Was Lysenko Right

8/12/2019 Was Lysenko Right

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Jaroslav Flegr

Was Lysenko Partly) Right? Michurinist Biology in the View of

M odern Plant Physiology and Genetics

1. In t roduct ion2 . Vegetative Hybridisation3 . Wobbled Heri tabi l i ty4 . Heritabili ty of Environmentally Induced Adaptive Changes in Plants5. Intrava rietal Cro ssing of Self-fertilizing Plan ts6. Epilogue

Key words. Heritability, Lysenko, Punctuated equilibrium, Somatic mutations,Directed mutations, Sir Sebright's effect, Frozen plasticity, Evolution.

bstract Soviet Lysenkoism was the darkest period of modern science, andits main product — Michurinist biology — was a collection of absurd theoriesusually based on anecdotal observations or on a few badly designed experi

men ts without proper controls and without any statistical evaluation of results. However, in the thirties and early forties, Lysenkoists a lso describedand m isinterpreted) some interesting data and observations which could

have been real and which might inspire modern biologists to construct test



2 6 Jaroslav Flegr

genetic and epigenetic polymorphism originating from somatic mutations,

somatic recombination and paramutations), the third phenom enon by theoccurrence of intraindividual selection of somatic cell lines, and the fourthphenomenon by low heritability of phenotypic properties and therefore alsolow capability to evolve) of outcrossing organisms in comparison with selffertilizing or asexual organisms), i.e., by a theory of frozen plasticity.

1. INTRODUCTION

T h e t e r m Ly s e n k o i s m is u s u a l l y u s e d t o d e n o t e t h e p o l i t i c a l ,social and prerogat ive act ivi t ies of Lysenko and his fol lowers whichresu l ted in p rac t i ca l de s t ru c t io n o f w ho le b ra nc he s o f sc ience a n dcarr iers , and of ten even l ives , of scient is ts in the Soviet Union andpart ly also in i ts pol i t ical satel l i tes . The roots and impacts of these

p e r s e c u t i o n s h a v e b e e n t h o r o u g h l y a n a ly z e d ( M e d v e d e v [ 1 9 6 9 ] ;R o l l - H a n s e n [ 1 9 9 9 ] ) . T h e t e r m Ly s e n k o i s m , h o w e v e r, h a s a lso as e c o n d m e a n i n g : a g e n e t i c a n d e v o l u t i o n a r y t h e o r y , t e r m e d

M i c h u r i n i s t b i o l o g y o r S o v i e t c r ea ti v e D a r w i n i s m b y i ts p r op o n e n t s , p r o m o t e d b y Ly s e n k o a n d h is f o ll o w e rs f r o m t h e e a r l yth i r t ies to the la te s ix t ies . M ic h u r i n is t b io lo gy is ba sed o n th e ass u m p t i o n o f c o m p l e t e l y s o ft h e r e d i t y. P r o p e r t i e s o f o rg a n i s m ss hou ld b e ea s i l y i n f luen ced by the en v i r o nmen t , and the en v i r on



Michurinist iology and Modern Genetics 261

I w o u l d li ke t o p r o v i d e a n e x p l a n a t i o n o f s o m e p h e n o m e n ades c r ibed by Ly s enk o , w h ich m igh t be co m pa t ib l e w i th t he t ene t so f m o d e r n b i o l o g y . I w o u l d i n t e n t i o n a l l y n e g l e c t t h e p o s s i b i l it yt h a t t h e s e p h e n o m e n a n e v e r o c c u r r e d a n d t h a t t h e r e s u l t s w e r ef a b r i c a t e d b y Ly s e n k o o r h i s c o - w o r k e r s . I n t h e l a t e t h i r t i e s ,M ichu r in i s t gen e t i c s coex i s t ed w i th s t an da r d M ende l i an g ene t i c s ,

and therefore the chance of forger ies was lower than af ter the off icial t r iu m p h of Ly senk oism in the for t ies. I wil l there fore focu s m yat t en t io n especia lly on the o lder pap ers inc lud ed in A grob io log y ,t h e b a s ic t e x t b o o k o f M i c h u r i n i s t g e n e t i c s ( Ly s e n k o [ 1 9 5 0 ] ) . I n

p a r t i c u l a r, I w i l l c o n c e n t r a t e o n t h e p r o b l e m s o f v e g e t a t i v e h yb r i d i z a t i o n , w o b b l e d h e r i t a b i l i t y, h e r i t a b i l i t y o f e n v i r o n m e n t a l l yin du ce d adap t ive m od if ica t ion s an d pos i t ive effec ts of in t rav ar ie ta lhy br id iza t io n of se l f - fer t il iz ing p l an t cu l t ivars .

