WP9

Analysis for cold tolerance in oat

P8- Luigi Cattivelli and Fulvia Rizza, Experimental Institute for Cereal Research,via S.Protaso 302, 29017 Fiorenzuola d’Arda (PC), Italy.

P9 – Daniela Murariu, Suceava Genebank, Romania

AVEQ - Clermont-Ferrand, 19-21 September2007

Valeria Terzi

Analysis for Cold Tolerance

Field testing to explore the genetic variability for cold tolerance in winter (and spring) oats and to identify genotypes with superior frost tolerance will be employed. The experiment will be carried out using the project

working collection developed within the project. A field evaluation of frost tolerance will be carried out in a nursery of small plots (1 m2) for 2 years in different locations (Fiorenzuola d’Arda –North Italy; Suceava Genebank

– Romania) to control the environmental effect over the genetic expression of the single genotype.

Among winter cereals, oat is the most frost sensitive and its insufficient level of winterhardiness is the main factor limiting sowing and yield of winter oat in Northern Italy and Central Europe.

WINTERHARDINESS IN OAT:IS THERE GENETIC VARIABILITY FOR THIS TRAIT?

Sixty-two genotypes with different origin (Europe, North America) were grown in Northern Italy (Fiorenzuola) in 1996-’97

Frost damage was estimated by a visual score (0: no damage 9:all plants killed)

A BROAD GENETIC VARIABILITY FOR

WINTERHARDINESSEXISTS IN OAT

Range between 2.5 and 8.59

(mean 5.8)

Frost reduces yield potential of winter genotypes

0.00

1.12

2.24

3.36

4.48

6.00

7.12

t/ha

Argentina Ava Flavia Norlys Aintree Origine

Winter oat yield 96/97

Winter sowingSpring sowing

LSD 0.05LSD 0.05

Highest yield potential is expressed in winter sowing , however only highly resistant cvs yielded more in winter than in spring sowing. The extent of yield decrease in winter sowing was related to the degree of frost injury

detected in field

.  

Frost resistance, the most important component of winterhardiness, is an inducible process, promoted by cold acclimation (HARDENING) at low non-freezing temperature

and associated with a number of biochemical and molecular changes

How to measure frost resistance?

LOW TEMPERATURE and LIGHT INTENSITY affect the PSII excitation pressure which plants are exposed to and, consequently,

their tolerance to stress

Explore the genetic variability for PSII stability and frost resistance in a set

of oat cvs

Chlorophyll fluorescence responds to changes in PSII photochemistry and therefore represents a convenient and rapid tool to evaluate the capacity of the photosynthetic machinery at low temperature.

Fv Fm-F0

--- = ---- Fm Fm

The ratio of variable to maximal fluorescence

(Fv/Fm) in dark-adapted state measures the

maximum quantum yield for PSII photochemistry

and represents a diagnostic probe for

measuring low temperature stress-

induced injury of photosynthesis

= 0.8in dark-adapted health plants

Experimental unit(PAM 2000)

RapidReliable

Sensitive,Not

destructive

The ratio Fv/Fm was determined to evaluate the frost resistance of 16 cultivars of different origin, growth habit and

year of release

1 AINTREE GBR W 2 ARGENTINA ITA W 3 BULBAN AUS S 4 COKER USA W 5 DONATA ITA W 6 EMPEROR GBR W 7 FLAVIA ITA W 8 FULVIA ITA W 9 GENZIANA ITA S10 ORIGINE FRA W11 PREVISION ESP W12 PRIMULA ITA S13 ROGAR 8 ITA W14 TROPICALE FRA S15 WEIBULL 17578 SWE S16 YEATS USA W

The standard treatment:

1 week-old plants were hardened at 3-1°C

(day/night) 200E m-2 s-1 for 4 weeks

and subjected to a freezing

treatment (–12°C, –13°C)

The maximum quantum yield of the Photosystem II (PSII) photochemistry was evaluated during hardening and after

freezing, through the chlorophyll fluorescence parameter Fv/Fm,

0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6 7

days

Fv

/Fm

stress recovery

Rizza et al. (Plant Breed.120: 389-396, 2001).

