Seed, Seed Types and Seed Quality

Seed Definition, Seed types, germination, classed of seed, seed quality

1. Seed: Types and Quality Dr. Tauqeer Yasir

2. What is seed? I n broad sense Seed is a material which is used for planting or regeneration purpose . scientifically Seed is a fertilized matured ovule together covered with seed coat is called seed or it is a propagating material. Technological point of view Seed is a fertilized ripened ovule consisting of three main parts namely seed coat , endosperm and embryo , which in due course gives rise to a new plant. It also refers to Propagating materials of healthy seedlings, tuber, bulbs, rhizome, roots, cuttings, setts, all types of grafts and vegetatively propagating materials used for production purpose.

3. Basic Parts of a Seed Embryo Endosperm Seed Coat The  embryo  is the baby plant. It consists of plumule , radicle and cotyledon. The embryo is the young multicellular organism before it emerges from the seed. The endosperm is a source of stored food, consisting primarily of starches. It is the structure that has been formed to provide nutrition for embryo in germination. The seed coat consists of one or more protective layers that encase the seed. The  seed coat  is tough and waterproof. It covers and protects the embryo and the food supply

4. Germination The emergence and development from the seed embryo of those structures which seed indicate the ability to produce a normal plant . Conditions Necessary for Germination Water Air Temperature Light Modes of Germination Seeds present two modes of germination based on the behavior of the cotyledons or storage organs . Epigeal Germination Hypogeal Germination

5. Types of Seeds MONOCOTS DICOTS Embryo with single cotyledon Embryo with two cotyledons Usually endospermic Usually non-endospermic (Except Castor seed) Germination usually hypogeal (Except in onion) Germination usually epigeal (except in pea, gram) Flower parts in multiples of three Flower parts in multiples of four or five Major leaf veins parallel Major leaf veins reticulated Stem vacular bundles scattered Stem vascular bundles in a ring Roots are adventitious Roots develop from radicle Secondary growth absent Secondary growth often present Grains, (wheat, corn, rice, millet) sugarcane , banana, ginger , onions, grass Legumes (pea, beans, lentils, peanuts) mint , lettuce, tomato, oak, tree, etc.

6. 1.Epigeal Germination The cotyledons come out above the soil surface and generally turn green and act as first foliage leaves. This type of germination present in groundnut, bean, cotton, sunflower and cotton seeds.

7. 1.Hypogeal Germination The cotyledons do not come above the soil surface. This type of germination is found in wheat, barley, maize and pea.

8. Classes of Seed Breeder’s Seed Pre-basic seed Basic Seed Certified Seed Breeder’s seed Progeny of nucleus seed Directly supervised by a breeder Genetically and physical pure Not available for commercial distribution 2. Pre-basic seed Progeny of breeder’s seed Handled so as to maintain specific genetic purity and identity Produced in the defined regions Must be approved by the Federal Seed Certification Department. White label with diagonal violet line

9. Classes of Seed 3. Basic seed Progeny of pre-basic seed Produced on extension farms , research farms and by progressive farmers Must be certified by the FSCD white label 4. Certified seed Progeny of basic seed Produced by registered growers of seed producing agencies Quality is controlled by the FSCD Certified Seed-I has Blue label and certified seed-II (improved seed) has red label

10. Species (botanical name) Cultivar name Category Reference number Date of issue of certificate Information on the Label ANALYSIS TAG A-1 Seed Co. Location, USA Variety & Kind Vernal Alfalfa Lot No. 307-98 Pure seed 98.90% Inert matter 01.05% Other crop seed 00.00% Weed seed 00.05% Noxious weeds 00.00% Germination 90.00% Hard seed 05.00% Date tested Jan. 2001 Net weight 60 lbs.

11. Seed Quality Seed quality is the sum of all properties contributing to seed performance. The quality of seed can decide whether a farmer’s crop will be good, bad or indifferent. Seed quality is determined by the following characteristics: Physical Attributes Physiological Attributes Genetic Attributes Storability

12. A minimum of damaged seed A minimal amount of weed seed or inert matter A minimum of diseased seed Near uniform seed size 1. Physical Attributes Seed Quality 2. Physiological Attributes Germination Percentage or Viability The germination percentage or viability is an indicator of the seed’s ability to emerge from the soil to produce a plant in the field under normal conditions Seed Vigour Seed vigour is the capacity of seed to emerge from the soil and survive under potentially stressful field conditions and to grow rapidly under favourable conditions

13. Seed of the same variety Adapted to the local conditions Pest and disease tolerance High yielding ability 3. Genetic Attributes Seed Quality 4 . Storability Moisture content Temperature of the environment Seed treatment