What is rice, and what is its significance as a global food source?

Rice is a cereal grain, specifically the seed of the grass species *Oryza sativa* (Asian rice) or, less commonly, *Oryza glaberrima* (African rice). It serves as the staple food for over half of the world's population, particularly in Asia and Africa, highlighting its critical role in global food security.

When and where were the two main species of domesticated rice first cultivated?

Asian rice (*Oryza sativa*) was first domesticated in China approximately 13,500 to 8,200 years ago. African rice (*Oryza glaberrima*) was domesticated independently in Africa about 3,000 years ago.

What was the global production of rice in 2023, and how does it rank among other crops?

In 2023, the world produced 800 million tons of rice, making it the third-largest crop by production volume, following sugarcane and maize.

What percentage of global rice production is traded internationally, and which countries are the largest consumers?

Only about 8% of rice produced globally is traded internationally. The largest consumers of rice are China, India, and Indonesia.

What factors contribute to post-harvest losses of rice in developing nations?

A substantial amount of rice produced in developing nations is lost after harvest due to factors such as poor transport and inadequate storage facilities. For instance, Nigeria loses a quarter of its rice crop post-harvest.

What are some common pests and diseases that can reduce rice yields?

Rice yields can be reduced by various pests, including insects, rodents, and birds, as well as by weeds. Diseases such as rice blast also pose a significant threat to the crop.

How do traditional and modern methods address pest control in rice farming?

Traditional methods like rice polycultures, such as rice-duck farming, and modern integrated pest management (IPM) strategies are employed to control damage from pests in a sustainable manner.

Describe the milling process for dry rice grain and the resulting products.

Dry rice grain is milled to remove its outer layers, specifically the husk and bran. Depending on the extent of removal, products can range from brown rice (only husk removed) to rice with germ, and finally, white rice (bran and germ removed).

What is parboiled rice, and what is its advantage?

Parboiled rice undergoes a steaming process before milling, which makes the grain harder and transfers some of its vitamins and minerals into the white part of the rice, ensuring these nutrients are retained after milling.

What are the nutritional characteristics of rice, particularly regarding gluten and protein?

Rice contains no gluten, making it suitable for gluten-free diets. While it provides protein, it is not considered a complete protein because it lacks all the essential amino acids required for good health in sufficient amounts.

How do the starch components of rice influence its texture after cooking?

The composition of starch components, specifically amylose and amylopectin, within the rice grain determines its different texture properties when cooked. For example, long-grain rice with higher amylose tends to be dry and fluffy.

What are the general classifications of rice based on grain length, and what are their typical culinary uses?

Rice varieties are typically classified as short-, medium-, and long-grained. Long-grain rice, like Basmati and Jasmine, tends to stay intact and is dry and fluffy. Medium-grain rice is moist and tender, often used in dishes like risotto. Short-grain rice has an oval shape and sticky texture, making it ideal for sushi and sweet dishes like mochi.

What is the typical height of a rice plant and its growth duration from seed to harvest?

A rice plant can grow to over 1 meter (3 feet) tall, and in deep water, it can reach a length of 5 meters (16 feet). The entire growth cycle from seed to harvest takes approximately six months.

How do rice plants reproduce, and what part develops into the edible grain?

Rice plants produce self-fertile flowers in a branched inflorescence called a panicle. Each panicle can contain up to 350 spikelets, each with male and female flower parts. A fertilized ovule then develops into the edible grain, known as a caryopsis.

What are the primary biotic and abiotic environmental factors influencing rice growth?

The principal biotic factors affecting rice growth are the crop variety itself, pests, and plant diseases. Abiotic factors include soil type (lowland or upland), the amount of rain or irrigation water, temperature, day length, and sunlight intensity.

Compare the direct seeding and transplanting methods for planting rice in terms of seed quantity and labor.

Direct seeding requires a higher quantity of grain, about 60 to 80 kg per hectare, while transplanting needs less seed, around 40 kg per hectare. However, transplanting, especially by hand, demands significantly more labor.

Describe different water management techniques used in rice cultivation.

Lowland fields are typically flooded to a depth of a few centimeters until about a week before harvest, requiring substantial water. The 'alternate wetting and drying' technique uses less water by flooding to 5 cm and then allowing the level to drop to 15 cm below the surface before re-flooding. Deepwater rice varieties are adapted to tolerate flooding exceeding 50 cm for at least a month, while upland rice is grown without flooding in hilly regions, relying on rainfall.

