The Influence of Light and Temperature on the Sporulation, Germination, and Infection of Phytophthora colocasiae Rac.

(1)

Title

The Influence of Light and Temperature on the Sporulation,

_{Germination, and Infection of Phytophthora colocasiae Rac.}

Author(s)

Tamori, Masao

Citation

沖縄農業, 3(2): 43-49

Issue Date

1964-12

URL

http://hdl.handle.net/20.500.12001/968

(2)

The Influence of Light and Temperature on the

Sporulation, Germination, and Infec ion

of

Phytophthora coJocasiae

Rae.

*

By

Masao

TAMORI

**

I. Introduction

nee lamp were u ed for the light ouce. i e milliliter of water wa poured onto a culture. Sporangiophore wi h porangla on the culture ere rubbed hth a fine bru h and the . po-rangia . ere upended in the ater. The porangia in the u pen ion wa counted with a Haemacytometer under ·a mi ro cope.

2.. The minimum tim for th b inning of indirect ermina ion

T 0' Incuba or hi h

24° C.

(3)

thl b ak r

pie weI'

theporangial

cion

1) Ho t plant: Leave of Taro of 3rd or t· I a1 from he top of the plant., collected fr m the diff r nt ag d plant, were applied to

th t The age of the plant re: 4 10,and

16 months old. The leave were cut into

piece. The diameter of the leaf piece wa B

em. Each of the piece wa put onto a et filterate paper in a Petri di h.

2) Inoculum: Sporangial u pension a

pre'pared from the lO-day-old culture grown at

24° C. In order to obtain zoo pores, the us·

pen ion wa kept at 24°C. in a incubator for

2 hour. The number of zoo pore in the sus-pen ion wa 2,000 per milliliter.

3) Inoculation: Inoculation te t were done at 16'\ 20°, 24°, 28°, 30°, and 32° C. The each three pieces of the leaf were incubated a the each temperature.· ive spot of Z

0-porangial uspen ion, each pot contained

0.1 rnl. were inoculated to the each piece. The infection was e amined by measuring the diameter of symptoms and by counting the 'nfected pot.

III. Result

1. The influence of light and temperature on he sporu! tion

hen the fungus was expo ed to the light,

it produced 230,000 of porangia per milliliter

at 200

C., and 450000 at 2 0 C. When the tungu a not expo ed to the light, the

por-uIation a 150000 at 2(}0C.. and 200,000 at

240

C. (Table 1).

2. The minimum time for the beginning of indirect germination

The indirect germination of the porangia of the fungu began in 15 minute when the porangia were placed in the light at 24'" C.

bile it began in 20 minutes in the dark at the same temperature. The fungus a1 0 germi-nated indirectly in 25 minutes in the dark, at

160

C.

3. The relation between concentration of porangia and their germin.ation

As the Table2 show total germination of

the sporangia decreased as the number of the porangia increased; ity-five percent of the

Tabl influ nce of li,ght ~nd temperature on tbe porulation of P. coloca iae.

Inoculation Temperature (0C.)

24

porangia per mill'lier. Average number 0 three plates.

In th~ dark 15:'.000*

230,000

20n.ono 4511.000

(4)

Tamori: porulation, Germination and Infection of phytophthora colo asiae

porangia ere germinated in the u pen ion hich 9,000 of porangia re contained per milliliter, 77% in 30,000, 3% in 40 000, and

62% in 50,000 of porangia. Direct germination increa ed a the number of porangia increa ed' nine percent of the porangia ere germinated in the u pension in which 9,000 of pprangia ere contained per milliliter 11% in 30,000 16% in 40000, and 20% in 50,000. Indirect ger-mination decrea ed as the number of porangia increa ed' seventy- i percent of the porangia

~ ere germinated in the u pen ion in which 9 000 of porangia were contained per milliliter,

66 0 in 3 000, 47% in 40,000, and 42%in50,000. he influence of light on the sporangia} germination

The total germination of porangia obtained from the cul ure which was expo ed to the light during the growth period was low. (Table 3). hen the porangial suspension a kept in the light, the total germination a 490/< and that in the dark was 70%, The direct germination of porangia obtained from the culture which wa exposed to the light

wa rather high. It a 13% in the light and 17o/c in he dark. The indirect germina ion of porangia obtained from the culture which a e po ed to the ligbt a r 10 . It wa 36~

in the light, and 53% in the dark.

