Variation in development of contrasting rice cultivars

1994 ◽  
Vol 123 (1) ◽  
pp. 35-39 ◽  
Author(s):  
N. Senanayake ◽  
R. E. L. Naylor ◽  
S. K. De Datta ◽  
W. J. Thomson
Keyword(s):  
Cultivar Differences ◽  
Rice Grain ◽  
Rice Cultivars ◽  
Growth Duration ◽  
Potential Yield ◽  
Maturity Date ◽  
Before And After ◽  
Initiation Stage ◽  
N Management ◽  
Yield Determinants

SummaryExperiments were conducted in glasshouses at IRRI, Philippines, during 1987 and 1988 to identify varietal differences in apical development using six rice cultivars having extreme characters; Jirasar 280 (early senescence), Neo-Dunghan 1 (late senescence), Macunting (small seeds), ABB (large seeds), C12474–1 (long culm), and B581–A6–458 (short culm); and five cultivars, IR20, IR22, IR34, IR54, IR64, of the same growth duration.The length of time from physiological panicle initiation (PI) to flowering varied from 25 to 50 days. The onset of physiological PI occurred when the fourth penultimate leaf was fully exserted. The visual panicle initiation stage (VPI) coincided with spikelet differentiation in all cultivars. Nitrogen top-dressing at 55–57 days before the anticipated maturity date (the present N management recommendation) did not coincide with the actual panicle initiation stage in any of the cultivars and the major yield determinants (i.e. the primary and secondary branches) therefore differentiated in conditions of internal nitrogen shortage. Spikelet abortion took place both before and after flowering. Reduction of pre-flowering abortion is important in increasing rice grain yields and could be achieved by improved N management. It is important to recognise cultivar differences and periods of loss of potential yield in developing efficient N management protocols.

scholarly journals Molecular and Physiological Responses of Rice and Weedy Rice to Heat and Drought Stress

Agriculture ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 9
Author(s):  
Leonard Bonilha Piveta ◽  
Nilda Roma-Burgos ◽  
José Alberto Noldin ◽  
Vívian Ebeling Viana ◽  
Claudia de Oliveira ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Heat Stress ◽  
Drought Stress ◽  
Intercellular Co2 Concentration ◽  
Tiller Number ◽  
Weedy Rice ◽  
Photosynthetic Parameters ◽  
World Population ◽  
Rice Grain ◽  
Rice Cultivars

Rice is the staple food for about half of the world population. Rice grain yield and quality are affected by climatic changes. Arguably, rice cultivars’ genetic diversity is diminished from decades of breeding using narrow germplasm, requiring introgressions from other Oryza species, weedy or wild. Weedy rice has high genetic diversity, which is an essential resource for rice crop improvement. Here, we analyzed the phenotypic, physiological, and molecular profiles of two rice cultivars (IRGA 424 and SCS119 Rubi) and five weedy rice (WR), from five different Brazilian regions, in response to heat and drought stress. Drought and heat stress affected the phenotype and photosynthetic parameters in different ways in rice and WR genotypes. A WR from Northern Brazil yielded better under heat stress than the non-stressed check. Drought stress upregulated HSF7A while heat stress upregulated HSF2a. HSP74.8, HSP80.2, and HSP24.1 were upregulated in both conditions. Based on all evaluated traits, we hypothesized that in drought conditions increasing HSFA7 expression is related to tiller number and that increase WUE (water use efficiency) and HSFA2a expression are associated with yield. In heat conditions, Gs (stomatal conductance) and E’s increases may be related to plant height; tiller number is inversely associated with HSPs expression, and chlorophyll content and Ci (intercellular CO2 concentration) may be related to yield. Based on morphology, physiology, and gene regulation in heat and drought stress, we can discriminate genotypes that perform well under these stress conditions and utilize such genotypes as a source of genetic diversity for rice breeding.