What is 'paddy' in the context of rice harvesting, and how has harvesting evolved?

'Paddy' refers to unmilled rice. Traditionally, it was harvested manually by smallholders across Asia. Larger farms now utilize machines like combine harvesters to reduce labor input.

What steps are involved in harvesting rice, and why is drying crucial?

Harvesting involves reaping the stalks, stacking them, threshing to separate the grain, and cleaning through winnowing or screening. Drying the rice grain as soon as possible is crucial to reduce its moisture content to 20–25%, preventing damage from mould fungi.

What genetic evidence supports a single domestication event for Asian rice (*Oryza sativa*)?

The functional allele for nonshattering, a key indicator of domestication in grains, along with five other single-nucleotide polymorphisms, is identical in both *indica* and *japonica* cultivars. This suggests that *Oryza sativa* originated from a single domestication event in China from the wild rice *Oryza rufipogon*.

How did Asian rice spread to different parts of the world after its initial domestication?

After its domestication in China, Asian rice was introduced to Sino-Tibetan cultures in northern China around 6000-5600 years ago, and to the Korean peninsula and Japan around 5500-3200 years ago. It also spread to Taiwan via the Dapenkeng culture, and then southwards through Austronesian migrations to Island Southeast Asia, Madagascar, and Guam, eventually reaching the Americas as part of the Columbian exchange after 1492.

What was the economic importance of rice in British North America before the American War of Independence?

In British North America, rice had become the fourth most valuable export commodity by the start of the American War of Independence, surpassed only by tobacco, wheat, and fish.

Which countries were the largest producers of rice in 2023, and what region accounts for most of the world's production?

In 2023, India and China were the largest producers, each contributing 207 million tonnes, accounting for a combined 52% of the total. Overall, 90% of the world's rice production comes from Asia.

Who holds the world record for rice yield, and what methods were used to achieve it?

Yuan Longping of China's National Hybrid Rice Research and Development Center set a world record for rice yield in 1999, achieving 17.1 metric tons per hectare. This was accomplished using specially developed hybrid rice and the System of Rice Intensification (SRI).

How has global per capita rice consumption changed in the 21st century, and where is an exception to this trend?

Globally, per capita rice consumption has decreased in the 21st century as people in Asia and other regions consume less grain and more meat. However, Sub-Saharan Africa is an exception, experiencing an increase in both per capita rice consumption and population.

What are the main components of cooked white rice in terms of macronutrients and energy content?

Cooked white rice consists of 69% water, 29% carbohydrates, and 2% protein, with negligible fat. A 100-gram serving provides 130 calories of food energy.

Which micronutrient is present in moderate levels in cooked white rice, and what fortification recommendations has the WHO made?

Cooked white rice contains moderate levels of manganese (18% Daily Value). In 2018, the World Health Organization strongly recommended fortifying rice with iron and conditionally recommended fortification with vitamin A and folic acid to address nutritional deficiencies.

What is Golden rice, and what is its intended purpose?

Golden rice is a genetically engineered variety designed to synthesize beta-carotene, a precursor of vitamin A, in its endosperm. Its purpose is to be grown and consumed in regions where Vitamin A deficiency is prevalent, aiming to improve public health.

What is the estimated contribution of rice production to global greenhouse gas emissions?

In 2022, greenhouse gas emissions from rice cultivation were estimated at 5.7 billion tonnes of CO2 equivalent, representing 1.2% of total global emissions. Within the agriculture sector, rice paddies account for approximately 48% of cropland greenhouse gas emissions.

Why do rice fields release methane, and what methods can reduce these emissions?

Methane is released from rice fields that are subject to long-term flooding because the waterlogged soil inhibits atmospheric oxygen absorption, leading to anaerobic fermentation of organic matter by methanogenic bacteria. Emissions can be reduced by planting new varieties, avoiding continuous flooding, removing straw, and implementing alternate wetting and drying techniques, which can cut methane emissions by up to 90%.

How is climate change projected to affect global rice yields?

Predictions vary, but one study projects a decrease in global rice yield by about 3.2% for every 1°C increase in global average temperature. Another study suggests an initial increase in global rice cultivation, plateauing at around 3°C warming.

What specific impacts of rising temperatures have been observed on rice yields in Asia?

