Aspects of growth control in kiwifruit and blackcurrant : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Massey University

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ASPECTS OF

^GRU#TH CUNTROL IN KIWIFRUI'r

A

^ND

BLACKCUHRAN'r

A

Thesis Submitted in Partial Fulfilment of the Requirements for the Degree of

Doctor of Philosophy at

Massey University

GEORGE STEPHBN LAWBS

1979

ACKNU 1'/LEDG ^EM.C:N'l' S

'l'h e author ackno >.Jl edge s t h e as s i s t anc e o f Pro f e s s o r J.A . V e al e and Dr . D . J. Woolley as

·supe rv i s o rs o f th i s the si s .

Thank s are al so ext end ed t o :

Mr . W . R . Boyc e , D i rec t o r , Ho rticul tural R e s e arch C entre , L evin , for making plan t mat eri al availabl e .

Pro f e s s o r W. W. Schwab e , 1iy e Col l e g e , England , for making fac i li t i e s avai l�bl e .

Me s srs . A . N . W at son and D . And erson for t e chnic al assi s t anc e .

S p e c i al thank s are ext end e d t o my wi f e Meryl , f o r h e r t o l eranc e and support , and for typing thi_s the s i s .

TABL.c; OP COHT.!!:NTS

ACKNO iVLEDG El'.liHT;::;

ABSTRACT

Part ^1. INTRODUCTION

A . l SHOOT GRm'/TH

1.1 Leaf effects 1.2 Root effects

1.3 Carbo^hydrate reserves 1.4 Growth regulators

B.l SAP FL011 AND SAP HOR!iiONES 1.1 Sap flow

2. Sap hormones

2.1 Gibberellin-like substances 2.2 Cytokinins

C.1 BUD ^DORMANCY

1.1 The development of dormancy 1.2 Bud bre^ak

1.3 Growth regulators and dormancy

C. 2 APICAL DOI\liNANCE AND CORaELATIVE INHIBITION

2.1 Growth regulators

S e c t i on ^1.

EXP EHHII.C:N'£AL SHOOT ^GHOWTH

A B

Sho o t growth of the k iwi frui t vine Expl ant sho o t growth

1

1 2 5 7 11

18 19 21 21 23

26 28 29 31

35 37

41 41 57

Page

DI;:)CUSSION 78

Sec t i on 2. KIWIFRUIT VINE SAP 95

A Sap flow 95

B Sap growth r egul ator s 106

DISCUSSION

A Sap flow 128

B Sap growth r egulat o r s 137

Sec t i on 3. DORMANCY AND BUD BURST 145

A Winter do rmancy and bud burs t 145

B Co rrel ative inhi b i t i on 180

DL:iCUSSION

A Bud d o rmancy and bud burst 188

B "Summer d ormancy" 201

Part 2. IN'rRODUCTION 207

JUVENILITY 207

EXPEHIMENTAL 215

DISCUSSION 227

FINAL DISCUSSION 232

LITERATURE CITED 244

Figure 1 2 3

4 5

TABL� OV FIGURES

Effect of dofoli�tion on sho o t ^gr^owt^h.

Effec t of defoliation on int ernode growth .

Effect o f dec:.::.pi tat i on and defoliat i o n on internode growth after 53 days .

Growth of kiwifrui t pl2.nt internodes .

Di stribut i on of grov1t

h

vvi thi n an int ernode .

6 Standard curve for lciv-: i frui t seedling's respon se to gibberellic ac id .

7

8 9 10

Effec t of growth regulu.tor ^sprays on plant height .

Effec t of GA on kh�ifrui t plant height . Effect of CCC on lciwifrui t plant height . Kiwifrui t res p irat ion aft e r ^{summer sprays.}

11 Treatment effect on stem elong:tti on

kiwifruit.

12 Typi cal effec t of ^growth re�ulut o r s on growth of kiwifruit cut t ings.

13 Relat ionship b e t ween Cl.l tting volume and sub sequent shoot growth.

14 1 5 1 6

1 7

Effect of ^lAA on kiwifrui t shoot growth. Effect of GA and �CIB on shoot growth.

Ext raction of soluble sugars and reserve po lysaccharides .

Sap flo� from individual sho o ts cut ⁰ⁿ Day 0, in eac h successive 24-hour period.