Biomass and nutrient accumulation rates of rice cultivars differing in their growth duration when grown in fertile and low-fertile soils

2019 ◽  
Vol 43 (2) ◽  
pp. 251-269 ◽  
Author(s):  
Lalith Suriyagoda ◽  
Dinarathne Sirisena ◽  
Deepthika Kekulandara ◽  
Pradeepa Bandaranayake ◽  
Gamini Samarasinghe ◽  
...  
Keyword(s):  
Nutrient Accumulation ◽  
Rice Cultivars ◽  
Accumulation Rates ◽  
Growth Duration

Availability of existing early-season rice cultivars as resources for selecting high-yielding short-duration cultivars of machine-transplanted late-season rice

2019 ◽  
Vol 56 (2) ◽  
pp. 218-226
Author(s):  
Jiana Chen ◽  
Min Huang ◽  
Fangbo Cao ◽  
Xiaohong Yin ◽  
Yingbin Zou
Keyword(s):  
Grain Yield ◽  
Short Duration ◽  
Good Yield ◽  
Rice Production ◽  
Hunan Province ◽  
Rice Cultivars ◽  
Growth Duration ◽  
Yield Performance ◽  
Early Season ◽  
Late Season

AbstractHigh-yielding short-duration cultivars are required due to the development of mechanized large-scale double-season rice (i.e. early- and late-season rice) production in China. The objective of this study was to identify whether existing early-season rice cultivars can be used as resources to select high-yielding, short-duration (less than 115 days) cultivars of machine-transplanted late-season rice. Field experiments were conducted in Yongan, Hunan Province, China in the early and late rice-growing seasons in 2015 and 2016. Eight early-season rice cultivars (Liangyou 6, Lingliangyou 211, Lingliangyou 268, Xiangzaoxian 32, Xiangzaoxian 42, Zhongjiazao 17, Zhongzao 39, and Zhuliangyou 819) with growth durations of less than 115 days were used in 2015, and four cultivars (Lingliangyou 268, Zhongjiazao 17, Zhongzao 39, and Zhuliangyou 819) with good yield performance in the late season in 2015 were grown in 2016. All cultivars had a growth duration of less than 110 days when grown in the late season in both years. Zhongjiazao 17 produced the maximum grain yield of 9.61 Mg ha−1 with a daily grain yield of 108 kg ha−1 d−1 in the late season in 2015. Averaged across both years, Lingliangyou 268 had the highest grain yield of 8.57 Mg ha−1 with a daily grain yield of 95 kg ha−1 d−1 in the late season. The good yield performance of the early-season rice cultivars grown in the late season was mainly attributable to higher apparent radiation use efficiency. Growth duration and grain yield of early-season rice cultivars grown in the late season were not significantly related to those grown in the early season. Our study suggests that it is feasible to select high-yielding short-duration cultivars from existing early-season rice cultivars for machine-transplanted late-season rice production. Special tests by growing alternative early-season rice cultivars in the late season should be done to determine their growth duration and grain yield for such selection.

scholarly journals Proteomic profiling reveals differentially expressed proteins associated with amylose accumulation during rice grain filling

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Hengdong Zhang ◽  
Jiana Chen ◽  
Shuanglü Shan ◽  
Fangbo Cao ◽  
Guanghui Chen ◽  
...  
Keyword(s):  
Amylose Content ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Adenosine Diphosphate ◽  
Differentially Expressed ◽  
Rice Grain ◽  
Rice Cultivars ◽  
Differentially Expressed Proteins ◽  
Proteomic Profiling ◽  
Rice Grains

Abstract Background Amylose accumulation in rice grains is controlled by genetic and environmental factors. Amylose content is a determinant factor of rice quality in terms of cooking and eating. Great variations in amylose content in indica rice cultivars have been observed. The current study was to identify differentially expressed proteins in starch and sucrose metabolism and glycolysis/gluconeogenesis pathways and their relationships to amylose synthesis using two rice cultivars possess contrasting phenotypes in grain amylose content. Results Synthesis and accumulation of amylose in rice grains significantly affected the variations between rice cultivars in amylose contents. The high amylose content cultivar has three down-regulated differentially expressed proteins, i.e., LOC_Os01g62420.1, LOC_Os02g36600.1, and LOC_Os08g37380.2 in the glycolysis/gluconeogenesis pathway, which limit the glycolytic process and decrease the glucose-1-phosphate consumption. In the starch and sucrose metabolic pathway, an up-regulated protein, i.e., LOC_Os06g04200.1 and two down-regulated proteins, i.e., LOC_Os05g32710.1 and LOC_Os04g43360.1 were identified (Figure 4). Glucose-1-phosphate is one of the first substrates in starch synthesis and glycolysis that are catalyzed to form adenosine diphosphate glucose (ADPG), then the ADPG is catalyzed by granule-bound starch synthase I (GBSS I) to elongate amylose. Conclusions The results indicate that decreasing the consumption of glucose-1-phosphate in the glycolytic process is essential for the formation of ADPG and UDPG, which are substrates for amylose synthesis. In theory, amylose content in rice can be regulated by controlling the fate of glucose-1-phosphate.