5. The inftuenc of temperat re on th infection

Temperature range for the infec ion of the fungu lie bet een 20° and 30° C. Optimum temperature seem t li betwe n 2 0 and 280

. (Table 4, 5 Fig 1, 2). Th i ibl ymptom , bro n pot, ere app ared in 70 hour at 20° C., in 36 hour at 2 0 and 28°

and in 40 hour at 30° C.

The diam ter of ymptom decr a ed a th plant become old. t 200

. , the diameter of

the ymptom v a 8 mm. on 11 leaf hi h wa taken from 4-month -old plant in 90 hour after inocultion, 7 mm. on the leaf of 0-month -old plant, and 6mm. on th 16-month-old plant. t 24° C., th y w r : 26.5 mm. n the 4-month -old plant, 20 mm. on th 10-month -old plant, and 1 mm. on th

1-Table 2. The relation between number of sporangia and their germination.

Number ofsporangia Germination of sporangia (%)

par milHlit,er Direct

I

Indrirect

---_. ---~.~ 9~OOO 9 716 30,000 11 66 40,000 16 47 50,000 20 42 0::-

-Total

Table 3. The influence of light, n the sporangia} gernlnation of P. 0,[0 asia.

- - - -

-en'1 n wa Direct Total 13 36 49 17 53 70 9 '78 87 7 76 83

- - - - -

----an ial wa

n in the dark, d - 'be porang'aL u 1 d 1* F'or germination Treatment * L - The culture x 0 e to t e ligh

- The ulture a gro no e po d to t e lig t.

••

D L' L or growth

(5)

46 our. Okina a gric. o. 2 (1964)

month -old plant. t 280

C.: 28 mm. on be 4month old plant, 22 mm. on he lOmonth -Id plant, and 21 mm. on the Hi-month -old plant. t 300 _{C: 21 mm. on the 4-month -old}

plant 19 mm. on the lO-month -old plant, and

o

mm. on the 16-months-old plant. (Table 5. & Fig. 2).

Table 4. The influence of temperature on the infection of P. colocasiae

to the different aged Taro plant (1)." Age of Taro

T mper- 4-month -old

I

IO-month -old l6-months-old Rate of ve. ize CK. Rate of Ave. size CK. Rate of

I

Ave. ize CK.

atuT _{' .} _I _{Rate of}

_I

_{Rate of} Rate of

me t. of ympt. 'n! t

I

Infec. of sympt. _infect. infect. of sympt. _infect.

e

.) _(%) _(mm.) 1 ec. (%) (%) (mm.) _(%) (%) (mm.) (%) 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 2 10 1 .5 0 80 11.5 0 67 10.5 0 8 16.8 0 80 13 0 53 11.5 0 7 0 53 8 0 0 0 0 0 0 0 0 0 0 0 0

In 64 hour after inoculation.

Th influence of temperature on the infection of P. colocasiae t tb differ nt aged Taro plant (2).·

ge of Taro

old

I

10-months-old l6-months-old CK. _{Rate of} _{Ave. size} CK. _{Rate of} _{Ave. size} CK.

Rate of

infect. of sympt. Rate of infect. of sympt. Rate of

infect. infect. infect.

(%) (%) (mm.) (%) (%) (mm.) (%) 0 0 0 0 0 0 0 0 87 7 0 87 6 0 0 87 20 0 67 19 0 0 87 22 0 53 21 0 0 53 19 0 0 0 0 0 0 0 0 0

I

0 0

- -

,.

- 4-months-Rate

~I

Ave. size

infect. of sympt

_(_0:_)

_1..

_(%_:_1

<m:-

l 20 87 8 2 100 26.5 28 83 28 30 7 21 32 0 0 ature

Temper-*

In 90 hour ,after inoculation.

IV. Discu sion

The porulation te of the fungu were done by orne writer. Leonian (7) reported hat the media contained dextrose wa the be t for porulation. Gomez (4) found that porangia were produced after a week in the mo t ca e . utler nd Kulkarni (2) reported that light doe not eff et on porulation hen temperature condition are uitable (250

C.).

