Potential of crude extract and isolated compounds from golden beard grass (Chrysopogon serrulatus) for control of sprangletop (Leptochloa chinensis) in aerobic rice systems

2014 ◽  
Vol 65 (5) ◽  
pp. 461 ◽  
Author(s):  
T. S. Chuah ◽  
H. Y. Oh ◽  
M. Habsah ◽  
M. Z. Norhafizah ◽  
B. S. Ismail
Keyword(s):  
Dibutyl Phthalate ◽  
Aerobic Rice ◽  
Rice Seed ◽  
Rice Seedlings ◽  
Inhibitory Effects ◽  
Shoot Height ◽  
Rice Plants ◽  
Natural Herbicide ◽  
Root And Shoot Growth ◽  
Aerobic Rice System

Extraction and fractionation of the culm plus leaves of Chrysopogon serrulatus Trin. produce three major compounds, dibutyl phthalate (DBP), diphenylamine, 4,4′-dioctyl and simiarenol, which potentially act as allelochemicals or phytotoxic compounds. The effects of these compounds were examined using Leptochloa chinensis (L.) Nees as the bioassay species. The isolated compounds showed different degrees of inhibitory effects against L. chinensis. Of the three, DBP was the most potent and was able to inhibit L. chinensis germination by >70% at 500 mg L–1, followed by simiarenol and diphenylamine, 4,4′-dioctyl with inhibition values ranging from 40 to 52%. Under aerobic conditions, DBP at 2.4 kg a.i. ha–1 reduced the emergence and shoot fresh weight of L. chinensis by >50%, with negligible effect on root and shoot growth of aerobic rice seedlings, suggesting this as the most suitable rate and compound to control L. chinensis without injuring rice seedlings. At an application on the day of sowing rice seed, across DBP rates, reduction in root and shoot height of rice plants was evident when assessed 14 days after DBP treatment. However, rice plants become less susceptible with increasing growth stage. The findings suggest that DBP has potential to be developed as a pre-emergence, soil-applied natural herbicide for control of L. chinensis in aerobic rice system.

scholarly journals Enhanced Resistance to Seed-Transmitted Bacterial Diseases in Transgenic Rice Plants Overproducing an Oat Cell-Wall-Bound Thionin

2002 ◽  
Vol 15 (6) ◽  
pp. 515-521 ◽  
Author(s):  
Takayoshi Iwai ◽  
H. Kaku ◽  
R. Honkura ◽  
S. Nakamura ◽  
H. Ochiai ◽  
...  
Keyword(s):  
Transgenic Rice ◽  
Rice Seed ◽  
Wild Type ◽  
Rice Seedlings ◽  
Bacterial Diseases ◽  
Rice Plants ◽  
Enhanced Resistance ◽  
Etiolated Seedlings ◽  
High Level ◽  
Bacterial Attack

Bacterial attack is a serious agricultural problem for growth of rice seedlings in the nursery and field. The thionins purified from seed and etiolated seedlings of barley are known to have antimicrobial activity against necrotrophic pathogens; however, we found that no endogenous rice thionin genes alone are enough for resistance to two major seed-transmitted phytopathogenic bacteria, Burkholderia plantarii and B. glumae, although rice thionin genes constitutively expressed in coleoptile, the target organ of the bacteria. Thus, we isolated thionin genes from oat, one of which was overexpressed in rice. When wild-type rice seed were germinated with these bacteria, all seedlings were wilted with severe blight. In the seedling infected with B. plantarii, bacterial staining was intensively marked around stomata and intercellular spaces. However, transgenic rice seedlings accumulating a high level of oat thionin in cell walls grew almost normally with bacterial staining only on the surface of stomata. These results indicate that the oat thionin effectively works in rice plants against bacterial attack.