2 . V E G E TA T I V E H Y B R I D I S AT I O N

V ege ta t i v e h y b r id i za t i o n ( g r a f t i ng ) i n p l an t s ha s be en a lw ays

a p p r e c i a t e d b y p l a n t - b r e e d e r s as a p o w e r f u l t o o l fo r p r o d u c t i o nand propagat ion of in terspecies hybr ids (wi th low or nul l fer t i l i ty)a n d of r a re r e c o m b i n a n t s w i t h u se fu l p r o p e r t i e s . M i c h u r i n i s t s ,however, c la imed tha t vege ta t ive hybr id iza t ion cou ld be used a l so



262 Jaroslav Flegr

of retroviruses transferring genes from stock into a scion? It is nvery surprising that the properties of stock influence epigeneticalthe propert ies of the scion. Not only low molecular weight moecules but also proteins and RNA can easily move through phloeand therefore also enter from the stock into the scion (Crawforand Zambryski [1999]). Current experience with transgenic plan

shows that regulation of gene expression is integrated across thw hole bo dy of a p lan t ( Jo rgen sen et al. [ 1 9 9 8 ] ; K o o t e r et al.[1999]): overproduct ion of a t ransgene product in one part of plant often results in gene inactivation (e.g. by a methylation

regulatory sequences of the gene) in all t issues of the transgenp l a n t . Th e r e d c o l o u r o f t o m a t o f r u i t s i n e x p e r i m e n t s oM ichu rinists and the Jap an au tho rs, how ever, has been tran sm ited to the next generat ion by seeds. Today we know that indvidual organs and tissues of a plant do not have to be geneticalidentical. Genomes of their cells might differ due to somatic mutations, somatic recombination (results of relat ively common mtotic crossing over), or due to hereditable (but often reversiblemodifications (e.g. methylations) of the genome (Otto and Has

ings [1998]) . Under normal condi t ions biochemical differencebetween parts of a plant are very difficult to observe because tranported molecules synthesized in other parts of the organism inflence both ontogeny and physiology (and therefore phenotype) of




3 . W O B B L E D H E R I TA B IL I TY

V i s u a l i z a t i o n o f h i d d e n g e n e t i c p o l y m o r p h i s m c o u l d h a v ep l a y e d a r o le a ls o i n t h e p r o d u c t i o n o f o rg a n i s m s w i t h w o b b l e dh e r it a b il it y ( Ly se n ko [ 1 9 5 0 ] , p p . 2 8 9 , 3 3 5 , 4 1 5 - 4 1 7 ) . A c c o r d i n g

to Lys enk o ' s def i n i t ion , h er i ta b i l i ty is th e ab i l i ty o f a l iv ing b o d yt o d e m a n d fo r i ts d e v e l o p m e n t s p e ci fi c c o n d i t i o n s a n d re a c t t othese o r d i fferen t co nd i t io ns in a spec if ic w ay. T he ref or e , g r ow ingthe p lan ts under condi t ions which they a re no t used to ( fo r example ou t o f the i r normal geographic range) , can resu l t in to deve lopm e n t o f p la n ts w i th so ca lled w ob ble d he r i tab i l i ty th a t co u ld bet h e n u s e d e . g . f o r b r e e d i n g o f n e w v a r i e t i e s . W h i l e t h e n o r m a lr a n g e p r o v i d e s t h e p l a n t s w i t h j u s t t h e c o n d i t i o n s d e m a n d e d f o rno rma l deve lopmen t , the fo re ign r ange p rov ides a l i en cond i t ions ,

a n d t h e p l a n t s r e a ct t o t h e m i n a n a b n o r m a l w a y. T h e n a t u r e o fthese ind ividu al react io ns is of ten h er i table , i .e . , co uld b e t ra ns m itted to the offspr ing.

W h a t used to be ca lled w ob bled her i tab i l i ty cou ld wel l be the

v i sua li za tion o f h i dd en gene t i c po lym or ph i sm , th is t im e , how evera t t h e le ve l o f a p o p u l a t i o n . C u r r e n t m o l e c u l a r b i o l o g y c l e a r lyshow s tha t a large f rac tion of genes in po pu la t io ns is p o l y m or ph ict h e y e x i s t i n a n y g i v e n p o p u l a t i o n i n s e v e r a l r e l a t i v e l y c o m m o n



2 6 4 Jaroslav Flegr

Phenotypical expression of many genes is also affected by epistasi

i.e., by activity of modificators, genes that influence the extent oout-manifestat ion of al leles in other loci (Martin and McGowa[1995 ] ; Nanjundiah [1993]) . Due to complex and of ten ra theindirect nature of their action, the modificators may work properl

only under normal condi t ions, i .e . , in the environment in whicthey were originally selected for. Under abnormal conditions manof these genes-modificators have lower capacity to mask the genetic differences, the hidden polymorphism becomes apparent anproduces phenotypic polymorphism that could be used in selecing organisms with new propert ies.