According to the present tests, sporulation of the fungu is influenced by the light. When the sporangia were obtained from the culture

hleh was exposed to the Ught at 200

C., the porangia sporulated more than 1.5 times of the porangia grown in the dark at the same temperature. At 240

C., the sporangia grown in the light sporulated approximately 2.5 times of the sporangia grown in the dark.

(6)

l'amori: Sporu ation, Germina ion, and Infection of phytophthora colocasiae

47

In the pre ent te t , the indirect germination of the porangia of the fungu wa rapid in the light than in the dark at the optimum temperature of the germination, In the light, the germination began ithin 15 minute at 24° C., hile it began in 20 minute in the dark at the arne temperature.

The total germination of the porangia of the fungu decrea ed a the number of the porangia 'n the porangial u pen ion increa ed. The direct g rmination inc rea ed and the indirect germination de rea d a the number increa ed.

not mentioned the influence of temperature, light, or other factor to the porangial germination of the fungu in the te t. One thing Gomez mentioned a that the time required for germination of the porangia varied with the age of he culture from hicb they were taken.

O'-;---~--~---::'l;--~~-~

10

, I

r port ha been made by re ear her beg-nning of indirectermination. Bu] r ulka (2) rep rted the ind"rec

rm~ ation f the porangia f the fungu n i 1n half an hour after 0 ing in

r_ om z ( ) rep ted he erminat'on a a ter 0 hour. lack ell at rhou

(7)

Jour. Okinav a gric. Vol. 3. o. 2 (1964)

abi are qually u cep ible. He a1 0 got in! tion on outia, aladium pp. at ura (6)

fund, on P. cap ici, tha there were three ay of penetration itb cy tic pore. They ar: 1) penetra ion ith a germ tUbe of miniature zoo poran ium which wa produced n the tip of the g rm tube of cy tic pore,2)

dire t penetration with a germ tube of cy tic por without forming appre oria of miniature zo porangium. 3) penetration with inva ion hy ha which wa gro n on the tip of the g rm tube of cy tic pore.

n the pre ent te t, u ing P. colocasiae,

thr e type were ob erved. In the rno t

the ppre oria, grown on the germ tube y tic pore , were ob erved. When the germ u p d through the epidermal cell, the rm tu e became narrow at the cell wall of th ho t. efor and after pa ing the cell w 11 th g rm tube wa elled. In the hyll the germ tube pur ed a trictly

jnt r lIular our , ending hou toria into the

n i hb ur ng 11. utI r and Kulkarni (2)

und lh ino ulali n on the lea e with living

ti zopor i di tUled water gaveinsome

1i: 1 ign f infection within 6 hour . 2 h U , ro n po at the point of

ul j n w 11 loped. On the econd

h he r lar er and the ellow

dr

r

Ii ui r ozing out on th ir urface. On the third day porangia were formed. The germ tubes from porangia hich germinate directly a sporangia were also found capable of penetrating leaf, entering across or between the lower epidermal cells. Gomez (4) found the brown pots appeared at the inoculated point in 3 to 7 days under field condition. In the chamber they occured in 36 to 48 hour . ccording to the present studies, brown spots a the i ible symtoms were observed in 70

hour at 20° C., in 36 hour at 24° and 28° C., and in 40 hours at 30° C. Temperature range for the infection of the fungu lies between 20° and 30° C. Optimum temperature lie be-t en 24° and 28° C. The diameter of symptom d r a ed a he plant becomes old.

Literature Cited

1. lack ell E. ., and Waterhouse, G. M. 1931. Spore and spore germination 'n the genus Phytophthora. Brit. ycol. oc. Trans. 15 (1930-31):

294-31l.

2. utler ., and G. S. Kulkarni. 1913.

01 ca iae blight cau ed by

Phytophthora colocasiae Rac. em. gric. India Bot. Ser. 5: 233-2051. 3. Cro ier, .1933. Culture of Phytophthora

infe tans. Phytopath. 23: 713-720.

4. Gomez, E. T. 1925. Leaf blight of Gabi Philipp. Agric. XIV: 7, 429-440. 5. Hori . 1935. On the relation between

cell contents and the infection in Phytophthora infestans. Jap. Phyto·

path. Soc. 5: 10-21.

