Abiotic Stresses In Maize: Some Issuues And Solutions, DMR

Abiotic Stresses in Maize: Some Issues and Solutions

Directorate of Maize Research (Indian Council of Agricultural Research) Pusa Campus, New Delhi 110 012 (India)

Abiotic Stressess in Maize: Some Issues and Solutions Sain Dass Ishwar Singh Chikkappa G.K. C.M. Parihar J. Kaul A. Singode Manivannan A. D.K. Singh

Directorate of Maize Research (Indian Council of Agricultural Research) Pusa Campus, New Delhi 110 012, India Website: www.maizeindia.org, Email: pdmaize@gmail.com Phone: 011-25841805, 25842372 Fax:011-25848195

Abiotic Stressess in Maize: Some Issues and Solutions Citation:

Abiotic Stressess in Maize: Some Issues and Solutions Directorate of Maize Research, Pusa Campus, New Delhi110012, Indian Council of Agricultural Research, pp. 16.

Edited by:

Sain Dass, Ishwar Singh, Chikkappa G.K., C.M. Parihar J. Kaul, A. Singode, Manivannan A. and D.K. Singh

Published by:

Directorate of Maize Research Pusa Campus, New Delhi-110 012 (India) Ph: 91-11-25841805, 25842372, 25849725 FAX: 91-11-25848195 Email: pdmaize@gmail.com

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Diffferent Abiotic Stressess in Maize

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CONTENTS Content

Page No.

Introduction

1

Moisture Stress

2

Temperature stress

8

Salinity stress:

10

Low nitrogen stress:

11

Abiotic Stresses in Maize: Some Issues and Solutions

1

Abiotic Stresses in Maize: Some Issues and Solutions 1. Introduction: Abiotic stresses are integral part of any agroecosystem, it affects crop plant in variety of ways. However, the severity and impact varies from location to location because several factors determine the severity and impact of abiotic stresses like Soil type, temperature, relative humidity, organic matter in the soil, local vegetation, precipitation etc.

temperate conditions. The crop is also very popular in the low and mid-hill areas of the western and northeastern regions. The total cultivated area for maize in India is 8.17 million hectares having production of 19.73 million tones with average productivity of 2.41 tones/ ha (2008-09).

Factors determining severity of abiotic stresses

The cultivation of single cross hybrid maize has helped in mitigating severity of stresses to some extent because of their inherent ability to perform well under stress conditions compared to open pollinated varieties (OPV).

The reason for better performance of SCH over OPV’s are viz., better root system, early vigor and quick growth out competes with weeds,

Abiotic stresses like moisture stress, high and low temperature stress, salinity; nutrient stresses etc. frequently limit growth and productivity of major crop species such as maize. Maize (Zea mays L.) is considered as queen of the cereals. It is one of the most important food crops in the world with highest production and productivity. Maize is grown in more than 166 countries for diverse uses, in diverse seasons, in different agro-ecological conditions due to its high yield potential. The major maize growing countries are USA, China, Brazil, Mexico, India etc. In India, maize is grown in a wide range of climates, extending from extreme semi-arid to sub-humid to

The maize area under irrigation has increased marginally from ~11% (1950-51) to only ~20% (2008-09). The average annually increase in irrigated area under maize was 0.15%. So 80% of the maize at present is confined to rainfed condition that is why the crop often suffers from abiotic stresses. This is one of the major reasons for low productivity of maize in India.

There are several biotic and abiotic stresses affecting the crop. Among the abiotic stresses moisture stress (Low/Excess soil moisture), temperature (high/low), salinity, sodicity, nutrient etc.

1.1 Major abiotic stresses: 1.

Moisture stress (a) Water deficit (Drought) (b) Excessive moisture stress (water logging or submergence); 2. Temperature stress (a) High temperature stress (b) Low or chilling temperature stress; 3. Salt stress; 4.

Nutrient stress.

2

Abiotic Stresses in Maize: Some Issues and Solutions

Abiotic stresses

Major abiotic stresses

Drought prone areas in India

2. Moisture Stress Moisture deficit is the most common limiting abiotic stress among all stresses.

2.1 Water deficit (Drought): Water plays a vital role in the survival of plants as it is universal solvent, transport medium and evaporative coolant as well as providing the energy to drive photosynthesis, the natural plant process that synthesize organic food.

Under moisture stress condition, the loss of water in the plant protoplasm results in the concentration of ions in the protoplasm to toxic levels resulting in possible protein degradation and membrane fusion and negatively impacting plant metabolism.

