Pathogenicity of the rice root nematode,Hirschmanniella oryzaeto rice plants in relation to nematode reproduction, plant growth, grain yield and biochemical changes

2012 ◽  
Vol 45 (19) ◽  
pp. 2324-2334 ◽  
Author(s):  
Nagwa A. Abd-Elbary ◽  
M.F.M. Eissa ◽  
M.M.A. Youssef
2001 ◽  
Vol 28 (9) ◽  
pp. 845 ◽  
Author(s):  
Youssef G. Yanni ◽  
Rizk Y. Rizk ◽  
Faiza K. Abd El-Fattah ◽  
Andrea Squartini ◽  
Viviana Corich ◽  
...  

This paper originates from an address at the 8th International Symposium on Nitrogen Fixation with Non-Legumes, Sydney, NSW, December 2000 This paper summarizes a multinational collaborative project to search for natural, intimate associations between rhizobia and rice (Oryza sativa L.), assess their impact on plant growth, and exploit those combinations that can enhance grain yield with less dependence on inputs of nitrogen (N) fertilizer. Diverse, indigenous populations of Rhizobium leguminosarum bv. trifolii (the clover root-nodule endosymbiont) intimately colonize rice roots in the Egyptian Nile delta where this cereal has been rotated successfully with berseem clover (Trifolium alexandrinum L.) since antiquity. Laboratory and greenhouse studies have shown with certain rhizobial strain–rice variety combinations that the association promotes root and shoot growth thereby significantly improving seedling vigour that carries over to significant increases in grain yield at maturity. Three field inoculation trials in the Nile delta indicated that a few strain–variety combinations significantly increased rice grain yield, agronomic fertilizer N-use efficiency and harvest index. The benefits of this association leading to greater production of vegetative and reproductive biomass more likely involve rhizobial modulation of the plant’s root architecture for more efficient acquisition of certain soil nutrients [e.g. N, phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), zinc (Zn), sodium (Na) and molybdenum (Mo)] rather than biological N2 fixation. Inoculation increased total protein quantity per hectare in field-grown grain, thereby increasing its nutritional value without altering the ratios of nutritionally important proteins. Studies using a selected rhizobial strain (E11) indicated that it produced auxin (indoleacetic acid) and gibberellin [tentatively identified as gibberellin (GA 7 )] phytohormones representing two major classes of plant growth regulators. Axenically collected rice root exudate significantly enhanced E11’s production of this auxin. This strain extensively colonized the rice root surface under gnotobiotic culture conditions, producing distributions of spatial patchiness that would favour their localized erosion of the epidermal surface, colonization of small crevices at epidermal junctions as a possible portal to enter into the root, and quorum sensing of diffusible signal molecules indicating that their nearest bacterial neighbours are in close proximity in situ. Studies of selected rhizobial endophytes of rice indicated that they produced cell-bound cellulase and polygalacturonase enzymes that can hydrolyze glycosidic bonds in plant cell walls, and non-trifolitoxin bacteriocin(s) that can inhibit other strains of clover rhizobia. Strain E11 was able to endophytically colonize rice roots of varieties commonly used by Filipino peasant farmers, and also to stimulate genotype-specific growth-promotion of corn (Zea mays, maize) under field conditions. An amalgam of these results indicate some rhizobia have evolved an additional ecological niche enabling them to form a three-component life cycle including a free-living heterotrophic phase in soil, a N2-fixing endosymbiont phase within legume root nodules, and a beneficial growth-promoting endocolonizer phase within cereal roots in the same crop rotation. Our results further indicate the potential opportunity to exploit this newly described, plant�rhizobia association by developing biofertilizer inoculants that may assist low-income farmers in increasing cereal production (especially rice) with less fertilizer N inputs, fully consistent with both sustainable agriculture and environmental safety.


