Abiotic Stress management in Vegetable Crops.pptx

1. Abiotic Stress Management in
Vegetable Crops

2. Stress
Stress is an external factor that exerts a disadvantageous
influence on the plant and is measured in relation to plant
survival, crop yield, growth (biomass accumulation), which
are related to overall growth.
(Taiz and Zeiger, (2006)

3. Definitions
Stress: Any environmental factor “un-favourable” for the living
organism under consideration (Levitt 1980).
Stress resistance: In accordance, the ability of the organism to
survive the un-favourable factor has been called “stress resistance”.
Stress, in the sense of a stressor or stress inducer (Cassells and Curry
2001), is an unusual factor or a usual factor of the biotic and abiotic
environment modified in such a way (excess or deficit) that it has the
capability of causing bodily injury, disease, or aberrant physiology.
Stress, in the sense of the physiological state, is the condition caused
by factors that tend to alter an equilibrium (Nilsen and Orcutt 1996).
The biophysical definition of stress is that it is the applied force
divided by the area of the force, or pressure.

4.  The term stress, in a plant physiological sense, is therefore reflective
of the amount of environmental pressure for change that is placed on
an organism’s physiology.
 Strain: Strain is defined as the proportional change in a substance as a
consequence of stress. Strain can be characterized as a physiological
change that occurs in response to environmental stress that does not
necessarily result in significant reduction of growth or reproduction
(Levitt 1982).
 According to Strasser (1988), strain is any physical and/or chemical
change produced by a stress, which is every established condition that
forces a system away from its thermodynamically optimal state. The
state is called optimal when the biological system is in full harmony
with its environment.

6. Introduction
 Phenotypic performance of a plant/line/population is determined by: (1)
Genotype (2) Environment (3) GxE Interactions
 Environment: Sum Total of all the factors other than the individual
concerned
 The various factors of the environment are called Biotic or Abiotic
depending upon their biological/ non biological nature.
 Stress free environment/optimal environment: There is no
interference by any environmental factor with the complete expression of
genotypic potential of an individual /line.
 Stress: When some environment factors interferes with the complete
expression of genotypic potential.
 Stresses are classified as: Biotic ( pathogens, pests, weeds etc) and Abiotic
( Moisture, temperature, minerals, soil pH,air pollution etc.)

7. Importance of Abiotic Stresses
 According to an estimate, 24.2% of the world's geographical area is arable.
 Only 10.6% of the geographical area is under cultivation and rest is under
abiotic stresses.
 In India 13.6% area is potentially , but not actually arable.
 Drought is the main abiotic factor as it affects 26% of the arable area.
 Mineral toxicities/deficiencies are second in importance, while freezing
stands close third.
 Quantification of degree of an abiotic stress is generally difficult.
 The severity of the stress on crop depends greatly on duration and stage of
crop growth (How long stress, stage of crop)

8. Percent of geographical area
potentially and actually arable
The Fraction of world’s arable
land subject to an abiotic stress
Region Potential Actual
World 24.2 10.6
Asia 24.1 18.9
India 56.0 43.6
Abiotic stress (%)
Drought 26
Mineral (toxicity/deficiency) 20
Freezing 15
No Stress 10

9. Characteristics of abiotic stresses
 The characteristics of abiotic stress may vary
depending on location.
 Region/location specific importance of abiotic
stresses.
 Occurrence and location of stresses is
unpredictable
 Degree of some stresses vary during cropping
season
 Some stresses can be managed e.g. drought, salinity
whereas some cannot e.g. temperature stress.

10. Cont..
 One abiotic stress may increase or decrease the effect
of other stress e.g./ high moisture stress can increase
salinity stress
 Different crop plants/varieties/species responds
differently to various stresses.
 Crop growth stage affect tolerance to various stresses
 Stress during reproductive phase cause more stress
as compared to vegetative stage.
 The effects generated by one abiotic stress may
overlap some of those generated by another stress.

11. Stress resistance mechanisms
 Mechanisms that permit stress survival are termed RESISTANCE
mechanisms and can allow an organism to tolerate or avoid stress.
Stress resistance mechanisms can be grouped into two general
categories:
1.Avoidance mechanisms
- prevents exposure to stress
2.Tolerance mechanisms
- permit the plant to withstand stress
 In one case, TOLERANCE, plants have mechanisms that maintain
high metabolic activity under mild stress (similar to that in the
absence of stress) and reduced activity under severe stress. In
contrast, mechanisms of AVOIDANCE involve a reduction of
metabolic activity, resulting in a dormant state, upon exposure to
extreme stress (Osmond et al. 1987).

12. .

