Abiotic stress is the negative impact of non-living factors on the living organisms in a specific environment. The non-living variable must influence the environment beyond its normal range of variation to adversely affect the population performance or individual physiology of the organism in a significant way.
Rice is a cereal grain and in its domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species Oryza sativa —or, much less commonly, Oryza glaberrima. Asian rice was domesticated in China some 13,500 to 8,200 years ago; African rice was domesticated in Africa about 3,000 years ago. Rice has become commonplace in many cultures worldwide; in 2021, 787 million tons were produced, placing it fourth after sugarcane, maize, and wheat. Only some 8% of rice is traded internationally. China, India, and Indonesia are the largest consumers of rice. A substantial amount of the rice produced in developing nations is lost after harvest through factors such as poor transport and storage. Rice yields can be reduced by pests including insects, rodents, and birds, as well as by weeds, and by diseases such as rice blast. Traditional rice polycultures such as rice-duck farming, and modern integrated pest management seek to control damage from pests in a sustainable way.
Oryza is a genus of plants in the grass family. It includes the major food crop rice. Members of the genus grow as tall, wetland grasses, growing to 1–2 metres (3–7 ft) tall; the genus includes both annual and perennial species.
Ribulose-1,5-bisphosphate carboxylase/oxygenase, commonly known by the abbreviations RuBisCo, rubisco, RuBPCase, or RuBPco, is an enzyme involved in the light-independent part of photosynthesis, including the carbon fixation by which atmospheric carbon dioxide is converted by plants and other photosynthetic organisms to energy-rich molecules such as glucose. It emerged approximately four billion years ago in primordial metabolism prior to the presence of oxygen on Earth. It is probably the most abundant enzyme on Earth. In chemical terms, it catalyzes the carboxylation of ribulose-1,5-bisphosphate.
Oryza sativa, having the common name Asian cultivated rice, is the much more common of the two rice species cultivated as a cereal, the other species being O. glaberrima, African rice. It was first domesticated in the Yangtze River basin in China 13,500 to 8,200 years ago.
Xanthomonas oryzae is a species of bacteria. The major host of the bacterium is rice.
Oryza rufipogon is a species of flowering plant in the family Poaceae. It is known as brownbeard rice, wild rice, and red rice. In 1965, Oryza nivara was separated off from O. rufipogon. The separation has been questioned, and some sources consider O. nivara to be a synonym of O. rufipogon. O. nivara may be treated as the annual form of O. rufipogon.
Oryza longistaminata is a perennial species of grass from the same genus as cultivated rice. It is native to most of sub-Saharan Africa and Madagascar. It has been introduced into the United States, where it is often regarded as a noxious weed. Its common names are longstamen rice and red rice.
Aromatic rice is one of the major types of rice. It is a medium- to long-grained rice. It is known for its nutty aroma and taste, which is caused by the chemical compound 2-acetyl-1-pyrroline. Varieties of aromatic rice include Ambemohar, Basmati, Jasmine, Sona Masuri, Texmati, Tulaipanji, Tulshimala, Wehani, Kalijira, Chinigura, Gobindobhog, Kali Mooch and wild Pecan rice. When cooked, the grains have a light and fluffy texture except for Gobindobhog rice which is sticky in texture.
A crop wild relative (CWR) is a wild plant closely related to a domesticated plant. It may be a wild ancestor of the domesticated (cultivated) plant or another closely related taxon.
Oryza glaberrima, commonly known as African rice, is one of the two domesticated rice species. It was first domesticated and grown in West Africa around 3,000 years ago. In agriculture, it has largely been replaced by higher-yielding Asian rice, and the number of varieties grown is declining. It still persists, making up an estimated 20% of rice grown in West Africa. It is now rarely sold in West African markets, having been replaced by Asian strains.
Oryza nivara is a possible wild progenitor of the cultivated rice Oryza sativa. It was separated from Oryza rufipogon in 1965; however, the separation has been questioned, and some sources treat it as a synonym of O. rufipogon. It may be treated as the annual form of O. rufipogon.
Oryza brachyantha is a grass in the rice genus Oryza, distantly related to cultivated rice O. sativa, and native to tropical Africa. It is an annual grass that grows as a tuft.
Orseolia oryzae, also called the Asian rice gall midge, is a species of small fly in the family Cecidomyiidae. It is a major insect pest of rice. The damage to the crop is done by the larvae which form galls commonly known as "silver shoots" or "onion shoots". The rice plant is stunted and the seed heads fail to develop.
Oryza is a genus in the plant family Poaceae, of which Oryza sativa is a member. Oryza is a genus of 24 species, most of which are annual and some perennial grasses, which are found in tropical and swampy parts of Africa, Asia and Australia. Given its wide geographic range, there exists a substantial diversity of specialized metabolites in the genus Oryza. Understanding this diversity can provide us solutions for mitigate crop losses due to disease and pest damage in rice, and boost agricultural production.
Oryza officinalis is species of flowering plant in the genus Oryza (rice) native to India, Nepal, the eastern Himalaya, southeast Asia, south-central and southeast China, Hainan, the Philippines, New Guinea, and the Northern Territory and Queensland in Australia. A perennial diploid with the CC rice genome, it can reach 3 m (10 ft) in height. It is the namesake of a widespread species complex.
The agricultural weed syndrome is the set of common traits which make a plant a successful agricultural weed. Most of these traits are not, themselves, phenotypes but are instead methods of rapid adaptation. So equipped, plants of various origins - invasives, natives, mildly successful marginal weeds of agriculture, weeds of other settings - accumulate other characteristics which allow them to compete in an environment with a high degree of human management.
Oryza eichingeri is a species of wild rice in the family Poaceae, with a disjunct distribution in Ivory Coast, Republic of the Congo, Democratic Republic of the Congo, Uganda, Kenya, Tanzania, and Sri Lanka. It is being studied as a source of genes for resistance to the brown planthopper, an important pest of cultivated rice.
In biology, parallel speciation is a type of speciation where there is repeated evolution of reproductively isolating traits via the same mechanisms occurring between separate yet closely related species inhabiting different environments. This leads to a circumstance where independently evolved lineages have developed reproductive isolation from their ancestral lineage, but not from other independent lineages that inhabit similar environments. In order for parallel speciation to be confirmed, there is a set of three requirements that has been established that must be met: there must be phylogenetic independence between the separate populations inhabiting similar environments to ensure that the traits responsible for reproductive isolation evolved separately, there must be reproductive isolation not only between the ancestral population and the descendent population, but also between descendent populations that inhabit dissimilar environments, and descendent populations that inhabit similar environments must not be reproductively isolated from one another. To determine if natural selection specifically is the cause of parallel speciation, a fourth requirement has been established that includes identifying and testing an adaptive mechanism, which eliminates the possibility of a genetic factor such as polyploidy being the responsible agent.
Barley is known to be more environmentally-tolerant than other cereal crops, in terms of soil pH, mineral nutrient availability, and water availability. Because of this, much research is being done on barley plants in order to determine whether or not there is a genetic basis for this environmental hardiness.