Phytotoxic Effects of the Extracts and Compounds Isolated from Napiergrass (Pennisetum purpureum) on Chinese Sprangletop (Leptochloa chinensis) Germination and Seedling Growth in Aerobic Rice Systems

Weed Science ◽  
2014 ◽  
Vol 62 (3) ◽  
pp. 457-467 ◽  
Author(s):  
Tse Seng Chuah ◽  
Md Zain Norhafizah ◽  
Sahid Ismail
Keyword(s):  
Methyl Oleate ◽  
Root Growth ◽  
Pennisetum Purpureum ◽  
Growth Stages ◽  
Aerobic Rice ◽  
Rice Seedlings ◽  
Isolation And Identification ◽  
Strong Inhibitor ◽  
Shoot Height ◽  
Phytotoxic Effects

Chinese sprangletop, a problematic weed in aerobic rice fields, has developed resistance to various groups of herbicides. In search of natural herbicides, the phytotoxic effects of napiergrass extracts on Chinese sprangletop were investigated. Phytotoxicity-directed extraction and fractionation of the culm plus leaves of napiergrass led to the isolation and identification of three major compounds: 2,4-di-tert-butylphenol (2,4-DTBP), cis-9-octadecenoic methyl ester (methyl oleate), and phthalic acid, mono-(2-ethylhexyl) ester (MEHP). These compounds showed different degrees of inhibition against the tested bioassay species. 2,4-DTBP was the most potent of the three compounds and completely inhibited the germination of Chinese sprangletop at the concentration of 0.5 g L−1, followed by MEHP, where 62% inhibition of germination was obtained. In contrast, methyl oleate showed only slight inhibition (< 10%) of germination. A soil bioassay further demonstrated that 2,4-DTBP is a strong inhibitor of root growth and completely prevented root growth of Chinese sprangletop at an application rate as low as 0.60 kg ai ha−1. Under aerobic conditions, 2,4-DTBP at 2.4 kg ai ha−1 reduced the emergence and shoot fresh weight of Chinese sprangletop by more than 60%, with negligible effect on root and shoot growth of aerobic rice seedlings, suggesting that 2.4 kg ai ha−1 2,4-DTBP is the most suitable rate to control Chinese sprangletop without injuring rice seedlings. Reduction in shoot height of rice plant was evident at 0 d after sowing across 2,4-DTBP rates. However, the rice plants became less susceptible with increasing growth stages. The present findings imply that 2,4-DTBP may potentially be developed as a PRE soil-applied natural herbicide for control of Chinese sprangletop and perhaps other weeds in aerobic rice system.

Interaction of silicon and cadmium in Brassica juncea and Brassica napus

Biologia ◽  
2012 ◽  
Vol 67 (3) ◽  
Author(s):  
Zuzana Vatehová ◽  
Karin Kollárová ◽  
Ivan Zelko ◽  
Danica Richterová-Kučerová ◽  
Marek Bujdoš ◽  
...  
Keyword(s):  
Lateral Roots ◽  
Root Apex ◽  
Brassica Species ◽  
Inhibitory Effects ◽  
Cd Uptake ◽  
Primary Roots ◽  
Suberin Lamellae ◽  
Root And Shoot Growth ◽  
The Impact ◽  
Si Addition

AbstractThe objective of this study was to determine the effect of silicon (Si) and cadmium (Cd) on root and shoot growth and Cd uptake in two hydroponically cultivated Brassica species (B. juncea (L.) Czern. cv. Vitasso and B. napus L. cv. Atlantic). Both species are potentially usable for phytoextraction. Inhibitory effects of Cd on root elongation were diminished by the impact of Si. Primary roots elongation in the presence of Cd + Si compared with Cd was stronger and the number of lateral roots was lower in B. juncea than in B. napus. Cd content per plant was higher in B. napus roots and shoots compared with B. juncea. Suberin lamellae were formed closer to the root apex in Cd + Si than in Cd treated plants and this effect was stronger in B. napus than in B. juncea. Accelerated maturation of endodermis was associated with reduced Cd uptake. Cd decreased the content of chlorophylls and carotenoids in both species, but Si addition positively influenced the content of photosynthetic pigments which was higher in B. napus than in B. juncea. Si enhanced more substantially translocation of Cd into the shoot of B. napus than of B. juncea. Based on our results B. napus seems to be more suitable for Cd phytoextraction than B. juncea because these plants produce more biomass and accumulate higher amount of Cd. The protective effect of Si on Cd treated Brassica plants could be attributed to more extensive development of suberin lamellae in endodermis.

