scholarly journals Sorghum Drought Tolerance is Associated with Deeper Root System and Decreased Transpiration Rate

2021 ◽  
Author(s):  
Srinivasan Gowsiga ◽  
Maduraimuthu Djanaguiraman ◽  
Nallasamy Thavaprakaash ◽  
Prabhakaran Jeyakumar ◽  
Govindaraj Mahalingam
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Root System ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Root Length ◽  
Total Root Length ◽  
Maximum Root Length ◽  
Maximum Root ◽  
Root And Shoot Traits

Drought decreases grain yield of sorghum [Sorghum bicolor (L.) Moench], and understanding the mechanism(s) related to drought tolerance is critical for sustaining sorghum production. Variation in root and shoot traits associated with drought tolerance were analyzed to provide an integrated view of factors that underlie the drought tolerance of sorghum. The plants were grown in the root column up to the five-leaf stage, then exposed to either 0.9 fraction of transpirable soil water (FTSW) or 0.4 FTSW for five days. In another experiment, at the five-leaf stage, stress was imposed for 14 days. Various root and shoot traits associated with drought tolerance were recorded. The seminal root angle of IS13540 was lower (24.4) than IS23143 (42.6). Drought stress increased the maximum root length (40%) and total root length (58%) of IS13540 than its irrigated control. In contrast, the maximum root length and total root length were decreased in IS23143. Similarly, across the lines, drought stress decreased stomatal conductance (37%), transpiration rate (42%), photosynthetic rate (40%), photosystem II quantum yield (20%), photochemical quenching (44%), and total dry matter production (34%) than irrigated control. An increased transpiration rate was observed in IS23143 than IS13540 under irrigated and drought stress. In IS23143, the reduction in photosynthetic rate under drought may be a combination of stomatal and non-stomatal factors. However, in IS13540, the reduction is especially by the stomatal factors. It is evident that IS13540 is a drought-tolerant line, and tolerance is related to a deep prolific root system and reduced tran-spiration rate.

scholarly journals Effects of Nitrogen and Shading on Root Morphologies, Nutrient Accumulation, and Photosynthetic Parameters in Different Rice Genotypes

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Shenggang Pan ◽  
Haidong Liu ◽  
Zhaowen Mo ◽  
Bob Patterson ◽  
Meiyang Duan ◽  
...  
Keyword(s):  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Root Length ◽  
Field Experiments ◽  
Photosynthetic Parameters ◽  
Nitrogen Accumulation ◽  
Nutrient Accumulation ◽  
Total Root Length ◽  
Root Volume ◽  
Superficial Area

Abstract Nitrogen availability and illumination intensity are two key factors which affect rice growth. However, their influences on total nitrogen accumulation, photosynthetic rate, root morphologies, and yields are not fully understood. We conducted two field experiments to (1) evaluate the effects of shading under different N treatments on photosynthetic parameters, root morphologies, total nutrient accumulation, and grain yields of rice; and (2) elucidate the relationship between total nutrient accumulation and root morphologies under different shading conditions and nitrogen treatments. Three nitrogen rates, three shading treatments, and three different rice cultivars were used in two field experiments. Double shading during the grain-filling stage decreased total nutrient accumulation, altered root morphological characteristics, and decreased yields in rice. There were also significant interaction effects between nitrogen and shading on photosynthetic rate, transpiration rate, and total root length, root superficial area, and root volume. Significant interactions were found among cultivars and shading for photosynthetic rate and transpiration rate. Correlation analysis revealed that total nitrogen accumulation (TNA) and potassium accumulation (TKA) were significantly positively correlated with total root length, root superficial area, and root volume. N application could alleviate the detrimental effects of shading on total nutrient accumulation and grain yield in rice.

scholarly journals Identification of Markers for Root Traits Related to Drought Tolerance Using Traditional Rice Germplasm

