scholarly journals Evaluation of rice wild relatives as a source of traits for adaptation to iron toxicity and enhanced grain quality

2019 ◽  
Author(s):  
Birgit Bierschenk ◽  
Melle Tilahun Tagele ◽  
Basharat Ali ◽  
Md Ashrafuzzaman ◽  
Lin-Bo Wu ◽  
...  
Keyword(s):  
Chronic Stress ◽  
Genotypic Variation ◽  
Wild Relatives ◽  
Interspecific Crosses ◽  
Spikelet Sterility ◽  
Rice Varieties ◽  
Stress Symptoms ◽  
Individual Traits ◽  
Fe Toxicity ◽  
Symptom Formation

AbstractRice wild relatives (RWR) constitute an extended gene pool that can be tapped for the breeding of novel rice varieties adapted to abiotic stresses such as iron (Fe) toxicity. Therefore, we screened 75 Oryza genotypes including 16 domesticated O. sativas, one O. glaberrima, and 58 RWR representing 21 species, for tolerance to Fe toxicity. Plants were grown in a semi-artificial greenhouse setup, in which they were exposed either to control conditions, an Fe shock during the vegetative growth stage (acute treatment), or to a continuous moderately high Fe level (chronic treatment). In both stress treatments, foliar Fe concentrations were characteristic of Fe toxicity, and plants developed foliar stress symptoms, which were more pronounced in the chronic Fe stress especially toward the end of the growing season. Among the genotypes that produced seeds, only the chronic stress treatment significantly reduced yields due to increases in spikelet sterility. Moreover, a moderate but non-significant increase in grain Fe concentrations, and a significant increase in grain Zn concentrations were seen in chronic stress. Both domesticated rice and RWR exhibited substantial genotypic variation in their responses to Fe toxicity. Although no RWR strikingly outperformed domesticated rice in Fe toxic conditions, some genotypes scored highly in individual traits. Two O. meridionalis accessions were best in avoiding foliar symptom formation in acute Fe stress, while an O. rufipogon accession produced the highest grain yields in both chronic and acute Fe stress. In conclusion, this study provides the basis for using interspecific crosses for adapting rice to Fe toxicity.

scholarly journals Genotypic Variation in Nutrient Uptake Requirements of Rice Using the QUEFTS Model

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Tao Sun ◽  
Xin Yang ◽  
Sheng Tang ◽  
Kefeng Han ◽  
Ping He ◽  
...  
Keyword(s):  
Nutrient Uptake ◽  
Field Experiments ◽  
Hybrid Rice ◽  
Genotypic Variation ◽  
Tropical Soils ◽  
Study Data ◽  
Japonica Rice ◽  
Rice Varieties ◽  
Indica Hybrid Rice ◽  
Validation Experiments

Nutrient requirements for single-season rice using the quantitative evaluation of the fertility of tropical soils (QUEFTS) model in China have been estimated in a previous study, which involved all the rice varieties; however, it is unclear whether a similar result can be obtained for different rice varieties. In this study, data were collected from field experiments conducted from 2016 to 2019 in Zhejiang Province, China. The dataset was separated into two parts: japonica/indica hybrid rice and japonica rice. To produce 1000 kg of grain, 13.5 kg N, 3.6 kg P, and 20.4 kg K were required in the above-ground plant dry matter for japonica/indica hybrid rice, and the corresponding internal efficiencies (IEs) were 74.0 kg grain per kg N, 279.1 kg grain per kg P, and 49.1 kg grain per kg K. For japonica rice, 17.6 kg N, 4.1 kg P, and 23.0 kg K were required to produce 1000 kg of grain, and the corresponding IEs were 56.8 kg grain per kg N, 244.6 kg grain per kg P, and 43.5 kg grain per kg K. Field validation experiments indicated that the QUEFTS model could be used to estimate nutrient uptake of different rice varieties. We suggest that variety should be taken into consideration when estimating nutrient uptake for rice using the QUEFTS model, which would improve this model.

