Correlation of yield with early seedling performance and physio-biochemical traits in Basmati rice mutants subjected to heat stress

The present study aims at deciphering the response of Basmati rice mutants to high temperature stress. The work aims to find an early screening method by correlating seedling and physiological response to yields. After rigorous screening in controlled environment (growth chamber) and field conditions over a period of four years 16 mutants’ lines were selected: HTT-18, HTT-29, HTT-31, HTT-39, HTT-51, HTT-53, HTT-74, HTT-81, HTT-92, HTT-97, HTT-98, HTT-104, HTT-114, HTT-119, HTT-132 and HTT-138. These have been tested against standards: Super Basmati and IR-64. Field trials were conducted at three locations while early seedling-stage traits and their biochemical analyses were studied in growth chamber experiments. Data of seedling traits were used to establish correlations with paddy yield under hot field conditions. The temperatures were high at two sites: Multan and Bahawalpur ranging 24-46 °C and 25-45 °C respectively), and relatively lower at NIAB field station (26-45 °C. The paddy yield was significantly correlated with early seedling-stage traits such as shoot length (0.79**), shoot fresh and dry weight (0.48* and 0.49*), and cell membrane thermo-stability (0.60**). Additionally, significant higher activities of antioxidants (SOD and APX) and lower stress indicators (MDA, esterase and TOS) were observed in the heat tolerant mutants. These mutants were classified for their heat tolerance by principle component analysis (PCA) using yield-correlated early seedling-stage and other physio-biochemical parameters. As a result, the heat tolerance classification of mutants based on PCA coincided with the yield of mutants grown under hot field conditions. The present study suggests that these seedling parameters may be used as surrogates for field performance and used in the selection of thermo-tolerant Basmati rice

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RECOVERY IN WHEAT FROM EARLY INFECTIONS BY HELMINTHOSPORIUM SATIVUM AND FUSARIUM CULMORUM

Canadian Journal of Plant Science ◽

10.4141/cjps59-027 ◽

1959 ◽

Vol 39 (2) ◽

pp. 187-193 ◽

Cited By ~ 5

Author(s):

B. J. Sallans

Keyword(s):

Fusarium Culmorum ◽

Seedling Stage ◽

Field Conditions ◽

Partial Recovery ◽

Helminthosporium Sativum ◽

Early Seedling

The tendency of wheat plants to recover from initial stunting by Helminthosporium sativum and Fusarium culmorum was studied under field conditions by comparing areas of the successively formed leaves of the main culm. The yields of grain were taken as the over-all measure of the influence of disease on the plants.H. sativum when applied to seed caused significant reduction in areas of the first and second leaves of the seedlings. Successive leaves were progressively larger in relation to those of the uninoculated plants. The two varieties in the experiment were about equally stunted in the early seedling stage. Reward made a notable recovery as indicated by increased areas of the later leaves and a substantially greater yield of grain than in the controls. Thatcher made only a partial recovery and its yield of grain was slightly depressed.F. culmorum produced less stunting than H. sativum in seedling leaves, and recovery as indicated in the later leaves was less marked though significant.H. sativum and F. culmorum on the same plants caused more initial stunting of leaves followed by greater recovery than with either fungus alone.

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Screening of Pearl Millet F1Hybrids for Heat Tolerance at Early Seedling Stage

Advances in Agriculture ◽

10.1155/2014/231301 ◽

2014 ◽

Vol 2014 ◽

pp. 1-17 ◽

Cited By ~ 4

Author(s):

Ashok Kumar Yadav ◽

Rajesh Kumar Arya ◽

M. S. Narwal

Keyword(s):

Pearl Millet ◽

Heat Tolerance ◽

Temperature Tolerance ◽

Seedling Stage ◽

Early Seedling ◽

Membrane Thermostability ◽

Highly Correlated ◽

Tolerance Indices ◽

Developmental Traits ◽

Seedling Thermotolerance

Ten pearl millet genotypes selected on the basis of response to supra-optimal temperature tolerance were crossed in a half-diallel mating system. The 45F1hybrids produced were tested along with parents for heat tolerance and related traits at seedling stage. Field screening and laboratory screening techniques were simultaneously used for the evaluation ofF1hybrids and their parents. Heat tolerance was measured as seedling thermotolerance index (STI) and seed to seedling thermotolerance index (SSTI) under field conditions, but membrane thermostability (MTS) in the laboratory. The hybrid H77/29-2×CVJ-2-5-3-1-3 showed highest STI value followed by H77/833-2×96AC-93. The genotype H77/833-2×96AC-93 had the highest worth for SSTI. These three indices were highly correlated among themselves. STI values were invariably high, whereas SSTI has lower values, as it also covers the effect of under soil mortality (USM). It was seen that the heat tolerance indices STI and SSTI were not showing any perceptible pooled correlation with developmental traits except germination and emergence rate. Based on our results, it could be suggested that membrane thermostability (MTS) may be used for screening large number of genotypes. Field based indices STI and SSTI may be used for evaluation of hybrids and varieties before they are released.

