BREEDING FOR SPECIAL TRAITS VIZ. OIL,

PROTEIN, VITAMINS, AMINO ACIDS

Special traits (Quality traits)“The suitability or fitness of an economic plant product in relation to its end use.”

A trait that defines some aspect of produce quality is called quality trait

Degree of excellence for a specific use or to serve a specific purpose

Breeding for Special Traits

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Each crop has a specific & often somewhat to completely different set of quality traits.

“Breeding for special traits deals with genetic improvement in some special aspect e.g. protein, oil, vitamins, amino acids and removal of anti-nutritional substances.”

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TRAITS METHODS AUTHORS

Oil

Nuclear Magnetic Resonance (NMR)

Nuclear Infrared Analyser (NIR)

Soxhlet method

-------

ProteinNuclear Infrared Analyser (NIR)

Micro-Kjeldahl method-------

Amino acid Colorimetric method -------

Iron Atomic Absorption Spectrophotometer Jones et al. (1981)

Calcium Flame Photometric Jackson (1958)

Phosphorous Colorimetric method Jackson (1958)

Aflatoxin 1) Thin layer Chromatography

2) ELISA Kit

-------

Screening Methods for Different Quality Traits

Classification of Quality traits

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► Morphological

► Organoleptic

► Nutritional

► Biological

► others

Morphological Traits

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related to produce appearance

mainly concerned with size & colour of the produce,

eg.,grain/fruit size, grain/fruit colour etc.

Easily observable.

Usually play the main role in determining consumer acceptance of the produce.

Organolaptic traits

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Concerned with palatability of the produce .

eg., taste,aroma, smale, juiciness, softness,etc.

Easily detected

Very important in influencing consumer preferences

Nutritional Quality

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Determine the value of the produce in human/ animal nutrition.

Includes protein content & quality, oil content & quality, vitamin content, mineral content, etc., and also the presence of ant-nutritional factors.

Not easily appreciated by consumers & farmers,

but they are of paramount value in determining human & animal health.

Biological quality traits

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The traits included in this group define the actual usefulness of the produce when consumed by experimental animals;

There usefulness to humans is usually predicted on this basis. eg.,Protein efficiency ratio,biological value, body weight gain,etc.

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

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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

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Wheatwhite 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.

RiceWhite coloured fine & long slender grains, taste & fragrance, less breakage in milling, more hulling recovery, better cooking quality, high protein & lysine contents.

Maizebold flint grains with attractive colour, high lysine, oil & sugar contentsThe 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. PulsesAttractive shape, size & colour of grains, high protein contents; high methionine & tryptophan; & less flatulenceOil seedsAttractive shape, size & colour of seeds, high oil content free from antinutritional factors & more proportion of unsaturated fatty acids

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.

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Cotton

Fibre length, strength, fineness, maturity, uniformity & colour

Tobacco

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.

Sugarcane

Moderate hardness, long internode, optimum (low) fibre for milling; sucrose ratio, high sucrose content & good quality of juice.

Potato

Attractive shape, size & colour of tubers, taste, cooking quality, thin skin, keeping quality & high starch content.

Vegetables

High vitamin & mineral contents, good taste, keeping quality & cooking quality .

Forage cropsGreater nutritive value, more palatability & freedom from toxic substances.

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Medicinal plants

High content of active substance.

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Four major goals for breeding for improved nutritional quality.

These are breeding for

(1) 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

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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 called nutrients.

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

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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 composition

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.

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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 through diet.

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.

EAA deficient in some vegetarian foods:

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Food Limiting amino acids

Cereals lysine, threonine, sometimes tryptophan

Pulses Methionine, tryptophan

Nuts & oilseeds Lysine

Green leafy vegetable

MethionineLeaves & grasses

Singh,2002

Vitamins

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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

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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

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In cereals, four types of protein, viz.1.Albumins (water soluble)2.Globulins (soluble in saline solutions)3.Prolamins (soluble in strong alcohol)4.Glutamine (soluble in dilute alkaline solutions)

Cereals contains about 70% Prolamins + Glutamine and 30% Albumins + Globulins.