Rising temperatures and decreasing solar radiation during the late 20th century led to a 10-20% decrease in rice yield across 200 farms in seven Asian countries, possibly due to increased night-time respiration. The International Rice Research Institute (IRRI) predicts Asian rice yields could fall by 20% for every 1°C rise in global mean temperature, and rice flowers cannot yield grain if exposed to 35°C or more for over an hour.

What are the two most serious diseases affecting rice worldwide?

Rice blast, caused by the fungus *Magnaporthe grisea*, and bacterial leaf streak, caused by *Xanthomonas oryzae* pv. *oryzae*, are perennially the two most serious diseases affecting rice worldwide.

How do rice plants naturally defend against pathogens, and how can pathogens overcome this defense?

Rice plants defend against pathogens by producing reactive oxygen species molecules at the entry site, triggered by pathogen-associated molecular patterns (PAMPs) that initiate innate immune responses. However, pathogens like *Magnaporthe oryzae* use effectors such as AVR-Pii to inhibit the rice plant's NADP-malic enzyme, thereby suppressing the production of reactive oxygen species and compromising the plant's immunity.

What are the four principles of sustainable pest management in rice cultivation?

Sustainable pest management in rice is based on four principles: promoting biodiversity, developing host plant resistance, understanding landscape ecology, and recognizing hierarchies in a landscape from biological to social factors.

Why are unnecessary pesticide applications often counterproductive in rice pest management?

Unnecessary pesticide applications can be counterproductive because they may induce a resurgence of rice pest populations, such as the brown planthopper, by destroying beneficial insects and enhancing the pest's reproduction.

What traditional polycultural practices are used by farmers to manage weeds and pests in rice paddies?

Farmers in China, Indonesia, and the Philippines traditionally manage weeds and pests by raising ducks and sometimes fish in their rice paddies. These animals provide additional crops, consume small pest animals, fertilize the rice, and ducks also help control weeds.

How can plant breeders enhance rice resistance to insect pests?

Plant breeders are working to create rice cultivars with resistance to various insect pests. This involves seeking resistance genes from wild rice species and applying genetic engineering techniques, despite challenges like rearing pests for testing and the continuous evolution of pests.

What is the role of the International Rice Research Institute (IRRI) in conserving rice varieties?

The International Rice Research Institute (IRRI) maintains the International Rice Genebank, which houses over 100,000 rice varieties, playing a crucial role in conserving rice genetic resources.

What is NERICA rice, and what is its significance for Africa?

NERICA, or 'New Rice for Africa,' refers to high-yield cultivars of rice specifically developed for cultivation in Africa. These varieties aim to improve food security and alleviate poverty in Sub-Saharan Africa.

How are rice cultivars grouped based on environmental conditions and planting seasons?

Rice cultivars are grouped into ecotypes based on environmental conditions, season of planting, and season of harvest. Examples include Japan-type, 'bulu' and 'tjereh' types in Indonesia, and 'aman' (winter), 'aus' (summer), and 'boro' (spring) in Bengal and Assam.

When was the complete genome of rice first sequenced, and what has been the subsequent progress in rice genomics?

The complete genome of rice was first sequenced in 2005, making it the first crop plant to achieve this status. Since then, the genomes of hundreds of wild and cultivated rice types, including both Asian and African species, have been sequenced.

What was the purpose of the Green Revolution in relation to rice, and what was the first high-yielding variety?

The Green Revolution aimed to radically increase global food production. The first high-yielding rice variety developed during this period was IR8, created in 1966 at the International Rice Research Institute by crossing Indonesian 'Peta' and Chinese 'Dee Geo Woo Gen' varieties.

How were Green Revolution rice varieties designed to be more productive?

Green Revolution rice varieties were specifically bred to have short, strong stems. This characteristic allowed them to remain upright and productive even when heavy applications of fertilizer were used, preventing lodging or falling over.

What human proteins has Ventria Bioscience genetically modified rice to express, and what are their potential benefits?

Ventria Bioscience has genetically modified rice to express lactoferrin, lysozyme (proteins typically found in breast milk), and human serum albumin. These proteins have antiviral, antibacterial, and antifungal effects, and rice containing them can be used in oral rehydration solutions to treat diarrheal diseases and help reverse anemia.

What is 'deepwater rice,' and why is flood tolerance important for rice cultivation?

'Deepwater rice' refers to flood-tolerant varieties that farmers plant in areas prone to flooding, which affects millions of hectares annually in South and Southeast Asia. Flood tolerance is crucial because standard rice varieties cannot survive stagnant flooding for more than about a week, leading to massive yield losses.