scholarly journals Efficacy of N-Methyl-N-Nitrosourea Mutation on Physicochemical Properties, Phytochemicals, and Momilactones A and B in Rice

2019 ◽  
Vol 11 (23) ◽  
pp. 6862 ◽  
Author(s):  
Kifayatullah Kakar ◽  
Tran Dang Xuan ◽  
Nguyen Van Quan ◽  
Imran Khan Wafa ◽  
Hoang-Dung Tran ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Functional Foods ◽  
Grain Quality ◽  
Antioxidant Activities ◽  
Total Phenolic ◽  
Rice Grain ◽  
Rice Cultivars ◽  
Phenolic Contents ◽  
Phytochemical Compounds ◽  
Beneficial Traits

Attempts regarding the improvement and development of novel rice with better quality and higher productivity have been increasing. Among approaches, mutation is a direct alteration on the genome and considered as one of the most beneficial routes to acquire new beneficial traits in rice. An experiment was carried out to explore the effects of N-methyl-N-nitrosourea (MNU) mutation on the antioxidant activities, phytochemical compounds, and momilactones A (MA) and B (MB) in rice. Two rice cultivars, K1 (an original cultivar DT84) and K2 (mutated DT84), were examined. Antioxidant activities, phenolic compounds, and momilactones of the rice grain, husk, and straw portions were measured and quantified. Antioxidant activities were higher in grain and straw of K2, whereas K1 showed greater antioxidant activity in rice husk. Additionally, K2 displayed higher total phenolic contents (TPC) in grain and straw as well as lower of it in the husk, but these variations significantly differed only in the straw portion. An increase in total flavonoid contents (TFC) was observed in the husk of K1, while K2 significantly enhanced TFC in straw. Both MA and MB, two compounds obtaining antidiabetes, anticancer, antimicrobial, antigout, and antiobesity properties, were detected and quantified in grain, husk, and straw of K1 and K2 samples. Generally, the contents of MA were higher than MB in all tested portions of rice crop. MA and MB were higher in straw followed by those in husk and grain, respectively. K2 contained higher amounts of MA and MB in straw and husk, but lower contents in grain compared with those in K1. This study illustrates that MNU mutation can improve grain quality and enhance bioactive compounds in straw, husk, and grain of rice. This approach has the potential to develop functional foods from rice, and therefore help farmers in developing countries to improve value in rice production.

scholarly journals The Genetic and Economic Impact of the University of Arkansas's Rice Breeding Program: 1983-2007

2011 ◽  
Vol 43 (1) ◽  
pp. 131-142 ◽  
Author(s):  
L. Lanier Nalley ◽  
Karen A. Moldenhauer ◽  
Nate Lyman
Keyword(s):  
Economic Benefits ◽  
Breeding Program ◽  
Test Plot ◽  
Rice Breeding ◽  
Rice Cultivars ◽  
Potential Yield ◽  
Rice Varieties ◽  
Yield Increase ◽  
Program Test ◽  
The University

This study estimates the proportion of rice yield increase in University of Arkansas Division of Agriculture's (UofA) released rice cultivars that are attributable to genetic improvements through the University's breeding program. Test plot data from eight UofA experiment stations were used to quantify the yield increases and potential yield growth decreases over time. In addition to quantifying the yield and yield variance evolution at the UofA, this study also calculates the economic benefits of the UofA rice breeding program. Results indicated that by releasing modern rice cultivars, the UofA rice breeding program increased average producer yield by 0.68 bu/ac annually. During the last decade, 1997-2007, the average annual economic benefits were 34.3 million (2007) dollars. When accounting for the spillover of UofA rice varieties to neighboring states the average annual economic benefit of the breeding program increases to 46.7 million (2007) dollars.