Major protein fraction of cereal proteins

Protein fraction Soluble in Amino acid profile Remarks

Albumins Water Balanced -

Globulins Saline Balanced -

Prolamines Strong Alcohol Deficient in Lys,Tsp; rich in Pro, Gln

Major fraction in wheat, barley, maize & sorghum

Glutelins Dilute alkali Balanced -

Singh,2002

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In all cereals, Prolamines are relatively rich in proline & glutamine but low in basic amino acids including lysine. Therefore, they have poor nutritional value.

Generally, prolamin content in cereals is negatively associated with total protein content.

Cereals contain about 70% prolamine & glutelin and 30% albumin & globulin.

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.

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Crop Mutant Origin Features Remarks

Maize Opaque-2 Opaque-7Floury-2

Brittle-2

Spontaneous High Lys,TrpHigh Lys,TrpHigh Lys & S-amino acids

High Lys,Trp

Reduced prolamineReduced prolamineReduced prolamine

Modified starch, reduced prolamine

Barley Hiproly(lys) Spontaneous High protein, Lys Also Several minor genes

Notch-1 EMS High protein, Lys Reduced prolamine

Notch-2

Riso 1508 EI High lysine Reduced prolamine; qualitative change in proteins

Sorghum IS 11167 (hl) Spontaneous High Lysine Shrivelled endosperm, reduced prolamine

IS 11758(hl)

P-721 opaque

DES High Lysine Reduced prolamine; monogenic; modifying genes make the endosperm vitreous

P-721 vitreous

Reduced prolamine

Source: Pirman et al.,1997

Barley The High protein and high lysine traits in barley mutants is governed by single recessive gene.The Hiproly is spontaneous mutant line while Notch-1, Notch-2 (Ethylmethane sulphonate) and Riso 1508(Ethylene imine) are nullisomic Induced mutant lines.High protein and lysine lines Hiproly (use as a non-recurrent parent) derived from a backcross programme with ‘Mona’ variety (use as a recurrent parent) of barley. In India, Agronomically superior strains and backcrossing had combined with sib-mating. The varieties Karan 15, Karan 92 and Karan 280 are good for malting quality.

SorghumThe IS-11167, IS-11758 is spontaneous and P-721 opaque and P-721 vitreose are Induced (Diethyl sulphate) high lysine mutants lines in sorghum.The P-721 opaque trait is governed by a single partialy dominant gene. But the P-721 opaque endosperm is disliked by farmers and consumers.

MaizeThe traits Opaque-2, Opaque-7, Floury-2 and Brittle-2 are high lysine and tryptophan spontaneous mutants line in maize.Protiena, Shakti and Ratna verities have been developed through the use of opaque-2 mutant.

Legume Protein Improvement28

Legumes contain protein from 18 to 28% which is almost double of cereals (exception,soybean:43%).

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.

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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.

In Pulse, two types of protein, viz.1.Albumins (water soluble)2.Globulins (soluble in saline solutions)

Pulses contains about 20% Albumins and 80% Globulins.High methionine and tryptophan

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Table 3 :Protein fractions present in legume seeds

Protein fraction Soluble in Amino acid balance Remarks

Albumin Water Balanced Minor fractions(20% or less)

Globulin Saline Deficient in S-containing AA

Predominant fraction(~80%)

In chickpea

α-Globuline - Deficient in S-containing AA

80% total globulins

β- and γ- Globulins - Balanced Relatively minor fraction

In pea, faba & French bean

Legumin Less salt soluble, noncoagulate

About balanced More predominant than in vicilin in faba bean

Vicilin More salt soluble, coagulates @ 950C

Deficient in S-containing AA

Almost the only globulin in french bean

Pirman et al.,1997

GENETICS OF NUTRITIONAL TRAITS

The quality traits may be governed by

(1) Oligogenic Inheritance,

(2) Polygenic Inheritance, &

(3) Maternal Effects  

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Oligogenic inheritance

Inheritance is governed by one or few major genes

Each gene has large & easily detectable effect on the expression of nutritional quality character.

The differences between characters of high & low value is clear cut.

In Sorghum, high lysine content is controlled by single gene with incomplete dominanace.

In barley, high lysine content is governed by one major gene plus several minor genes.

In safflower, fatty acid composition is governed by one major gene with three major alleles.

