Effects of environmental stress on the relationship of free amino‐N to fresh weight of rice plants

1991 ◽  
Vol 14 (11) ◽  
pp. 1151-1164 ◽  
Author(s):  
Manlio S. Fernandes
Weed Science ◽  
1980 ◽  
Vol 28 (4) ◽  
pp. 429-432 ◽  
Author(s):  
T. E. Dutt ◽  
R. G. Harvey

Pronamide [3,5-dichloro-(N-1, 1-dimethyl-2-propynyl) benzamide] phytotoxicity was compared in 10 Wisconsin soils and the relationship of activity to soil physical and chemical properties appraised. Twelve soil properties were measured and correlated with pronamide I50(50% fresh weight inhibition) values using oats (Avena sativaL. ‘Portal’) as the indicator plant in bioassays conducted under greenhouse conditions. Organic matter was the soil variable most inversely correlated with pronamide phytotoxicity. Cation exchange capacity, field moisture capacity, and Mg content were also inversely correlated with pronamide phytotoxicity, but probably reflect changes in soil organic matter levels. Clay content did not significantly affect pronamide phytotoxicity.


2010 ◽  
Vol 22 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Marcin Bartczak ◽  
Jolanta Lisiecka ◽  
Mikołaj Knaflewski

Abstract The aim of this study was to determine the effect of fresh and dry weight, as well as the number and length of roots and number of crowns of different types of plants, on the yield of strawberry grown for the spring and autumn harvests. Three different types of frigo strawberry plants (waiting bed plants, plug plants, A+ plants) and two strawberry cultivars (‘Honeoye’ and ‘Elsanta’) were compared in the experiment. The plants were grown in polypropylene bags in an unheated glasshouse in the years 2002-2005. The correlation coefficients were calculated to estimate the relationship of the strawberry plants’ parameters to the yield quantity. An analysis of regression for the plant parameters that most significantly correlated to the strawberry yield was carried out, which determined that the fresh and dry weight of the strawberry plants, crown number, as well as length of roots were positively correlated to the quantity of the strawberry yield. The highest positive correlation coefficient was found for the fresh weight of a whole plant and the lowest one for the number of roots.


2015 ◽  
Vol 49 (7) ◽  
pp. 4245-4254 ◽  
Author(s):  
Sonja Milić ◽  
Jelena Bogdanović Pristov ◽  
Dragosav Mutavdžić ◽  
Aleksandar Savić ◽  
Mihajlo Spasić ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1075
Author(s):  
Ok Jin Hwang ◽  
Kyoungwhan Back

We investigated the relationship between the blue-light photoreceptor cryptochrome (CRY) and melatonin biosynthesis by generating RNA interference (RNAi) transgenic rice plants that suppress the cryptochrome 1b gene (CRY1b). The resulting CRY1b RNAi rice lines expressed less CRY1b mRNA, but not CRY1a or CRY2 mRNA, suggesting that the suppression is specific to CRY1b. The growth of CRY1b RNAi rice seedlings was enhanced under blue light compared to wild-type growth, providing phenotypic evidence for impaired CRY function. When these CRY1b RNAi rice plants were challenged with cadmium to induce melatonin, wild-type plants produced 100 ng/g fresh weight (FW) melatonin, whereas CRY1b RNAi lines produced 60 ng/g FW melatonin on average, indicating that melatonin biosynthesis requires the CRY photoreceptor. Due to possible feedback regulation, the expression of melatonin biosynthesis genes such as T5H, SNAT1, SNAT2, and COMT was elevated in the CRY1b RNAi lines compared to the wild-type plants. In addition, laminar angles decreased in the CRY1b RNAi lines via the suppression of brassinosteroid (BR) biosynthesis genes such as DWARF. The main cause of the BR decrease in the CRY1b RNAi lines seems to be the suppression of CRY rather than decreased melatonin because the melatonin decrease suppressed DWARF4 rather than DWARF.


2021 ◽  
Author(s):  
Daniele Aparecida Matoso ◽  
Maelin da Silva ◽  
Hallana Cristina Menezes da Silva ◽  
Eliana Feldberg ◽  
Roberto Ferreira Artoni

Transcriptionally inactive portions of genomic DNA, condensed with histones and architectural proteins, are known as heterochromatic regions, often positive C band. The advent of epigenetics and new methodological approaches, showed that these regions are extremely dynamic and responsive to different types of environmental stress. The relationship of the constitutive heterochromatin with the transposable elements inactivation, especially from the Rex family, seems to be a frequent condition in fish. In this manuscript we review the existing knowledge of the nature and function of these genomic regions, based on species-based studies, with a focus on species of fish from the Amazon region.


Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.


Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Sign in / Sign up

Export Citation Format

Share Document