Studies on waterlogging tolerance in lucerne, Medicago sativa, L.

STUDIES ^ON I^JATERLOGG]NG TDLERANCE I N L[JC! INJI-r-f4edic ag.o--.lativa. L.

A thesis submitted in fr.llfilment of the requirements for the ^degree of Master of Agrícultural Science

at the UniversÍtY of ^Adelaide

by

Ion Du Kaahne, B.Ag"Sc. (Adelaíde).

DEPARTMENT OF AGRONOMY

ìJìJAITE AGRICULTI.JRAL RESEARDH INSTIl.UTE UNIViRSII'Y 0F ADELAIDE, 50LlTH AUSTRALIA

APRIL, ^L916.

f,a

SLIM¡4ARY

The toferance to waterlogging of eiEht ^Lucerne valieties was assesse¡l

in the glasshouse using three South Australian soil-s ^which ale ^prone to water-logging during the winter. Four int¡oduced varj.eties from ^Russía and Nolth America, which have a common ancestry in the fl-oodland ecotypes of central European Russia, were more tolerant than four Austral-ian

registered varieties. Under f-looding the introduced varieties were higher yielding anC ¡eteined a higher proportion of actively ^grov.ring plants. The

effect of flc¡oding varied between the three soi.l-s, but the ranking of the response of the varieties ^hras generally similar j-n atl the soils"

I n a second glasshouse expe¡iment hybrid populatiorrs of c.rosses bet;ween

the four tolerani varieties and the four Australian verrieties ^were inter:- mediate in perfor¡Ìlance when assessed for yi.e1d, shoot production, retentj-on

of meristemmatic activity and a score for Ieaf colour, sene$cence and l-oss.

The population x soil- interactions within the flooded treatment were agaín

generally insign.if icant _"

A group cf f our parents, two tol-e¡ant anrl two intolerant under g.ì-ass- house condj-tions, and hybrids between these tolerant and into-lerant

parents were studied as replicated clones of individual plants in a ffooded field experiment conduced dur-ing the winter at Meadows, near Adelaíde"

Survir¡ors from the prev-ious experiment and unselectecJ control c.Iones ^were:

included" There were few significant differences be'[ween the survivors ar¡d

the controJ- populatíon when they ^{were eompared} by measuring components of plant growth and assessing their appearance.

In the field the tol-eran'b íntroduced parents were more winter-dormant than the intolerant Austrafian varieties and for a rrumber of weeks after flooding was -imposed they suffered less deterioration of tl-r eir leaf tissue

arrd the hybrid pcptrlations once again were intermecliate.

After proJ-onged flooding all the parental ^clones, variety ¡ ^{had t¡een} killed _"

The most consistent

almost all the survivi.ng except for a smai.J- number

l_aa

utere hy[:rids ^and introduced clon ^es

of one

for assessing the tolerance of ^pop- glasshouse or fiefd were the retention ulations alrd clones in either ^the

of meristemmatic activity and the was not a rel-i-able c¡iterion for prevailing iernperature and li.ght differences j-n winter-dormancyo was not a sui.table index for the

criteria

appearance of l-eaf tissue.

se.l-ectj-on in the glasshouse

conditiorrs did not ^permit

Re growth

s e-lect ion

after fJ.ooding in ^the

Plant yietd

because the reso.Iution ^{o P}

glasshouse

Sh oot of tol-erarrt plants.

production pet' plant under both flooded and nonf.l-ooded conditions reflected varietal dífferences irr the propensity to ^{produce shoots and} plant dornrancy

rather than fl-ooding tolerance"

Tlre rnethods which nright be used to continue se.l-ection for a lucerne population incorporating both waterlogging tolerance and other desirable agr.onomic characterj"stics are díscussed" The intravarj-etaf variation expressed by the four. introduced varieties and one Australian variety,

rDemnatr, and the superíor performance after prcÌonged fJ-ooding of ^some índividual clones from first generation hybrids indicate that the ^breeding of a waterlogging to.l-erant variety adapted to southern Australia can be pursued.