4. HERITAB1LITY OF ENVIRONMENTALLY INDUCED

ADAPTIVE CHANGES IN PLANTS

Certain categories of results described in the Lysenkoist literature suggest the existence of a phenomenon only rarely accepteby modern biologists, namely the possibility of a heritable adapttion of individual organisms to local conditions in organisms lacking the Weissmann barrier (e.g. in plants) by the mechanism of aintraindividual selection of somatic cell l ines. For example, th



Michurinist Biology and Mod ern Genetics 2 6 5

l a r t o k a l e , t h e o r i g i n a l w i l d p a r e n t o f b o t h g a r d e n v a r i e t i e s

( Tu r b i n [ 1 9 5 2 ] , p p . 1 8 8 - 1 8 9 ) .Ev e n mo re imp o r t a n t wa s th e o b se rv a t io n c o n c e rn in g th e in f lu

ence o f env i ronmenta l cond i t ions on he r i t ab le p roper t ie s o f p lan tsM a n y p l a n t s a r e s e l f - i n c o m p a t i b l e the y c a n n o t be fe r ti li zed byt h e i r o w n p o l l e n . P o l l e n i n c o m p a t i b i l i t y e x t e n d s a l s o t o c l o n e sob ta ined f rom the sam e ind iv id ua l by vege ta tive rep rod uc t ion (e.gb y c u t t i n g a s t o o l o r a b u l b ) . A c c o r d i n g t o M i c h u r i n i s t s , t h i s i ncompa t ib i l i ty wi th in the c lone can be evaded i f two c lones o f thesame p lan t a re grown in d ivergent condi t ions (e .g . , one in dry, one

i n m o i s t) ( T u r b i n [ 1 9 5 2 ] , p . 1 3 8 ) .To expla in such resu l ts we must accept the poss ib i l i ty of ex is t

e n c e o f f r e q u e n t g e n e t i c o r s t a b l e e p i g e n e t i c c h a n g e s i n t h e s om at ic t is sues o f p la n ts (O t t o an d H as t in gs [1 99 8] ) . T h e re la t ive ly

ra re ( a n d u n d i r e c t e d ) t r a d i t i o n a l m u ta t io n s a r e a r a th e r u n l ik e lyca nd ida te . A far m or e feasible source of such c han ges m ay be param u ta t io n s , i .e ., p r o g ra m m e d a n d o f te n r e v e rs ib l e m o d i f i c a t io n s or e g u l a t o r y e l e m e n t s o f g e n e s ( I t o h et al. [ 1 9 9 7 ] ) , o r s o m a t i c r ec o m b i n a t i o n d u e t o c r o s s i n g o v e r b e t w e e n t w o h o m o l o g o u s c h r om o s o m e s d u r i n g a n o r m a l m i t o t i c c y cle . U n l i k e m e i o t i c r e c o mb i n a t i o n s , s o m a t i c r e c o m b i n a t i o n s o c c u r m a n y t i m e s d u r i n g t h el i f e o f i n d iv id u a l p l a n t . I n so ma t i c r e c o mb in a n t s , t o t a l DNA c o n



2 6 6 Jaroslav Flegr

(and therefore individual branches) might be more or less adapteto the exist ing condit ions, which could result in differences ingrowth rates or differentiation competency of these lines. In thlatter stages of the plant life only cell lines best adapted to the local conditions will participate in the development of germinal organs. Also the resistance of different apical meristems to local ad

verse conditions (which may manifest i tself in the efficiency opo l len and f ru i t p ro du c t io n ) m ay vary w i th in th e p la n t . T h icould be a principle underlying genotrophs and s imilar phenomena recognized by nowadays' botany (Cull is [1973], [1984]) analso the heri table adaptations in plants described (and misinterpreted) by Michurinists .

