Wheat (Gehun)

Botanical name: Triticum aestivum

Family: Gramineae (poaceae)

Parts used: Grain (caryopsis) (dry single seeded indehiscent fruit)

Cultivated in: Uttar Pradesh, Punjab, Madhya Pradesh, Maharashtra, Bihar, and Rajasthan

Harvesting: March-April

Morphology:

How Wheat Changed the World
  • Annual herb
  • 0.6-1.5 m high
  • Wild as well as cultivated
  • Cultivated grows to a height of 2-4 ft.
  • Stem of wheat:     Culm , erect as well as cylindrical. It is differentiated into : Nodes ( solid ) and Internodes ( hollow ).
  • Roots are fibrous

Roots have two sets:

First set:          it is differentiated into two parts,

1). Seedling roots or seminal roots: Initially the roots originate from the embryo which are 3 to 6 in number, they are soon replaced. 

 2). Adventitious roots or coronal: It arises from the basal underground nodes of the stem. Represent the permanent root system of the plant.

Second set:     Tillers:  Tillers are produced from axillary buds present on the underground portion of Culms known as: Secondary shoots.

  • Leaves are long, narrow with prominent parallel veins. Each leaf consists of:
  • Auricle: two claw like appendages present at base of blade.
  • Membranous ligule: at junction of blade and leaf sheath. It is provided by hairy margins.
  • Leaf sheath: encircles the stem tightly.
  • Leaf blade/laminar: linear, it is glabrous hairy on one or both the surfaces.
  • Inflorescence  is a terminal spike or head consisting of 15-20 spiklets borne singly on alternative sides of zig-zag rachis. Floret attached on: Rachilla. Each spiklet is sessile and solitary. It consists of 1-5 flowers or florets each. Each floret has its own lemma and thin nerved palea, investing 2 lodicules, 3 stameds and single pistil with 2 feathery stigmas. Perianth is represented by 2 lodicules. Which regulate the opening of the flower.

Spike are referred to as: Awned: bearded and Awnless: beardless.

  • Mature edible grain  is a dry, one seeded, indehiscent fruit known as Caryopsis.

Grain in whole consists of carbohydrates, fats, proteins, and vitamins.

Wall of ovary and seed coat remains fused so as to form complex structure known as Bran

Bran = ovary wall + seed coat

Internal to this lies: Aleurone layer: rich in fats and proteins.

Next it lies: Endosperm: it contains major part of grain by weight. Rich in starch grains along the traces of proteins and fats.

  • Embryo part: rich in vitamins, proteins, and fats.
  • Composition of wheat:

Proteins: 7-18%

Mineral matter: 1.5-2%

Lipids: 1.5-2%

Starch: 60-68%

Cellulose: 2-2.5%

Moisture: 8-18%

Amino acid present in wheat: Arginine, Histidine, Leucine, Isoleucine, Phentalanine

Vitamins: Flavin, Thiamine, Riboflavin, Choline, Carotene.

  • Why wheat flour is elastic?

When wheat flour is mixed with water and kneaded , it becomes elastic only because of the proteins: Gliadin and Glutenin.

  • Economic importance:
  • Wheat is the staple food (essential) of the North Indian people
  • It is staple food of at least one third of world’s population
  • Wheat grain are grounded into flour (atta) and consumed in form of chapatee i.e., 80-85%
  • It is used for making flakes and sweet meals like kheer, shira, etc
  • It is used for preparing starch, gluten, beer, alcohol, distilled spirit, etc in industry
  • In laundries, wheat starch is used for the finishing of clothes
  • Wheat bran is used in protein production
  • Wheat straw is used as fooder, padding material and mulching material. Also for seating chairs, baskets, etc.
  • Wheat straw pulp is used for manufacturing writing, printing, wrapping papers
  • Depending upon variety of wheat: it is differentiated into

Hard (less starch) used for manufacturing of rawa, suji, sewaya, and Bread

Soft (more starch) used for making flour, chapatee, bread, cake, biscuits, pastry and other bakery products.