Jurnal BiBieT ◽  
2016 ◽  
Vol 1 (1) ◽  
pp. 9
Author(s):  
Dewi Rezki

<p align="center"><strong>ABSTRAK</strong></p><p align="center"><strong> </strong></p><p>Tingginya laju pertumbuhan penduduk dan alih fungsi lahan pertanian, menyebabkan perlunya dilakukan upaya untuk meningkatkan produksi beras. Sedangkan produksi yang diperoleh dari lahan pertanian yang ada belum mencapai hasil yang optimal.  Upaya yang perlu dilakukan  untuk meningkatkan produksi padi diantaranya adalah memperbaiki tingkat kesuburan tanah dan metode budidaya tanaman padi.  Penelitian ini bertujuan untuk memperoleh kombinasi yang paling tepat antara bahan  organik kaya sumber hayati (BOKASHI) dan pupuk NPK terhadap produksi padi yang ditanam secara jajar legowo.  penelitian dilakukan di Kecamatan Pulau Punjung Kabupaten Dharmasraya Provinsi Sumatera Barat pada bulan Juli-Desember 2015.  Penelitian menunjukkan bahwa kombinasi bokashi + 75 % pupuk buatan memberikan hasil gabah 6.3 ton/Ha, sementara produksi padi tanpa penambahan bokashi + 100 % pupuk buatan memberikan hasil gabah 3.9 ton/Ha, dengan demikian dapat disimpulkan bahwa penambahan bokashi dapat meningkatkan produksi gabah sebanyak 2.4 ton/Ha.  Penambahan 2 ton/Ha bokashi yang ditanam secara sistem jajar legowo pada tanaman padi berpengaruh nyata terhadap pertumbuhan dan produksi tanaman padi dan dapat mengurangi penggunaan pupuk buatan sebanyak 25 %.</p><p>Kata Kunci : Bokashi, Produksi Padi, Jajar Legowo, Kombinasi</p><p> </p><p align="center">ABSTRACT</p><p align="center"> </p><p>The high rate of population growth and the conversion of agricultural land, causing the need for efforts to increase rice production. While the production obtained from existing agricultural lands yet to achieve optimal results. Efforts should be made to increase the rice production of which is to improve soil fertility and method of rice cultivation. This study aims to obtain the most appropriate combination of organic material rich in biological resources (Bokashi) and NPK fertilizer on rice production are grown Legowo row. Research conducted in the District Pulau Punjung Dharmasraya West Sumatra province in July to December 2015. The study showed that the combination of Bokashi + 75% of artificial fertilizers provide grain yield of 6.3 tonnes / ha, while rice production without adding Bokashi + 100% synthetic fertilizers provide grain yield 3.9 tonnes / ha, thus it can be concluded that the addition of bokashi can increase grain production as much as 2.4 tons / ha. Addition of 2 tons / ha planted Bokashi system Legowo row in rice plants significantly affect the growth and production of rice plants and can reduce the use of artificial fertilizers as much as 25%.</p><p>Keywords: Bokashi, Rice Production, Jajar Legowo, Combination</p>


Author(s):  
Dong Van Nguyen ◽  
Huong Mai Nguyen ◽  
Nga Thanh Le ◽  
Kien Huu Nguyen ◽  
Hoa Thi Nguyen ◽  
...  

2012 ◽  
Vol 11 (1) ◽  
pp. 101-114 ◽  
Author(s):  
Jin Seo Jeong ◽  
Youn Shic Kim ◽  
Mark C. F. R. Redillas ◽  
Geupil Jang ◽  
Harin Jung ◽  
...  

2022 ◽  
Vol 8 ◽  
Author(s):  
Mohammad Imran Mir ◽  
Bee Hameeda ◽  
Humera Quadriya ◽  
B. Kiran Kumar ◽  
Noshin Ilyas ◽  
...  

A diverse group of rhizobacteria persists in the rhizospheric soil, on the surface of roots, or in association with rice plants. These bacteria colonize plant root systems, enhance plant growth and crop yield. Indigenous rhizobacteria are known to promote soil health, grain production quality and serve as sustainable bioinoculant. The present study was aimed to isolate, identify and characterize indigenous plant growth promoting (PGP) diazotrophic bacteria associated with the rhizosphere of rice fields from different areas of Jammu and Kashmir, India. A total of 15 bacteria were isolated and evaluated for various PGP traits, antagonistic activity against phytopathogens, production of hydrolytic enzymes and biofilm formation under in-vitro conditions. The majority of the isolated bacteria were Gram-negative. Out of 15 bacterial isolates, nine isolates produced IAA (12.24 ± 2.86 to 250.3 ± 1.15 μg/ml), 6 isolates exhibited phosphate solubilization activity (36.69 ± 1.63 to 312.4 ± 1.15 μg/ml), 7 isolates exhibited rock phosphate solubilization while 5 isolates solubilized zinc (10–18 mm), 7 isolates showed siderophore production, 8 isolates exhibited HCN production, 6 isolates exhibited aminocyclopropane-1-carboxylate (ACC) deaminase activity, 13 isolates exhibited cellulase activity, nine isolates exhibited amylase and lipase activity and six isolates exhibited chitinase activity. In addition, 5 isolates showed amplification with the nifH gene and showed a significant amount of nitrogenase activity in a range of 0.127–4.39 μmol C2H4/mg protein/h. Five isolates viz., IHK-1, IHK-3, IHK-13, IHK-15 and IHK-25 exhibited most PGP attributes and successfully limited the mycelial growth of Rhizoctonia solani and Fusarium oxysporum in-vitro. All the five bacterial isolates were identified based on morphological, biochemical and 16S rDNA gene sequencing study, as Stenotrophomonas maltophilia, Enterobacter sp., Bacillus sp., Ochrobactrum haematophilum and Pseudomonas aeruginosa. Rice plants developed from seeds inoculated with these PGP strains individually had considerably higher germination percentage, seed vigor index and total dry biomass when compared to control. These findings strongly imply that the PGP diazotrophic bacteria identified in this work could be employed as plant growth stimulators in rice.