Moisture stress is one of the major constraints in maize productivity. Out of the total area for maize cultivation about 4.0 million hectares are prone to drought in India as 80% of the India in Kharif season is rainfed. Moisture stress is very common in the areas where maize is predominantly grown under rainfed conditions. Whether in India or elsewhere in the world generally in rainfed areas rainfall is either unpredictable or uneven distribution.

2.1.1 Consequences of moisture stress: • •

• • • • • • • • •

Moisture stress adversely affect the source sink relationship in plant Reduced plant height, growth, and leaf area expansion which further reduces radiation interception.

Leaf senescence is accelerated, Delay in silking and an increased anthesis– silking interval (ASI).

Stomatal closure leads to declination of photosynthesis.

Reduced assimilate fluxes to growing organs.

Low biomass production Crop becomes more susceptible to pests and diseases attack.

Ear abortion Tassel blasting can occur if drought coincides with high temperature.

Remobilization of stem reserves can occur, when stress coincides with the phase of linear grain growth. In extreme cases this can result in premature lodging.

Abiotic Stresses in Maize: Some Issues and Solutions Sensitive stages to moisture stress: Crop stage

Consequences

Seedling (primordial stage) Knee high

Initial establishment, root growth, Plant vigor, cob length, kernel/row etc.

Plant height, Photosynthetic rate, LAI, total biomass Reduce pollen production, pollen viability, tassel blasting, prolong ASIUp to 80-90% reduction in yield Reduced seed size/ test weight, 20-50% reduction in yield

Flowering*

Grain filling**

• • • • • • • • • •

3

Short ASI/ Longer pollen shedding Erect leaves Earliness Protogyny Dark Green Leaf /Stay green/ High chlorophyll stability Low Canopy Temperature Non-barreness Osmotic Adjustment Pubescence, waxy leaves More Proline, ABA and Glycine-Betaine accumulation in specific tissue of plants.

*Most sensitive **Second most sensitive stage

The crop is particularly sensitive to water stress in the period one week before and two week after flowering. Moisture stress during this period results in an increase in the anthesissilking interval (ASI) and grain abortion.

2.1.2 Drought adaptations: Soil texture, temperature, rainfall, humidity, oozing, nutrient availability or uptake will determine the severity of stress.

Earliness

a. Soil texture - light soils retain less water leads to drought even with good rainfall (Raj, UP). b. The behavior of drought tolerant genotypes varies from location to location in relation to soil type, humidity and temperature. c. Screening has to be done in the targeted environment. d. Low rainfall but soil with good moisture retention shows variation in the drought situation.

Traits associated with drought tolerance: • Deeper Root System

Erect leaves Traits associated with drought tolerance

4

Abiotic Stresses in Maize: Some Issues and Solutions

Control

Drought

Deeper root system as an adaptive trait to drought 2.1.3 Screening techniques for drought stress: Screening to identify the tolerant source of genotype in order to develop drought tolerant hybrids for drought prone areas. It can be achieved in field condition by (i) Limiting the irrigation at different crop growth stages, (a) for large number of genotypes, (b) for limited number of genotypes; (ii). Evaluating genotypes under high plant density; 3. By using modern tools-SPAD and Green seeker etc.

Screening Technique for confirming the tolerance (Screening of promising genotypes) by limiting irrigation at 4 crop stages (Seedling, Knee high, Flowering and Grain filling) for identification and categorization of genotypes and associated traits at various stages

Rain-out Shelter Technique {The promising genotypes identified by screening, are further evaluated under Rain-Out Shelter to confirm their tolerance to drought}

2.1.4 Modern Tools for screening genotypes under abiotic Stresses: Field screening of large number of genotypes (limiting irrigation at 3 stages) Crop stages (Knee high, Flowering, Grain filling)

路 路

Chlorophyll meter/SPAD meter Green Seeker Optical Sensor

Abiotic Stresses in Maize: Some Issues and Solutions

5

Because -

2.1.5 Management of drought:

• Screen large number of genotypes • Overcome shortage of technical manpower • Quick method • Cost effective • Comprehensive out-put results Chlorophyll Content Meter/SPAD

Adaptation of single cross hybrids: Single cross hybrids have better tolerance due to its inherent genetic capacity to cope better in the drought than other OPV’s and composites.