Let 's now return to the problem of pollen incompatibil i ty between clonal plants grown under same conditions, and compatibili ty between the same plants grown under diss imilar condi t ionsRegardless of the stochastic nature of somatic recombination, thselection operating on cell l ines and its results are more or lesdetermined by environmental condi t ions. Therefore, the genet i(and epigenetic) information of germinative cells of two plant

developed in ident ical condi t ions wil l be more s imilar to eachother than that of two plants developed under diss imilar condit ions . Such intraindividual select ion-induced (both genet ic andepigenetic) differences between clonal plants grown under dissimi

Mi h i i Bi l d M d G i 267



Michurinist Biology and Mo dern Gene tics 267

bizar re . Ho w ev er, i f w e take in to acc ou n t the po ss ib i l i ty o f d iffe ren t co nd i t io ns se lec t ing for d i ffe ren t a lleles , th e re co m m en d at io n s

o f S e b r i g h t , D a r w i n a n d o t h e r s c a n b e c o n s i d e r e d q u i t e r e a s o nable .

5. INTRAVARIETAL CROSSING OF SELF-FERTILIZING PLANTS

Intravar ie ta l cross ing of se l f - fer t i l iz ing plants was or ig inal ly reco m m e n d e d b y Ly s e n k o f o r w h e a t v a r i e t i e s , l a t e r t h e s a m e t e c hn iq u e w as t r i ed a l so w i th o th e r spec ie s o f se l f - f e r t il i z ing p l an t s .Ly s e n k o p o i n t e d o u t t h a t , i n c o n t r a s t t o v a r i e t i e s o f r y e ( o u tc ross in g p la n t ) , t he va r i e t ie s o f se l f -f e r ti l iz ing w h ea t w ere h ig h lyuns tab le , g radua l ly lo s ing the i r bene f i c i a l p rope r t i e s . Many e s tabl i shed var ie t ies o f rye a re be ing cu l t iva ted for long t ime on la rge

a r e a s , w h i l e m o s t o f th e va r i e t i e s o f w h ea t d i sa pp ea r f rom f ie ld sand f rom ca ta logues o f seed companies wi th in th i r ty years (Lysenk o [ 1 9 5 0 ] , p p . 1 0 5 , 111 ) . A c c o r d i n g t o Ly s e n k o , o l d v a r ie t ie s o fw h e a t m u s t b e c o n t i n u o u s l y s u b s t i t u t e d b y n e w o n e s b e c a u s e t h ese l f -f e r ti li z ing p la n t s a re un s ta b le an d the i r go od p ro pe r t i e s ( fo rw h ic h they hav e be en o r ig ina l ly se lec ted ) a re g e t t in g lo s t du r i n glong- te rm cu l t iva t ion . He c la imed tha t th i s p rocess can be s toppeda n d r e v e r t e d b y a r t i f i c i a l o u t c r o s s i n g b e t w e e n t h e p l a n t s o f t h e



268 Jaroslav Flegr

h a rm fu l . S i m i l a rl y, t h e i n f lu e n c e o f a p a r t i c u l a r g e n e o n t h e p h e -n o t y p e is o f t e n c o n t e x t sp e c if ic ( th i s t i m e g e n o t y p e -c o n t e x t sp e

c i f ic ) . Due to ep is ta t ic in te rac t ions be tween genes , the e ffec t o f ana l l e l e o n t h e p h e n o t y p e d e p e n d s o n t h e c o n t e x t o f t h e a l l e l e s o fo t h e r g e n es (W r i g h t [1 9 3 1 ] ; M a y r [1 9 6 3 ] ; Ka n a v a k i s et al. [ 1 9 8 2 ] ;Wa i n s c o a t et al. [ 1 9 8 3 ] ) . I n a s e x u a l o rg a n i s m s t h e g e n o t y p e o fo r g a n i s m s is t r a n s m i t t e d b e t w e e n g e n e r a t i o n s i n a n u n c h a n g e dfo rm . T he re f o r e , a pa r t i cu la r al le l e has th e sam e in f luen ce o n thep h e n o t y p e ( a n d f it n es s ) o f b o t h p a r e n t a n d p r o g e n y . I n s e x u a lou tc ross ing o rgan i sms , the geno types o f o ff sp r ing a r i se eve ry gene r a t i o n d e n o v o b y m i x i n g g e n e s f ro m t w o p a r e n t s . T h e r e f o r e ,

t h e s a m e a ll ele (m u t a t i o n ) o c c u r s i n e v e ry g e n e ra t i o n i n t h e c o nt e x t o f a d i f f e r e n t g e n o t y p e , a n d it s i n f l u e n c e o n t h e p h e n o t y p ea n d f i t n e s s mi g h t d ra ma t i c a l l y d i f f e r. I t ma k e s t h e e v o l u t i o n a ryre sp o n se o f s e x u a l sp e c i e s o n s e l e c t i o n p re s su re d i f f ic u l t . W h i l e

