Question

Explain how varieties/cultivars can be distinguished through seed laboratory tests. Provide four examples of cultivar purity tests.

Answer 1

Seed testing is determining the standards of a seed to get quality seeds. So main objectives are to get quality seeds by minimising the risk of planting low quality seeds. Seed testing laboratories are essential organization in seed certification and seed quality control programmes. Test results may cause rejection of poor seed multiplication or low grade seed in a count of law. Analysis of seed in laboratory can be done by observing section for purity testing, section for moisture testing, section for viability , germination and section for vigour testing.

Difference between varieties/cultivers through seed testing laboratories are in short a cultiver does not produce true-to-seed whereas varieties usually produces true- to seed.

The techniques used in creating a new cultiver are- mass selection, recurrent selection, top crossing, and synthetic variety development.

Cultiver purity or genuiness of the cultiver is tested by means of heritable characters of seeds, seedlings or plants.

Morphological methods include seed morphology, Examination of seedlings, Examination in green houses, grow out test.

Chemical tests include phenol test, modified phenol test, potassium hydroxide, ferrous sulphate test, NaOH test.

Biochemical methods include Electrophoresis. Molecular markers includes RAPD, SCAR, SSR, STS.