scholarly journals Assessment of Rice Panicle Blast Disease Using Airborne Hyperspectral Imagery

2016 ◽  
Vol 10 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Takashi Kobayashi ◽  
Masashi Sasahara ◽  
Eiji Kanda ◽  
Kiyoshi Ishiguro ◽  
Shu Hase ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Hyperspectral Imagery ◽  
Disease Incidence ◽  
Blast Disease ◽  
Rice Grain ◽  
Large Area ◽  
Potential Yield ◽  
Band Ratio ◽  
Panicle Blast ◽  
Remote Sensing Techniques

Rice blast disease occurs in rice production areas all over the world and is the most important disease in Japan. Remote sensing techniques may provide a mean for detecting disease intensity for large area without being subjected to raters. This study evaluated the use of airborne hyperspectral imagery to measure the severity of panicle blast in field crops. Hyperspectral remote sensing imagery was acquired at the dough stage of rice grain development in northern Japan. The most consistent relationship, with high R2 and low P, was the simple band ratio R498 to 515/R700 to 717 (i.e., the reflectance at 498 to 515-nm divided by the reflectance at 700- to 717-nm). The band ratio of R498 to 515/R700 to 717 increased significantly (P < 0.001) with increasing visual estimates of disease incidence, defined as the percentage of diseased spikelets (R2 = 0.83). Assessment of disease distribution and severity could provide useful information for making decisions regarding the necessity of fungicide application and estimate potential yield loss due to the disease.

scholarly journals Aspects of cultivar variation in physiological traits related to Cd distribution in rice plants with a short-term stress

2020 ◽  
Author(s):  
Wan-Ting Chiao ◽  
Bo-Ching Chen ◽  
Chien-Hui Syu ◽  
Kai-Wei Juang
Keyword(s):  
Shoot Growth ◽  
Rice Grain ◽  
Rice Cultivars ◽  
Cd Accumulation ◽  
Physiological Regulation ◽  
Rice Plants ◽  
Cd Contamination ◽  
Cultivar Variation ◽  
Cd Distribution ◽  
Cd Translocation

Abstract Background Genotypic variations are seen in cadmium (Cd) tolerance and accumulation in rice plants. Cultivars that show low Cd translocation from the root into shoot can be selected to reduce Cd contamination in rice grains. This study aims to clarify the physiological regulation related to Cd absorption by rice plants for screening out the cultivars, which have relatively low Cd accumulation in grains. Eight Taiwan mega cultivars of paddy rice: japonica (TY3, TK9, TNG71, and KH145 cultivars), indica (TCS10 and TCS17 cultivars), and glutinous (TKW1 and TKW3 cultivars), which are qualified with the criteria for rice grain quality by the Council of Agriculture, Taiwan, were used for illustration. An experiment in hydroponics was conducted for the rice seedlings with a treatment of 50 μM CdCl 2 for 7 days. Results and discussion After the Cd treatment, the reductions in shoot growth were more significant than those in root growth; however, Cd absorbed in the rice plant was sequestered much more in the root. The malondialdehyde (MDA) was preferentially accumulated in rice root but the hydrogen peroxide (H 2 O 2 ) was increased more significantly in the shoot; the antioxidative enzymes, superoxide dismutase (SOD) and ascorbate peroxidase (APX), were pronounced more in rice shoot. Conclusions The rice cultivars preferentially accumulated Cd in the root rather than the shoot with the Cd treatment, which resulted in significant enhancements of MDA and growth reductions in the root. However, H 2 O 2 accumulation was toward the shoot to retard shoot growth suddenly and then the root could keep a gradual growth. Also, the rice cultivars, which preferentially accumulate Cd in the root, would have the regulation tendency of SOD toward the shoot. Due to that SOD is responsible for H 2 O 2 production, H 2 O 2 accumulation would be thus toward the shoot. Moreover, the cultivars, which have a less regulation tendency of APX toward the shoot, would present higher translocation of Cd into the shoot.

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