Rice Plant Development: from Zygote to Spikelet. Comments. 2009;Jagadish et al. (2015) recently showed that genetic gains in the yield potential of tropical irrigated rice during the past 20–30 years have been marginal. Despite worldwide production increased due to improved varieties and agronomy, it is stagnating since about 10 years in many regions (Ray et al., 2013). 10. Reproductive stage drought stress results in dramatic reduction of spikelet fertility and grain yield of upland rice (Oryza sativa L.). Rice genotype IR55419-04 showed least effect of water stress treatments for 1000 grain weight i.e., 6.28% and 10.44% reduction, spikelet fertility percentage with 19.99% and 40.01% reduction and the paddy yield per plant of 24.97% and 51.35% under one week and two weeks water stress, respectively. Cause. Dingkuhn et al. Rice is a key tropical staple food crop and demand for rice is projected to increase as populations continue to grow in Asia and as rice consumption increases rapidly in Sub‐Saharan Africa (Global Rice Science Partnership, 2013).The impacts of climate change are increasingly evident and extreme weather events around the world increasingly threaten food security. 2011).In the last few decades, much effort has been made to elucidate the effect of HT on rice yield, and its relation to rice growth and spikelet sterility. In a sorghum flower, only one spikelet of each pair is fertile. The LSU AgCenter and the LSU College of Agriculture, 101 Efferson Hall Sorghum: Specialty Types. The spikelet is an inflorescence structure unique to grasses. 2017c ). to spikelet temperature and the tolerance of a rice variety to high air-temperature induced spikelet sterility depends directly on the temperature inside the spikelet itself (Weerakoon et al., 2008). In cereal crops, the number of florets in a spikelet is an important factor affecting the grain number per panicle and then the grain yield. Shi et al. 225-578-4161 By definition a spikelet consists of two glumes and one or more florets. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional. See more. The reproductive stage of rice is the most sensitive to heat stress, which can lead to spikelet sterility. During the reproductive period in rice, salinity causes morphological variations similar to other environmental stresses, which cause inhibition of the growth of plant structures, such as the degeneration of primary, secondary and panicle spikelets (CUI et al., 1995). The _spikelets_ are rather small, narrow, greenish or purplish, 1/15 inch long or less, the rachilla is slender, produced to about half the length of the spikelet behind the palea. Furthermore, global climate change is likel… Elucidating the factors that The growing global demand for rice means that this staple food will have to be produced more intensively in Asia, Africa, Latin America and the Caribbean. The spikelet sterility in rice is sensitive to high temperature but, the degree of sensitivity depends upon developmental stages of the spikelet (Zakaria et al. After the hulls are removed, the bran layers are removed, producing the familiar milled white rice. (2008) observed that rice pollen germinated on the stigma within 2 min of pollination, and the tube reached 2008; Quampah et al. Rice in this form is called brown rice. The outer protective structures are called the hulls. The endosperm is mostly carbohydrates. However, different responses to heat stress are seemed to show between the superior and inferior spikelet, and this response is scarcely documented that the intrinsic factors remain elusive. Spikelet definition, a small or secondary spike in grasses; one of the flower clusters, the unit of inflorescence, consisting of two or more flowers and subtended by one or more glumes variously disposed around a common axis. Spikelets are arranged into inflorescences of variable size and form: from small, tight heads in many genera to panicles, the usual form of the inflorescence; panicles as long as one metre or more can be found in… The hulls are made up of two parts; the outer is called the lemma and the inner is the palea. Rice is a major world food crop (FAOSTAT, 2012) and breeding for improved yield potential is crucial (IRRI, 2010). (2015) found a significant negative relationship between spikelet tissue temperature and spikelet … ). The small structures labeled "glumes" are rudimentary structures sometimes called bracts instead of glumes. Asian urban centers hold the majority of the world’s urban poor and, within the next 25 years, nearly 55% of the population of Asia will be located in these areas. It often bears a long bristle called an awn, and may be similar in form to the glumes—chaffy bracts at the base of each spikelet. The bran, embryo and other miscellaneous by-products make up about 10% of the original rough rice weight.The embryo is also called the "germ" because it is the part of the seed that germinates or produces a new plant if the seed is planted rather than milled for consumption. Actual performances are also threatened by yield instability due to increasingly variable … In rice there is a single floret represented here by the lemma, palea and grain. Because rice has no well-developed glumes, the spikelet and floret are basically the same unit. web@agcenter.lsu.edu, 106 Martin D. Woodin Hall Evaluation of Awn Length. In rice there is a single floret represented here by the lemma, palea and grain. Insect. 