In tomato, high beta carotene content is conditioned by two major genes plus modifires.

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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.

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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 selection.

Therefore, selection schemes must make allowances for maternal effects if & where present.

Table 4: Genetics of nutritional quality characters in some crop plants

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Crop species Quality character Inheritance controlled by

Sorghum High lysine Single partially dominant gene

Barley High lysine One major gene & several minor genes

Oats Protein content Complex, low content is dominant over high

Maize, Sunflower, Safflower

Seed oil content Additive genes

Sesame Seed oil content Additive genes with partial dominance for low oil content

Rape seed Erucic acid & eicosenoic acid

Two genes with multiple alleles

Turnip rape Erucic acid & eicosenoic acid

Single genes with multiple alleles

Safflower Fatty acid composition Three major alleles at one locus

Tomato High beta carotein content Two major genes plus modifiers

Carrot Carotenoid content The inheritance is complex

Gupta,1992

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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 For wheat most preferred source eg. Atlas 66 (USA) & Naphal (INDIA) have been used as sources of high Lysine and protein content

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2) A Germplasm Lineeg. 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

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many quality traits have been contributed by spontaneous/induced mutants (Table 2).

There are also examples of isolation of desirable mutants from mutant lines for quality traits.

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

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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)

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Crop Wild relative Quality trait

Cotton G. thurberi Fibre strength(latent trait)

G. armourianum Fibre strength(latent trait)

G. anomalum Fibre fineness, strength & maturity

G.raimondii Fibre strength & fineness

G. tomentosum Fibre strength & fineness

Tomato L. hirsutum Fruit colour, carotene content (latent trait)

L. pimpinellifolium Vitamin C content

L. peruvianum Vitamin C content

Pigeonpea Atylosia spp. High protein content

Soybean Glysine soja High protein (has 45% protein), reduced lipoxygenase activity

Oats Avena sterillis High protein (27% protein)

6) A Transgene

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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 atleast 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’ (anti-thrombin 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 ofcrop produce.

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BREEDING APPROACHES:

►1)Evolution of germplasm.

►2)Mutagenesis.

►3)Hybridization.

►4)Interspecific hybridization.

►5)Somaclonal variation.

►6)Genetic engineering

1) Screening of Germplasm

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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).

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Crop Origin Mutant Features

Rice

IIT-48 India Thylene cocideo3% Fine grain bitter test weight compared with IR 8

P-721 vitreous DES High lysine

X-rays, 30 kr direct selection in M2 (T.141)

Medium slender grain good cooking quality

Jagannath USSR Mutant 428 Cooking quality

zolotistyi Cooking quality

HU 2005 Good Cooking quality

Daisenminori Torikei 4 x satominori

Good Cooking quality

Miyukimochi- gamma rays Glutinous endosperm

Wheat

Sharbati sonora

India Dry seeds (12%) 60 CO gamma rays (Sonora 64)

Amber grain colour, higher protein and lysine content

Pusa Lerma Seeds gamma irradiation (Lerma Rojo 64)

Amber grain colour , elasticity and polshenke value

Stadler USA Thermal neutrons (Mo W 6243)

Strong straw, excellent soft quality and winter hardiness

Novosibirskaira 67

USSR Air dry seeds 5Kr 60 CO gamma rays (Novosibirskaira 7)

Baking quality

Varieties release for quality through mutation breeding

Crop Origin Mutant Features

Barley

Spontaneous Hiproly (lys) High protein, lys

EMSNotch -1 High protein, lys

Notch -2 High protein, lys

EI

Riso 1508 High lysine

Canor – Trunpf x Nordal 1976

Good malting quality

Vienna Austria Dry seeds. 9400 rad x-rays High 1000 kernel weight

Pennrad USA Thermal neutrons Increased winter hardiness

Jutta Germany 5 KR X-rays Increased winter hardiness

Pallas Sweden Presoaked seeds, Y 350 rad x-rays

Stiff strane

Mari Sweden Dry seeds, 20 Krad x-rays Stiff straw

Kristina Sweden Selection from Domen X Mari

Good straw

Bonneville 70

USA Seeds, 15 Krad gamma-rays Improved threshability

Contd……….