Easier method to determine the chlorophyll content • Screen large number of genotypes • Low cost technique Green Seeker Optical Sensor •

• • •

Physically scan the plant Measures Normalized Difference Vegetation Index (NDVI) Used for large scale field screening

Performances of single cross hybrids under water stress

Furrow sowing: • • • •

Conserves moisture Provide microclimate for better plant growth Better root development in furrows Prolong availability of moisture to sustain plant life

Chlorophyll Content Meter/SPAD

2.2 Excessive soil moisture stress:

Green Seeker Optical Sensor

High water table and poor drainage are responsible for excessive soil moisture which is one of the major maize production constraints. In India, about 8.5mha of arable soil is prone to this problem. Approximately, 2.4mha, or 33% total area planted under maize, is subjected to excessive moisture/water logging causing considerable loss of maize production almost every year.

6

Abiotic Stresses in Maize: Some Issues and Solutions

Major excess moisture stress affected states in India: • • • • •

Eastern UP Bihar Jharkhand West Bengal Orissa

Effect of seedling stage water logging on different maize hybrids. cellular metabolism is generated by oxidative phosphorylation) because it requires O2 as a terminal accepter of electrons and checks the ATP production. Low ATP availability leads to cellular damage, owing to a deterioration of cellular components, such as membranes and may also lead to cytoplasmic acidosis in sensitive genotypes.

Excessive Soil Moisture affected states in India Excessive soil moisture causes major changes in physical and chemical properties of the rhizosphere. The oxygen diffusion rate in flooded soil is about 100 times lower than that in air and respiration of plant roots, soil micro flora and fauna leads to a rapid exhaustion of soil oxygen resulting in hypoxia (deficiency of oxygen) followed by anoxia (complete absence of oxygen) occurs when water logging or flooding persists for long duration.

2.2.1 Consequence of excess soil moisture stress on plants: Energy crisis: ESM stress leads to hypoxic/ anoxic condition which ultimately ceases the oxidative phosphorylation (majority of ATP for

Toxicities: Reduced soil components such as Mn2+, Fe2+, S2- and some volatile lower organic acids like propionic and butyric acid can accumulate in water logged soils and damage roots.

At re-aeration after a period of O2 deprivation, ethanol remaining in tissues will be converted to acetaldehyde that can induce post anoxic cell injuries. The maximum affected is root system, this is due to the anaerobic condition that leads to loss of ATP molecules which are required to drive various metabolic pathways (there is also a drop in the intracellular pH). In healthy maize cells, the vacuole content are usually more acidic (pH 5.8) than the cytoplasm (pH 7.4). But under extreme O2 deficiency the protons gradually leak out from vacuoles in the cytoplasm making it more acidic. These changes were associated with the onset of cell death.

Excessive soil moisture leads to the produc-

Abiotic Stresses in Maize: Some Issues and Solutions tion of reactive oxygen species (eg. Superoxide radicals, hydroxyl radicals, hydrogen peroxide, singlet oxygen) which causes cellular damage.

Excessive soil moisture stress can cause wilting of shoot organs and this response is mediated by a decrease in the hydraulic conductivity of roots and finally results logging of the plants.

2.2.2 Consequence of excess soil moisture on soil: • •

Less diffusion of oxygen in root zone More CO2 accumulation in root zone

7

Most critical crop growth stages, duration and temperature for water logging: Stages

Seedling, knee high, flowering, grain filling stage

Duration

Within 48 hours the oxygen supply in a flooded soil is depleted.Respiration process gets impaired, leads to mortality.

Temperature More than 250C during flooding even for 24 hours, causes mortality.

2.2.3 Consequence of excess soil moisture on nutrients availability: • •

•

•

•

Loss of N through denitrification and leaching.

Reduced activity of ammonifiers and nitrifiers leads to lesser availability of N to plants.

Anaerobic condition causes the deficiency of zinc and Molybdenum but releases the toxic elements like Fe2+, Al2+, and Mn2+.

Excessive soil moisture condition restricts the root development leading to logging of the plants.

Decreased total root volume leads to less transport of water and mineral nutrients from source to sink.

(Closer view)

In general the presence of excess water in the rhizosphere negatively affects maize at every growth stages. But the extent of susceptibility varied remarkably at different growth stages.

Traits associated with water logging: The most prominent morphological, anatomical and metabolic changes widely observed in maize genotypes under low oxygen partial pressure in rhizosphere are as follows-

Development of brace root nodes as an adaptive trait for water logging

8 • • • • •

Abiotic Stresses in Maize: Some Issues and Solutions Development of brace root system.