Evaluation of three herbicides for the control of grasses in rices

1966 ◽  
Vol 6 (21) ◽  
pp. 219 ◽  
Author(s):  
BB Fischer ◽  
DJ Swain ◽  
EB Boerema
Keyword(s):  
Rice Yield ◽  
New South ◽  
Effective Control ◽  
Rice Seed ◽  
Rice Seedlings ◽  
Barnyard Grass ◽  
Treated Soil ◽  
Stage Of Development ◽  
South Wales ◽  
Excellent Control

Increased rice yield was obtained when the predominant grasses infesting rice fields in the Murrumbidgee irrigation areas of New South Wales were effectively controlled. Ordram (ethyl hexahydro-1 H-azepine-1-carbothioate) applied at pre-sowing and at post-emergence of the rice and grass, gave excellent control of grasses. Propanil, applied to vigorously growing barnyard grass in its 2-3 leaf stage of development, also gave very effective control. Ordram, applied at pre-sowing at less than two inches from the germinating rice seed in the soil of applied at pre-emergence in the water when the plumule of the germinating seed had to grow through the herbicide treated soil, reduced the density of the stand or the vigour of the rice seedlings.

scholarly journals Comparative study on the influence of silicon and selenium to mitigate arsenic induced stress by modulating TCA cycle, GABA and polyamine synthesis in rice seedlings

2021 ◽  
Author(s):  
Susmita Das ◽  
Barsha Majumder ◽  
Asok Kumar Biswas
Keyword(s):  
Tca Cycle ◽  
Future Application ◽  
Rice Seedlings ◽  
Respiratory Enzymes ◽  
Rice Plants ◽  
Regulatory Enzymes ◽  
Joint Application ◽  
Defensive Role ◽  
Gaba Accumulation

Abstract Arsenic contamination of groundwater is a major concern for its use as drinking water and crop irrigation in many regions of the world. Arsenic is absorbed by rice plants from arsenic contaminated water during irrigation, hampers growth and agricultural productivity. The aim of the study was to mitigate the activity of TCA cycle, synthesis of γ-aminobutyric acid (GABA) and polyamines (PAs) in rice (Oryza sativa L. cv. MTU-1010) seedlings under arsenate (As-V) stress [25 µM, 50 µM and 75 µM] by silicon (Si) [2 mM] and selenium (Se) [5 µM] amendments, and to investigate which chemical was more potential to combat this threat. As(V) application decreased the activities of tested respiratory enzymes while the levels of organic acids (OAs) were increased in the test seedlings. Co-application of Si and As(V) increased the activities of respiratory enzymes, consequently further increased accumulation of OAs that were more than Se with As(V) application in the test seedlings. GABA accumulation along with the activities of its regulatory enzymes were enhanced under As(V) stress. During joint application of Si and As(V) and Se and As(V) said parameters were decreased showing defensive role of these chemicals to resist As(V) toxicity in rice but amendment of Si was more potential than Se amendment resulted reduction of stress induced damage in the test seedlings. PAs trigger tolerance mechanism against stress in plants. PAs viz., Putrescine, spermidine and spermine were synthesized more during Si and Se amendments in As(V) contaminated rice seedlings to combat the effect of stress. Si amendment substantially modulated the toxic effects caused by As(V) over Se amendment in As(V) challenged test seedlings. Thus in future application Si enriched fertilizer will be beneficial than application of Se enriched fertilizer to grow rice plants with normal vigor in arsenic contaminated soil.

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