Slide 1: COURSE SEMINAR
“BREEDING FOR QUALITY IN CROP PLANTS”
Dr. R. S. Nandanwar
Department of Agricultural Botany,
Post Graduate Institute, Dr. PDKV, Akola. Major Advisor
Senior Research Scientist,
Sorghum Research Unit,
Dr.PDKV, Akola 1 Slide 2: 2 Quality refers to the suitability or fitness of an economic plant product in relation to its end use.
Definition of quality varies according to our needs from the viewpoint of seeds, crop growth, crop product, post-harvest technology, consumer preferences, cooking quality, keeping quality, transportability etc. (Gupta,2001). What is Quality? Slide 3: 3 QUALITY TRAITS
A trait that defines some aspect of produce quality is called quality trait.
Each crop has a specific & often somewhat to completely different set of quality traits. Classification of Quality traits : Classification of Quality traits Morphological
others 4 Morphological Traits : Morphological Traits 5 related to produce appearance
mainly concerned with size & colour of the produce,
eg.,grain/fruit size, grain/fruit colour etc.
Usually play the main role in determining consumer
acceptance of the produce. Organolaptic traits : Organolaptic traits 6 Concerned with palatability of the produce .
eg., taste,aroma, smale, juiciness, softness,etc.
Very important in influencing consumer preferences Nutritional Quality : Nutritional Quality 7 Determine the value of the produce in human/ animal
Includes protein content & quality, oil content & quality,
vitamin content, mineral content, etc., and also the
presence of antinutritional factors.
Not easily appreciated by consumers & farmers,
but they are of paramount value in detremining human
& animal health. Biological quality traits : Biological quality traits 8 The traits included in this group define the actual
usefulness of the produce when consumed by
There usefulness to humans is usually predicted on this
eg.,Protein efficiency ratio,biological value, body weight
These traits are not obvious to consumers & growers
but are extremely valuabe in detrmining the utility of
produce for human &/or animal consumption Other quality traits : Other quality traits 9 Includes all other quality traits that are not
included in the above categories.
eg., cooking quality of rice, keeping quality of fruits &
vegetables, fibre strengh of cotton etc.
Many of the traits in this group are of prime importance
in determining the usfulness of the concerned produce. QUALITY TRAITS OF SELECTED CROPS : QUALITY TRAITS OF SELECTED CROPS 10 Slide 11: 11 Wheat
white or amber grain colour, medium to bold size, hard vitreous texture,
& lustrous appearance are important features for good market quality.
High lysine content & good baking quality are essential for use in biscuit
& bread manufacturing.
White coloured fine & long slender grains, taste & fragrance, less
breakage in milling, more hulling recovery, better cooking quality, high
protein & lysine contents. Maize
bold flint grains with attractive colour, high lysine, oil & sugar contents
The seed colour should be yellow or white. Sorghum
Bold, thin pericarp, white grains of attractive shape & size, high
protein & lysine content Pearl milletBold lustrous & pearly amber colour grains with high iron contents BarleyIn malting barley, low protein content & high extract of soluble oligosaccharides after malting are desirable characters. Low protein produces less haze in beer & high oligosaccharides are suitable for fermentation. : Pearl milletBold lustrous & pearly amber colour grains with high iron contents BarleyIn malting barley, low protein content & high extract of soluble oligosaccharides after malting are desirable characters. Low protein produces less haze in beer & high oligosaccharides are suitable for fermentation. 12 Pulses
Attractive shape, size & colour of grains, high protein contents; high methionine & tryptophan; & less flatulence. Oil seeds
Attractive shape, size & colour of seeds, high oil content free from antinutritional factors & more proportion of unsaturated fatty acids. SugarcaneModerate hardness, long internode, optimum (low) fibre for milling; sucrose ratio, high sucrose content & good quality of juice. : SugarcaneModerate hardness, long internode, optimum (low) fibre for milling; sucrose ratio, high sucrose content & good quality of juice. 13 Cotton
Fibre length, strength, fineness, maturity, uniformity & colour
Short & thin leaves with less branched veins are preferred for cigar.
Thin leaves are also preferred for pipe smoking.
Thick leaves are suitable for cigarettes.
High nicotin content for bidi, hookah & chewing & low for cigarettes are preferred.