Source:Vijaykumar ,2002

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Crop Origin Mutant Features

Pigean pea

Vishakha-1 BARC Fast neutrons(T-21) 35% increased in seed size

Co-3 Coimbatore 0.6% EMS (CO-1) Bold seeded, higher degree of shelling

TAT-5 PKV Akola & BARC 1.5 Krad fast neutrons (T-21) Approximately 50 % larger seed size

TAT-10 PKV Akola & BARC Cross of mutant TT-2 (large seeded compact) x TT-8 (early) both induced by 2.5 Krad fast neutrons (T-21)

Medium large grains

Blackgram

TAU-1 PKV, Akola Cross: T-9 x 4-196 (mutant induced by gamma-rays) (No.55)

Larger seed size

Chickpea NIFA-95 High protein

Cowpea TNAU CO5-Gamma rays Nutritional value

Linseed

Linola 989 India Mutant Oil quality

Sunflower

Prevenets India Chemical Oil content

Contd……

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Crop Origin Mutant Features

Groundnut

Somnath Gujrat Mutant Seed size & oil content

Vikram BARC γ-rays Seed size

BP-1 BARC γ-rays Seed size

BP-2 BARC γ-rays Seed size

Sesame

Sinai White 48

Egypt γ-rays Seed colour

Suvon 155 Korea γ-rays Oil quality

Yangbaek Korea SA Higher oil content

Seodum Korea SA Somewhat higher oleic acid

Source:Vijaykumar ,2002

Contd……

3) Hybridization

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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 traits.These considerations apply when quality trait is governed by oligogenes (Table 6 ).

Table 6 :Selected examples of breeding for improved protein/lysine content

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Crop Breeding method Improvement Remarks

French bean(rajma)

Recurrent selection Protein content 2.7% increase in two cycles

Soybean Recurrent selection Protein content 3.3% increase in five cycles

Sorghum Pedigree method Lysine content -

Barley Backcross method Lysine content -

Sorghum Mutagenesis High lysine Diethyl sulphonate

Barley Mutagenesis High lysine EMS & ethylene imine

Singh, 2002

Quality traits governed by polygenes may be improved by subjecting the segregating generations to a form of recurrent selectionRecurrent selection for two cycles increased seed protein content of rajma (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.

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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 VariationGenetic 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.

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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 content.

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.

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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 hull content.

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.

Di-ethyl-sulphonate (DES) has been used in Sorghum & EMS & EI in barley for induction of high lysine mutants.

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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 & antinutritional factors.

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.

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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.

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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 microbiological method.

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.

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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 animal.

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.

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Antinutritional factor

Action in human body Source Methods to overcome

Type A1. Protease inhibitors

Interferes in human digestive process and nutrients utilization

Chickpea, pigeonpea , limabean , kidney bean, peanuts, cowpea, garden pea

By heat treatments, germination,fermentation

2. Lectins or hemaggluttins

Agglutinates red blood cells and other types of cells, toxic to human when exceeds the limits

Lentil, peas, soybean, kidney beans, peanuts

Traditional cooking, germination

3. Saponins Bitter taste, hemolyze red blood cells

Alfalfa , soybean, french bean, pisum

--

Type B

1. Phytic acid Makes mineral insoluble by binding strongly with them particularly with Ca, Fe, Mg, Zn and other trace elements

Soybean , fababean, lentil, chickpea and phaseolus beans

Germination, applying phytase enzyme

2. Gossypols Binds with Fe and amino acids

Cotton seed meal CaOH addition reduces gossypol

3.Glucosinolates Causes legume goitre in childrens, due to iodine deficiency

Brasica, soybean, peanuts

Antinutritional factors in legumes

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Antinutritional factor Action in human body Source Methods to overcome

Type C

1. Antivitamins Decomposes vitamins and many combine with them to form unabsorable complexes

Green beans, green peas, kidney beans, common beans , soybean, pea sprouts

--

2.lathrogens Neuro -paralysis of lower limbs

Lathyrus sp. Cooking in excess water and draining off the excess water overnight cooking cold water. Steeping the dehusked seeds is hot water. Roasting seeds at 150 o C for 20 minutes.