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Antioxidative and Metabolic Contribution to Salinity Stress Responses in Two Rapeseed Cultivars during the Early Seedling Stage

Antioxidants ◽

10.3390/antiox10081227 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1227

Author(s):

Ali Mahmoud El-Badri ◽

Maria Batool ◽

Ibrahim A. A. Mohamed ◽

Zongkai Wang ◽

Ahmed Khatab ◽

...

Keyword(s):

Salt Stress ◽

Salinity Stress ◽

Stress Responses ◽

Antioxidant Activities ◽

Tricarboxylic Acid Cycle ◽

Seedling Stage ◽

Plant Performance ◽

Salt Tolerant ◽

Brassica Napus L ◽

Early Seedling

Measuring metabolite patterns and antioxidant ability is vital to understanding the physiological and molecular responses of plants under salinity. A morphological analysis of five rapeseed cultivars showed that Yangyou 9 and Zhongshuang 11 were the most salt-tolerant and -sensitive, respectively. In Yangyou 9, the reactive oxygen species (ROS) level and malondialdehyde (MDA) content were minimized by the activation of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) for scavenging of over-accumulated ROS under salinity stress. Furthermore, Yangyou 9 showed a significantly higher positive correlation with photosynthetic pigments, osmolyte accumulation, and an adjusted Na+/K+ ratio to improve salt tolerance compared to Zhongshuang 11. Out of 332 compounds identified in the metabolic profile, 225 metabolites were filtrated according to p < 0.05, and 47 metabolites responded to salt stress within tolerant and sensitive cultivars during the studied time, whereas 16 and 9 metabolic compounds accumulated during 12 and 24 h, respectively, in Yangyou 9 after being sown in salt treatment, including fatty acids, amino acids, and flavonoids. These metabolites are relevant to metabolic pathways (amino acid, sucrose, flavonoid metabolism, and tricarboxylic acid cycle (TCA), which accumulated as a response to salinity stress. Thus, Yangyou 9, as a tolerant cultivar, showed improved antioxidant enzyme activity and higher metabolite accumulation, which enhances its tolerance against salinity. This work aids in elucidating the essential cellular metabolic changes in response to salt stress in rapeseed cultivars during seed germination. Meanwhile, the identified metabolites can act as biomarkers to characterize plant performance in breeding programs under salt stress. This comprehensive study of the metabolomics and antioxidant activities of Brassica napus L. during the early seedling stage is of great reference value for plant breeders to develop salt-tolerant rapeseed cultivars.

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Selection of drought tolerant wheat genotypes by osmotic stress imposed at germination and early seedling stage

SAARC Journal of Agriculture ◽

10.3329/sja.v15i2.35147 ◽

2018 ◽

Vol 15 (2) ◽

pp. 177-192

Author(s):

RR Saha ◽

A Hannan ◽

A Nessa ◽

MA Malek ◽

MR Islam

Keyword(s):

Osmotic Stress ◽

Dry Weight ◽

Seedling Stage ◽

Metabolic Efficiency ◽

Wheat Genotypes ◽

Shoot Dry Weight ◽

Vigour Index ◽

Peg Treatment ◽

Early Seedling ◽

Different Levels

An experiment on hundred wheat genotypes under different levels of osmotic stress was carried out during 2014 to select the genotype(s) tolerant to drought at germination and early seedling stage. Different levels of osmotic stress were imposed by using polyethylene glycol (PEG). Three osmotic stress levels viz. control (distilled water), 15% PEG solution and 25% PEG solution were used. Among the 100 genotypes the rate of germination percentage, final germination (%), root and shoot dry weight, amount of respiration and vigour index under PEG treatment was found significantly lower than that of control condition. Compared to control condition relative decrease in rate of germination, final germination, amount of respiration and vigour index among the wheat genotypes were found more at 25% PEG than that of 15% PEG treatment. However, the seed metabolic efficiency was significantly higher in wheat genotypes under both 15% PEG and 25% PEG treatment compared to the control condition. A significant positive correlation exists between the important growth parameters like rate of germination (%), final germination (%), shoot dry weight, root dry weight and vigour index. On the basis of these physiological traits against osmotic stress, nine genotypes of wheat such as BD-480, BD-498, BD- 501, BD-513, BD-514, BD-519, BD-592, BD-618 and BD- 633 were selected as drought tolerant.SAARC J. Agri., 15(2): 177-192 (2017)

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Effect of Heat Treatment on Physiological and Recovery Growth Status of Two Tomato Cultivars With Different Heat Susceptibility

10.20944/preprints202102.0122.v1 ◽

2021 ◽

Author(s):

Sherzod Nigmatullayevich Rajametov ◽

Eun Young Yang ◽

Hyo Bong Jeong ◽

Myeong Cheoul Cho ◽

Soo-Young Chae ◽

...