2021 ◽  
Author(s):  
Harendra Verma ◽  
R. N. Sarma
Keyword(s):  
Drought Tolerance ◽  
Root System ◽  
Root Length ◽  
Complex Traits ◽  
Genome Wide Association Study ◽  
Root Traits ◽  
Coefficient Of Determination ◽  
Root Weight ◽  
Shoot Weight ◽  
Root And Shoot Traits

Abstract Background: Drought is one of the important constraints affecting rice productivity worldwide. The vigorous shoot and deep root system help to improve drought resistance. In present era, genome-wide association study (GWAS) is the preferred method for mapping of QTLs for complex traits such as root and drought tolerance traits. In the present study, 114 rice genotypes were evaluated for various root and shoot traits under water stress conditions. All the genotypes were genotyped using 65 SSR markers covering all 12 chromosomes for the identification of various QTLs for root and shoot traits using MLM (Q+K) model in GWAS. Results: All genotypes showed a significant amount of variation for various root and shoot traits. Correlation analysis revealed that high dry shoot weight and fresh shoot weight is associated with root length, root volume, fresh root weight and dry root weight. A total of 11 significant marker-trait associations were detected for various root, shoot and drought tolerance traits with the coefficient of determination (R2) ranging from 18.99% to 53.41%. Marker RM252 and RM212 showed association with three root traits which suggests their scope for improvement of root system in rice improvement breeding programmes. In the present study a novel QTL was detected for root length associated with RM127, explaining 19.30% of variation. Conclusion: The marker alleles with increasing phenotypic effects for root and drought-tolerant traits can be exploited for improvement of root and drought tolerance traits using marker-assisted selection.

The Effects of Drought on Leaf Gas Exchange and Growth of Three Species of Herbaceous Perennials

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 540a-540
Author(s):  
K.J. Prevete ◽  
R.T. Fernandez
Keyword(s):  
Drought Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Drought Tolerance ◽  
Transpiration Rate ◽  
Leaf Gas Exchange ◽  
Gas Analysis ◽  
Herbaceous Perennials ◽  
Effects Of Drought ◽  
Analysis System

Three species of herbaceous perennials were tested on their ability to withstand and recover from drought stress periods of 2, 4, and 6 days. Eupatorium rugosum and Boltonia asteroides `Snowbank' were chosen because of their reported drought intolerance, while Rudbeckia triloba was chosen based on its reported drought tolerance. Drought stress began on 19 Sept. 1997. Plants were transplanted into the field the day following the end of each stress period. The effects of drought on transpiration rate, stomatal conductance, and net photosynthetic rate were measured during the stress and throughout recovery using an infrared gas analysis system. Leaf gas exchange measurements were taken through recovery until there were no differences between the stressed plants and the control plants. Transpiration, stomatal conductance, and photosynthesis of Rudbeckia and Boltonia were not affected until 4 days after the start of stress. Transpiration of Eupatorium decreased after 3 days of stress. After rewatering, leaf gas exchange of Boltonia and Rudbeckia returned to non-stressed levels quicker than Eupatorium. Growth measurements were taken every other day during stress, and then weekly following transplanting. Measurements were taken until a killing frost that occurred on 3 Nov. There were no differences in the growth between the stressed and non-stressed plants in any of the species. Plants will be monitored throughout the winter, spring, and summer to determine the effects of drought on overwintering capability and regrowth.

EFFECTS OF ALUMINIUM ON THE ADVENTITIOUS ROOT SYSTEM, AERIAL BIOMASS AND GRAIN YIELD OF MAIZE GROWN IN THE FIELD AND IN A RHIZOTRON

2006 ◽  
Vol 42 (3) ◽  
pp. 351-366 ◽  
Author(s):  
J. J. COMIN ◽  
J. BARLOY ◽  
V. HALLAIRE ◽  
F. ZANETTE ◽  
P. R. M. MILLER
Keyword(s):  
Grain Yield ◽  
Root System ◽  
Soil Solution ◽  
Root Length ◽  
Adventitious Root ◽  
Adventitious Roots ◽  
Total Root Length ◽  
Al Tolerance ◽  
Root Branching ◽  
Four Levels