0

0.2

0.4

0.6

0.8

0 5 10 15 20 25 30days

Fv

/Fm

EFFECT OF A HARDENING TREATMENT

(4 weeks at 3-1°C) ON Fv/Fm (mean ± stand.dev for 16 oat genotypes)

EFFECT OF A FREEZING STRESS ( –12°C) ON Fv/Fm

(mean ± stand.dev for 16 oat genotypes)

0.79

0.72

HARDENED

NON HARDENED

0.750.790.78

a) Plants at first-leaf stage hardened at 3-1°C, 200E m-2 s-1 4 weeks

6 cvs showed the highest Fv/Fm: ‘Coker’ ‘Donata’ ‘Emperor’ ‘Flavia’ ‘Fulvia’ ‘Yeats’Only 4 maintained a value close to 0.8

Lsd 0.05 A (genotype) 0.119

Lsd 0.05 A (genotype) 0.175 4 cvs showed the highest Fv/Fm

(for 3 it was close to 0.8): ‘Coker’ ‘Donata’ ‘Emperor’ ‘Yeats’

stress at -13°C

00.10.20.30.40.50.60.70.80.9

AIN

TREE

ARG

ENTI

NA

BUL

BAN

CO

KER

DO

NATA

EM

PERO

R

FLA

VIA

FUL

VIA

GEN

ZIA

NA

ORI

GIN

E

PREV

ISIO

N

PRIM

ULA

ROG

AR

8

TRO

PICA

LE

WEI

BULL

175

78

YEA

TS

Fv/F

m 2

4h re

cove

rystress at -12°C

00.10.20.30.4

0.50.60.70.80.9

AIN

TR

EE

AR

GE

NT

INA

BU

LB

AN

CO

KE

R

DO

NA

TA

EM

PE

RO

R

FL

AV

IA

FU

LV

IA

GE

NZ

IAN

A

OR

IGIN

E

PR

EV

ISIO

N

PR

IMU

LA

RO

GA

R 8

TR

OP

ICA

LE

WE

IBU

LL

17

57

8

YE

AT

S

Fv

/Fm

24

h r

ec

ov

ery

winterspring

Lsd 0.05 A (genotype) 0.12

Lsd 0.05 A (genotype) 0.17

A CRUCIAL ASPECT OF STRESS RESISTANCE IS THE CAPACITY OF A PLANT TO RESPOND EARLY TO AN

ENVIRONMENTAL STIMULUS

b) Plants pre-hardened at 12-7°C, 200E m-2 s-1, 4 weeks (second-third leaf)

6 cvs showed the highest Fv/Fm (close to 0.8) ‘Aintree’ ‘Coker’ ‘Donata’ ‘Emperor’ ‘Flavia’ ‘Yeats’

3 cvs showed the highest Fv/Fm (close to 0.8): ‘Coker’ ‘Donata’ ‘Emperor’ ‘Origine’ ‘Yeats’

stress at -5°C

00.10.20.30.4

0.50.60.70.80.9

AIN

TREE

AR

GEN

TIN

A

BU

LBA

N

CO

KER

DO

NA

TA

EMPE

RO

R

FLA

VIA

FULV

IA

GEN

ZIA

NA

OR

IGIN

E

PREV

ISIO

N

PRIM

ULA

RO

GA

R 8

TRO

PIC

ALE

WEI

BU

LL 1

7578

YEA

TS

Fv

/Fm

48

h r

ec

ov

ery

winterspring

stress at -6°C

00.10.20.30.40.50.60.70.80.9

AIN

TREE

AR

GEN

TIN

A

BU

LBA

N

CO

KER

DO

NA

TA

EMPE

RO

R

FLA

VIA

FULV

IA

GEN

ZIA

NA

OR

IGIN

E

PREV

ISIO

N

PRIM

ULA

RO

GA

R 8

TRO

PIC

ALE

WEI

BU

LL 1

7578

YEA

TS

Fv

/Fm

48

h r

ec

ov

ery

Lsd 0.05 A (genotype) 0.14

Lsd 0.05 A (genotype) 0.17

r = 0.87

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fv/Fm after stress -12-13°C (plants hardened at 3-1°C)

Fv/F

m a

fte

r s

tre

ss

-5-

6°C

(p

lan

ts

pre

-har

de

ne

d a

t 12

-7°C

)

16 oat genotypes

Data were highly correlated in oat, suggesting that the capacity to respond precociously to an environmental stimulus (like a

moderate drop in temperature) has an important role in the acquisition of the tolerance to a more severe stress