3. Favic agents Favism , hemolytic anamia and hemoglobinurea

Faba beans Drying the bean, cooking

4. Estrogenic factors Induces the growth of feminine parts

soybean germination

5. Toxic amino acids Kidney mal function Djenkol bean --

6. Antienzymes Inhibits amylose Navy bean and its relatives

--

7. Flatulence factors Resists digestion soybean

8.cynogens Human poisoning, mental confusion, muscle paresis and respiratory distress

Lima bean Cooking and discarding cooking cooking water

Contd……..

Source:Manickam,2002

TABLE 7 . Toxic substances found in different food & fodder crops

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Crops species Toxic substance

Food crops

Khesari Lathyrogen or nurotoxin

Pigeon pea Tripsin inhibitors

Cowpea

French bean Haemagglutinine

Tripsin & amylase inhibitorsSoybean Tripsine inhibitor & goitrogens

Rapeseed &

Mustard

Erucic acid

Eicosenoic acid

Cotton seed Gossypol

Safflower Polyphenolics

Potato Steroidal alkaloids

Cucurbits Cucurbitacines

Brinjal Bitter principle

Cassava CN glucocides

Yarn Alkaloids

Mango ResignsField pea Anti vitamin E factor

Crops species Toxic substance

Fodder Crop

Sorghum Tannins & cyanogenic

Glucocides

Sudan grass Cynogenic glucocides

White clover Cynogenic glucocides

Alfalfa Saponins & plant estrogenes

Sweet clover Coumarin

Lespedeza Tannins

Singh,2002

60

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

61

Crop species Quality character Varieties released

Maize High lysine content Protina, Shakti & Rattan

Sugarcane High sucrose content Co 671, Co 6806, Co 7314,Co 7704 & Co 62174

Barley Malting quality Karan 15, Karan 92 & Karan 280

Lathyrus Low neurotoxin Pusa 24

Soybean High protein &

high oil content

Lee (Protein 43-45% & oil 23-25%)

Rapeseed High oil content K 88 (48.8% oil)

Singh,2002

Breeding for Oil Content in

G’nut

Important Quality Traits

• A) Morphological and Physical Quality Characters

• B) Organolaptic Quality Parameters

• C) Biological Quality Parameters

• D) Other Quality Parameters

• E) Biochemical Quality Parameters

• F) Undesirable Quality Parameters

A) Morphological and Physical Quality Characters

• Following traits are related to external appearance of the seed. These traits are easily observable and usually play the main role in determining consumer acceptance of the produce.

• Seed shape

• Uniformity in seed mass

• Integrity of testa

• Absences of extraneous materials and immature seeds

• Integrity of seed during processing and Blanching

• Moisture content

• Seed colour ( Variegated and non variegated)

• Seed size ( Ranges - length- 7 to 21 mm , diameter- 5 to 13 mm )

• Seed texture

• Seed surface

• Seed weight ( ranges 0.17 to 1.24g, larger and heavier var. hypogaea > var. fastigata) ( Varisai,1973)

Quality Attributes of Confectionary Groundnut For Export Purpose

Traits Desirable aspects Seed size 155 to 170 seed /100g

Seed shape Round or elongated with tapering ends

Colour Pods : Light golden-yellow and Kernels : Tan rose and red testa of kernels are preferred.

Flavour (Roasted) Almond ,coffee, nutty popcorn, smoky and sweet

Texture ( Roasted)

Firm and crispy

Biochemical and Nutritional

Low oil content, high protein content, high O/L ratio, high vitamins B1,B2,E, high in minerals like Ca, Mg, Fe: low in anti nutritional compounds like oxalic and phytic acid

Aflatoxins Free from aflatoxins

Source- Groundnut Research in India, DGR

B) Organolaptic Quality ParametersFollowing traits are related to palatability of the produce. They are easily detected and are very important in consumer preferences. Aroma - roasted peanutty, raw beany, dark roast peanut, woody/

hulls/skins, cardboard, painty, other(brunt, green, earthy, fishy, rainy chemical/ plastic, sweet fruity/fermented)

Flavour and Seed taste – sweet ,sour, bitter, saltySoftness.Feeling factors – astringent, metallic

Note: Screening of Organolaptic traits is carried out with the help of taste panel of 7 to 8 expert members. Source- Sanders (1995)

C) Biological Quality Parameters

The traits included in this group define the actual usefulness of the produce, when consumed by the experimental units

These includes • Protein efficiency ratio• Biological value• Body weight gain• Digestibility

D) Other Quality ParametersD) Other Quality Parameters

These included prime importance in determining the usefulness of the concerned produce.

