scholarly journals Studies on the Emergence of Rice Seedlings in the Direct-Sowing Culture. : 3. Strength of elongation of coleoptile and foliage leaves of rice plants.

1966 ◽  
Vol 35 (3-4) ◽  
pp. 161-167 ◽  
Author(s):  
Jun INOUYE ◽  
Yoshiichi OKADA ◽  
Tsukuda KATAYAMA
Keyword(s):  
Rice Seedlings ◽  
Rice Plants ◽  
Direct Sowing

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.

scholarly journals ​Development and Performance Evaluation of a Two-row Mechanical Paddy Transplanter

2021 ◽  
Author(s):  
Sapunii Sebastian ◽  
E.V. Thomas
Keyword(s):  
Field Capacity ◽  
Machine Construction ◽  
Asian Countries ◽  
Rice Seedlings ◽  
Huge Amount ◽  
Hilly Region ◽  
Actual Field ◽  
And Performance ◽  
Four Bar Linkage ◽  
Direct Sowing

Background: Paddy is one of the most important staple food in most south-east Asian countries. It is grown either by direct sowing or by transplanting under wetland conditions depending upon the availability of water. India produces 116.48 million tonnes of rice with a productivity of 2659 kg ha-1. Manual transplanting of rice seedlings by hand is generally done in stooping posture which is laborious and drudgery. It also requires a huge amount of labour during peak season. Considering the need and to suit the hilly region, a two-row manually operated paddy transplanter was developed. Methods: For picking the seedlings, a four-bar mechanism was selected as the basis of design. The machine construction consists of a float, seedling tray, fixed-fork type finger, chain sprocket system and lugged wheel. For operation, the operator has to rotate the crank handle which transmits the motion through the chain sprocket system and four-bar linkage which in turn picks the seedlings and plants them onto the soil. Result: The machine was tested in the actual field condition and was working satisfactorily. The designed fixed fork-type finger can hold 5 to 8 seedlings at a time. The developed machine was found to be comfortable working at a speed of 0.5 kmph. The actual field capacity of the machine was 0.02 ha/h.

scholarly journals Enhanced accumulation of gibberellins rendered rice seedlings sensitive to ammonium toxicity

2019 ◽  
Vol 71 (4) ◽  
pp. 1514-1526
Author(s):  
Baolan Wang ◽  
Haifang Wei ◽  
Hui Zhang ◽  
Wen-Hao Zhang
Keyword(s):  
Physiological Function ◽  
Wild Type ◽  
Rice Seedlings ◽  
Gene Encoding ◽  
Ammonium Toxicity ◽  
Rice Plants ◽  
Worldwide Phenomenon ◽  
Increased Sensitivity ◽  
Ga Biosynthesis

Abstract Ammonium (NH4+) phytotoxicity is a worldwide phenomenon, but the primary toxic mechanisms are still controversial. In the present study, we investigated the physiological function of gibberellins (GAs) in the response of rice plants to NH4+ toxicity and polyamine accumulation using GA biosynthesis-related rice mutants. Exposure to NH4+ significantly decreased GA4 production in shoots of wild-type (WT) plants. Both exogenous GA application to the WT and increases in endogenous GA levels in eui1 mutants rendered them more sensitive to NH4+ toxicity. In contrast, growth of sd1 GA-deficient mutants was more tolerant to NH4+ toxicity than that of their WT counterparts. The role of polyamines in GA-mediated NH4+ toxicity was evaluated using WT rice plants and their GA-related mutants. The eui1 mutants with GA overproduction displayed a higher endogenous putrescine (Put) accumulation than WT plants, leading to an enhanced Put/[spermidine (Spd)+spermine (Spm)] ratio in their shoots. In contrast, mutation of the SD1 gene encoding a defective enzyme in GA biosynthesis resulted in a significant increase in Spd and Spm production, and reduction in the Put/(Spd+Spm) ratio when exposed to a high NH4+ medium. Exogenous application of Put exacerbated symptoms associated with NH4+ toxicity in rice shoots, while the symptoms were alleviated by an inhibitor of Put biosynthesis. These findings highlight the involvement of GAs in NH4+ toxicity, and that GA-induced Put accumulation is responsible for the increased sensitivity to NH4+ toxicity in rice plants.

scholarly journals The Effectiveness of Several Plant Extracts to Induce Rice Plant Resistance against Bacterial Leaf Blight - (Xanthomonas oryzae pv. oryzae)

2019 ◽  
Vol 23 (1) ◽  
pp. 16
Author(s):  
Fitri Widiantini ◽  
Avissa Ayuningdiyas ◽  
Endah Yulia ◽  
Tarkus Suganda
Keyword(s):  
Plant Extracts ◽  
Seed Treatment ◽  
Defense Mechanism ◽  
Leaf Blight ◽  
Xanthomonas Oryzae ◽  
Bacterial Leaf Blight ◽  
Rice Seedlings ◽  
Control Techniques ◽  
Rice Plants ◽  
Plant Defense Mechanism

Resistant plants are one of the disease control techniques that considered to be effective. Resistant plants can be produced in various ways including the application of plant extracts. The aim of this study was to examine the ability of several plant extracts to increase the resistance of rice plants to bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo). A total of 13 plants were extracted and applied in two methods, which were seed treatment and seedling treatment which sprayed on two-week old rice seedlings. Xoo bacteria were inoculated on rice plants two weeks after planting. The observations on the intensity of BLB disease infection showed that water hyacinth extract (Eichhornia crassippes), spiny amaranth (Amaranthus spinosus) and jasmine leaves (Jasminum grandiflorum) can suppress the development of BLB disease in both application methods. The application of plant extracts as inducing agents needs to be repeated to maintain the activated plant defense mechanism.

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.

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