How does the Swarna Sub1 cultivar and 'scuba rice' improve flood tolerance?

The Swarna Sub1 cultivar can tolerate week-long submergence by efficiently consuming carbohydrates and continuing to grow. 'Scuba rice,' which incorporates the Sub1A transgene, offers even greater flood survival, robustly tolerating submergence for up to two weeks.

What is the significance of drought for rice production, and what research is being done to address it?

Drought is a major environmental stress, putting millions of hectares of rainfed rice production in South and Southeast Asia at risk. The International Rice Research Institute (IRRI) is developing drought-tolerant varieties like Sahbhagi Dhan, Sahod Ulan, and Sookha dhan. Additionally, research has successfully inserted the *DRO1* gene into commercial varieties, creating deeper root systems that improve nutrient access and reduce yield drops under moderate drought conditions.

Why is soil salinity a threat to rice crops, and how are scientists developing salt-tolerant varieties?

Soil salinity severely threatens rice crop productivity, especially in low-lying coastal areas, by affecting plant physiology during early growth stages. Scientists are developing salt-tolerant varieties, such as a hybrid created from IR56 and the wild species *Oryza coarctata*, which uses specialized leaf glands to remove salt and was developed through extensive cross-breeding and backcrossing.

How does cold temperature affect rice plants, and what is the outlook for cold-tolerant rice cultivation?

Rice is sensitive to temperatures below 12°C; sustained cold reduces growth, harms germination and seedling development, and encourages rice blast in larger plants, severely reducing yield. Researchers are studying chilling tolerance mechanisms, and cold-tolerant varieties have been successfully trialed in England, suggesting that with global warming, rice could be grown more widely in such regions.

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Rice: A Global Overview

The Essential Cereal Grain

Rice, a fundamental cereal grain, serves as the staple food for over half of the world's population, particularly across Asia and Africa. It is derived from the seeds of two primary grass species: Oryza sativa (Asian rice) and, less commonly, Oryza glaberrima (African rice).

Global Production and Consumption

In 2023, global rice production reached an impressive 800 million tonnes, positioning it as the third-largest crop after sugarcane and maize. Despite this vast production, only about 8% of rice is traded internationally. China, India, and Indonesia stand as the largest consumers, highlighting its regional importance.

Domestication and Spread

Asian rice (*Oryza sativa*) was first domesticated in China between 13,500 and 8,200 years ago. African rice (*Oryza glaberrima*) followed, domesticated in Africa approximately 3,000 years ago. This ancient grain has since integrated deeply into numerous cultures worldwide, becoming a cornerstone of diets and traditions.

Botanical Characteristics

Plant Morphology

The rice plant can attain a height exceeding 1 meter (3 feet), and in deep-water conditions, some varieties can stretch up to 5 meters (16 feet). Its growth cycle from seed to harvest typically spans about six months. A single plant develops multiple leafy stems, known as tillers, each with jointed upright stems and slender leaves emerging from nodes along their length.

Reproductive Biology

Rice flowers are self-fertile and are organized into a branched inflorescence called a panicle, which originates from the stem's uppermost internode. A single panicle can bear up to 350 spikelets, each containing both male (anthers) and female (ovule) reproductive parts. Upon fertilization, the ovule matures into the edible grain, or caryopsis.

Growth Cycle and Adaptations

As a tropical crop belonging to the Poaceae family, rice can be cultivated during both dry and wet seasons, provided adequate water is available. While typically an annual plant, in tropical climates, it can persist as a perennial, yielding subsequent ratoon crops from the same root system.

Agronomic Practices

Cultivation Methods

Rice cultivation is influenced by both biotic factors (crop variety, pests, diseases) and abiotic factors (soil type, water availability, temperature, day length, sunlight). Farmers employ two primary planting methods: direct seeding, which requires 60-80 kg of grain per hectare, and transplanting, which uses less seed (around 40 kg/hectare) but is more labor-intensive, often done by hand in Asia or mechanically with specialized seedlings.

Water Management

Traditional lowland rice fields are typically flooded to a depth of a few centimeters until shortly before harvest, demanding substantial water resources. However, techniques like "alternate wetting and drying" (AWD) significantly reduce water usage by allowing water levels to drop below the surface before re-flooding. Deepwater rice varieties are adapted to tolerate prolonged flooding exceeding 50 centimeters, while upland rice is grown without flooding in hilly, rainfed regions.