2016 ◽  
Vol 46 (3) ◽  
pp. 284-291 ◽  
Author(s):  
Adriano Stephan Nascente ◽  
Anna Cristina Lanna

ABSTRACT The presence of cover crop straw and early application of total N at sowing may provide significant changes in the microbial population, reflecting on the N dynamics in the soil and in upland rice plants. This study aimed at determining the effect of the early application of nitrogen doses as mineral N and microbial biomass carbon in the soil, as well as in the activity of nitrate reductase, and grain yield of upland rice plants cultivated under no-tillage system (NTS). A randomized blocks design, in a split-plot scheme, with four replications, was used. The treatments consisted of N doses (0 kg ha-1, 40 kg ha-1, 80 kg ha-1 and 120 kg ha-1) and the presence or absence of U. brizantha cover straw. Maintaining the straw on the soil surface reduces the ammonium levels and increases the microbial biomass carbon content of the soil. The application of increasing doses of N in the soil provides increases in the levels of nitrate and ammonium in the soil up to 28 days after emergence. The activity of the nitrate reductase enzyme in the plants increases and the contents of ammonium and nitrate in the soil decrease with the crop development. The number of panicles and grain yield of upland rice increase with the increase of the nitrogen fertilization, but decrease in the presence of U. brizantha straw. Thus, it is recommend the use of early N fertilization in upland rice crop.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e5877 ◽  
Author(s):  
Ram B. Khadka ◽  
Norman Uphoff

Many benefits ofTrichodermainoculation for improving crop production have been documented, including growth and yield enhancement and the alleviation of biotic and abiotic stresses. However, because rice is usually cultivated under continuous flooding that creates anaerobic soil conditions, this limits the benefits of these beneficial fungi. Cultivating rice with the methods of the System of Rice Intensification (SRI) provides rice plants with a more favorable environment for their colonization by beneficial microbes in the soil because the soil is more aerobic under SRI management and contains more organic matter. This study evaluated the effects ofTrichodermainoculation of rice plants under SRI management compared with transplanted and flooded rice plants, considering also the effects of different means of fertilization and different varieties in rice. Experiments were conducted in 2015 and 2016 under the tropical climate of Nepal’s western terai (plains) during both the rainy season (July to November) and the dry season (March to July). The results indicated significantly better performance (P = 0.01) associated withTrichodermainoculation for both seasons and for both systems of crop management in terms of grain yield and other growth-contributing factors, compared to non-inoculated rice cropping. Relatively higher effects on grain yield were recorded also with organic compared to inorganic fertilization; for unimproved (heirloom) varieties compared with improved varieties; and from SRI vs. conventional flooded crop management. The yield increase withTrichodermatreatments across all trials was 31% higher than in untreated plots (4.9 vs 4.5 mt ha−1). WithTrichodermatreatment, yields compared with non-treated plots were 24% higher with organic SRI (6.38 vs 5.13 mt ha−1) and 52% higher with non-organic SRI (6.38 vs 3.53 mt ha−1). With regard to varietal differences, under SRI managementTrichodermainoculation of the improved variety Sukhadhan-3 led to 26% higher yield (6.35 vs 5.04 mt ha−1), and with the heirloom variety Tilkidhan, yield was 41% higher (6.29 vs 4.45 mt ha−1). Economic analysis indicated that expanding the organic cultivation of local landraces under SRI management should be profitable for farmers where such rice has a good market price due to its premium quality and high demand and when SRI enhances yield. These varieties’ present low yields can be significantly increased by integratingTrichodermabio-inoculation with SRI cultural methods. Other recent research has shown that such inoculation can be managed profitably by farmers themselves.


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