a s e x u a l ( a n d p a r t l y s e l f - f e r t i l i z in g ) p o p u l a t i o n s a r e as a r u l ee v o l u t i o n a r i l y p l a s t i c f o r t h e w h o l e t i m e o f t h e i r e x i s t e n c e , t h ep o p u l a t i o n s o f s e x u al sp e ci e s a re p l a s t i c o n l y u n d e r c o n d i t i o n s o flow gene t i c po lymorph i sm (when a l l e l e s occur in eve ry genera t ionin the same or very s imi la r contex t ) (Flegr [1998]) . Such s i tua t iono c c u r s fo r e x a m p l e a fte r a b o t t l e n e c k - i n c l u d i n g s p e c i a t i o n e v e n t( C a r s o n a n d T e m p l e t o n [ 1 9 8 4 ] ; T e m p l e t o n [ 1 9 8 0 ]) o r i n e x p e rim e n t s w i t h s m a l l o r i n b r e d p o p u l a t i o n s ( G o o d n i g h t [ 1 9 8 7 ] ;

Mi h i i i l d M d G i 269




pos i t ive and nega t ive va lues . To p reven t de te r io ra t ion o f a rye var i e t y, w e o n l y n e e d t o a v o i d c o n t a m i n a t i o n b y p o l l e n (o r se e d s )

from foreign varie t ies . O n th e ot he r h a n d , a varie ty of w h ea t (or ofo t h e r s e l f- f e rt il iz i n g p l a n t ) m u s t b e c o n t i n u o u s l y s u b j e c t e d to aselect ion pressure for i t s useful propert ies , or i t must be from t imet o t i m e su b s t i t u t e d b y a n e w v a r i e t y. Th e o re t i c a l l y, i t m i g h t a l sohe lp to prepare seed for sowing by forced ou tcross ing (as has beenr e c o m m e n d e d b y Ly s e n k o ) , a l t h o u g h o n e m a y d o u b t t h e e c o n o m ica l feas ib i l i ty of th i s p rocedure .

6 . E P I L O G U E

The theo r i e s o f Lysenko i s t s a re so c razy tha t t he i r exper imen t sn o b o d y e ls e h a s r e p e a t e d , a n d t h e i r r e p u t a t i o n is so b a d t h a t n o

w e l l - i n fo rm e d a n d d e c e n t s c ie n t i s t is w i l l i n g t o r e a d t h e i r wo rk s .Desp i t e th i s , i n t e res t ing da ta and obse rva t ions tha t migh t in sp i re ab i o l o g i s t t o c o n s t ru c t t e s t a b l e h y p o t h e se s m i g h t b e c o n c e a l e d i nt h e b o d y o f M i c h u r i n i s t l i t e r a t u re . It is r a t h e r a n e th i c a l p r o b l e mwhether the sc ien t i f ic works of c r imina ls should be ignored or no t .

I t shou ld be , however, a rgued tha t by avo id ing the top ics and theareas of sc ience tha t were in the cen ter o f a t ten t ion of these peoplewe ac tua l ly a l low them to shed mal ice even long af te r the i r phys i

l l i t i l d th



27 Jaroslav Flegr

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Jaroslav Flegr

LYSENKO AVEVA (IN PARTE) RAGIONE?LA BIOLOGIA M ICIUR INISTA ALLA LUCE

DELLA MODERNA GENETICA E FISIOLOGIA VEGETALE

Riassunto

II Lysenkoismo sovietico pub essere considerato uno dei periodi piii

tragici nella storia della scienza moderna e il suo principale prodotto, labiologia Miciurinista, un insieme di teorie assurde, solitamente basate suosservazioni anedd otich e о su pochi esperime nti m al im postat i , privi dcontroll i adeguati e di verifiche stat ist iche dei risultat i . D'al tro canto,negli anni '30 e '40 i Lysenkoisti riportarono, e interpretarono erronea-

mente, alcune interessanti osservazioni che potrebbero riferirsi a fenome-ni reali e da cui potrebbero trarre ispirazione i biologi moderni. Abbia-mo presentato una spiegazione in termini di moderna biologia di alcunidi questi feno m eni, o w e ro l' ibridazio ne vegetativa, la ereditarieta tra-ballante , l 'ereditarieta di modificazioni adattative e l 'ibridazione tra di

verse varieta di cultivars riproducentesi per autofecondazione.

Was Lysenko Right

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