TAELE OF ^CONTENTS

2.1

TITLE

sUMMARY

TABLE OF ^CONTENTS

STATEME NT

A CKNOt,ILEDGE ME NT5 INTRODUCTION

LTTERATURE REVTEl/ü INTRODUCTION

2.2, THE EFFECT OF WATERLOGG]NG ON THE PHYS]CAL AND

CHEMICAL S'I-ATE OF ^SOTLS

2.2,r" The effect of waterlogging ^on the concerltration of oxygen j-n the soil

2t2 The effect of waterlogging ^on the oxidatj-on - reduction potential in soíI

2.2,3. The effect of waterJ-ogging on the pH of soil 2.2.4. The effect of waterlogging ^on the specifíc

conduc'bance in the soil solution

2.2.5. Changes in the concentration of nutrient ^ions and other e]ements in the soil- as a result of waterlogg in g

t-v

aa

AV r-

X

xt-

1

4 4 5

1

2

5

6

I

B

9

2.2.5"1"

2 "2.5.2 ^.

2 "2.5 ^{"3 .} 2.2.5 _"4 . 2 "2.5 "5 "

2.2"6"

2.2 _"7 .

2.2.7.L.

Nitrogen

Phosph or u s Man gane se I ron

Other elements

The metabolism

of

^carbon

in

waterlogged soifs

The production

of

phytotoxic Dornpounds

in

water- logged soils

Nitrite

^and nit¡ot-ls oxide

Et i'ry1en e

9

10 10 IO 11 11 11

11

2 "2.7 "2. 12

TABLE 0F CûNTENTS (Contd. )

2.2.7 .3 .

2.2.7 .4 .

2.3 _"

a')4 2 "3 "2.

a.7 1

2.3"3,,1.

2.3 .3 ,2 _"

2.3 .4.

2.3 ,5 ^.

2.3 "6.

2,3 _"7

2.3 .7 .L.

2 "3 "1 "2,

2"3"7.3.

110

2.3 .9 .

2.4

2.4.1 .

2,4 "2.

Carbon dioxide I2

Organíc acids ¹³

THE PHYSTOLOG]CAL AND BIOCHEMICAL RI-:SPONSE OF ¹³

PLANTs TO hIATERLOGGING AND REDUCED OXYGEN SUPPLY TO THE ^ROOTS

I n trod uc ti on ^l-3

The oxygen ^{demand o-F} loot tissue ^and'bhe physical- ¹³ and chemical restraints upon supplying that ^denand

The response of root systems to reduced oxygen ¹⁵

supp Iy

The measurement of soif aeration ¹⁵

The response of roots to reduced oxygen concentration ¹⁵ The response ^o-F whole plants arrd top ^growth to ¹⁷ reduced oxygen supplY

The effec-b of oxygen deficiency in the roots upon I7 water absorption ^and transpiratiotr

The response of nutrient and mine¡al ^uptake to ¹⁷ oxygen deficiency ^and waterlogging

Eiochemícal changes ^ancl production of autotoxic ¹⁸ substances in plants as a resuft of waterlogging

Introduction ^tB

Glycolysis ^induced by anoxic condi'bions in the ¹⁸ roots

The effect of waterlogging ^{upon pJ-ant} hormone ²⁰

syn t hes is

Tlre effect of waterlogging ^upon plant hormone ²⁰

syrr th ^es is

The effect of waterlogging ^upon nitrogen fixation in ²² leguminous species

THE ADAPTIVE MECHANTSMS OF PLANTS TOLERANT TO ²⁴

ì/,JATERLOGGED S0IL C0NDITIONS

0xygen diffusion within the plant to the roots ^and from the roots into ^oxygen deficient ^media

The formation of adventitious root ^{systems and} changes in roo'[; distribution

Biochemical adaptation of plants'bo waterl-ogged

conditions in the root ^zone

24

28

2"4 _{"3 "} ^3D

TABLE OF CONTENTS (Contd. ₎

accumulation of toxic ethanol ci¡ncentrations 2.4.3.1 . Non-

2 "4 "3 .2. The adaptive significance of the activity of alcohol dehydrogenase

2 "4 .3.3. The adaptive significanee of nítrate reductase and amino acid synthesis

2.4.3"4. Abscence of precursors of ^'boxic substances 2.4 _{"4 "} Mineral accumulation j-n _species tolerant to

waterlog ging

2.5 THE ADAPTABiLITY OF SPECIES USTD IN AGRICULTURAL SYSTEMS 'IO IIATERLOGGING, HIGH lfJATERTABLES AND FLOOD I N G

2.s.1 .