Assessment of genetic variability for quantitative characters in rice (Oryza sativa L.) under post flood situation in sali

2021 ◽  
Vol 58 (1) ◽  
pp. 43-48
Author(s):  
Dalibha Pathak ◽  
Umesh Ch. Kalita
Keyword(s):  
Grain Yield ◽  
Coefficient Of Variation ◽  
Quantitative Traits ◽  
Oryza Sativa L ◽  
Block Design ◽  
Genetic Advance ◽  
Spikelet Sterility ◽  
Rice Varieties ◽  
Randomized Block Design ◽  
Spikelets Per Panicle

Sixteen genotypes of rice (including one check) were evaluated on 18 quantitative traits during sali (August), 2018 in a randomized block design with three replications at Instruction cum Research Farm, Department of Plant Breeding and Genetics, Assam Agricultural University, Jorhat to study the nature and magnitude of variability, heritability and genetic advance under delayed sown condition. The analysis of variance for 18 quantitative traits revealed the presence of significant differences for grain yield and its component characters. The highest genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) was observed for chaffs per panicle followed by grains per panicle, spikelet sterility (%), spikelets per panicle, grain yield (kg/ha). A high heritability coupled with high genetic advance was observed for plant height (cm), spikelets per panicle, spikelet sterility (%), chaffs per panicle, grains per panicle, grain yield (g/hill), grain yield (kg/ha), biological yield (kg/ha), straw weight (kg/ha) and harvest index (%) indicating that selection might be effective for improvement of these characters under delayed sown condition with low input. From the findings of this investigation, one genotype viz., Gandhari emerged as the outstanding genotype which yielded 4170 kg/ha and could be directly used for cultivation in delayed sown situation with low inputs. Some other promising genotypes that yielded higher than the check Manoharsali under delayed sown condition were JR 29, JR 16, Basundhara and JR 60 and could be utilized as potential parental material in the hybridization programmes designed to develop suitable rice varieties for delayed sown situation.

scholarly journals Contribution of Wild Relatives to Durum Wheat (Triticum turgidum subsp. durum) Yield Stability across Contrasted Environments

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1992
Author(s):  
Hafid Aberkane ◽  
Ahmed Amri ◽  
Bouchra Belkadi ◽  
Abdelkarim Filali-Maltouf ◽  
Jan Valkoun ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Triticum Turgidum ◽  
Wild Relatives ◽  
Yield Stability ◽  
Yield Potential ◽  
High Yield ◽  
Interspecific Crosses ◽  
Aegilops Speltoides ◽  
Recurrent Parent ◽  
Environment Interaction

Durum wheat (Triticum turgidum subsp. durum) is mostly grown in Mediterranean type environments, characterized by unpredictable rainfall amounts and distribution, heat stress, and prevalence of major diseases and pests, all to be exacerbated with climate change. Pre-breeding efforts transgressing adaptive genes from wild relatives need to be strengthened to overcome these abiotic and biotic challenges. In this study, we evaluated the yield stability of 67 lines issued from interspecific crosses of Cham5 and Haurani with Triticum dicoccoides, T. agilopoides, T. urartu, and Aegilops speltoides, grown under 15 contrasting rainfed and irrigated environments in Morocco, and heat-prone conditions in Sudan. Yield stability was assessed using parametric (univariate (e.g., Bi, S2di, Pi etc) and multivariate (ASV, SIPC)) and non-parametric (Si1, Si2, Si3 and Si6) approaches. The combined analysis of variance showed the highly significant effects of genotypes, environments, and genotype-by-environment interaction (GEI). The environments varied in yield (1370–6468 kg/ha), heritability (0.08–0.9), and in their contribution to the GEI. Several lines derived from the four wild parents combined productivity and stability, making them suitable for unpredictable climatic conditions. A significant advantage in yield and stability was observed in Haurani derivatives compared to their recurrent parent. Furthermore, no yield penalty was observed in many of Cham5 derivatives; they had improved yield under unfavorable environments while maintaining the high yield potential from the recurrent parent (e.g., 142,026 and 142,074). It was found that a limited number of backcrosses can produce high yielding/stable germplasm while increasing diversity in a breeding pipeline. Comparing different stability approaches showed that some of them can be used interchangeably; others can be complementary to combine broad adaption with higher yield.