1a) (Ikemoto et al. This unit is referred to as a spikelet before grain formation. Thus, heat-tolerant and heat-susceptible genotypes were used to investigate their differences in terms of phenotypic responses and expression changes of Hsf genes at the pre-flowering stage under heat stress. In wild-type rice, one spikelet produces one fertile floret. (1875, p. 125) of the rice spikelet ilndicates six bracts, four of whIiel are called glumes. 3.2. The typical rice (Oryza sativa) spikelet contains a single fertile floret and produces only one grain; by contrast, Brachypodium distachyon spikelets contain multiple fertile florets and produce several grains. Number of Panicles, Total Number of Spikelets, and Filled Spikelet Percentage. Because of the oils and other compounds associated with the embryo, brown rice cannot be stored as long as milled rice. Rice (Oryza sativa), a model monocotyledonous plant species, is the staple food for most of the global population.Consequently, breeding high‐yielding rice varieties is urgently required to cope with food shortages worldwide. 2011). By definition a grass spikelet is the unit of the inflorscence of a grass, a member of the Poaceae or Gramineae family of plants. Introduction. Lemma is a phytomorphological term referring to a part of the spikelet. Rice is a staple food for more than half of the world’s population. The insect attacks during spikelet stage of rice crop. In this step the area labeled "embryo" is also removed. The inflorscence is the arrangement of flowers on a plant and, even though the flowers of … Rapid population growth and economic development have imposed growing pressure upon increased food production (Zhang 2007), and a rice yield increase of more than 1.2 % per year will be required in the next decade (Normile 2008).At the same time, paddy area has been decreasing because of expanding construction land … This leads to unfilled, empty and discolored grains. About this Attention Score Good Attention Score compared to outputs of the same age (66th percentile) 1b). Overview of attention for article published in Plant & Cell Physiology, January 2005. The molecular mechanisms underlying spikelet development and evolution are unclear. Notably, the spikelet of wild-type rice is determinate and produces only one fertile floret, but “two-florets spikelet” and “three-florets spikelet” mutants have been genetically selected (Ren et al. It is the lowermost of two chaff-like bracts enclosing the grass floret. Chen et al. Global warming is rising as a serious concern affecting agricultural production worldwide. Rice is a staple food crop and the threshold temperature for its pollination is 35 °C. Baton Rouge, LA 70803. In general, the fertility and kernel weight of inferior spikelets of rice (Oryza Sativa L.) are obviously lower than those of superior spikelets, especially under abiotic stress. The hulls make up about 20% of the rough rice weight. High temperature (HT) during the rice-growing season is a major factor limiting rice yield and grain quality in many agricultural regions (Jia et al. 2019, 2018; Zhang et al. Rice is extensively grown in irrigated cropping systems, allowing production in the warmer, high radiation post-monsoon and summer months. Rice production has also intensified in rainfed-lowland and dryland (upland) cropping systems, many of which are prone to drought and high temperature (Coffman, 1977). It consists of two glumes and one or more florets. The mature rice kernel or grain is made up of several parts. It is usually interpreted as a bract but it has also been interpreted as one remnant (the abaxial) of the three members of outer perianth whorl (the palea may represent the other two members, having been joined together). Grain yield was examined by breaking the yield into its four yield components: number of panicles, spikelet number/panicle, filled spikelet percentage, and 1000-grain weight. Because rice has no well-developed glumes, the spikelet and floret are basically the same unit.The first step in milling rice is to remove the hulls - the lemma, palea and glumes. Altmetric Badge. The hypothesis investigated here is that spikelet sterility under pre-anthesis drought is triggered by deficient plant water status that inhibits peduncle elongation, panicle exsertion and anther dehiscence. The panicle size, an important agronomic trait that makes valuable contributions to the grain productivity in rice (Oryza sativa L.), mainly depends on the number of spikelets on a panicle [1,2,3,4].The final panicle size depends on the developmental processes of both spikelet differentiation and spikelet degeneration [].The phenomenon of young spikelet degeneration in cereal crops such … Baton Rouge, LA 70803 In wild rice, awn length varies according to the spikelet position in the panicle (Fig. This study characterized a gain-of-function mutant lateral florets 1 (lf1) in rice. Yield Components of Rice 3.2.1. 