13. ABIOTIC STRESSES: Situations where environmental
stimuli that normally influence plant development, growth,
and productivity, exceed thresholds (species-specific),
damaging the plant.
 Drought
 Cold (chilling and freezing)
 Salt
 Heavy metals
 Heat shock
 Anoxia
 Nutrient stress

14. 26 %
Blum (1988) and Dudal (1976)

16. Abiotic stress management
Abiotic stresses may lead to suboptimal yields to total crop
failures. These losses can be reduced/eliminated by the
following approaches:
(1) Crop Management
(2) Development of resistant varieties
(3) Use of resistant rootstocks
(1) Crop Management:
 Advisory for drought management practices in vegetable
crops.
 Seedling production in plug trays/pro trays (Tray vs
open)

17. Cont..
 Season of planting: select appropriate season
 Land Preparation:
 Deep tillage reduce run off, increase depth of penetration
and profile soil moisture stress, surface runoff in ridges
and furrows is low.
 Raised bed method of cultivation
 Enhancing soil organic matter content
 Enrichment of FYM with bio-fertilizers and bio-agents
 Drip irrigation/fertigation
 Foliar nutrient application
 Micro sprinkler irrigation

18. Cont..
 Wind breaks, hedges and intercropping
 Mulching practices
 Use of growth regulators
 Soil fertility management
 Crop and variety selection
 Soil and moisture conservation
 Use of hydrophyllic polymers

19. 2. Development of Resistant varieties
 Indirect breeding for Stress Resistance: The material
is not deliberately developed for stress resistance ; it is only
evaluated for stress resistance.
 Direct breeding for Stress Resistance: Deliberate
breeding for stress resistance. The stress environment for
selection may be (1) present in a field or (2) it may be
created in laboratory.When a genetically variable material is
grown under stress environment, selection could be based
on (1) Survival (2) For Yield (3) Selection for traits
contributing to stress resistance.

20. Genetic sources
 Cultivated varieties
 Adapted variety
 No compromise on yield
 Breeding material
 Transfer of trait is easy and with minimum linkage
drag
 Landraces
 Problem of undesirable linkages
 Subjected to artificial and natural selection
 Wild relatives
 Aim is to survive not the yield
 Transfer of trait is major problem
 Transgenes
 Cloning of target gene
 Transfer requires technical expertise
S.habrochaites
Solanum torvum

21. CROP WILD RELATIVES
CROP WILD RELATIVES (CWR): Which include the progenitors of crops as well as
other species more or less closely related to them, have been undeniably beneficial to
modern agriculture, providing plant breeders with a broad pool of potentially useful
genetic resources.
• The genetic potential of wild relatives in crop is well documented, particularly for crops
like potato, tomato etc. (Hawkes 1977; Stalker 1980; Plucknett et. al. 1987). Not
surprisingly, the greatest contribution of wild species has been in resistance breeding.
BRIEF HISTORY
• Wild relatives were used in crop improvement in sugar cane in the first half of the 20th
century. Their utility was recognized in breeding programs of major crops in the 1940s
and 1950s (Plucknett et al. 1987), and wild gene use in crop improvement gained in
prominence by the 1970s and 1980s with their use being investigated in an increasing
wide range of crops (Hoyt 1988).
• When the level of resistance to various abiotic and stresses in cultivated germplasm is
low or the range of genetic variability is narrow and selection results in virulent
biotypes of the pests and diseases the discovery and incorporation of additional for
resistance from wild species becomes key crop productivity.

22. Abiotic stresses and their source of resistance in
tomato
.
Species tolerant to environmental stress in Tomato
Species Environmental stress tolerance
S. cheesmanii Salt tolerance, heat tolerance for fruit set, cold tolerance,
water logging
S. pimpinellifolium Heat tolerance for fruit set, Drought tolerance, water
logging
S. chilense Drought tolerance, cold tolerance
S. hirsutum Cold tolerance, chilling tolerance, salt tolerance
S. pennellii Drought tolerance, salt tolerance, moisture stress
S. lycopersicoides Cold tolerance
L. esculentum var.
cerasiforme
Water logging condition, moisture stress

23.  Tomato varieties / hybrids tolerant to abiotic stress
Variety Abiotic Stress Tolerance
Pusa Sheetal Fruit set up to 8°C (low) night temperature
Pusa Hybrid-1 Fruit set up to 28°C (high) night temperature
Pusa Sadabahar Fruit set up both low (6°C) and high (30°C) night temperature
Sabour Suphala Salt tolerant at seed germination stage
Arka Vikas Tolerant to moisture stress
S. cheesmanii S. chilense S. hirsutum S. lycopersicoides

24. Brinjal
Solanum species (non-tuberiferous) and brinjal cultivars resistant to abiotic
stress
Abiotic
stress
Resistant
Species Cultivars
Drought S.macrocarpon,
S.gilo
SM-19 and SM-1
(tolerant), SM-30
(moderatly tolerant) and
their crossed progenies,
Supreme,Violette Round
Salt tolerant - JC-1, RAH-51, Pragati,
Pusa Bindu, Co-1
High
temperature
- R-34, PH-4
S.macrocarpon

25. Capsicum
Capsicum species resistant to abiotic stress
Species Resistance
C.chinense Resistance to drought
C.baccatum var.pendulum Drought and high
temperature
C.ciliaum Waterlogging
C.eximium Drought, high temperature
C.flexuosum Soil salinity
C.cardenasii Low temperature
C.chinense
C.flexuosum
C.baccatum var.pendulum C.ciliaum