Harvesting and Drying

Rice, or "paddy," is ready for harvest when its moisture content is between 20-25%. Harvesting traditionally involves manual reaping, stacking, threshing to separate grains, and cleaning through winnowing or screening. Large farms increasingly utilize combine harvesters for efficiency. Post-harvest, rapid drying is crucial to reduce moisture content and prevent mold, often achieved by spreading grains under the sun or using mechanical dryers.

Evolutionary Journey

Phylogenetic Context

Edible rice species belong to the BOP clade within the Poaceae (grass) family. The rice subfamily, Oryzoideae, is closely related to bamboos (Bambusoideae) and other cereals (Pooideae). The genus *Oryza* comprises about 300 species or subspecies, including the two domesticated forms: *O. sativa* and *O. glaberrima*.

Domestication of Oryza sativa

Oryza sativa was first domesticated in Neolithic China approximately 9,000 years ago. Genetic evidence, particularly the identical functional allele for nonshattering (a key domestication trait) and other single-nucleotide polymorphisms in both *indica* and *japonica* cultivars, suggests a single domestication event from the wild rice *Oryza rufipogon*. While *japonica* originated in China, *indica* likely arose when *japonica* hybridized with another rice species in India around 4,500 years ago.

Global Dispersal

From its origins, rice spread across Asia: to Sino-Tibetan cultures in northern China (6,000-5,600 years ago), and to the Korean peninsula and Japan (5,500-3,200 years ago). Austronesian migrations carried it to Taiwan (5,500-4,000 years ago) and further south to Island Southeast Asia, Madagascar, and Guam. It reached Mainland Southeast Asia and southern China's Austroasiatic and Kra-Dai speakers by 5,000 years ago. Later, as part of the Columbian exchange, rice arrived in the Americas after 1492. *Oryza glaberrima* was independently domesticated in Africa around 3,000 years ago and also introduced to the Americas by the Spanish.

Commerce & Economics

Production Landscape

In 2023, global rice production reached 800 million tonnes, with China and India collectively contributing 52% of this total. Other significant producers include Bangladesh, Indonesia, and Vietnam. Asia alone accounts for approximately 90% of worldwide rice production, underscoring its critical role in regional economies and food systems.

International Trade Dynamics

Despite massive production, less than 8% of rice is traded internationally, indicating that most rice is consumed within its producing regions. Developing countries are key players in this trade; by 2012, India emerged as the largest exporter, followed by Thailand and Vietnam. Notably, China, once an exporter, became the world's largest importer by 2013.

Food Security Challenges

Rice is a vital food staple for over half the global population, particularly in Asia, Latin America, and parts of Africa. However, significant post-harvest losses occur due to inefficient transportation, storage, and milling. For instance, Nigeria can lose a quarter of its crop after harvest. Proper drying is essential to prevent mold, as evidenced by China's low 0.2% loss in modern silos compared to 7-13% in rural household storage.

Yield Achievements

The average world rice yield in 2022 was 4.7 metric tons per hectare. Remarkable achievements in yield have been recorded, such as Yuan Longping's world record of 17.1 metric tons per hectare in 1999. This was accomplished using specially developed hybrid rice and the System of Rice Intensification (SRI), an innovative farming methodology.

Food & Nutrition

Culinary Diversity

Rice is a globally consumed food, with varieties broadly categorized by grain length: short-, medium-, and long-grained. *Oryza sativa indica* typically yields long grains, while *Oryza sativa japonica* produces short- or medium-grains. Examples include aromatic Jasmine and Basmati rice, sticky Japanese sushi rice, and medium-grain Italian Arborio rice used for risotto. The starch composition, specifically amylose and amylopectin, dictates its texture upon cooking, from dry and fluffy to moist and sticky.

Nutritional Profile

Cooked white rice consists of 69% water, 29% carbohydrates, and 2% protein, with minimal fat. A 100-gram serving provides 130 calories and a moderate amount of manganese (18% Daily Value), but other micronutrients are present in smaller quantities. The World Health Organization recommends fortifying rice with iron, and conditionally with vitamin A and folic acid, to address prevalent deficiencies. Rice is naturally gluten-free, making it suitable for individuals with gluten sensitivities.