High sugar content is also preferred. PotatoAttractive shape, size & colour of tubers, taste, cooking quality, thin skin, keeping quality & high starch content.VegetablesHigh vitamin & mineral contents, good taste, keeping quality & cooking quality .Forage cropsGreater nutritive value, more palatability & freedom from toxic substances. : PotatoAttractive shape, size & colour of tubers, taste, cooking quality, thin skin, keeping quality & high starch content.VegetablesHigh vitamin & mineral contents, good taste, keeping quality & cooking quality .Forage cropsGreater nutritive value, more palatability & freedom from toxic substances. 14 Medicinal plants
High content of active substance. Jute, kenef & sunnhemp
length, strength, fineness, colour, luster & freedom from knots & specks. Slide 15: 15 Four major goals for breeding for improved nutritional quality.
These are breeding for
high content & quality of protein,
(2) high content & quality of oil,
(3) high vitamin contents, &
(4) low toxic substances which are harmful for human health. NUTRITION & NUTRIENTS : NUTRITION & NUTRIENTS 16 The scientific study of food in relation to health is referred to as nutrition.
Various chemical components of food which provide nourishment to the body are
These are carbohydrates, fats, proteins, vitamins, minerals & water.
Good nutrition refers to adequate intake of well balanced diet, which supplies all
essential nutrients required by the body.
Malnutrition may result from deficiency, excess or imbalance of nutrients.
Hence all the nutrients should be taken in adequate quality. Protein content & Quality : Protein content & Quality 17 Proteins are an essential component of the diet.
Protein are organic macromolecules consisting of a long chain of amino acids
linked with each other by peptide bonds formed by carboxyl(-COOH) group of
one amino acid with amino group(-NH2) of other amino acid
The nutritional properties of proteins are determined by their amino acid
There are 21 amino acids which are important in human nutrition.
These can be classified into two groups, viz. (1) essential amino acids & (2)
non essential amino acids. Slide 18: 18 EAA can’t be synthesized in human body & their requirement has to be met
through dietary intake.
There are ten EAA (methionine, isoleucine, leucine, lysine,
threonine,tryptophan, valine, phenylalanine, histidine, & arginine).
Out of these arginine & histidine are considered non essential for the adult.
The non EAA can be synthesized in human body & they need not be supplied
These are cystine, cysteine, proline, glycine, serine, alanine, aspartic acid,
hydoxyproline, glutamic acid, norleucine & tyrosine.
The quality of protein is determined by the content of essential amino acids.
The sulphure containing amino acids (Tryptophan, Threonine, Isolecine,
Lysine, Valine & Methionine) are referred to as limiting amino acids. Table 1: EAA deficient in some vegetarian foods: : Table 1: EAA deficient in some vegetarian foods: 19 Singh,2002 Vitamins : Vitamins 20 A vital substance which is required in very small quantity & is essential for
proper growth & good health is called vitamin.
Vitamins are essential for body growth, maintenance & reproduction.
Based on their solubility, vitamins are of two types. Viz. (1) fat soluble (A, D,
E & K) & (2) water soluble: (B group vitamins & vitamin C).
Vitamin D & folic acid can be partly synthesized in the body.
Rest of the vitamins has to be supplied through diet.
Vitamin D is found in fats
other vitamins are found in fleshy fruits & green vegetables. NUTRITIONAL QUALITY OF CEREALS & PULSES : NUTRITIONAL QUALITY OF CEREALS & PULSES 21 Cereals are important sources of carbohydrates.
The contribution of cereals is 70% to the total calories in human diet.
They contribute 50% to the global protein requirement,
while grain legumes contribute only 20 %.
Remaining 30% comes from animal products.
The average protein content in the cereals ranges from 10 to 13%.
However, the cereal protein is deficient in lysine, tryptophan & threonine. Cereal Protein Quality : Cereal Protein Quality 22 Cereal proteins are classified in to four groups based on their solubility:
4)glutelins Major protein fraction of cereal proteins Singh,2002 Slide 23: 23 In all cereals, Prolamines are relatively rich in proline & glutamine but low in
basic amino acids including lysine. Therefore, they have poor nutritional
Generally, prolamin content in cereals is negatively associated with total
Cereals contain about 70% prolamine & glutelin and 30% albumin &
Several mutants with improved protein quality have been identified in
cereals like maize, jowar & barley (Table 2). Table 2:The list of mutants affecting protein quality in cereals. : Table 2:The list of mutants affecting protein quality in cereals. 24 Source: Pirman et al.,1997 Legume Protein Improvement : Legume Protein Improvement 25 Legumes contain protein from 18 to 28% which is almost double of cereals
In pulses, two types of proteins, viz. albumin & globulin are found.