The aim of this work was to study the effects of soluble aluminium on the morphology and growth of the adventitious root system, aerial biomass and grain yield of maize (Zea mays). The analysis focuses on two hybrid cultivars (Al-sensitive HS7777 and Al-tolerant C525M). Experiments were carried out in the field and in a rhizotron in Curitiba, Paraná, Brazil. In the field, four levels of lime application were used: T0 = 0 t ha−1, T1 = 3.5 t ha−1, T2 = 7.0 t ha−1, and T3 = 10.5 t ha−1. Two levels were used in a rhizotron: T0 and T3. In the surface horizon (0–15 cm), the Al concentrations of the soil solution were: T0 = 15, T1 = 5.1, T2 = 4.4, and T3 = 3.1 μM. In the field, neither Al concentration in the soil solution nor cultivar affected the number of primary adventitious roots per internode or the total number of primary adventitious roots. However, root diameter, plant population and grain yield of the two cultivars confirmed the differences in Al tolerance between them. Al was observed to have an adverse effect on the grain yield from C525M, while low yields from HS7777, at all levels of Al, precluded any response to liming. In the rhizotron studies, Al concentration and cultivar affected the root branching and total root length. Cultivar C525M had more branches and total root length than HS7777, mainly at low concentrations of soil Al solution, leading to greater spatial colonization of the soil down to 0.9 m depth.

The transcription factor ZmNAC49 reduces stomatal density and improves drought tolerance in maize

2020 ◽  
Author(s):  
Yang Xiang ◽  
Xiujuan Sun ◽  
Xiangli Bian ◽  
Tianhui Wei ◽  
Tong Han ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Drought Stress ◽  
Stomatal Conductance ◽  
Drought Tolerance ◽  
Transpiration Rate ◽  
Transcriptional Activation ◽  
Stomatal Density ◽  
Stomatal Development ◽  
Expression Of Genes ◽  
Growth Development

Abstract Drought stress severely limits the growth, development, and productivity of crops, and therefore understanding the mechanisms by which plants respond to drought is crucial. In this study, we cloned a maize NAC transcription factor, ZmNAC49, and identified its function in response to drought stress. We found that ZmNAC49 is localized in the nucleus and has transcriptional activation activity. ZmNAC49 expression is rapidly and strongly induced by drought stress, and overexpression enhances stress tolerance in maize. Overexpression also significant decreases the transpiration rate, stomatal conductance, and stomatal density in maize. Detailed study showed that ZmNAC49 overexpression affects the expression of genes related to stomatal development, namely ZmTMM, ZmSDD1, ZmMUTE, and ZmFAMA. In addition, we found that ZmNAC49 can directly bind to the promoter of ZmMUTE and suppress its expression. Taken together, our results show that the transcription factor ZmNAC49 represses ZmMUTE expression, reduces stomatal density, and thereby enhances drought tolerance in maize.

Identification of drought stress tolerance in wild species germplasm of rice based on leaf and root morphology

2017 ◽  
Vol 16 (4) ◽  
pp. 289-295 ◽  
Author(s):  
Kumari Neelam ◽  
Gurpreet K. Sahi ◽  
Kishor Kumar ◽  
Kuldeep Singh
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Stress Tolerance ◽  
Root Morphology ◽  
Wild Species ◽  
Root Length ◽  
Wide Spectrum ◽  
Abiotic Stress Tolerance ◽  
Oryza Rufipogon ◽  
Sub Saharan Africa