2"5.1"1"

VI

30 30

32

32 32

33

37

39

42 42

42 42

The adaptation of lucerne to waterlogging, flooding 33

and high watertab-l-es

The effect of ^'bhe duration of flooding on .l-ucerne 33

growth

The sensitivity of lucerne roots to waterlogging 34

The effect of submersion on l-ucerne 36

The effect of waterJ-ogging on iron, manganeEe

and aluminium uptake by luce¡ne

36

2.5"1"2"

2.5.1"3.

2"5"1"4.

2.5.2.

2.5 .2.1 .

2.5 .2..2.

The e'Ffects of a high watertable on crop and pasture 37 specl'-es

The e'Ffect of wa-berlogging on pasture species otherbhan lucerne

39

The adaptation to high wate¡tables and waterlogging of species, o'bher than l-ucerne, which are used in agriculture

L,eguminous species Graminaceous species

THE ^ECOLOGY OF LUCERNE

The taxonomy

of

U-rdiç-W.g. salivg and

its

close

relatives

The

distribution of

lucerne

in

the wo¡Id

The origin of l-ucerne varj.eties which are tole¡ant to poorly drained soil- conditions

The p:aductivity of Lucerne ecotypes in Australia Soils in South Austr:alia which are liabl-e to water-

J-ogg ín ^g 2.5 .2 "2.1 "

2 .5 .2 "2 "2.

2.6 .

2"6.1.

2 "6.2 "

2.6 .3 .

2.6 _{"4 "}

2.7 .

4I

44 44

TABLE 0F C0NTENTS (Contd.)

a

3.1, 3.1.1.

3"1.2.

3.1.2"1"

3.1 .2.2.

3.1 .2.3.

3.2 _"

3.3.

3"3,1.

3 .3.2 3.3 ,2 _"1

3 .3.2.2.

3"3.3"

3.3.3.1 Plant tops 3.3 _"3.2.

3"3"4"

3.4 4"

4.1 .

4.2"

4o3o

EXPERIMENT

1:

THE EFFECT OF h/ATERLOGGTNG ON THE GROI,J'IH OF EIGHT LUCERNE VARIETIES ESTABLISHED I N THRËE ^D I FI. E RENT SOI L5

MATERIALS

Varie ties

SoiIs

Sofodized Solonetz Groundwater Rendzina

Later-i-bic ^{Pcd sol-}

METI]DDS

RE SULTS

The

overall

effec'b

of

ftooding and

soil

type ^on

plant

^growth

The effeet of the flooding tleatmetrts upon the ^growth of th e eight -lucerne Growth in the non-flooded treatment G::owth ín th e f l-ooded tre atment

and the soils varieties

var-

45

45 45 45 46 46 46 46 49 49

54

54

6I

62

62

The effect of flooding upon the dry weiglrt: ^fresh weight ratio in plant tops ^{and roots}

Roo ts ⁶²

The effect of flooding upon the proportion of plants ⁶⁵ re'baining active apical ^meristems

i]T SCUSS]ON A N]] ^{CONDLUSI ONS 6s}

TXPERIMENT

2:

THE EFFECT OF FLOODING IN THREE SOILS 73 ON THE ^GRTh/TH OF HYBRID LUCERNE PÛPULATIONS DERiVED FROM CROSSES BET!ilEEN TOLTRAN'I AND NON-TOLERANT VARIETIES

PRODUC-IItJN OF HYBRID PTPULATJON5 73

EXPERTMENTAL DEsTGN AND ^METHODS 75

RESULTS ANl] DISCUSSiON 76

The over-all ^e.Ê'Fects of flooding and soil type on the avÊrilge dry weight and the nurnber of shoots per

plan'b

4.3.1. ¹⁶

TABLE 0F C0NTENTS ([ontd. )

4.3 _{"2 "}

4 "3 .2.1 _"

4.3"2"2"

4.3.3:

4"3.3.1.