Specialized Varieties

While rice is a good protein source, it is not a complete protein, lacking some essential amino acids. To address nutritional gaps, "Golden Rice" has been genetically engineered to synthesize beta-carotene, a precursor to vitamin A, in its endosperm. This innovation aims to combat Vitamin A deficiency in vulnerable populations, though it has faced opposition from anti-GMO activists. Over 100 Nobel laureates have advocated for the use of genetically modified organisms like Golden Rice for their potential benefits.

Rice & Climate Change

Greenhouse Gas Emissions

Rice cultivation significantly contributes to global greenhouse gas emissions. In 2022, emissions were estimated at 5.7 billion tonnes CO2 equivalent, accounting for 1.2% of total global emissions. Within the agricultural sector, rice paddies contribute nearly half of cropland emissions, approximately 30% of agricultural methane, and 11% of agricultural nitrous oxide. Methane is primarily released from continuously flooded rice fields where anaerobic fermentation of organic matter occurs in the soil.

Impact on Yields

The effects of climate change on rice yields are complex and vary geographically. Some projections indicate a decrease of about 3.2% in global rice yield for every 1°C rise in average temperature. Increased night-time respiration due to rising temperatures has already been linked to 10-20% yield reductions in Asian farms. Furthermore, rice flowers are highly sensitive to heat, with sustained temperatures of 35°C or more for over an hour leading to complete crop loss.

Drought Vulnerability

Drought poses a substantial threat to rice production, particularly in rainfed areas of South and Southeast Asia, affecting 19-23 million hectares annually. Conventional rice varieties struggle under drought conditions, as insufficient water hinders nutrient uptake from the soil. The Po Valley in Italy, for instance, has experienced poor risotto rice harvests due to 21st-century droughts, prompting the development of drought-resistant varieties with deeper root systems.

Pests, Weeds, & Diseases

Major Pests and Weeds

Rice yields can be significantly diminished by weed competition and a diverse array of pests, including insects (e.g., armyworms, rice bugs, leafhoppers), nematodes, rodents (e.g., rats), snails, and birds. High applications of nitrogen fertilizer can exacerbate aphid outbreaks, while specific weather conditions, such as high rainfall or drought, can worsen infestations of pests like rice gall midge and thrips, respectively.

Prevalent Diseases

Rice blast, caused by the fungus *Magnaporthe grisea*, is globally the most severe disease affecting rice. Alongside bacterial leaf streak (*Xanthomonas oryzae pv. oryzae*), these are consistently ranked among the top ten most impactful diseases across all crop plants. Other significant diseases include sheath blight (*Rhizoctonia solani*), false smut (*Ustilaginoidea virens*), bacterial panicle blight (*Burkholderia glumae*), and various viral diseases like rice tungro and rice yellow mottle.

Integrated Pest Management

Crop protection scientists are actively developing sustainable pest management strategies based on biodiversity, host plant resistance, and landscape ecology. Unnecessary pesticide applications are often counterproductive, sometimes leading to pest resurgence by eliminating beneficial insects or enhancing pest reproduction. The International Rice Research Institute (IRRI) has demonstrated that significant reductions in pesticide use can lead to an overall decrease in pest populations. Traditional polycultural practices, such as raising ducks and fish in rice paddies, offer natural pest and weed control while providing additional crops.

Biotechnology & Cultivars

High-Yielding Varieties

The Green Revolution introduced high-yielding rice varieties, such as IR8 (developed in 1966 by IRRI from "Peta" and "Dee Geo Woo Gen"), which radically increased global food production. These varieties were specifically bred with short, strong stems to prevent lodging (falling over) under heavy fertilizer application, thereby maximizing productivity.

Genetic Engineering for Health

Biotechnology has enabled the genetic modification of rice to express human proteins like lactoferrin and lysozyme (found in breast milk) and human serum albumin. These modified rice varieties can be used in oral rehydration solutions to treat diarrheal diseases, shortening their duration and reducing recurrence, and potentially aiding in reversing anemia. Golden Rice, engineered to produce beta-carotene, is another example aimed at combating Vitamin A deficiency.

Stress Tolerance

Significant research focuses on developing rice varieties with enhanced tolerance to environmental stresses:

Flood-tolerance: Cultivars like Swarna Sub1, with the Sub1A transgene, can withstand week-long submergence, crucial for regions prone to flooding.
Drought-tolerance: Varieties such as Sahbhagi Dhan and IR64 + DRO1 (with the *DEEPER ROOTING 1* gene) develop deeper root systems, improving nutrient access during droughts.
Salt-tolerance: Hybrids of commercial rice and wild species like *Oryza coarctata* are being developed to thrive in saline coastal soils.
Cold-tolerance: Researchers are studying mechanisms to improve rice's sensitivity to temperatures below 12°C, with trials for cold-tolerant risotto and basmati varieties showing promise in new regions.

