544 K u r z e O r i g i n a l m i t t e i l u n g e n Die Natffr- wissenschaften

Iokal a n der In jek t ionss te l l e schnel l w a c h s e n d e u n d ba ld z u m Tode I i ihrende T u m o r e n , die s i imtl ieh h is to logisch yon Pro- fessor Dr. H . HAIVlPXRL, Bonn, als Sp inde lze l lensarkome dia- gnos t iz ie r t wurden .

Da s u b c u t a n e Sa rkome bet unse r en R a t t e n s p o n t a n sehr se l ten v o r k o m m e n (unter 0,5 %) u n d alle T n m o r e n s t reng an der In jek t ionss te l l e au f t r a t en , k a n n der K a u s a l z u s a m m e n h a n g als ges icher t gelten. Die hohe A u s b e u t e yon 7 u n t e r 12 R a t t e n bet e iner m i t t l e r en Gesamt dos i s yon 500 m g spr ich t fiir eine beach t l i che ca rc inogene W i r k s a m k e i t des Pa ra fuchs ins .

Die Arbe i t en w u r d e n du rch die D e u t s c h e F o r s c h u n g s - g e m e i n s c h a f t e rm6gl icht .

Laboratorium der Chirurgischen Universit~itshlinik, Fret- burg i. Br.

H. D R U C K R E Y , H.A. NIEPER n n d H . W . Lo Eingegangen am 2. November 1956

i) SCHILLER, W.: Amer. J. Canc. 3t, 486 (1937). - - HARRIS, P.N.: Canc. Res. 7, 35 (t947).

~) WILLHmM, R., u. A.C. Joy : Cane. Res. 12, 308 (1952). 8) DRUCKREY, H., u. D. SCHMXHL: Naturwiss. 8, 215 (1955). ~) YOSmDA, T., T. SHIMANCHI U. C. KI.~: Gann 35, 272 (1941).

EiniluB des Gibberellins auf die B1/itenbildung bei Kalanchoe bloflfeldiana

Wie wir fr t iher mi tge te i l t haben~), k a n n m a n bet der Lang - K u r z t a g p f l a n z e B r y o p h y l l u m und bet der L a n g t a g p f l a n z e L a p s a n a c o m m u n i s u n t e r s t r eng v e g e t a t i v e n B e d i n g u n g e n Bl t i t enb i ldung du rch Gibberel l in aus l6sen. Schon wesen t l i ch Irtiher als bet d iesen Ob j ek t en h a b e n wir m i t der Gibberel l in- b e h a n d l u n g bet der K u r z t a g p f l a n z e K a l a n c h o e bloBfeldiana begonnen . Obgleich wir die B e h a n d l u n g s w e i s e auf3erordent- l ich s t a rk var i ie r t haben , is t his hen te , d .h . m e h r als 5 Mona t e sei t B e g i n n der Versuche, an ke iner der m e h r als 150 Ver- suchsp f l anzen eine F 6 r d e r u n g des B1/ihens zu beobach t en . I m Gegentei l , es m a c h t sich eine gewisse H e m m u n g ge l t end : die Blt i ten werden an den Gibbere l l inpf lanzen zwar e twa z u m gleichen Z e i t p u n k t s i ch tba r wie an den d u t c h K u r z t a g indu- z ier ten Kont ro l len , aber es k o m m e n n u r re la t iv wenige Bl i i ten zur E n t w i c k l u n g , n n d n a c h einiger Zeit f inde t ein Riick- sch lag zur v e g e t a t i v e n P h a s e s ta r t . A u c h das L ~ i ngenwachs tum der In te rnod ien , das bet n i ch tb l f i henden K a l a n c h o e p f l a n z e n wesen t l i ch s tbxker i s t als bet b l i ihenden, i s t bet den Gibberel- l inp f l anzen s t a r k gef6rdert , u n d die B l a t t s u k k n l e n z , die bet b l i ihenden P f l anzen besonders hoeh ist, i s t bet den Gibberel l in- E x e m p l a r e n gering. Bet K a l a n c h o e werden die v e g e t a t i v e n Merkma le also du rch Gibberel l in gef6rdert , die r e p r o d u k t i v e n aber g e h e m m t .

