Temporal changes in race frequency of <i>Pyricularia oryzae</i> on leaves during multiline cultivation of rice cultivar Koshihikari with its isogenic lines agree with a simulation model

Leaf sheaths of susceptible and resistant (Pi-zt) near-isogenic lines of rice were inoculated with Pyricularia oryzae (Magnaporthe grisea) and the host – parasite interactions in living tissues were continuously observed using fluorescence and bright field microscopy. Growth of invading hyphae in the resistant line was restricted within cells that underwent hypersensitive death during fungal penetration. Experiments using heat shock and NaAsO2 treatments suggested that cell death alone is not responsible for restriction of hyphal growth within the penetrated cell. Fungal hyphae grew unimpeded in dead cells of treated tissue unless the dead cells had also developed the capacity to autofluoresce under blue light. Electron microscopic studies showed that hypersensitive cell death occurred specifically in the resistant line after penetration of the cuticle, and in some cases it occurred before cell walls were completely penetrated. In the susceptible line, wall appositions were induced in the epidermal cells at a similar stage of fungal penetration (i.e., before infection hyphae had reached the cell lumen). Inward indentation of the cuticle and cell wall and inward folding of the cuticle at the penetration site suggested that the cuticle was breached mechanically. Wall penetration appeared to be facilitated by enzyme action because the microfibrils of host cell walls around infection pegs were disorganized and nonhomogeneous in electron density. Key words: resistance, penetration, ultrastructure, autofluorescence, rice blast, Pyricularia oryzae (Magnaporthe grisea).

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Genetic Performance of the Semidwarfing Allele sd1 Derived from a Japonica Rice Cultivar and Minimum Requirements to Detect Its Single-Nucleotide Polymorphism by MiSeq Whole-Genome Sequencing

BioMed Research International ◽

10.1155/2018/4241725 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Motonori Tomita ◽

Kazuo Ishii

Keyword(s):

Reference Genome ◽

Green Revolution ◽

Rice Cultivar ◽

Chromosome 1 ◽

Japonica Rice ◽

Loss Of Function ◽

Nucleotide Polymorphism ◽

Single Nucleotide ◽

Isogenic Lines ◽

Minimum Requirements

The influence of the semidwarfing gene sd1 derived from the rice cultivar Jukkoku (Jukkoku_sd1) and IR8 (IR8_sd1), which contributed to the Green Revolution, d60 from Hokuriku 100, as well as the combination of sd1 and d60 (Jukkoku_sd1 plus d60 and IR8_sd1 plus d60), was investigated using isogenic lines raised by backcrossing with the cultivar Koshihikari. The isogenic lines carrying Jukkoku_sd1, IR8_sd1, d60, Jukkoku_sd1 plus d60, and IR8_sd1 plus d60 had considerably shorter culm lengths than Koshihikari by 19.2%, 22.8%, 26.0%, 45.1%, and 43.4%, respectively. The sd1 plus d60 lines showed additively reduced culms, indicating that the function of d60 was different from sd1. In contrast to the culm reduction, Jukkoku_sd1 showed productive merit with a panicle length of 2.5% greater than the origin. MiSeq next-generation sequencer was used to optimize a minimum scale to detect Jukkoku_sd1 in practical breeding. Mapping with the reference genome of Nipponbare gained the average depths of Koshihikari Jukkoku_sd1 and Koshihikari being 9.17 and 7.29, respectively. Comparing the vcf files of the entire genomes of Koshihikari Jukkoku_sd1 and the virtual Koshihikari revealed a G to T SNP at position 38,382,746 in the sd1 locus on chromosome 1 of Koshihikari, causing a loss-of-function mutation of GA20-oxidase.

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Developing Isogenic Lines of Japanese Rice Cultivar 'Koshihikari' with Early and Late Heading

Japan Agricultural Research Quarterly JARQ ◽

10.6090/jarq.45.15 ◽

2011 ◽

Vol 45 (1) ◽

pp. 15-22 ◽

Cited By ~ 7

Author(s):

Yoshinobu TAKEUCHI

Keyword(s):

Rice Cultivar ◽

Isogenic Lines

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Effect of a Multiline of Rice Cultivar Sasanishiki and Its Isogenic Lines on Suppressing Rice Blast Disease.

Japanese Journal of Phytopathology ◽

10.3186/jjphytopath.62.227 ◽

1996 ◽

Vol 62 (3) ◽

pp. 227-233 ◽

Cited By ~ 12

Author(s):

Toshihiko NAKAJIMA ◽

Ryoichi SONODA ◽

Hiroshi YAEGASHI

Keyword(s):

Rice Blast ◽

Rice Cultivar ◽

Rice Blast Disease ◽

Blast Disease ◽

Isogenic Lines

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A Numerical Fire Simulation-Model

International Journal of Wildland Fire ◽

10.1071/wf9930111 ◽

1993 ◽

Vol 3 (2) ◽

pp. 111 ◽

Cited By ~ 13

Author(s):

G Wallace

Keyword(s):

Simulation Model ◽

Fire Management ◽

Temporal Changes ◽

Visual Simulation ◽

Numerical Implementation ◽

Fire Simulation ◽

Considerable Potential ◽

Ellipse Model

An extension of the simple ellipse model of a vegetation fire is presented. This facilitates numerical implementation, and can therefore incorporate irregular topographical features and temporal changes in burning conditions. The model has been encoded into an interactive PC program which gives a visual simulation of the spread of a fire on a graphics screen. The model has considerable potential for fire management.

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