This includes • Cooking quality •Milling quality• Cooking time • Keeping quality

Oil Protein Vitamins Minerals Carbohydrates High in antioxidants ( Tocopherols)

E) Biochemical Quality Parameters

F) Undesirable Quality Parameters Aflatoxins Goiterogens Saponins Allergens Phytates Oxalates Oligosaccharides Hydrogen cyanide (HCN)

THE GENETICS OF IMPORTANT QUALITY TRAITS IN GROUNDNUT

Trait Type of gene action ReferencePod size Large pod dominant to small pod size Balaiah et al., 1977

Controlled by three genes Badami, 1928Pod reticulations

Deep pod reticulation dominant to shallow reticulations, single gene

Jadhav and Sinde, 1979

Pod beak Non-beaked pod dominant to beaked, single gene Balaiah et. al., 1977

Pod beak was dominant over the beakless Patel et. al., 1997Black pod Single dominant gene Branch et. al., 1997Seed number Fewer than three seeds/ pod-one dominant

three or more seeds/pod (monogenic) Balaiah et. al., 1977

Seed shape Long seed shape dominant to short, two genes

Hayes, 1933

Shrivelled seed

Single recessive gene Jakkula et. al., 1997

Testa colour Duplicate recessive loci model for red testa colour Branch 1995

Seed size Large seed is dominant to smallseed size

Hassan 1964; Balaiah et. al., 1977

Controlled by five pairs of genes, fourhaving iso-directional effect

Martin 1967

Trait Type of gene action Reference

Oil content Low oil content dominant to high oil Shany 1977

Two recessive genes (Ol1 and Ol2)control high oleic acid character

Moore and Knauft 1989

Protein content High protein content dominant tolow protein

Shany 1977

Albinism Two duplicate loci interacting with a third locus in an epistatic manner

Upadhyaya and Gopal 1995

Sound mature kernels Additive and non-additive gene action Vindhiyavarman and Raveendran, 1994

Shelling outturn Additive and non-additive gene action Vindhiyavarman and Raveendran, 1994

Sound mature kernels Additive and non-additive gene action Vindhiyavarman and Raveendran, 1994

Soluble sugar Additive gene effects Basu et al., 1988

100-seed weight Additive gene action Manoharan and Ramalingam, 1993

cont…

Aflatoxin in Groundnut Mainly 3 mycotoxins are found in groundnut

Aflatoxin Aspergillus spp Ochratoxin Penicillium spp T-2 toxin Fusarium spp

Deteriorate quality Aflatoxins are produced by toxigenic strains of

Aspergillus flavus and Aspergillus parasiticus fungi in various foods and feeds.

Aflatoxin contamination is due to certain problems at pre and post harvest levels.

List of some groundnut varieties with desirable quality traits

Name of variety

Year of release

Pedigree Salient feature

TMV 10 1970 Natural mutant of Argentina High oil content

Mutant 28-2

2003 EMS (0.5%) of VL 1 Large seed, resistance to late leaf spot

TPG 41 2003 TG-28A x TG-22 Medium maturity, large seed, high oleic acid

BG 2 1979 X-ray mutant of 41-C Large seed, semi-erect

Dh 40 1994 Dh 3-30 x TGE 2 Early maturity, large seed

MH 4 1990 Selection from MH 2 High yield, Large seed

J 11 1964 Ah 4218 x Ah 4354 Aflatoxin resistant

GG4 1993 CGC 3 x Chico 50.8 % oil content

GG5 1996 27-5-1 x JL24 Bold seeded

GG 14 2001 GG11 x R33-1 High oil content (52.0%)

GG21 2004 Somnath x NCAc 2232 Bold seeded , High oil content (53.0%)

TAG 24 1992 TGS 2 x TGE 1 Large seed, high HISource- DGR,2004

Limitations73

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.