26. Potato
Sources of resistance in wild/semi-cultivated species to abiotic stress
Stress Resistance source
Frost S. acaule, S. ajanhuiri, S. boliviense, S. brachistotrichum, S.
brevicaule, S. brevidens, S. canasense, S. chomatophilum, S.
commersonii, S. curtilobum, S. demissum, S. vernei, S.
juzepczukii, S. megistacrolobum, S multidissectum, S.
raphanifolium,S.sanctae- rosae,S.toralapanum
Heat and drought S. acaule, S. bulbocastanum. S. chacoense. S. megistacrolobum,
S.microdontum,S.papita,S.pinnatisectum and S.tarijense
Tuber blackening S.hjertingii
Salinity Solanum curtilobum, S. ochanum, S. acaule and S. demissum
and Solanum juzepczuckii

27. Pea
 Breeding peas for cold resistance or cold hardiness by
recurrent selection and resistance to waterlogging has
been undertaken abroad.The‘leafless’ pea is tolerant to
waterlogging.

28. French bean
 Environmental stress tolerance
 Important environmental stresses for French bean are drought, heat,
and cold.
 Drought tolerance is often associated with a well-developed root
system.
 A breeding line 5 BP 7 has been reported to be heat tolerant.
Wild types as sources of resistance
Character Source
ColdTolerance Phaseolus filiformis and P.angustissimus
DroughtTolerance Phaseolus acutifolius
SalinityTolerance Phaseolus filiformis
Phaseolus filiformis

29. Classification of vegetable crops
 Classification based on hardiness:
This classification is based on ability to withstand frost and low temperature and
it will be useful to know season of cultivation of a crop. Here the vegetable crops
are classified into hardy, semi hardy and tender. Hardy vegetables tolerate frost
and low temperature and are basically winter or cool season or temperate
vegetables. Warm season or subtropical or tropical vegetables are considered as
tender since they cannot withstand frost.
Hardy Semi-hardy Tender
Asparagus, Crucifers,
Garlic, Leek, Onion,
Parsley, Peas, Radish,
Rhubarb, Spanish
Carrot, Celery, Beet
root, Globe artichoke,
Lettuce, Palak, Parsnip,
Potato
Amaranth, Okra,
Brinjal, Chilli, Cluster
bean, Cucurbits,
Tomato, Colocasia,
Amorphophallus, Yams,
Sweet potato

30. .

31.  Classification based on tolerant to soil acidity:
 Classification based on tolerant to soil salinity:
Less tolerant
(pH 6.0-6.8)
Moderately tolerant
(pH 5.5- 6.8)
Highly tolerant
(pH 5.0-6.8)
Cabbage, cauliflower,
beet root, lettuce,
muskmelon, okra, onion,
lettuce, celery, palak,
cowpea
Beans, brinjal, carrot,
cucumber, garlic, peas,
pepper, radish, tomato,
pumpkin, turnip,
kholrabi
Potato, sweet potato,
watermelon, rhubarb.
Less tolerant Moderately tolerant Highly tolerant
Celery, peas, beans,
radish, potato, sweet
potato, snake gourd,
sweet pepper, brinjal
Tomato, chilli, water
melon, cucumber,
pumpkin, musk melon,
bottle gourd, amaranth,
cabbage, cauliflower,
carrot, onion
Beet root, palak, turnip,
kale, lettuce, asparagus,
bitter gourd, ash gourd

32.  Classification based on water requirement:
High Moderate Low Very low
Cole crop, radish,
leafy vegetables
Brinjal, chilli,
tomato, potato
Beans, ridge
gourd
Water melon,
musk melon,
pumpkin, ash
gourd

33. 3.Grafting technology for abiotic stress
management
 A plant’s first line of defense against abiotic stress is in its roots.
 A special method of adapting plants to counteract environmental
stresses is by grafting elite, commercial cultivars on selected
vigorous rootstocks
 Grafting is useful to initiate flowering and fruit set at low
temperature.
 Grafted plants have more content of Linolenic acid, which
helps in the survival of plants under low temperature(Pandey
and Rai, 2003).
 Concentration of proline, vitamin-c and water soluble sugars were
higher in grafted seedling than in ungrafted seedling (Ai et
al, 1999).

34.  Use grafted tomato may give certain degree of
resistance against thermal stress.
(Rivero et al, 2003)
 The use of eggplants as rootstocks for tomato at
higher temperature seemed to be more promising.
(Abdelmageed and Gruda,2009)
 Inter-generic grafting imparts flood tolerance in
cucurbits. (Pandey and Rai, 2003 IIVR,Varanasi)
 Grafting improved flooding tolerance of bitter gourd
(Momordia charanthia L. cv. New Known You ) when
grafted onto sponge gourd (Luffa cylindria Roem cv.
Cylinder).

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