The major storage protein in grain legumes is globulin which constitutes
about 80% of the total seed protein.
In chickpea, globulin is of three types, viz. alpha, beta & gamma.
The alpha globulin accounts for more than 80% of the total protein.
In faba & pea, globulin is of two types, viz. legumin & vicilin.
Legumin is less soluble in salt solution than vicilin.
Moreover, legumin does not coagulate at high temperature (950C) while
vicilin coagulates. Slide 26: 26 Proteins legumes are deficient in methionine & tryptophan.
Moreover, they contain several toxic substances such as protease inhibitors,
haemagglutinins, lathyrogens, glucocides, goitrogens, cyanogens, metal
binding factors & antivitamin factors.
However, many of these toxic compounds are destroyed during cooking.
Some of these toxins have to be eliminated through breeding.
The mixture of cereals & pulses in 3 : 1 ratio provides nutritionally balanced diet. Slide 27: 27 Table 3 :Protein fractions present in legume seeds. Pirman et al.,1997 GENETICS OF NUTRITIONAL TRAITSThe quality traits may be governed by (1) Oligogenic Inheritance, (2) Polygenic Inheritance, & (3) Maternal Effects : GENETICS OF NUTRITIONAL TRAITSThe quality traits may be governed by (1) Oligogenic Inheritance, (2) Polygenic Inheritance, & (3) Maternal Effects 28 Slide 29: 29 Oligogenic inheritance
Inheritance is governed by one or few major genes
Each gene has large & easily detectable effect on the expression of nutritional
The differences between characters of high & low value is clear cut.
In Sorghum, high lysine content is controlled by single gene with incomplete
In barley, high lysine content is governed by one major gene plus several minor
In safflower, fatty acid composition is governed by one major gene with three
In tomato, high beta carotene content is conditioned by two major genes plus
modifires. Slide 30: 30 Polygenic inheritance
Inheritance is governed by several genes each with small additive effect
In such inheritance, the variation for a character is continuous from one
extreme to another.
Classification of plants into clear cut classes is not possible.
The protein content in cereals & pulses & seed oil content in oilseed crops are
governed by polygenes.
Characters which are governed by polygenes are sensitive to environmental
changes & generally have low heritability.
In carrot, high carotenoid content exhibits complex inheritance pattern. Slide 31: 31 Maternal Effects:
Important/present in case of some quality traits.
Usually, such traits are concerned with grain characteristics, eg.,seed
size(quite common),protein content,etc.
For ex., reported for protein content in chickpea, fatty acid composition in
maize, soybean & rapeseed is influenced by genotype of maternal parent.
Maternal effects have same effect on genetic advance under selection
as other environmental factors, i.e., they confuse correspondence
between genotype & phenotype &, thereby, reduce the progress under
Therefore, selection schemes must make allowances for maternal
effects if & where present. Table 4: Genetics of nutritional quality characters in some crop plants : Table 4: Genetics of nutritional quality characters in some crop plants 32 Gupta,1992 Slide 33: 33 SOURCES OF QUALITY TRAITS:
(1) a cultivated variety,
(2) a germplasm line,
(3) a spontaneous or induced mutant,
(4) a somaclonal variant,
(5) a wild relative and
(6) a transgene 1) A cultivated Variety : 1) A cultivated Variety 34 most preferred source
eg. Atlas 66 & Naphal have been used as sources of high protein content in USA. 2) A Germplasm Line
eg. High lysine (3% of total protein) lines of sorghum, viz., IS 11167 & IS 11758,
were identified from Ethiopian collections.
These lines also have (15%) protein but their seeds are shrivelled & red in colour.
They have been extensively used in breeding programmes. 3) A mutant : 3) A mutant 35 many quality traits have been contributed by spontaneous/induced mutants
There are also examples of isolation of desirable mutants from mutant lines for
eg. P-721 opaque mutant of sorghum has opaque endosperm, which is not
liked by consumers.
A vitreous endosperm DES-induced mutant was isolated from P-271 opaque
line; this mutant has high lysine content. 4) A Somaclonal Variant : 4) A Somaclonal Variant 36 Somaclonal variants may sometimes show an improvement in a quality trait.
eg., a somaclonal variant of sweet potato had deeper & more stable root colour,
which is preferred by consumers; this variant was released as a new variety
called ‘ Scarlet’ 5) A wild Relative
There are several instances where genes for improved quality were contributed
by a wild relative (Table 5)
In many cases, the quality trait is not expressed as such in the wild species, but
it is detected only in the segregants recovered from its cross with the cultivated
relative; such traits are called latent traits.
eg., L.hirsutum, a wild relative of tomato, produces small green fruits.