Root growth towards ground surface Development of arenchyma cells More root porosity Low ethanol accumulation

2.2.4 Management of water logging: Genetic approaches Selection for brass root plant type-brass root anchors the plant and give the mechanical strength to withstand flooded conditions.

Cultural management •

• • •

Sowing of seeds at the top of the bed.

Avoid heavy clay soils.

Provide proper drainage.

3. Temperature stress 3.1 Low temperature stress: Maize is highly sensitive to frost and moderately sensitive to chilling. The extreme cool temperature affects the maize growth in a number of ways right from emergence till flowering and seed setting. Temperature below threshold level (10/40C, day/night) causes various type of irreversible physiological damage during late vegetative/early flowering stage. The severity of damage depends on temperature and its duration, developmental stage and the genotype. Early flowering with long grain filling duration and extended stay green character provided the basis for hybrid with high yield potential under low temperature stress. Low temperature stress injuries can be categorized under two heads.

1. Chilling injury - Between the temperature range 0 - 150C 2. Freezing injury - occurs only when external temperature drops below 00C. Major cold affected states in India:

Cold affected states in India 3.1.1 Consequences of low temperature stress: • • • • • • • • •

Reduced germination, plant height.

Induces wilting Yellowing, discoloration of leaves Leaf tip firing due to death of leaf tissues Delayed anthesis Reduced tassel size/branches Reduced pollen viability Reduced silk size and proliferation due to non-fertilization Crop becomes more sensitive to soil borne pathogen

Yellowing and discoloration of leaves due to low temperature stress

Abiotic Stresses in Maize: Some Issues and Solutions Maize is very sensitive to chilling especially during early autotrophic growth. Seemingly, photosynthesis is strongly affected due to the inhibition of certain enzymes of the C4 and the Calvin cycle. The reduced photosynthetic activity promotes dissipative mechanisms and affects the antioxidative defense in maize leaves.

3.1.2 Management of low temperature stress: Cultural •

Sowing on southern side of the ridge where it gets maximum sunlight during day time.

Planting of tall barrier crops in northern side of the field protects the crop from cold winds.

Potassium application helps to protect roots from cold stress.

• Frequent irrigation is needed to equalizes the root temperature with surrounding microclimate.

Genetic approaches: •

9

increased cold tolerance.

3.2 High temperature stress: High temperature stress is the 2nd major abiotic problem after drought that reduces grain yield more than 15 percent. Spring season is most suitable time for the cultivation of maize in India but transitory or constantly high temperatures cause an array of morphological, anatomical, physiological and biochemical changes, which affect plant growth and development. Especially more effects at reproductive stage through pollen abortion, silk desiccation and reduced grain set, ultimately leading to reduction in economic yield.

3.2.1 Consequences of high temperature stress: • • • • • • • •

Stunted plant growth Leaf rolling and firing Reduced net photosynthetic rate Increased transpiration rate Tassel blasting Increase in ASI Poor receptivity of silk Pollen abortion and poor seed set

Northern Southern

Management of low temperature stress by sowing the seeds on southern side of the ridge

• • • •

Single cross hybrids (Late and Medium) Selection of traits such as dark green, purple color and erect leaves plants.

Selection of genotypes with high density lateral roots.

ABA induced somaclonal variants showed high accumulation of proline resulted in

Major high temperature stress affected states in India

10

Abiotic Stresses in Maize: Some Issues and Solutions Sensitive stages to High temperature stress:

Major consequences of high temperature stress Maize growth is affected adversely when temperature increases beyond 32 0C. Net photosynthesis is inhibited at leaf temperature above 380C due to thermal inactivation of enzymes. The activation state of Rubisco decreases at temperature exceeding 32.50C with nearly complete inactivation at 450C. High temperature stress and low humidity can desiccate exposed silk and pollen grain due to their thin outer membrane when these are released from anthers. The degree of damage depends on the intensity and duration of high temperature spell.

• • •

•

• • •

Selection of early maturing single cross hybrids.

Planting the seed in furrows.

Creation of congenial microclimatic condition by application of water, if possible sprinkler irrigation system helps to reduce the temperature effect on plants.

Avoid sowing at improper time, which might result in coincidence of high temperature with flowering time Selection of hybrids which have shorter ASI. Use of organic waste, mulching helps in conserving soil moisture.

In case of large area sowing, go for staggered sowing, this prolongs the pollen availability throughout the period.

Crop stage

Consequences

Seedling (primordial stage) Knee high

Poor seed germination, root growth and Plant vigor.

