Search results

Search:
in the keywords: Rice

Sort By:

Limit search:

Rice Blast Biology and Reaction of Host to the Disease

100%

Zewdu Z.

vol. 39

11-21

Rice blast (Magnaporthe grisea) is first reported in China and then in Africa in1922. The disease is now the most widespread and devastating rice disease in all rice producing areas of the world. The disease can cause from mild yield reduction to total crop loss as depends on the variety and severity level. The rice blast isolate is closely related to the isolate of other blast like fungus and distinctly described as Magnaporthe grisea. Rice blast fungus starts the infection cycle after a three-celled conidium lands on the rice leaf surface. Thousands of spores can be produced from a single lesion within 15 days after infection. Symptoms on leaves start as small brown necrotic lesions that evolve to larger elliptical or spindle-shaped lesions, colored whitish to gray with darker borders while infected seeds display brown spots, which may result from the infection of the florets as they matured into seeds. The rice blast needs at least a 12-hour period of moderate temperatures (25 to 30 °C), high relative humidity (90-92 %), and high moisture which are conducive for its development. The disease can be managed by using resistant varieties, using integrated disease management options and nutrient managements like application of recommended nitrogen fertilizers and application of silicon fertilizers. The rice plant responds differently for reducing the occurrence and damage of the disease either fungus is incapable causing sporulating lesions on the plant or the plant develop residual resistance that remains when complete resistance has been overcome by the pathogen.

A study on the toxicity of aluminum in rice, Oryza sativa L.

86%

Muthukumaran M.

World News of Natural Sciences

2022

vol. 40

13-25

Aluminum trivalent (Al3+), which commonly occurs on 40% of arable land, is highly phytotoxic to crop growth and yield in acidic soils. As one of the major pollutants in the atmosphere, this element reduces chlorophyll activity, CO2 assimilation, and photosynthesis. Rice is a staple food crop in India and Asian countries. A widely recognized metal toxicity of rice (Oryza sativa) includes soluble aluminum. The processes of senescence are known to be characterized by loss of chlorophyll, lipids, total protein, photosynthetic activity, and RNA. The author illustrates the aluminum effect in rice plants (ADT 43 & PA 6129) under different aluminum exposure levels (100 µM, 200 µM, & 300 µM), in regard to photosynthetic activity (total chlorophyll degradation, depleted CO2 fixation, inhibited stomatal conductance) bioaccumulation, and histological analysis during leaf senescence. Rice varieties PA 6129 and ADT 43 were compared to assess photosynthetic degradation, bioaccumulation, and histological changes associated with aluminum-mediated degradation. Consequently, accelerated leaf senescence was observed after prolonged exposure to variety PA 6129 with increasing aluminum concentration. As an alternative, there is ADT 43, a precision aluminum tolerance mechanism.

Refine search results

2 World News of Natural Sciences

1 2022

1 2021

1 Muthukumaran M.

1 Zewdu Z.

Search results

Rice Blast Biology and Reaction of Host to the Disease

A study on the toxicity of aluminum in rice, Oryza sativa L.