Effects of Ozone Stress on Stem Lodging Resistance of Different Rice Cultivars

The present study aimed to assess the response of 15 rice cultivars exposed to elevated ozone stress. The plants were exposed to 100 ppb ozone (10:00– 17:00 h) for 30 days at the reproductive stage. Elevated ozone significantly alters the physiological, biochemical, growth and yield traits of all test rice cultivars. Elevated ozone exposure significantly decreased photosynthetic rate maximally in MDU5 (42.90%) and TRY(R)2 showed maximum reduction in stomatal conductance (42.39%) and chlorophyll content (41.22%). In terms of yield traits, a decrease in tiller number, number of effective tillers, number of filled spikelets per panicle and 1000 grain weight over the control were also observed. The multivariate analysis with a total variance of 58.86% categorized the 15 rice cultivars into ozone sensitive (TRY(R) 2, ASD16, ADT(R)45 and MDU5), moderately ozone sensitive (ASD18, ADT43, Rice MDU6, ADT36 and ADT37), moderately ozone tolerant (ADT(R)48 CO47 and Rice CO51) and ozone tolerant (Rice TPS5, Anna(R)4 and PMK(R)3) under 100 ppb ozone. The present results revealed that the ozone tolerant rice cultivars would be recommended to cultivate in the regions experiencing high ozone concentration.

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Detection of ozone stress in rice cultivars using spectral reflectance

Environmental Advances ◽

10.1016/j.envadv.2021.100129 ◽

2021 ◽

pp. 100129

Author(s):

Ambikapathi Ramya ◽

Periyasamy Dhevagi ◽

S.S Rakesh ◽

M Maheswari ◽

Subburamu Karthikeyan ◽

...

Keyword(s):

Spectral Reflectance ◽

Rice Cultivars ◽

Ozone Stress

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A method to evaluate lodging potential in rice cultivars based on elastic stability theory

Australian Journal of Experimental Agriculture ◽

10.1071/ea9940953 ◽

1994 ◽

Vol 34 (7) ◽

pp. 953 ◽

Cited By ~ 2

Author(s):

PM Moldenhauer ◽

KAK Moldenhauer

Keyword(s):

Plant Height ◽

Cross Section ◽

Modulus Of Elasticity ◽

Elastic Stability ◽

Elastic Behavior ◽

Rice Cultivars ◽

Lodging Resistance ◽

Bending Modulus ◽

The Difference ◽

Panicle Weight

Physical characteristics of rice which may be used to evaluate lodging resistance have been measured or calculated. The main characteristics considered were plant height, plant cross-section properties measured by the second moment of area, and the elastic behavior of the culm measured by the bending modulus of elasticity. A method for determining the modulus of elasticity is described. Plant height, modulus of elasticity, and relative straw strength scores were compared. The concept and application of natural stability was discussed in the context of Euler column theory. Euler column theory was applied to near-harvest rice. Predicted critical loads and the difference between predicted loads and average panicle weight were compared with relative straw strength scores.

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Lodging Resistance In Rice Cultivars Under Rates of Nitrogen Fertilizer; Does The Main Culm Represent The General Pattern of Lodging In Primary Tiller?

10.21203/rs.3.rs-528725/v1 ◽

2021 ◽

Author(s):

Solomon Oladimeji Olagunju ◽

Precious A. Aremu ◽

Tolulope A. Ayodele ◽

Oluwapelumi J. Ismail ◽

Oladele A. Oguntade ◽

...

Keyword(s):

Nitrogen Fertilizer ◽

Upland Rice ◽

General Pattern ◽

Bending Moment ◽

Rice Cultivars ◽

Lodging Resistance ◽

Primary Tiller ◽

Application Rates ◽

Culm Wall ◽

Selection Of

Abstract Purpose Lodging resistance (LR) in rice cultivars is usually established using the main culm (MC) as a good representative of tillers on the plant. However, it remains unclear whether LR of MC represents LR of the primary tiller (PT) to guide in the selection of tillers during LR assessment in rice cultivars under rates of nitrogen fertilizer. Methods Four lodging resistant cultivars namely: NERICAs 1, 4, 6 and Moroberekan were established under three rates (0, 60, 120 kg ha-1) of nitrogen fertilizer. At 20 days after heading of each of the MC and PT, the culms were harvested for assessment of LR. Results Increasing application rates of nitrogen fertilizer increased the culm morphological traits (CMTs) such as culm wall thickness, internode and lumen diameters, bending moment and breaking strength of MC and PT with little effect on lodging index (LI). The CMTs were however, higher in the MC and with lower LI than in the PT. The higher CMTs in MC did not translate to lower LI in all the rice cultivars such as Moroberekan compared with the PT. Correlations of CMTs with LI were higher and significant in the MC than in the PT. Conclusion Main culm remains reliable for the mechanical assessment of LR in upland rice but does not represent the general pattern of lodging in the PT. There is need for consistency in selection of tiller for mechanical assessment of lodging in rice cultivars under rates of nitrogen fertilizer.

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Lodging Resistance Related to Root Traits for Mechanized Wet-Seeding of Two Super Rice Cultivars

Rice Science ◽

10.1016/j.rsci.2021.01.009 ◽

2021 ◽

Vol 28 (2) ◽

pp. 200-208

Author(s):

Zhang Minghua ◽

Mo Zhaowen ◽

Liao Juan ◽

Pan Shenggang ◽

Chen Xiongfei ◽

...

Keyword(s):

Root Traits ◽

Rice Cultivars ◽

Lodging Resistance

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Response of rice (Oryza sativa L.) cultivars to elevated ozone stress

10.21203/rs.3.rs-613582/v1 ◽

2021 ◽

Author(s):

Ambikapathi Ramya ◽

Periyasamy Dhevagi ◽

Sengottiyan Priyatharshini ◽

R Saraswathi ◽

S Avudainayagam ◽

...

Keyword(s):

3D Model ◽

Oryza Sativa L ◽

Principal Component ◽

Growth And Yield ◽

Rice Cultivars ◽

Spikelet Sterility ◽

Elevated Ozone ◽

Specific Variation ◽

Ozone Stress ◽

1000 Grain Weight

Abstract The current study aimed to evaluate the cultivar specific variation in rice exposed to elevated ozone. Fifteen short duration rice cultivars were exposed to 50 ppb ozone for 30 days at reproductive stage. The physiological, biochemical, growth and yield traits of all test cultivars were significantly affected in response to elevated ozone. On average, ozone stress decreased tiller number by 22.52%, number of effective tillers by 30.43%, 1000 grain weight by 0.62 % and straw weight by 23.83% over control. Spikelet sterility increased by 19.26% and linear multiregression 3D model significantly fits the spikelet sterility and photosynthetic traits with the R 2 of 0.74 under elevated ozone. Principal Component Analysis with total variance of 57.5% by first two principle components categorized 15 rice cultivars into four major groups, ie., ozone sensitive (MDU6, TRY(R)2 and ASD16), moderately ozone sensitive (ASD18, ADT43 and MDU5), moderately ozone tolerant (ADT37, ADT(R)45, TPS5, Anna(R)4, PMK(R)3 and ADT(R)48) and ozone tolerant (CO51, CO47 and ADT36).

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