scholarly journals Mechanistic understanding of iron toxicity tolerance in contrasting rice varieties from Africa: 2. Root oxidation ability and oxidative stress control

2020 ◽  
Vol 47 (2) ◽  
pp. 145
Author(s):  
Dorothy A. Onyango ◽  
Fredrickson Entila ◽  
James Egdane ◽  
Myrish Pacleb ◽  
Meggy Lou Katimbang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Sub Saharan Africa ◽  
Rice Varieties ◽  
Excess Iron ◽  
Improvement Programs ◽  
Sub Saharan ◽  
Breeding Efficiency ◽  
Biochemical Analyses ◽  
Fe Toxicity ◽  
And Control

To enhance breeding efficiency for iron (Fe) toxicity tolerance and boost lowland rice production in sub-Saharan Africa, we have characterised the morphological, physiological and biochemical responses of contrasting rice varieties to excess iron. Here, we report the capacity of four varieties (CK801 and Suakoko8 (tolerant), Supa and IR64 (sensitive)) to oxidise iron in the rhizosphere and control iron-induced oxidative stress. The experiments were conducted in hydroponic conditions using modified Magnavaca nutrient solution and 300 ppm of ferrous iron (Fe2+) supplied in the form of FeSO4. Severe oxidative stress was observed in sensitive varieties as revealed by their high levels of lipid peroxidation. Histochemical and biochemical analyses showed that tolerant varieties exhibited a better development of the aerenchyma and greater oxygen release than the sensitive varieties in response to excess Fe. Both suberin and lignin deposits were observed in the root, stem and leaf tissues but with varying intensities depending on the variety. Under iron toxic conditions, tolerant varieties displayed increased superoxide dismutase (SOD), glutathione reductase (GR), peroxidase (POX) and ascorbate peroxidase (APX) activities in both the roots and shoots, whereas sensitive varieties showed increased APX and catalase (CAT) activities in the roots. This study had revealed also that Suakoko8 mainly uses root oxidation to exclude Fe2+ from its rhizosphere, and CK801 possesses a strong reactive oxygen species scavenging system, in addition to root oxidation ability. Key traits associated with these tolerance mechanisms such as a well-developed aerenchyma, radial oxygen loss restricted to the root cap as well as strong activation of antioxidative enzymes (SOD, GR, POX and APX) could be useful selection criteria in rice varietal improvement programs for enhanced Fe toxicity tolerance.

Hypothalamic paraventricular nucleus, but not vasopressin, participates in chronic hyperactivity of the HPA axis in diabetic rats

2006 ◽  
Vol 290 (2) ◽  
pp. E243-E250 ◽  
Author(s):  
Dóra Zelena ◽  
Ludmila Filaretova ◽  
Zsuzsa Mergl ◽  
István Barna ◽  
Zsuzsanna E. Tóth ◽  
...  
Keyword(s):  
Adrenal Gland ◽  
Chronic Stress ◽  
Paraventricular Nucleus ◽  
Water Consumption ◽  
Anterior Lobe ◽  
Diabetic Rats ◽  
Hypothalamic Paraventricular Nucleus ◽  
Stress Symptoms ◽  
Pomc Mrna ◽  
Thymus Involution