Rice as a Model Organism

The complete genome of rice was sequenced in 2005, making it the first crop plant to achieve this status. This has established rice as a crucial model organism for investigating fundamental plant biological processes, such as the mechanisms of meiosis and DNA repair in higher plants. For example, studies in rice have elucidated the role of genes like *OsRAD51C* in accurate DNA double-strand break repair during meiosis.

Rice in Human Culture

Religious and Symbolic Roles

Rice holds profound significance in various religions and popular beliefs, often symbolizing fertility, prosperity, and purity. In Hindu wedding ceremonies, rice is traditionally thrown into the sacred fire, a custom that has evolved into the Western tradition of throwing rice over newlywed couples. In Malay weddings, sweet glutinous rice is a prominent feature among special wedding foods.

Celebrations and Deities

Rice wine is a customary beverage for weddings and other celebrations in countries like Japan and the Philippines. The goddess Dewi Sri, revered across the Indo-Malaysian archipelago, is a deity associated with rice and other crops, often depicted in ancient statues. The commencement of the rice planting season is a significant event in many Asian nations, marked by ceremonies such as the Royal Ploughing Ceremony in Nepal and Cambodia, which seek blessings for a bountiful harvest.

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References

Rice. Cgiar.org. Retrieved on 2012-05-13.

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The Global Grain

💡 Dive in with Flashcard Learning! 💡

Rice: A Global Overview 🌍

🍚 The Essential Cereal Grain

📈 Global Production and Consumption

🌾 Domestication and Spread

Botanical Characteristics 🌿

🌱 Plant Morphology

🌸 Reproductive Biology

💧 Growth Cycle and Adaptations

Agronomic Practices 🚜

👨‍🌾 Cultivation Methods

💦 Water Management

☀️ Harvesting and Drying

Evolutionary Journey 📜

🧬 Phylogenetic Context

🗺️ Domestication of *Oryza sativa*

🌐 Global Dispersal

Commerce & Economics 💰

📊 Production Landscape

⚖️ International Trade Dynamics

🛡️ Food Security Challenges

🏆 Yield Achievements

Food & Nutrition 🍽️

🍲 Culinary Diversity

💪 Nutritional Profile

🌟 Specialized Varieties

Rice & Climate Change 🌡️

💨 Greenhouse Gas Emissions

📉 Impact on Yields

💧 Drought Vulnerability

Pests, Weeds, & Diseases 🐛

🦗 Major Pests and Weeds

🦠 Prevalent Diseases

🛡️ Integrated Pest Management

Biotechnology & Cultivars 🔬

🌱 High-Yielding Varieties

🧬 Genetic Engineering for Health

resilient Stress Tolerance

🔬 Rice as a Model Organism

Rice in Human Culture 🎭

🙏 Religious and Symbolic Roles

🎉 Celebrations and Deities

Teacher's Corner 🧑‍🏫

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References

📜 References

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Rice: A Global Overview

The Essential Cereal Grain

Global Production and Consumption

Domestication and Spread

Botanical Characteristics

Plant Morphology

Reproductive Biology

Growth Cycle and Adaptations

Agronomic Practices

Cultivation Methods

Water Management

Harvesting and Drying

Evolutionary Journey

Phylogenetic Context

Domestication of Oryza sativa

Global Dispersal

Commerce & Economics

Production Landscape

International Trade Dynamics

Food Security Challenges

Yield Achievements

Food & Nutrition

Culinary Diversity

Nutritional Profile

Specialized Varieties

Rice & Climate Change

Greenhouse Gas Emissions

Impact on Yields

Drought Vulnerability

Pests, Weeds, & Diseases

Major Pests and Weeds

Prevalent Diseases

Integrated Pest Management

Biotechnology & Cultivars

High-Yielding Varieties

Genetic Engineering for Health

Stress Tolerance

Rice as a Model Organism

Rice in Human Culture

Religious and Symbolic Roles

Celebrations and Deities

Teacher's Corner

True or False?

Test Your Knowledge!

Gamer's Corner

Discover other topics to study!

References

Feedback & Support

Disclaimer

Important Notice