C) Plants pre-hardened at 12-7°C, 700E m-2 s-1, 4 weeks (second-third leaf)

stress at -5°C

00.1

0.20.30.4

0.50.60.7

0.80.9

AIN

TR

EE

AR

GE

NT

INA

BU

LB

AN

CO

KE

R

DO

NA

TA

EM

PE

RO

R

FL

AV

IA

FU

LV

IA

GE

NZ

IAN

A

OR

IGIN

E

PR

EV

ISIO

N

PR

IMU

LA

RO

GA

R 8

TR

OP

ICA

LE

WE

IBU

LL

17

57

8

YE

AT

S

Fv

/Fm

48h

re

cov

ery

stress at -6°C

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

AIN

TR

EE

AR

GE

NT

INA

BU

LB

AN

CO

KE

R

DO

NA

TA

EM

PE

RO

R

FL

AV

IA

FU

LV

IA

GE

NZ

IAN

A

OR

IGIN

E

PR

EV

ISIO

N

PR

IMU

LA

RO

GA

R 8

TR

OP

ICA

LE

WE

IBU

LL

17

57

8

YE

AT

S

Fv

/Fm

48h

re

co

ve

ry

The improvement of the PSII stability after

freezing was especially evident in

the cultivars with intermediate level of

resistance

Lsd 0.05 A (genotype) 0.13

Lsd 0.05 A (genotype) 0.15

Pre-hardened plants 12-7°C, 200 E

Pre-hardened plants 12-7°C, 700 E

Growth at 12/7°C, associated to higher light intensity (700E) implied a morphological adaptation in frost

resistant and frost sensitive cultivars

Frost resistant

Frost sensitive

Molecular analysis:COR14 accumulation in pre-hardened plants

1 week at 12-7°C 4 weeks at 12-7°C

200 E m-2 s-1

700 E m-2 s-1

P R W C D Y P R W C D Y

SUSCEPTIBLE RESISTANTP: ‘Primula’ C: ‘Coker’R: ‘Rogar 8’ D: ‘Donata’W:‘Weibull’ Y: ‘Yeats’

HOW DOES A RESISTANT OAT BEHAVE WITH RESPECT TO RESISTANT CVS OF OTHER

CEREALS SPECIES?

1 PICASSO rye2 CHEYENNE wheat3 OFANTO durum wheat4 AUBRAC triticale5 NURE barley6 PAMINA barley7 COKER oat

Rye wheat durum triticale barley barley oat wheat

mean of three experiments (-14, -15°C)

Survival rate %

a) Plants at first-leaf stage hardened at

3-1°C, 200E m-2 s-1 4 weeks 0

20

40

60

80

100

P ICASSO CHEYENNE OFANTO AUBRAC NURE P AMINA COKER

re

gro

wn

pla

nts

(%

)

0

20

40

60

80

100

P ICASSO CHEYENNE LESINA AUBRAC NURE P AMINA COKER

pla

nt

reg

row

n (

%)

0

20

40

60

80

100

P ICASSO CHEYENNE OFANTO AUBRAC NURE P AMINA COKER

pla

nt

reg

row

n

(%)

b) Plants pre-hardened at 12-

7°C, 200E m-2 s-1, 4 weeks

C) Plants pre-hardened at 12-

7°C, 700E m-2 s-1, 4 weeks

mean of three experiments

(-5, -6°C)

mean of three experiments

(-5, -6°C)

Rye Triticale Wheat Barley Oat Durum Wheat

Rye Triticale Wheat Barley Oat Durum Wheat

12/7°C 200 E 12/7°C 700 E

CONCLUSION AND PERSPECTIVESSignificant differences in frost resistance were detected within winter

cultivars

The most resistant showed a behaviour comparable to that of a winter resistant barley, suggesting that it should be possible to improve the

resistance of winter oat to a level similar to that of winter barley.

Basis for a possible winter sowing in oat and for breeding.

The freezing evaluation test represents a useful tool for the evaluation of frost tolerance

AVEQ project is a unique opportunity to evaluate biodiversity for this trait.

PEOPLE INVOLVED IN FROST TOLERANCE

STUDIES

Fulvia RizzaLuigi CattivelliDonata PaganiFabio Reggiani

Cristina Crosatti