Diabetes mellitus (DM), as chronic stress activates the hypothalamo-pituitary-adrenocortical axis. We examined whether arginine vasopressin (AVP) and the hypothalamic paraventricular nucleus (PVN) participate in DM-induced chronic stress symptoms. AVP-deficient Brattleboro or PVN-lesioned Wistar rats were used with heterozygous or sham-operated controls. The rats were studied 2 wk after a single injection of streptozotocin. The appearance of DM (enhanced water consumption and blood glucose elevation) and the chronic stress-like somatic changes (body weight decrease, thymus involution, adrenal gland hypertrophy) were not influenced by the lack of AVP. By contrast, PVN lesion significantly attenuated DM-induced thymus involution and adrenal gland hypertrophy as well as the increase in water consumption. The corticotropin-releasing hormone mRNA in PVN was diminished by DM and elevated by the lack of AVP without interaction. DM elevated the proopiomelanocortin (POMC) mRNA in the anterior lobe of the pituitary. The lack of AVP had no effect, whereas lesioning the PVN significantly diminished the elevation. The elevated basal corticosterone plasma levels detectable in DM were influenced neither by the lack of AVP nor by lesioning the PVN. Thus the lack of AVP had no influence on DM-induced chronic stress symptoms, but lesioning the PVN attenuated part of them. However, the lack of elevation in POMC mRNA after PVN lesion, together with the maintained corticosterone elevation, suggests that direct adrenal gland activation occurs in untreated DM.

scholarly journals Tolerance of Iron-Deficient and -Toxic Soil Conditions in Rice

Plants ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 31 ◽  
Author(s):  
Anumalla Mahender ◽  
B. Swamy ◽  
Annamalai Anandan ◽  
Jauhar Ali
Keyword(s):  
Fine Tuning ◽  
Fe Deficiency ◽  
Soil Conditions ◽  
Rice Cultivars ◽  
Rice Varieties ◽  
Genetic Traits ◽  
The Past ◽  
Iron Deficient ◽  
Fe Toxicity ◽  
Uptake And Transport

Iron (Fe) deficiency and toxicity are the most widely prevalent soil-related micronutrient disorders in rice (Oryza sativa L.). Progress in rice cultivars with improved tolerance has been hampered by a poor understanding of Fe availability in the soil, the transportation mechanism, and associated genetic factors for the tolerance of Fe toxicity soil (FTS) or Fe deficiency soil (FDS) conditions. In the past, through conventional breeding approaches, rice varieties were developed especially suitable for low- and high-pH soils, which indirectly helped the varieties to tolerate FTS and FDS conditions. Rice-Fe interactions in the external environment of soil, internal homeostasis, and transportation have been studied extensively in the past few decades. However, the molecular and physiological mechanisms of Fe uptake and transport need to be characterized in response to the tolerance of morpho-physiological traits under Fe-toxic and -deficient soil conditions, and these traits need to be well integrated into breeding programs. A deeper understanding of the several factors that influence Fe absorption, uptake, and transport from soil to root and above-ground organs under FDS and FTS is needed to develop tolerant rice cultivars with improved grain yield. Therefore, the objective of this review paper is to congregate the different phenotypic screening methodologies for prospecting tolerant rice varieties and their responsible genetic traits, and Fe homeostasis related to all the known quantitative trait loci (QTLs), genes, and transporters, which could offer enormous information to rice breeders and biotechnologists to develop rice cultivars tolerant of Fe toxicity or deficiency. The mechanism of Fe regulation and transport from soil to grain needs to be understood in a systematic manner along with the cascade of metabolomics steps that are involved in the development of rice varieties tolerant of FTS and FDS. Therefore, the integration of breeding with advanced genome sequencing and omics technologies allows for the fine-tuning of tolerant genotypes on the basis of molecular genetics, and the further identification of novel genes and transporters that are related to Fe regulation from FTS and FDS conditions is incredibly important to achieve further success in this aspect.

scholarly journals Mechanistic understanding of iron toxicity tolerance in contrasting rice varieties from Africa: 1. Morpho-physiological and biochemical responses