4 5 45

47 49 49

51

51 5 3 5 3 5 5

59 - 61

6 4

68 7 1 7 1

74

97

Figure

18

Ai r temp8rature s

ⁱ

n relation

to

t h e first day' s sap fl ow rat e .

19 Daily sap

flow from each main s t em o f

98

d e capi t at e d kiwi fru.i

t plan t s , cut on

^{Day 0. 102} 20

21

Rat e of

sap

flo�

at

each

cutt ing

dat e , for thre e d

^ay

s aft er d e c api tat i on .

So i l and a i r t emperatur e s .

22

Ex traction o f gi bberel lins and cyt okinins from sap .

23

His t ograms o f GA-like sub s t anc es in

ble eding sap , spring

^1973,

at suc c e s s i ve c o l l e c tion

dat es.

24

Histograms o f GA-lik e sub s tanc e s in

103 103

109

113

b l e eding s ap at int erval s aft er d e c ap i t ation ,

aft e r grad i ent elu t i on from silic a gel c o1.umn .

¹¹⁵ 25

Extrac t i on o f gibberel lins and cytokinins

from sap .

26

Standard curve s for barley endo sperm

respon s e t o GA3 d e t e rmin ed r e frac t ometri c ally

117

and c olourimetri c ally .

¹¹⁹

27

Hi s t o grams o f GA-lik e sub s t anc e s in

b l e ed ing s ap , s pring

^{1975 ,}

at suc c e s sive

dat e s from d i f ferent pl ant s .

¹²⁰

28

Hi st ograms o f soybean bio as s ay o f

cytokinin s from bl eeding sap s , spring

^1975,

from diff e r ent plant s .

29

Hi stograms o f s oybean bio assay o f

c y t okinin s from bl e eding s a p i n suc c e s s ive

122

days , Plan t

^{20. 125}

Figure

3 0 HPLC trac e o f cytokinin extrac t o f kiwifruit

saps ,

Pl an t 20 , Day 4 , an d s o ybean callus bio a s s ay result f o r e ach frac tion .

3 1 Effect o f t emperature o n kiwifrui t bud

burs t .

3 2 Eff e c t o f pruning

t .. ,;atment

o n bud burs t at three harv e s t d:·.

'" es.

3 3

3 4 35

Effect o f e th e phon

and

pruning tre atment on bud burst .

Kiwifruit r o o t growth .

Ext rac tion o f cy t okinins from woody t i s sue .

36 Soybean b i o assay o f butanol- s o lubl e cyt okinins in kiwifruit bud s during bud burst .

37 S oyb ean b i o a s s ay of bu tano l - s o lubl e

cytokinins in buds and sap during spring

1 27

150

154

156 159 1 6 2

1 66

bud burs t . 1 6 8

38 Soybean b i oa s s ay of but ano l- s o lubl e c y t okinins in kiwi f rui t s t ern s .

39 Hi s t o gram o f cytokinin ac t i vity in

kiwifruit st em s

and

bud s during do rmancy . 40 C omparison o f cy t oki·:in ac t i vity in s t em

171

1 7 3

tis sue

follo�in�

di f fe rent l evels o f chill.ing . 175 4 1 Ext rac t i on o f absc i sic ac i d from buds .

4 2 C o mpari s on

of

inhibi t o r ec t ivity i n bud s

177

following d i fferent l evels of wint e r c hilling . 179

4 3 Soybean bion s say o f c�·tokin in a c t i vity in kiwi frui

i.

sho o

L, cts

affec t e d by auxin

ap plication .

188

Figure

44 Purification of blackcurrant tis su e f o r gibb ere l lin d e t ermination .

4 5 Bio a s say o f 2 5g s t em tis sue ±GA a f t e r extraction and c hromat ography .

46 His t ograms o f bio a s s ay s o f GA-like subs t anc e s in adult blackcurrant s t em .

47 Histogram s o f bioas say of GA-like sub s t anc e s in adult s t ems from fruiting bushe s .

4 8 Histograms o f bio a s s ay s o f GA-like sub stanc e s in adul t s t ems .

49 His t o gram s o f GA-lik e sub s t anc e s in

218

220

2 21

2 21

2 2 2

juvenil e-lik e s t em and ro o t s Wellingt o n XXX

.