AbstractDrought is the major abiotic constraint to the rice production in the rain-fed areas across Asia and sub-Saharan Africa. Wild species of Oryza offer a wide spectrum of adaptive traits and can serve as potential donors of biotic and abiotic stress tolerance. At the Punjab Agricultural University, we are maintaining an active collection of 1630 accessions of wild species germplasm (AA, CC, BBCC and CCDD) of rice. These accessions were screened to assess genetic variation for drought tolerance under field conditions. Severe water stress was imposed at the late vegetative stage by withholding water initially for 25 d and then extended further to 35 d during kharif season in the years 2013–14 and 2015–16. The tolerance score for drought stress was based on the extent of leaf rolling and leaf drying. Based on the 2 years’ data, seven accessions from Oryza rufipogon, four from Oryza longistaminata and one each from Oryza officinalis and Oryza latifolia were found tolerant to drought stress. These selected accessions were further phenotype for root morphology. The average root length among the selected accessions ranges between 36 and 80 cm and the number of primary roots vary from 30 to 87 cm. The O. rufipogon accession IRGC 106433, O. longistaminata accession IRGC 92656A, O. officinalis accession IRGC 101152 and O. latifolia accession IRGC 80769 showed approximately 2–2.5 times longer root length and number than the indica rice elite cultivar PR121. The results indicated potentiality of selected wild species germplasm for conferring drought tolerance to the elite cultivars.

Effects of Prodiamine on Tall Fescue (Festuca arundinacea) Rooting

1995 ◽  
Vol 9 (4) ◽  
pp. 736-740
Author(s):  
Sangwook Han ◽  
Thomas W. Fermanian ◽  
Thomas B. Voigt
Keyword(s):  
Tall Fescue ◽  
Root Length ◽  
Dry Weight ◽  
Kentucky Bluegrass ◽  
Individual Response ◽  
Root Dry Weight ◽  
Significant Difference ◽  
Maximum Root Length ◽  
Maximum Root ◽  
The Mean

With the increased development of new tall fescue cultivars used in turf, it is important to understand their individual response to herbicide treatment. The effect of prodiamine on tall fescue root dry weight and root length of selected tall fescue cultivars was studied in the greenhouse in 1.3-m-deep pots of calcined clay. Prodiamine at 0.8 kg ai/ha did not significantly affect either root dry weight or root length. However, the mean root dry weight and maximum root length averaged over all cultivars were significantly reduced at 4 wk after treatment with 1.7 kg/ha. When the prodiamine treatments were repeated in a second experiment, both rates caused a significant reduction in the mean root dry weight and maximum root length but there was no significant difference between prodiamine rates. Single degree of freedom contrasts between the untreated and treated turfs for each cultivar had some differential response in root dry weight. The reduction in root dry weight in the prodiamine treatments was more pronounced in the second study because the turf was less mature. ‘Olympic’ and ‘Rebel’ tall fescue had significantly reduced root dry weight at the 1.7 kg/ha rate in first study; whereas, ‘Amigo,’ Olympic, ‘Sundance,’ and ‘Taurus' tall fescue had significant reduction in root dry weight at both 0.8 and 1.7 kg/ha prodiamine rates. ‘Midnight’ Kentucky bluegrass had significantly reduced root length at both prodiamine rates in the second experiment but in general there was little difference among tall fescue cultivars treated with prodiamine.

scholarly journals EVALUATION OF FUNGICIDES AGAINST PHYTOPHTHORA AND FUSARIUM (root rot spp.) OF CITRUS ROOTSTOCKS SEEDLINGS

2021 ◽  
pp. 145-154
Author(s):  
Shakila Yasmeen ◽  
Muhammad Mumtaz Khan ◽  
Saeed Ahmad ◽  
Mazhar Abbas ◽  
Bushra Sadia ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Root Rot ◽  
Fungal Pathogens ◽  
Weight Ratio ◽  
Dry Weight ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Maximum Root

