Future traits and technique:-challenges in seed testing

Course Leader: Dr. S. K. yadavBy: NIRAJ KR. JHA ( Roll No. 20342)

DIVISION OF SEED SCIENCE AND TECHNOLOGY

INDIAN AGRICULTURAL RESEARCH INSTITUTENEW DELHI

• The seed is the starting point, or the first determinant of the future plant development and consequently the master key to success of cultivation.

• “Seed quality” is used in practice to describe the overall value of seed for its intended.

INTRODUCTION

Achievement of Seed quality requirements is assisted by the methodologies of seed testing that are developed and standardized by the ISTA and other STL at time to time.

introduction of GM crop, trait specific crops, enhanced seeds broaden the area of seed science .and seed-testing laboratories were being faced new challenges day to day.

To handle this type of challenge we should to improve our method as well as we have to developed new technique , for testing of new trait specific crops.

SEED TESTING : NEW TRAIT AND TECHNIQUES

NEW TRAIT SPECIFIC SEED: TESTING

1.GM CROP SEED

2.SEED ENHANCEMENT

A .PRIMED SEED

B. COLOURED SEED

C. COATED SEED

3.TEST OF HYBRIDITY

NEW TECHNIQUE : FOR SEED TESTING

Chlorophyll Fluorescence of Dry Seeds

Ethanol Assay

Flow cytometry

Molecular Technologies

Proteomics

Testing of GM SEEDSThree levels;- A. DETACTION To determine ,whether a sample contains GM seed or not. screening method is used for this purpose sample size for detection of genetic purity is similar to other seed -400 seed/assay PCR used for screening of GM seeds.

B. IDENTIFICATION To identify which is GM line or which is not. based on PCR C. QUANTIFICATION To assess its compliance with specific “threshold level “ fixed by a country. Method for quantification 1.Lateral flow strip protocol 2. ELISA method 3. Bioassay (herbicide resistant genes) 4.Moleculer method (DNA based)

SEED ENHANCE MENT

A. SEED FILM COATING

Application of precise amount of active ingredients along with liquid material directly on to seed surface without obscuring its shape.• May be polymer or plasticizer•More resistance to mechanical injury•Improved physical appearance of seed•Good storability•eg.• 1.chiekpea Jalshakthi @10-20 g/kg of seeds (mehar et .al,1991)• 2.tomato polykote @ 3g /kg of seeds (Ramya 2003)

B. Colored seedsSeeds with precise amount of dyes or pigment directly on seed to improve its brand identity and marketability

Pelleted seedsThe seed with small quantity of ingredients along with filler materials to produce a globular unit of uniform size to facilitate planting.

ADVANTAGE:-

1.Pelleting regulates the size of seeds for precision planting by machine /man2.Reduce the quantity of seeds required for planting and reduce the crop thinning work3.More resistance to mechanical injuries4.Help to enhance seedling establishment under a wide range of environmental condition.DISADVANTAGE:- cost and weight are more than bare seeds Less storability SOME EXAMPLE: 1.Nutrient seed pelleting-------coating with macro and micro nutrients (DAP ,borax)------------------filler materials (gyupsum ,chalk powder)……..adhesive(rice gruel, gelatin etc. 2. Organic seed pelleting………….leaf powder coating……………filler materials(leaf powder)…………….adhesive(rice gruel , gelatin, gum , etc.)

conventional method : grow out testBut now DNA test is done for genetic purity test

HYBRID PURITY TEST

.

chlorophyll fluorescence of seeds given by Jalink et al. 1998 . This technology we could detect chlorophyll in almost every seed, and that levels differed considerably. These technology were used to a measure for seed maturity. Since we know that maturity correlates strongly with quality aspects like germination, speed of germination and seed health working procedure:

The technology is based on exciting seeds with a laser beam and measuring the resulting fluorescence: this fluorescence decreases with maturity. Less mature seeds show higher levels of fluorescence and have therefore higher levels of chlorophyll than fully mature seeds. The technology has now become so fast that we can analyze seed-by-seed in milliseconds and build it in color sorters.

Chlorophyll Fluorescence of Dry Seeds

Ethanol Assay:-

THIS technology uses the production of ethanol vapor by seeds . This very new technology is based on the fact that when seeds deteriorate they disintegrate slowly under the production of ethanol. The measurements are made with a slightly modified breathalyzer, as is normally used by traffic police.

Immature seeds contain more ethanol where as mature seeds contains less ethanol.

Proteomics

Proteomics is the large-scale study of proteins, particularly their structure and function.

Flow Cytometry:-To detection of seed-borne viruses and bacteria, flow cytometry (FCM)-based techniques were developed. FCM enables multiparameter analysis and quantification of particles, such as bacterial cells and fungal spores. Particles are analyzed on the basis of size, granularity and emissionof fluorescence, if particles are auto fluorescent or have been stained with a fluorescent probe. Now in days FCM developed for Xanthomonas axonopodis pv. phaseoli, X.campestris pv. campestris and Clavibacter michiganensis subsp. michiganensis in seed extracts.

Flow Cytometry Analysis of Seed Extracts of Beans showing Presence of Xanthomonas axonopodis

(Source: Plant Research International)

CONCLUSION

Continuous improvements and research are necessary and are required to enhance efficiency and effectiveness of seed testing in thease days.

To provide the specific tests needed to meet the changing needs of the seed market and provide Quality assurance management needs to be further developed to minimize the risks and give customers confidence.

THANK YOU