Stunted plant height, Leaf rolling, leaf firing, Reduced photosynthetic rate, LAI, total biomass and increased transpiration rate.

Flowering* Reduce pollen production, duration of pollen shedding, pollen viability, induce tassel blasting and pollen abortion, and delay silking and poor receptivity of silk.

Grain filling** Poor seed set & reduced seed size/test weight, 2550% reduction in yield *Most sensitive **Second most sensitive stage Management of high temperature stress:

Sowing in furrows to mitigate high temperature stress

4. Salinity stress: Soil salinity affects plant production in many part of the world, particularly on irrigated land.

Maize (Zea mays L.) is considered as a moder-

Abiotic Stresses in Maize: Some Issues and Solutions ately salt-sensitive plant. Salt resistance in plants is a complex phenomenon that involves biochemical and physiological process as well as morphological and developmental changes.

In addition to general osmotic stress, Na+ is toxic to maize. Salt tolerance is a multigenic trait that allows plant to grow under salt stress condition by maintaining salt balance through osmotic adjustment without reduction in economic yield.

4.1 Consequences of salinity stress: • • • • •

Poor germination Yellowing of leaves Burning of leaf tips Rottening of leaves Plant mortality

4.2 Management of salinity stress: Sowing of the seeds on the side of the ridges, because salt has the tendency to move in the upward direction due to evapotranspiration.

Upward movement of salts

5. Low nitrogen stress: Indian nitrogen map shows that only 15 districts of north eastern hills and Himalayan regions covering about 5% of the total cultivated area are rich in nitrogen content. The remaining 95% soils are either low (62.5% of

11

Effect of different level of salinity on growth and development of maize (Source C. Zörb et al. (2004). Plant Science. 167: 91–100). the area) or medium (32.5% of the area) in nitrogen. Further more, nitrogen level in semi arid region where maize is grown are typically low in organic matter often containing less than 1% organic matter with a total nitrogen not exceeding 0.1%.

5.1 Traits affected by low nitrogen stress: • • • • • • • •

Plant Growth – height is reduced Plant strength - weak Cob length and girth - affected Leaf senescence – leaf turn to yellow Grain filling - patchy Kernel size – reduced/abortion ASI - Increased Susceptible to diseases like Stalk Rot and pest like Chilo partellus

12

Abiotic Stresses in Maize: Some Issues and Solutions

5.2 Approaches to overcome the nutrient stress Genetic Management Single cross hybrids Agronomic Management Organic manure, green manure, organic mulching, N fixing Bio fertilizer and proper method of sowing.

Zero till with residue Meena Kumari, Sain Dass, Vimala,Y. and Arora, P. (2004). Physiological parameters governing drought tolerance in maize.

Ann. Agric. Res. News Series. 25(3): 422428.

Mulching 5.3 Efficient Plant Type for Stress Tolerance: • • • • • • • •

Better root system Shorter ASI Stay green Erect leaves Strong plant Efficient nutrient utilizer Ears per plant Low stress index

References: Meena Kumari, Sain Dass, Vimala,Y. and Arora, P. (2004). Physiological parameters governing drought tolerance in maize.

Indian J. Plant Physiol. 9(2): 203-207.

Pollmer, W.G., D. Eberhard, D.Klein, and B.S. Dhillon (1979). Genetic control of nitrogen uptake and translocation in maize. Crop Sci. 19: 82-86.

Robson P.R., Donnison, I.S., Wang, K., Frame, B. and Pegg, S.E., (2004).Leaf senescence is deleyed in maize expressing the agrobacterium IPT gene under the control of a novel maize senescence enhanced promoter. Plant Biotech J. 2:101112.

Sain Dass, Pal, D., Kukreja, S., Arora, P., Dhanuja, K.S., Mahla, J.C, Yadav, G. and Arora, V (2004). Identification of nitrogen efficient genotypes of maize on the bass of yield efficiency index. Annals of Agri-Bio Research. 9(1): 21-24.

Sain Dass, Meena Kumari, and Arora, P. (1999).

Morphological traits associated with drought tolerance in maize (Zea mays L.). Annals of Agri-Bio Research. 4(2): 193196.

Directorate of Maize Research (Indian Council of Agricultural Research) Pusa Campus, New Delhi 110012 (India) Website : www.maizeindia.org Email: pdmaize@gmail.com Phone: 011-25841805, 25842372, 25849725 Fax: 011-25848195