Citrus is one of the most important fruit crop in the world and is usually grown through grafting technique. Rootstock is one of the significant part in grafted plants and has crutial effect on production, including yield, fruit quality, tree size, tolerance to salts and diseases, and scion compatibility. Citrus is susceptible to several fungal pathogens causing incalculable losses to the crop. Among all soil-borne fungal pathogens, Phytophthora and Fusarium cause the most severe damage to the nursery or orchards plants. This research was planned to evaluate the effectiveness of fungicides as soil drenching and root dipping to control Phytophthora and Fusarium attacking citrus rootstock seedlings at the nursery stage. Different physiological and morphological parameters were studied in the infected plants and data were compared with that of control. The data were recorded and compared concerning rootstock seed and seeding response using standard measures and statistical analysis. The results showed that plants inoculated with Phytophthora and Fusarium root rot spp.when treated with Aliette and Ridomil Gold showed maximum root shoot ratio, fresh dry weight ratio, photosynthetic rate, stomatal conductance, water potential and transpiration rate as compared to untreated plants. The results also depicted that plants treated with Aliette and Ridomil Gold through soil drenching have maximum root shoot ratio, fresh dry weight ratio, photosynthetic rate, stomatal conductance and transpiration rate as compared to root dipped plants. Keywords: Fungal diseases, pathogens, root rot, nursery plants.

scholarly journals Assessment of Groundnut Elite Lines under Drought Conditions and Selection of Tolerance Associated Traits

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Achirou Bacharou Falke ◽  
Falalou Hamidou ◽  
Oumarou Halilou ◽  
Abdou Harou
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Root Length ◽  
Root Length Density ◽  
Block Design ◽  
Genotypic Variation ◽  
Water Regimes ◽  
Year Effect ◽  
Fodder Production ◽  
Selection Of

Investigation of groundnut genotypes response to drought stress could contribute to improving drought tolerance and productivity. The objective of this study was to investigate new improved groundnut varieties response to drought stress under controlled conditions to identify tolerant materials and drought tolerance related traits. Thus, three experiments were conducted during off-seasons: two experiments in lysimetric system in 2017 and 2018 and one experiment in pots in 2017, to assess twelve varieties in a randomized complete block design with 2 water regimes and 4 replications. The water regimes were a full irrigation (WW) and an intermittent drought imposed at flowering times (WS). The investigated morphophysiological traits like transpiration, specific leaf area, root dry matter, root length density, and yield components decreased under WS. Significant year effect and genotypic variation were observed on most of investigated traits. Genotypes ICGV 92206 and ICGV 06319 showed low transpiration and revealed high pod yielding and early maturing genotypes under both water regimes, while genotypes ICGV 92035, ICGV 92195, ICGV 02038, ICGV 07211, and ICGV 07210 were drought-sensitive for pods production but produced high haulm under both water regimes. ICGV 92206, ICGV 02005, ICGV 02125, and ICGV 06319 showed higher yielding than 55-437 and Fleur 11. In this study, low total transpiration to control water loss, chlorophyll content, and root length density revealed drought tolerance associated traits for pod production, while TTW, TE, RDW, and RV revealed drought tolerance associated traits for fodder production.

scholarly journals Genetic Bases of Root System Architecture in Durum Wheat Seedlings

2016 ◽  
Vol 10 (1) ◽  
pp. 25-28
Author(s):  
Ghasemali Nazemi ◽  
Silvio Salvi
Keyword(s):  
Durum Wheat ◽  
Root System ◽  
System Architecture ◽  
Root Length ◽  
Recombinant Inbred Lines ◽  
Primary Root ◽  
Root System Architecture ◽  
Total Root Length ◽  
Wheat Seedlings ◽  
Significant Difference

Root system architecture (RSA) traits are characterized by constitutive genetic inheritance components which may enable to predict the root phenotypes based on genetic information. The research presented in this study aimed at the identification of traits and genes that underlie root system architecture (RSA) in a population of 176 recombinant inbred lines (RILs) derived from the cross between two durum wheat cvs. Meridiana and Claudio, in order to eventually contribute to the genetic improvement of this species. The following seedling-stage RSA traits were: primary root length, seminal root length, total root length, diameter of primary and seminal roots. Results of ANOVA showed a significant difference among durum wheat cultivars for all traits and the largest heritability was observed for total root length (30.7%). In total, 14 novel QTLs for RSA traits were identified, and both parents contributed favorable alleles to the population.International Journal of Life Sciences 10 (1) : 2016; 25-28

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