Yet some of the lines extracted from a cross between tomato & L. hirsutum
showed enhanced red colour, while some others showed considerably higher
carotene content. Table 5: Wild relatives from which quality traits have been/can be transferred.(Chopra ,1989) : Table 5: Wild relatives from which quality traits have been/can be transferred.(Chopra ,1989) 37 6) A Transgene : 6) A Transgene 38 A gene from any organism, including the species into which it is transferred, that
is introduced into the genome of an organism using the techniques of genetic
engineering is called transgene.
Transgenes provide a powerful means for modification of quality traits.
In order to use transgenes effectively & successfully, biosynthetic pathway, or at
least key enzymes involved in biosynthesis, leading to production of concerned
trait should be known.
eg., ‘Laurical’ ( B. napus variety having high lauric acid) & B. napus variety
producing ‘hirudin’(antithrombin protein of high pharmaceutical value)
Production of hirudin & similar other novel proteins/ biochemicals in plants may be
regarded as a novel quality trait, which drastically changes the end use pattern of
crop produce. Slide 39: 39 BREEDING APPROACHES:
1)Evolution of germplasm.
6)Genetic engineering 1) Screening of Germplasm : 1) Screening of Germplasm 40 important for such traits that are not obvious,
viz.,traits related to chemical composition.
eg.,The lysine germplasm lines of sorghum
Further breeding effort will be required to combine the quality trait with good
agronomic features &/or yield since the germplasm line is expected to be inferior in
yield & agronomic characteristics. 2) mutagenesis
A desired quality trait may be present in spontaneous/induced mutant (Table 2). Slide 41: 41 Varieties release for quality through mutation breeding Slide 42: Contd………. Source:Vijaykumar ,2002 42 Slide 43: 43 Contd…… Slide 44: 44 Source:Vijaykumar ,2002 Contd…… 3) Hybridization : 3) Hybridization 45 Most widely used breeding approach to develop high yielding varieties with
desirable quality traits.
The breeding methods used to handle segregating generations derived from
appropriate crosses depend mainly on the type of parents involved in the cross.
If both parents of a cross are high yielding varieties having good agronomic
features, pedigree method will be the most suitable .
If one of the parents has inferior agronomic features, backcross scheme will be the
most appropriate; only a limited number (2-3) of backcross may be made, if the
inferior parent has some desirable features as well (in addition to the quality trait).
The segregating generation may be subjected to sib-mating, in place of selfing, &
selection in an effort to break undesirable linkages with the gene controlling quality
These considerations apply when quality trait is governed by oligogenes (Table 6 ). Table 6 :Selected examples of breeding for improved protein/lysine content : Table 6 :Selected examples of breeding for improved protein/lysine content 46 Singh, 2002 Quality traits governed by polygenes may be improved by subjecting the segregating generations to a form of recurrent selection
Recurrent selection for two cycles increased seed protein content of rajna
(french bean) from 21.9% to 24.6%.
In case of soybean, there was an increase of 3.3% (from 42.8 to 46.1 per cent)
in seed protein content in response to 5 cycles of recurrent selection. Slide 47: 47 4) Interspecific Hybridization
When individual from two distinct species of the same genus are crossed.
Wild relative often contribute useful quality genes, eg.,fruit colour, fruit size, pro-
vitamin A & vitamin C content in tomato etc.(Table 5)
In any case, the high quality lines derived from such crosses will usually serve as
parents in hybridization programmes; it is unlikely that they will be used directly
as varieties. 5) Somaclonal Variation
Genetic variation present in tissue culture-raised plants (somaclonal variation)
has been exploited for crop improvement & several somaclonal variants are
being used as commercial varieties.
eg., ‘Scarlet’ variety of sweet potato has improved & more stable root colour. Slide 48: 48 BREEDING METHODS
Breeding methods used for improvement of quality do not differ from breeding
methods used for any other character.
Breeding methods that are extensively used for improvement of quality traits
include backcross, pedigree method, single seed descent, recurrent
selection, progeny selection & mutation breeding.
In common bean (Phaseolus vulgaris), pedigree, single seed descent &
recurrent selection methods have been used for improvement of protein
Two cycles of recurrent selection increased seed protein from 21.9% to 24.6%.
In soybean, five cycles of recurrent selection increased seed protein from 42.8
to 46.1 per cent.