Aus dieser g~gzl ich a n d e r s a r t i g e n IReaktion der K u r z t a g - p f lanze K a l a n e h o e gegenf iber u n s e r e n ande ren Versuchsob jek - t e n erg ib t sich, dab das Gibberel l in keinesfal ls der allein a u s s c h l a g g e b e n d e F a k t o r fiir die B l i i t enb i ldung sein k a n n Evgl. ~ ) ] .

M i t U n t e r s t f i t z u n g der D e u t s c h e n F o r s c h u n g s g e m e i n - schaf t .

Gdttingen, P/lanzenphysiologisches Institut der Universit~l t~. HARDXR u n d R. B /3~sow

Eingegangen am 26. November 1956

t BONsow, R., u. R. HARDER: Naturwiss. a) 43, 479 (1956); b) 43, 527 (1956).

fiibberellin and Flower Formation

As r epo r t ed previously1) , gibberel l in induces f lower for- m a t i o n in nonco ld - t r e a t ed b iennia l tfyoscyamus niger, t h u s enab l ing th i s p l a n t to b y p a s s i ts n o r m a l cold r e q u i r e m e n t . T h e e x p e r i m e n t s h a v e meanwh i l e been e x t e n d e d to o the r cold- r equ i r ing p l an t s a n d to a n u m b e r of long- a n d s h o r t - d a y p l an t s , all of t h e m m a i n t a i n e d u n d e r n o n i n d u c t i v e condi t ions . Th i s no t e is to s u m m a r i z e t h e resul ts . A fuller a c c o u n t will be pub - l ished elsewhere.

Cold-requiring plants. Some, b u t n o t all p l a n t s of a v a r i e t y of ca r ro t (Ear ly F r ench Forcing) f o r m e d f lowers a f te r 11/2 to 21/o m o n t h s of da i ly app l ica t ions of t0 [zg or more of g ibberel - lina). I n a n o t h e r v a r i e t y (DANvER'S Ha l f Long), a bo l t ing response on ly ha s been obse rved so far, a n d t h e s a m e is t rue of pa r s l ey (Hamburg ) and t u r n i p s (Purple T op Globe). The t r e a t m e n t is be ing con t inued . In w in te r rye ( P E T K U S ) s t e m e longa t ion was g rea t ly p romo t ed , b u t no effect on f lower

in i t i a t ion was to be de tec ted (same leaf n u m b e r to f i rs t f lower a n d same developmental s t age of the terminal shoot meristem in treated plants and controls)3).

Long-day plants. A rapid flowering response, equalling the effect of long-day exposure, was obtained in Samolus parviflorus with daily applications of 2 ~g or 5 ~g of gibberellin. Flower buds became visible after about one month, open flowers appeared one week later (5 ~zg treatment). A similar r e sponse seems to occur in Crepis tectorum (the e x p e r i m e n t is still in progress) . I n Silent armeria and in a n n u a l ttyoscyamus niger t h e response was m u c h slower a n d so far par t i a l (only p a r t of t he t r e a t ed p l an t s responding , s imi lar to t he Ea r ly F r ench Forc ing carrot) . The m i n i m u m effect ive dose was 10 txg daily, a n d t h e f irst f lower b u d s b e c a m e visible a f te r a b o u t 7 to 8 weeks in Silene a n d af ter f0 weeks in H y o s c y a m u s . In H y o s c y a m u s , t he buds failed to develop fu r t he r ; however , c o n t i n u e d d e v e l o p m e n t m a y be a m a t t e r of p rope r dosage a n d per iods of t r e a t m e n t . I n P e t k u s sp r ing rye, the resu l t s were ident ica l wi th those in nonve rna l i zed win te r rye.

Short day plants. A four week long appl ica t ion of 1 to /0 b~g gibberel l in da i ly g rea t ly e n h a n c e d s t e m e longa t ion in cocklebur (Xanthium saceharatum), b u t t he p l an t s r e m a i n e d s t r i c t ly vege ta t ive . An e x p e r i m e n t wi th s o y b e a n (Biloxi), still in progress , ind ica tes a s imilar behavior .

