The basis of seed vigour and

vigour testing

Alison A Powell

University of Aberdeen

United Kingdom

Battleships built in Aberdeen:

Ryūjō (1864) and Hosho Maru: Japanese navy

Kagoshima: for Satsuma clan

Japan Brewery Company, later

the Kirin Brewery Company Ltd

Glover whisky

1st Scottish-Japanese blend, 2015

Hanyu distillery in Japan

Longmorn and Glen Garioch

Ship building company that became

Mitsubishi Corporation of Japan

What links Aberdeen with Nagasaki?

Thomas Glover (1838 – 1911)

The Scottish Samurai

Order of the Rising Sun,

1908 Japan

Outline

• Background to vigour in the ISTA Rules

• What vigour differences mean – In the field

– In transplant production

– In storage

• Summary of effects of vigour

• Requirements of a vigour test

• Types of vigour test

• Vigour tests in use

• What do vigour tests tell us?

• The aim of our presentations

Summary of the History of Vigour

• 1876: Friedrich Nobbe:‘Triebcraft’, driving force

• 1950: ISTA President WJ Franck - ISTA

Biochemical and Seedling Vigour Committee

• Many years discussion and debate!

• 2001: ISTA Ordinary Meeting accepted Seed

Vigour Testing as Chapter 15 in the ISTA Rules

ISTA definition of vigour (2001)

Seed vigour is the sum of those properties that determine the

activity and performance of seed lots of acceptable

germination in a wide range of environments

Make comparisons of the performance of

commercial seed lots with acceptable germination

Species No. of lots Range among lots in :

Normal

germination (%)

Field

emergence (%)

Garden pea 80 >80 8-85

Green bean 90 75-100 34-93

Soybean 18 83-96 17-88

Maize 29 92-98 48-98

Oilseed rape 9 89-99 65-93

Onion 12 77-92 46-72

Lettuce 22 88-98 27-71

Cabbage 31 80-98 7-78

Cauliflower 12 85-96 10-64

Germination and field emergence of commercial seed lots

Emergence differences: Maize

Low vigour

High vigour

Photo courtesy E. Noli

Wide-spaced crop; Non-tillering

Low emergence due to low vigour means yield penalty

High vigour

Guerbiny

Northern France

Photo courtesy

T. Loeffler

Emergence differences: Phaseolus vulgaris

High vigour Low vigour

Photo courtesy C. Gallo

Emergence differences: chickpea (Cicer arietinum)

Photos courtesy S. Goertz

High vigour Low vigour

Emergence differences: Oilseed rape (Brassica napus )

26 March 2012 9 April 2012 23 April 2012

Low

vigour High

vigour

Yield differences: due to emergence

and plant development? Low

vigour

Low

vigour

High

vigour

High

vigour Oilseed rape

Field sown lettuce: Impact on marketable yield

60- 90% of variation in head weight due to variation in timing of emergence Gray (1976) Annals of Applied Biology 82, 569–575

Tagetes

Photos courtesy H. Ilbi

Transplant production

Requires large uniform seedlings

Cabbage

High vigour Low vigour

Melon

High vigour Low vigour

Photo courtesy of J. Marcos Filho

Lettuce

High vigour

Low vigour

Photos courtesy of J. Marcos Filho

Species Normal

germination

(%)

Mean

emergence

time (days)

Emergence

(%)

Plant height

(mm) at first

leaf stage

Variation in

plant height

(CV)

White cabbage

98

4.4

98

21.1

27.0

93 5.3 92 18.2 36.9

Cauliflower 98 4.4 92 26.7 21.5

91 6.2 88 19.8 25.9

Brussels sprouts 98 4.2 100 30.8 23.9

87 5.0 44 23.2 27.7

Red cabbage 97 4.6 98 25.6 22.1

85 5.7 100 16.8 32.5

Calabrese 93 4.1 92 21.1 20.5

88 4.6 91 21.0 25.6

Transplant module emergence of Brassica species

(50 modules per lot)

Bell pepper

Low vigour High vigour

Photo courtesy I Demir

Normal germination (13 seed lots) 88 – 99%

Low temperature sowing date (13 seed lots) (min /

max temperature 11/ 23oC)

Emergence 71 - 96 %

MET 16.9 - 22.1 days

High temperature sowing date (13 seed lots)

(min / max temperature 19/ 42oC)

Emergence 63 – 93 %

MET 11.2 – 16.2 days

Germination after storage (10 seed lots)

at 8% MC 5oC for 4 months

60 – 92%

Pepper emergence in glasshouse conditions

Başak et al. (2006) Seed Sci. & Technol, 24, 701-712

Storage potential

Initial lab

germination (%)

Germination (%) after storage for 2

years

Store 1

(ambient)

Store 2

(ambient)

Store 3

(DH)

84 28 33 56

97 84 88 91

93 54 63 73

91 17 21 39

Brassica oleracea var gemmifera, Brussels sprouts

Ambient = ambient in UK

DH = dehumidified and low temperature store

Good storage potential

Poor storage potential

Summary of aspects of performance associated with

seed vigour

• Emergence ability of seeds

– particularly under unfavourable environmental conditions

• Rate and uniformity of seed germination and seedling

growth

• Performance after storage

– particularly the ability to germinate

What vigour differences mean

Vigour level

High Low

Mean rate of

germination

Fast Slow

Spread of

germination time

Narrow Wide

Mean seedling size Large, uniform Small, variable

Emergence Good Poorer

Storage potential Good Poorer

• Simple to complete

applicable in a wide range of seed testing environments

more ‘hi-tech’options may also be available

• Results should correlate with a practical expression of seed vigour

emergence in the field or glasshouse, or

seedling size and uniformity, or

seed longevity in store.

• Repeatable both within and between laboratories.

results from different laboratories would be comparable

trust in results of testing

essential for ISTA accreditation / QA

• Preferably a quantitative method of assessment

avoids subjective assessments

standardization easier.

• Quick

enables prompt reporting of results.

• The test should be economically practical.

a critical aspect in the running of any seed testing laboratory,

Requirements of a vigour test

Types of vigour tests

• Physiological assessments

– aspects of germination e.g. rate of germination, radicle emergence test

– stress tests e. g. cold test, cool germination test

• Biochemical assessments e.g. conductivity; tetrazolium

• Application of the ageing process

– accelerated ageing

– controlled deterioration

ISTA Validated tests Non-validated tests

Conductivity: grain legumes, radish * K+ leakage

Single seed conductivity

Accelerated ageing: soyabean* Accelerated ageing for other species*

Saturated salt accelerated ageing: small

seeded species*

Controlled deterioration: Brassica * spp.

Stress tests:

Cold test: maize * Saturated cold test: maize

Cool test: cotton

Radicle emergence: * maize, oilseed rape, radish

Seedling growth: range of species *

Tetrazolium staining: soyabean* Tetrazolium staining : species other than

soyabean

Vigour tests in use

What do vigour tests tell us ?

• Information about:

– the planting value in a wide range of environments and/or

– storage potential of seed lots

• Additional information to the standard germination test

– differentiation between seed lots of acceptable germination

• Information that will help

– companies make marketing and storage decisions

– allow farmers to judge risks when sowing

Our aim: Basis of vigour, vigour tests and their use

Two key concepts

0

20

40

60

80

100

0 24 48 72 96 120 144

Time from set to germinate (h)G

erm

ination (

%)

F

H

I

Seed survival curve Germination progress curve

Our aim

To illustrate how these two concepts help provide an integrated

explanation for differences in vigour and vigour tests

The use of vigour tests in Japan

Takashi Shinohara

Tokyo University of Agriculture