6. Kat ura, K. 1961. Mycological and Ph to·

pathological studies on Phytophthora capsid Leonian in connection with

the two type of zoo porangial germination. Technical Bulletin, o. 1. Loboratory of Phyto-pathology Faculty of Agriculture Kyoto Prefectural Uni ersity.

7. Leonian, L. H. 1925. Phy iological tudies on the genus Phytophthora. Amer. Journ. of Botany XII: 7, 444-498. 8. Pri tou and Gallegly. 1954. Phytopatb. 4 :

81-86.

9. Roder, K. 1935. Phytophthora zeit ch, 8:

589-614.

10. Sawada, K. 1911. Infection of Taro. Special Reports of the Formo an gric. Exper. Sta. II.

n.

ppal, B. . 1926. Relation of ox gen to

pore germination in orne pecie of tbe peronosporale. Pbytopath.

(8)

Tamori:Sporu lation.Germi nation.aLndInfectionofPJlytOP.如horacoLocasiae 49

光と温度が

Phyt

opht

んor

｡c

o†

oc

a

s

i

J

e

Rd

C

の胞子のう形成 ,胞子のう発芽 , および宿主体への侵入と発病に与える影響 (掃要 ) 田盛正雄 1,この雑文は,.光と温度が,サトイモ譲受柄園 Ph,y(ゆ-1t.lwr,a col･O,casiaeRae.の胞子のう形成,胞子のう発芽開始 ,胞子のう密度と発芽関L軌胞子のうの値脚芽七開披発芽,鰍束子の宿主体への侵入および菜摘に阜見る影響について研究した結果をまとめたものである｡ 2.その実験には,滞除菌の培地として,Ⅴ-8ジューrス寒天を併用し,また供訴随物の薮は,4カ月. 10 カ月,16ヵ月目rのタロ.イモの頂集から3-也番田のもの密使附した｡ 3.この病菌は,光費あてると胞子のう形成が促進される010日日の機蘭で20oCの恒温室内では,暗い . ところで1mlあたり(5m弧の蒸留水を蘭の生育しているシャーレ1個に泳いで胞子のう浮遊液をつくり,それかに対し,.光をあてると.,230..0.00個の胞子のう変形成したOまた.,別.oCでは,暗室で200.000個に対し,光をあてると450,000個の胞子のう密形成 IL.,た. 4

.

この蘭の胞苛のうは,･雄穿最適温庇で,光を蕗てると開披発芽が早くなる.す●なわち.24oCにおいて光をあてると15卦間で助走予を1出して開披尭評をするのに対し∴暗室では,それが20･卦間も加かつ･た｡また,16o Cにおいては,陪審で,25卦間もかかって間接発芽をする｡ 5.この蘭は,胞子のう浮遊淡における胞子のうの数が増えると,その韓凝鮮卑はさまたげられる｡幡捷発芽 (胞子のうから低技に発弊管を出して発芽すること) は胞子のう数が増えると,やや増える.これに対 LJ,閲歴発芽 (髄克子を出して発芽する)は胞子のう数が増えるにしたがって,いもじるL/く織る.(T温ble･2封剛 6.生育期間中,光をあてたこの蘭の胞子のうの撤発芽率は低い｡･ここでは,低壊発芽率は職くなるのに対し,間接発芽率はいもじるしく償い｡とくに発芽処理期間中に光をあてると,その現象がはっきりあらわれているoこれに対 IL,,･鹿骨期間中略劃こおくと.檎選評串は嵩 (.･直脚芽革は低くなり,間接節評率は商くなる｡ (TAbl.er.3参照)ふ 7･この蘭の宿主体への侵入には間接発芽によって生じた曲連子のみが関係することがみられた｡臥この病索の腰痛する温度の範捌ま.20oCから 30℃ の間にある｡発酒蔵直観掛ま湖Oから28oCl{こある･病斑は,20℃ で70時間徽 240と28oCで36時間軌 30 o Cで40略間後に認められた｡ 9.衛敗の酷径は,植物体の額命が長くなるにしたがって小さくなる｡とくに4カ月国の縫物体からとった沸上では,その節_■触軌､もじるしく大凱ヽのLlG対し..16 (Table4声5参閑)..