Comments. I t is ev iden t t h a t gibberel l in is capab le of i n d u c i n g flower fo rma t ion in a considerable n u m b e r of p l a n t s a n d u n d e r s t r i c t n o n i n d u c t i v e condi t ions . However , th i s effect of gibberel l in does no t seem to be general . P r o m o t i o n of f lowering was n o t obse rved in rye (winter a n d spring) nor in s h o r t - d a y p l a n t s kep t in l ong-day condi t ions , a l t h o u g h t h e v e g e t a t i v e effects of gibberell in appl ica t ion were ve ry pro- nounced . W h e r e flower fo rma t ion did occur in b iennia l an d long-day p lan t s , t he response was var iable : r ap id and com- plete in some species, slow a n d poss ib ly pa r t i a l in o thers . This var iab i l i ty c a n n o t be a t t r i b u t e d to differences in photoper iod ic r equ i r emen t , s ince t h e sens i t i v i ty of Samolus and Crepis to l ong -day induc t ion is no t g rea te r t h a n t h a t of H y o s c y a m u s an d Silene. A t present , to a ccoun t for t he var iab le effect of gib- berel l in on f lower f o r m a t i o n two exp l ana t i ons appear m o s t p robab le : 1. Gibberell in, or a s u b s t a n c e of s imi lar physiological ac t iv i ty , is n o t t he sole r egu la to r of f lower fo rmat ion , b u t pa r t i c ipa t e s in th i s process in con junc t ion wi th o the r factors. Thus , t h e fac tors neces sa ry for t he comple te func t ion ing of gibberel l in in f lower fo rma t ion m a y be l imi t ing in some p lan t s , b u t no t in o thers . 2. The gibberel l ins of d i f ferent p l an t s are n o t ident ical a n d no t comple t e ly in te rchangeab le , so t h a t a g iven gibberel l in will n o t be equa l ly effective in all p lan ts , even if gibberel l in is t h e fac tor l imi t ing f lower f o r m a t i o n in t he se p lan t s .

W h e t h e r t h e ac t ion of gibberell in in flower fo rma t io n is d i rec t or indirect , r ema ins to be seen. If t he p l an t s which fo rm flowers af ter gibberel l in t r e a t m e n t are i nduced in t h e n a t u r a l w a y (by a cold t r e a t m e n t or b y long days), bo l t ing a n d flower in i t i a t ion occur a l m o s t s imu l t aneous ly . I n con t ras t , gibberel l in t r e a t m e n t causes s t e m e longat ion to occur first, while f lower in i t i a t ion m a y be more or less delayed. Therefore i t s eems possible t h a t t h e p r i m a r y effect of gibberel l in is ini t ia- t ion of s t e m e longat ion , a n d t h a t f u r t he r processes are se t in m o t i o n in t h e e longa t ing s t e m which in t u r n lead to f lower fo rma t ion . I n th i s case, f lower f o r m a t i o n would be a secon- d a r y effect of gibberell in.

Th i s work was s u p p o r t e d in p a r t b y a resea rch g r a n t (RG-3939) f rom t h e N a t i o n a l I n s t i t u t e s of Hea l th , U.S. Pub l i c H e a l t h Service.

Department of Botany, University o/ California, Los Ange- les 2g, Cal. ANTON LANO

Eingegangen am t6. November t956

t) LANE A.: Naturwiss. 43, 284 (t956). 3) Par t of the experiments was done with a mixture of gibberel-

lin A and gibberellie acid, kindly supplied by Dr. F .H . STODOLA, U. S. D. A . Northern Utilization Research Branch, Peoria, Ill., par t with a preparation containing gibberellic acid only, obtained through the courteousy of Dr. CURT LEBEN, Lilly Research Labora- tories, Indianapolis, Ind.

8) Rye was treated either by applying a drop of gibberellin solu- tion to the base of the blade of the youngest fully expanded leaf, or by immersing a leaf blade, with the tip cut, into the solution. The other plants were treated by applying the solution to the apical region of the shoot. Most experiments were carried out by Mrs. PATRJCIA B. FINN.

Herausgeber und verantwortlicher Redakteur: Professor Dr, Ernst Lamla. G6tfingen. - - Veraixtwortlich ffir den Anzeigenteih Gfinter HoItz, Berlin W 35, Reichpietschufer 20. - - Springer-Verlag, Berlin-Gbttingen-Heidelberg. - - Drnck der Universitiitsdrnckerei H. Sttixtz AG., Wfirzburg. - - Printed in Germany