2 2 4 50 His t o grams o f GA-lik e substanc e s in Baldwin

s e edling s . 2 2 6

...

LI::>'l' ^U}' 'l'ABLt.:S

Table

l M e an

e;rowth

r esponc; e

to pruning

t reatment s.

2 Bffect

of pr'.Aning

and

�rowth regulutor

t

r

eatme

n

t on

pl�nt crowth.

3

Eff ect

of growth regulator

t reatm ent on explant rr1ean dry we ieh t dL::;t ri but i o n .

4 Change s in explan t carbohyd rat e l eve l s . 5 Gibberellin- l ik e activity in s ap .

6 Cyt o kinin-l i ke act i vi ty in sap .

7

Cytokinin ac t ivi ty in s ap over five d ay s aft e r d ecapi tat i on .

8 Bud burst at d i f f

e

rent harve st date s . 9 Bud burst f o l l owine

prQnine

t reatment

10 The effect o f ro o t remo val on kiwi fru i t bud burs t .

11

12

Comparison

of cyt ok inin l e ve l s in bud s during bud bur s t .

C ompari s on o f cyt o k inin l evel s in sap and bud s during bud bur s t .

1 3 Bud movement i n re spon s e t o hormone treatment in d i fferent

seasons.

1 4 Effe c t o f bud

position

on cut ting on bud burs t .

1 5 Bud burst re s ponse t o varying l ev e l s o f wint e r chi lling .

6 2

6 6 7 7 119 1 2 3

124 147 1 5 3 1 57

16 5

16 9

1 8 3

1 8 6

1 9 0

LIST

OF

PLNrES

Plate

1 The effec t o f gibbere l l in on sho o t growth of

^an

Abbo t t kiwi fruit cut ting .

2 The effect o f a pre-bud burst appl i cat i on o f gibb e rellin

and

cytokinin on sho o t growth .

Page

6 5

6 5

...

ABS'l'HACT

This study emphasized the interplay of s ev e ral typ es of growth regulator in t he control of growth and d evelopment in the kivlifru i t plant. Hence different

parts of the p lant are seen to contribut e to this control , th e p l ant appearing as a fully-integrated syst em with the shoots and roots interacting with each othe r .

The gibb erellins w ere active in the promotion of st em elongat ion , and it is consid ered stem g rowth is d ep e ndent on the photosynthate sup ply , and that this is med i at ed by the growth ree;ulators. A leaf had a dominant

effect on internod e gro·nth , and therefor e shoot length , at a v e ry early stag e of its developmen t - but the effect of an individual leaf w as very loc alis ed . The plant

roots w e re not clearly shown to be ess ent i al for breaking dormancy , bud burst , or early shoot growth . How ever it was found the roots could be supplying gibb e r e llins as one of the factors reou ired to maintain normal shoot growth . Cytok inins for early bud growth could have been suppl i ed in th e bl eedine sap either from th e roots o r the stem tissu e . R es ervations ar e exp r essed about the need for h i gh spring sap flows for plant growth . H i gh sap flows may b e a r esult of a c o mbination of c i rcumstanc es at the t im e , and not a necessary pre-requis it e to growth .

SADH and mal e i c hydrazide are effective shoot growth retardants , and may f i nd co�nerc i al ac c eptanc e , exc ept their apparent effect in enhanc ing post-harvest f ruit r espi rat ion must receive further study .

Bud dormancy was great est before l e af fall , and

dormancy was broken by about 7 0 0 hours b elow7. 2°C , although warm t emp eratures were just as eff e ctive i n overcoming this dorraant condit ion . Winter dormanc y appeared to b e bas i-

c ally the sam e type of condition as correlative inh ibition , and i t is sugg est ed ^th8t eac_h i s , in large part a r e sult of an inab i l ity to utilise cytokinins or oth er growth promo ter s .

It i s ^consid^ere^{d that} the juvenile-like condition in blackcurrru1t i s distinct from t rue juveni lity, and the form er did not app ear to be the r e sult of prox im ity to gibb erellins from the roots . Further , it c ould no t b e shown for true juveni l ity that i t w a s lik ely to b e du e to th e production of inhibitory l ev e l s of gibber e llin by the roots.