In Sorghum, pedigree breeding procedure was used for developing high lysine
lines. Slide 49: 49 In barley, backcross method was used for development of high lysine lines. In
barley, high lysine line had small seed size & low grain yield.
In sunflower, seed oil content was increased from 30% to almost 50% by
Russian breeders in 50 years using modified recurrent selection.
In safflower, oil content was increased from 37% to 50% through reduction in
In maize, seed oil content increased from 4.7 to 17% & protein from 10.9 to
23.5 after 70 cycles of recurrent selection in USA. But there was a drastic
reduction in grain yield.
Mutation breeding has been used for development of high lysine lines in
Sorghum, barley & maize.
Diethylsulphonate (DES) has been used in Sorghum & EMS & EI in barley for
induction of high lysine mutants. Slide 50: 50 SCREENING TECHNIQUES
Breeding for enhanced nutritional quality involves lot of chemical analysis.
The breeding material has to be screened for protein content, amino acid
composition, seed oil content, fatty acid composition, vitamin contents &
This requires close cooperation of biochemist.
The selection of plants with better nutritional quality is done based on chemical
analysis should be simple, cheap & rapid.
Now rapid chemical analysis methods are available for protein estimation, seed
oil estimation, fatty acids & amino acid analysis. Slide 51: 51 Seed Oil Analysis
The seed oil analysis is done with the help of Nuclear Magnetic Resonance
(NMR) or Nuclear Infrared Analyser (NIR).
This is the non destructive method of oil analysis. After oil analysis the seeds
can be used for sowing purpose.
Several single plants in segregating populations can be analyzed.
This method is quite simple, highly accurate & very fast. By this method, 300-
400 samples can be easily analyzed per day. Slide 52: 52 Protein Analysis
Now analysis of grain protein is done with the help of protein analyser.
The analysis is based on the principle of infra-red reflectance measurement.
The seed is grouped into flour which is used for the analysis.
This method is very fast. By this method 200-300 samples can be easily
analysed per day.
Individual amino acids can be estimated by colorimetric method or
Analysis of antinutritional factors is carried out by chemical method.
The old methods of protein estimation (Kjeldahl method) & oil analysis (Soxhlet
method) were very much time consuming though more accurate.
Now fast methods have been developed. Slide 53: 53 BREEDING FOR LOW TOXIC SUBSTANCES
In some grain legumes, oilseeds. Vegetables, fruits & forage crops toxic
substances are found.
These toxic substances have adverse effects on human & animal health.
Feeding of forage with toxic substance will adversely effect the health of
Therefore, it is essential to develop varieties of forage & food crops with low
level of toxic substance so that it should not have adverse effect when
consumed by animals.
Considerable progress has been made in the development of varieties with
low toxin content in above crops.
Breeding for reduction in toxic substances requires lot of chemical analysis.
Hence development of simple, cheap, rapid & reliable methods of chemical
analysis is essential. Slide 54: 54 Antinutritional factors in legumes Slide 55: 55 Contd…….. Source:Manickam,2002 TABLE 7 . Toxic substances found in different food & fodder crops : TABLE 7 . Toxic substances found in different food & fodder crops 56 Singh,2002 Slide 57: 57 PRACTICAL ACHIEVEMENTS
Varieties with improved nutritional quality have been developed in several food
crops in many countries.
In common bean, seed protein has been increased from 21.9 to 24.6, & in
soybean seed from 42.8 to 46.1%.
In sunflower, seed oil content has been increased from 32% to almost 50% in
USSR, & in safflower from 37 to 50%.
In maize, seed oil content has been increased from 4.7 to 17% & protein
content from 10.9 to 23.5%.
In wheat, Atlas-66 is an important source of high protein which is being used in
breeding programmes for improvement of protein content. Varieties with improved quality released in some crop plants in India : Varieties with improved quality released in some crop plants in India 58 Singh,2002 Limitations : Limitations 59 Most are polygenic
Difficult to estimate & evaluate, hence more finance required
Low heritability & affected by environment
There is negative association of seed protein with grain yield in both
cereals & pulses.
In some cases, improvement in quality leads to reduction in grain
size and yield.
For example, in barley selection for high lysine content causes
reduction in grain size and grain yield.
Sometimes, the quality character is found in wild relatives or species
The analysis requires close cooperation of biochemist which
sometimes becomes limiting factor in the progress.
Biotechnological tools have not been used widely in all crops. Slide 60: 16-60 THANK YOU