4.3 "3.2 "

4 "3 .4.

4"3.5.

4.4.

5.

5.'l .

5.2.

s.2"1.

5.2 "2.

tr1

5.3"1.

The overal-I effect of ffooding and soiJ- type upon

the appearance of lucerne plants Sco¡es for plant ^appearanse

Proportion of plants active at the apical ^meristem The effect of flooding and soil type upon the growth of parental and hybrid populations Growth of non-flooded control popul.ations Growth of flooded populations

The effect of flooding and scil- type upon the appearance of parental and hybrid populations The effect of flooding otr the meristemmatic activity of parental ard hybrid populations

DTSCUSSION AND CONILUSIONS

EXPERIMENT

3:

THE ^RESPONSE OF SELECTED PARENTAL AND HYBRID CLONES TO WA'ì-ERLOGGING UNDER FTELD

CO ND I1'I ON S

I NTRODUDTI ON

EXPERIMINTAL METHODS

Selection and establishment of clonal materiel Experimental cJesign and measurements

RESULTS AND ^DISCUSSION

Overa11 comparison of the sel-ected and control clones

vl-l_r-

BO

80 B4 84

86 94 9B

'l 01

f01 108

'l0B 108 108 110 113 113

5"3"2" Comparisons t¡etween selected and control clones with ín poPulations

Ela Comparison of parental and hybrid populations 5.3"4, Selecti.on of indivídual clones whi.ch a¡e tolerant

to floodj-ng and agronomiealJ-y suitable for souther-n Austral-ia

5.4 _" SUMMA RY

6 GENTRAL DISCUSSION

The expression of waterlogging toferance by the varj.eties and hybrid popul;rtions rnhi-ch were studied

113

117 126

130 132

6.1 132

TABLE 0F CONTENTS (Contd") 6"2

6.3 _"

6.4 "

The effect of differences between the ^glasshouse and fíeld environments on the assessment of waterlogging tolerance

The morphological and physíological consequences

of waterloggíng and the expression of adaptive

mech anísms

SeIectíon of a waterlogging tolerant ^luce¡ne variety ^whích is agronomicaJ-Iy suiteble for southern Australia

APPENDICES

B TBLI O GRA P HY

r-x

134

137

139

144

B1

X

STATEMENT

This thesis contains no material which has been aecepted

for

the award

of

any other degree

or

diploma

in

^any Uníversity and thatt

to

the best

of

my knowleöge and

belief, this

thesis contains no

material previously ^published

or written

by another person, except when due reference

is

made

in

the

text of

tl-e thesis.

IAN D. KAEHNE

APRIL, 1976,

I

wish to

s uP ervr_s ors

exp erim ent al

B.M" Martin

thank D¡s.

for th eir

and

xl-

A CKNO\/ilLEDGEME NTS

R. Knight ^and A.J. Rathjen for acting ^as advice and helpful criticism during the

preparation of the manuscript; Miss

5. Britton and C.S" Morner for assistance

programme

and Mess¡s"

and

R

in the experimental- progranme;

Mrs. P. ^ì¡rjoods for assistance in Mrs" A"M. Kaehne for typing the I also wish to thank the Mr. M.R" Irving ^and

Mr. l-l.P.C. Trumble

studies ; ^an d the ^A ustral-ian ^{lrrl oo1}

Messrs. J. V. El-Lis and R" Kenyon and

and my wífe computing the

manuscript _"

former Director

analyses,

of

Agriculture,

the Acting Director of Agriculture and Fisheries, for permission'bo unde¡take and complete these

the Department of Agriculture

My thanks is extended to

and

Corporation Fish eries

for financial for personnel G. Hampton and his

the use of part of

grants through and equipment"

family of

their imigated in this study.

un derstand in ^g

Mr" ^D

Meadows,

p as'b ure I

field experimentation the encouragement and

of my farníIy, f'ri.ends and coll-eagues during the course of my candidature.

South Austrafia, who alLowed

lanrl and equipment for the

am deeply appreciative for