2019 ◽  
Vol 46 (1) ◽  
pp. 93 ◽  
Author(s):  
Dorothy A. Onyango ◽  
Fredrickson Entila ◽  
Mathew M. Dida ◽  
Abdelbagi M. Ismail ◽  
Khady N. Drame
Keyword(s):  
Cell Membrane ◽  
Lateral Roots ◽  
Soluble Sugars ◽  
Membrane Stability ◽  
Photosynthesis Rate ◽  
Rice Varieties ◽  
Cell Membrane Stability ◽  
Biochemical Responses ◽  
Fe Toxicity ◽  
Physiological And Biochemical

Iron (Fe) is a fundamental element involved in various plant metabolic processes. However, when Fe uptake is excessive, it becomes toxic to the plant and disrupts cellular homeostasis. The aim of this study was to determine the physiological and biochemical mechanisms underlying tolerance to Fe toxicity in contrasting rice varieties adapted to African environments. Four varieties (CK801 and Suakoko 8 (tolerant), Supa and IR64 (sensitive)) selected from our previous work were analysed in more detail, and the first part of this study reports morphological, physiological and biochemical responses induced by Fe toxicity in these four varieties. Morphological (shoot length, root length, number of lateral roots), physiological (photosynthesis rate, stomatal conductance, transpiration rate, fluorescence, relative water content and cell membrane stability) and biochemical (tissue Fe, chlorophyll pigments, soluble sugars, protein and starch) traits were measured, as appropriate, on both shoot and root tissues and at different time points during the stress period. Fe toxicity significantly (P≤0.05) reduced growth and metabolism of all the four varieties. Tolerant varieties showed more lateral roots than the sensitive ones, under Fe toxic conditions as well as higher photosynthesis rate, chlorophyll content and cell membrane stability. Strong dilution of Fe concentration in cells was identified, as one of the additional tolerance mechanisms used by CK801, whereas Suakoko 8 mainly used strong mobilisation of carbohydrates at the early stage of the stress period to anticipate metabolite shortage. Traits associated with Fe toxicity tolerance in this study could be specifically targeted in trait-based breeding programs of superior lowland rice varieties tolerant of Fe toxicity.

Minimising cold damage during reproductive development among temperate rice genotypes. II. Genotypic variation and flowering traits related to cold tolerance screening

2006 ◽  
Vol 57 (1) ◽  
pp. 89 ◽  
Author(s):  
T. C. Farrell ◽  
K. M. Fox ◽  
R. L. Williams ◽  
S. Fukai ◽  
L. G. Lewin
Keyword(s):  
Low Temperature ◽  
Cold Tolerance ◽  
Field Experiments ◽  
Cold Water ◽  
Genotypic Variation ◽  
Pollen Grains ◽  
Microspore Development ◽  
Spikelet Sterility ◽  
Temperature Conditions ◽  
Anther Length

Low temperature during microspore development increases spikelet sterility and reduces grain yield in rice (Oryza sativa L.). The objectives of this study were to determine genotypic variation in spikelet sterility in the field in response to low temperature and then to examine the use of physio-morphological traits at flowering to screen for cold tolerance. Multiple-sown field experiments were conducted over 4 consecutive years in the rice-growing region of Australia to increase the likelihood of encountering low temperature during microspore development. More than 50 cultivars of various origins were evaluated, with 7 cultivars common to all 4 years. The average minimum temperature for 9 days during microspore development was used as a covariate in the analysis to compare cultivars at a similar temperature. The low-temperature conditions in Year 4 identified cold-tolerant cultivars such as Hayayuki and HSC55 and susceptible cultivars such as Sasanishiki and Doongara. After low temperature conditions, spikelet sterility was negatively correlated with the number of engorged pollen grains, anther length, anther area, anther width, and stigma area. The number of engorged pollen grains and anther length were found to be facultative traits as their relationships with spikelet sterility were identified only after cold water exposure and did not exist under non-stressed conditions.

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