Keyword(s):

Heat Stress ◽

High Temperature ◽

Stress Tolerance ◽

Heat Tolerance ◽

Fruit Set ◽

Fruit Size ◽

Seedling Stage ◽

Screening Methods ◽

Tomato Cultivars ◽

Heat Tolerant

High temperature seriously effects on plant vegetative and reproductive development and reduces productivity of plants, while to increase crop yield is the main target in most crop heat stress tolerance improvement breeding programs, not just survival, under high temperature. Our aim was to compare temperature stress tolerance in two commercial tomato cultivars “Dafnis” (big fruit size) and “Minichal” (cherry fruit size) to develop early screening methods and find out survival rate and physiological responses of tomato cultivars on high temperature (40°C and within 70% RH, day/night) in 4-5 true leaf seedling stage- (4LS) and identifies the linkage of heat tolerance with fruit set and leaf heat damage rates (LHD) in seedling stage with subsequent vegetative traits at recovery. Results showed that heat stress significantly affected on physiological-chemical and vegetative parameters of seedlings regardless of tomato cultivars. Survival and the threshold level of high temperature tolerance in the seedlings of cv. “Dafnis” and “Minichal” were identified on days 7 and 9, respectively. Our findings revealed that photosynthesis (PN, Gs, Ci, Tr) parameters were increased and CHL content persisted steady value in cv. “Minichal” during heat stress period, however EC and RPL rates were lower than cv. “Dafnis”. Heat stress reduced the SFW in both cultivars in seedling stage, but PH and RFW were significantly decreased in the heat tolerant cv. “Minichal”, whereas this parameters were not significantly ranged in the heat susceptible cv. “Dafnis”. Additionally, there no found linkage between vegetative parameters with decreasing of PN and CHL rates during HT of seedlings. In plants of cv. “Minichal” with LHD-25, 50 and 75% were no found significant differences in PH, whereas in cv. “Dafnis” significant differences were determined in plants with LHD-75%, and the significant differences in rates of SFW and RFW were observed in plants of cv. “Dafnis” having LHD-75% for 28 days of recovery at NT condition. Taken together, we concluded that heat stress affected on physiological parameters regardless of tolerance level, and to identify heat tolerant genotype in tomato breeding program, screening and selection genotypes have to be evaluated at the vegetative and reproductive stages with consideration fruit size types. Since we could not find linkage between heat tolerances in seedling stage with fruit set at the reproductive stage and fruit set cannot be used as a general predictor of heat tolerance.

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Physiological Evaluation of Different Rice Genotypes to Two Salinity Level during Seedling Stage under Hydroponic System

International Journal of Plant & Soil Science ◽

10.9734/ijpss/2020/v32i830317 ◽

2020 ◽

pp. 42-56

Author(s):

S. Lakshmi ◽

V. Ravichandran ◽

L. Arul ◽

K. Krishna Surendar

Keyword(s):

Salt Stress ◽

Dry Weight ◽

Seedling Stage ◽

Salinity Level ◽

Ion Concentration ◽

Growth And Yield ◽

Root Shoot Ratio ◽

Ion Absorption ◽

Early Seedling ◽

Rice Genotypes

Hydroponics study was conducted to screen eight rice genotypes (CO 51, ADT 53, ADT 37, IR 64, CO 43, ASD 16, Pokkali; TRY 3) under salinity stress on early seedling stage. Two Saline treatments (75 and 100 mM NaCl) were given at 15 days old seedling; observations were recorded at 10 days after salt stress. Results showed that shoot length, root length, total fresh and dry weight, shoot and root fresh weight, shoot and root dry weight and root- shoot ratio were reduced under saline conditions compared to control. Na+ ion Concentration and Na+/ k+ ratio was higher in saline treatments than control. However, K+ ion absorption decreased with increasing salinity level. Electrolyte leakage and osmotic potential had increasing trend with increasing level of salinity. In this study, rice genotypes Pokkali, TRY 3 and CO 43 perform as tolerant; CO 51, ADT 53 and ASD 16 perform as moderately tolerant; ADT 37 is susceptible and IR 64 is highly susceptible. This type of study is required to develop salt tolerant genotypes at salt stress during seedling stage; to increase the growth and yield of rice there by satisfy the need of country’s requirement.

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