage-2 was rapid screening of 160 maize genotypes at germination stage, under the dark room to select tolerance genotypes. The stage-3 was to study physiological mechanism of maize growth under low light intensity stress by planting nine tolerant and susceptible genotypes. The results showed that rapid screening of maize for tolerant to low light intensity stress can be done by growing newly germinating maize for 8 days in the dark room. Genotypes G02 x 7; CY 15 x MAL03; AP.1 x 1042-37; B11 x 265-A; MR12 x MAL04; MR14 x 270C; G02 x 5; AMB07 x CML161 and 1044-9 x 1027-11 were found to be tolerant to low light intensity stress. Growing maize seedling in the dark room had decreased chlorophyll content, carbohydrates and fat, however, the Nitrogen (N) content in the leaves increased. Tolerance genotypes response to low light intensity was indicated by decreasing chlorophyll, carbohydrates and fat content, as well as increasing Nitrogen content, much less than those of susceptible genotypes.

scholarly journals Response of Photosynthesis and Chlorophyll Fluorescence Parameters of Castanopsis kawakamii Seedlings to Forest Gaps

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Zhong-sheng He ◽  
Rong Tang ◽  
Meng-jia Li ◽  
Meng-ran Jin ◽  
Cong Xin ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Light Intensity ◽  
Seedling Growth ◽  
Group Treatment ◽  
Control Group ◽  
Low Light ◽  
Chlorophyll Fluorescence Parameters ◽  
Forest Gaps ◽  
Low Light Intensity ◽  
Weak Light

Light is a major environmental factor limiting the growth and survival of plants. The heterogeneity of the light environment after gap formation in forest influences the leaf chlorophyll contents, net photosynthetic rate (Pn), and chlorophyll fluorescence, thus influencing the growth and regeneration of Castanopsis kawakamii seedlings. The aim of this study was to explore the effects of weak light on the photosynthetic physiology of C. kawakamii seedlings in forest gaps and non-gaps. The results showed that (1) the contents of chlorophyll a (Chl-a), chlorophyll b (Chl-b), and total chlorophyll (Chl-T) in forest gaps were lower than in non-gaps. Seedlings tended to increase chlorophyll content to absorb light energy to adapt to low light intensity in non-gap environments. (2) The Pn values of C. kawakamii seedlings in forest gaps were significantly higher than in non-gaps, and forest gaps could improve the seedlings’ photosynthetic capacity. (3) The C. kawakamii seedlings in forest gaps were more sensitive to weak light and control group treatment, especially the tall seedlings, indicating that seedlings require more light to satisfy their growth needs in the winter. The seedlings in non-gaps demonstrated better adaptability to low light intensity. The light intensity was not adequate in weak light conditions and limited seedling growth. We suggest that partial forest selection cutting could improve light intensity in non-gaps, thus promoting seedling growth and regeneration of C. kawakamii more effectively in this forest.

scholarly journals The Effect of Low Light Intensity on the Early Development of Radish Hypocotyl

1983 ◽  
Vol 51 (4) ◽  
pp. 421-426 ◽  
Author(s):  
Yasuyoshi HAYATA ◽  
Yutaka SHINOHARA ◽  
Yoshio SUZUKI
Keyword(s):  
Light Intensity ◽  
Early Development ◽  
Low Light ◽  
Low Light Intensity

scholarly journals Nighttime Temperatures and Sunlight Intensities Interact to Influence Anthocyanin Biosynthesis and Photooxidative Sunburn in “Fuji” Apple

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaomin Xue ◽  
Ying Duan ◽  
Jinzheng Wang ◽  
Fengwang Ma ◽  
Pengmin Li
Keyword(s):  
Light Intensity ◽  
Low Temperatures ◽  
Anthocyanin Biosynthesis ◽  
High Light ◽  
Anthocyanin Accumulation ◽  
Low Light ◽  
Low Light Intensity ◽  
Apple Peel ◽  
Fuji Apple ◽  
Nighttime Temperatures

Light and low temperatures induce anthocyanin accumulation, but intense sunlight causes photooxidative sunburn. Nonetheless, there have been few studies of anthocyanin synthesis under different sunlight intensities and low nighttime temperatures. Here, low nighttime temperatures followed by low light intensity were associated with greater anthocyanin accumulation and the expression of anthocyanin biosynthesis genes in “Fuji” apple peel. UDP-glucose flavonoid-3-O-glucosyltransferase (UFGT) activity was positively associated with anthocyanin enrichment. Ascorbic acid can be used as an electron donor of APX to scavenge H2O2 in plants, which makes it play an important role in oxidative defense. Exogenous ascorbate altered the anthocyanin accumulation and reduced the occurrence of high light–induced photooxidative sunburn by removing hydrogen peroxide from the peel. Overall, low light intensity was beneficial for the accumulation of anthocyanin and did not cause photooxidative sunburn, whereas natural light had the opposite effect on the apple peel at low nighttime temperatures. This study provides an insight into the mechanisms by which low temperatures induce apple coloration and high light intensity causes photooxidative sunburn.

scholarly journals Light intensity regulates phototaxis, foraging and righting behaviors of the sea urchin Strongylocentrotus intermedius

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8001 ◽  
Author(s):  
Jiangnan Sun ◽  
Xiaomei Chi ◽  
Mingfang Yang ◽  
Jingyun Ding ◽  
Dongtao Shi ◽  
...  
Keyword(s):  
Light Intensity ◽  
Foraging Behavior ◽  
Sea Urchins ◽  
High Light Intensity ◽  
High Light ◽  
Strongylocentrotus Intermedius ◽  
Low Light ◽  
Low Light Intensity ◽  
Light Intensities ◽  
Significant Difference

Small sea urchins Strongylocentrotus intermedius (1–2 cm of test diameter) are exposed to different environments of light intensities after being reseeded to the sea bottom. With little information available about the behavioral responses of S. intermedius to different light intensities in the environment, we carried out an investigation on how S. intermedius is affected by three light intensity environments in terms of phototaxis, foraging and righting behaviors. They were no light (zero lx), low light intensity (24–209 lx) and high light intensity (252–2,280 lx). Light intensity had obvious different effects on phototaxis. In low light intensity, sea urchins moved more and spent significantly more time at the higher intensity (69–209 lx) (P = 0.046). S. intermedius in high light intensity, in contrast, spent significantly more time at lower intensity (252–690 lx) (P = 0.005). Unexpectedly, no significant difference of movement (average velocity and total distance covered) was found among the three light intensities (P > 0.05). Foraging behavior of S. intermedius was significantly different among the light intensities. In the no light environment, only three of ten S. intermedius found food within 7 min. In low light intensity, nine of 10 sea urchins showed successful foraging behavior to the food placed at 209 lx, which was significantly higher than the ratio of the number (two of 10) when food was placed at 24 lx (P = 0.005). In the high light intensity, in contrast, significantly less sea urchins (three of 10) found food placed at the higher light intensity (2,280 lx) compared with the lower light intensity (252 lx) (10/10, P = 0.003). Furthermore, S. intermedius showed significantly longer righting response time in the high light intensity compared with both no light (P = 0.001) and low light intensity (P = 0.031). No significant difference was found in righting behavior between no light and low light intensity (P = 0.892). The present study indicates that light intensity significantly affects phototaxis, foraging and righting behaviors of S. intermedius and that ~200 lx might be the appropriate light intensity for reseeding small S. intermedius.

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