1 INTRODUCTION. spikelets synonyms, spikelets pronunciation, spikelets translation, English dictionary definition of spikelets. But under two water condition, the selection efficiencies were lower (relative efficiency 0.44 to -0.02) based on Pn at early filling stage, the flowering period, plant height, NP, number of panicles per plant; NGP, number of grains per panicle; NSP, number of, After several branches are produced, the IM switches and generates axillary meristems that produce one, The test cross nursery was raised and observations were recorded on agronomical traits of interest and also on pollen and, Rice straw mulching in aerobic rice improved, The modes of damage to wheat crop were, loopering of tops of wheat plant, poor pollination/fertilization, shattering of, Dictionary, Encyclopedia and Thesaurus - The Free Dictionary, the webmaster's page for free fun content, QUANTITATIVE AND QUALITATIVE RESPONSE OF WHEAT TO PSEUDOMONAS FLUORESCENS RHIZOBACTERIA APPLICATION, Rice Seed Production Under Conditions of Salinity Stres/Producao de sementes de arroz em condicoes de estresse por salinidade, IMPACT OF FOLIAR APPLICATION OF MICRO-NUTRIENTS FERTILIZERS (SUPER DAWN) ON THE GROWTH AND YIELD OF TWO WHEAT (Triticum aestivum L.) VARIETIES, EFFECT OF SEEDING RATE AND SEED SOAKING DURATION ON PRODUCTIVITY OF RELAY - INTERCROPPED WHEAT IN COTTON, Genetic Correlation Analysis of Photosynthetic Characteristics, Yield and Drought Resistance in Spring Wheat (Triticum aestivum), Detection of QTLs for Yield Heterosis in Rice Using a RIL Population and Its Testcross Population, Homogenization and truncation processes in inflorescences of Cyperaceae, Marker assisted development of effective fertility restorers suitable for use in temperate three-line hybrids, Comparison on the effects of mulching and fertilizer treatments on the yield components of aerobic rice MRQ74, Climate variability - a major cause of low yield of Wheat. 2017), and the seeds shatter in the mature stage.Therefore, the upper 1st to 5th spikelets on the top primary branch in a panicle were collected in the flowering stage, and their awn lengths were measured (Fig. Other articles where Spikelet is discussed: Cyperaceae: Characteristic morphological features: …a single flower), forming the spikelet, the basic unit of a sedge inflorescence. If the infestation is severe it may cause yield loss up to 30%. Define spikelets. All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. 2010;Rang et al. Key words: Dry weight, Gibberellic acid, Number of spikelets, Rice, Spikelet degeneration, Spikelet differentiation. Similarly, Africa’s i… Introduction. Both nymphs and adults suck the content out of grains from pre-flowering spikelets to soft dough stage. https://medical-dictionary.thefreedictionary.com/spikelet, Hassan and Bano, (2015) applied tryptophan combined with Pseudomonas moraviensis and Bacillus cereus to wheat and reported that this application increase number of plants per square meter, spike length, number of, During the reproductive period in rice, salinity causes morphological variations similar to other environmental stresses, which cause inhibition of the growth of plant structures, such as the degeneration of primary, secondary and panicle, For instance, some[10] reported that foliar application with combination of micronutrients (Cu+Fe+Mn+Zn) produced the highest values of plant height (85.03 and 87.17 cm), tillers number m-2, spikes number m-2, spike length, number of, (2007) whom found the substantial increase in. Plants harvested at the high cutting height produced higher grain yield of the second crop because of the larger spikelet number m −2 and better grain filling using abundant leaf area index (LAI) and nonstructural carbohydrate (NSC) in the stubble. Rice (Oryza sativa) produces an inflorescence belonging to the raceme class, with long branches, generally called ‘panicles’, whereas wheat (Triticum aestivum) and barley (Hordeum vulgare) form inflorescences without branches, called ‘spikes’ (Itoh et al., 2005). Reduction or elimination of spikelet degeneration to increase spikelet number is critical in increasing the grain yield of cereals. To increase yield, rice breeders have traditionally focused on panicle morphology (branch number and length, spikelet density), but have not considered the number of florets in each spikelet. The number of rice spikelets per square meter (S) is often positively correlated with the yield of rice (Evans, 1993) and is the most important component of grain yield (Yoshida, 1981). 225-578-4143 This unit is referred to as a spikelet before grain formation. The phenomenon of young spikelet degeneration in cereal crops such as rice (Oryza sativa L.) occurs frequently and is a serious physiological defect that causes grain yield loss (Tang et al., 2011; Liao et al., 2012; Wang et al., 2018; Zhang et al., 2018). By definition a spikelet consists of two glumes and one or more florets. Schuster (1910) interprets this to mean that there are two bracts (stunted glumnes) below the structures ordiinarily regarded as glulmes, these presumably represented by the cup below the articulation. n. A small or secondary spike, characteristic of grasses and sedges, bearing one or more florets and usually subtended by one or two bracts. In this study, we characterized three allelic recessive mutants in rice ( Oryza sativa ): nonstop glumes 1-1 ( nsg1-1 ), nsg1-2 , and nsg1-3 . Both the urban and rural poor require food at affordable prices and this must come from increased productivity in intensive rice systems, which account for 75% of total rice production. high tube growth rate characterize rice cultivars,which main-tain spikelet fertility and seed set in hot or cold temperature stress (Endo et al. African Rice. Rice (O. sativa and O. glaberrima) is one of the world's most important crops, particularly in Asia, but increasingly so in Africa and Latin America as well. Elucidating the factors that rice is extensively grown in irrigated cropping systems, allowing production the... To increase spikelet number is critical in increasing the grain yield of cereals and Filled spikelet Percentage synonyms, pronunciation... 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