KHOA HOC CONG NGHE
HIEU QUA KICH KHAIXIG V A TiCH TLI POLYPHEIXIOL TROIVG TilVH KHAIXIG B£IX1H VET IXIAU LA LUA CUA
ACID SALICYLIC V A DfCH TRiCH CO CUT HEO
L6 Thanh T o ^ \ Luong Thi Kim Y^, T r ^ Van D^t^
T6MTAT
Trong nhung nam gan day, cung vol su boc phat cua cac dich hai quan trpng, m^t sd b?nh hai thii yeu da tra thanh quan trong. Nam Curvulana sp. la mot trong nhiing tac nhan gay km lep hat tr^n liia va b^nh vet nau tren tan la liia. Hi^n nay, di^n tich trong liia theo xu huong nong nghiep huu ca ngay c ^ g tang nham han ch^ anh huong ciia nong duac den con nguoi cung nhu moi truong. Kich thich tinh khang b&nh cay trong la mot phuong phap quan ly djch hai theo huong an toan va da dat dugc nhung ket qua nhat dinh.
Nghien cuu da duQ€ thuc hign nham danh gia hieu qua giam benh va khao sat ca che kich thich tinh khang b^nh vet nau tren cay liia sau khi xii ly voi acid salicylic 1 mM hoac dich trich co cut heo 4%. Ket qua cho thay sau khi xu ly, hieu qua giam benh vet nau dat khoang 28,62-31,92%. Ngoai ra, salicylic acid 1 mM va dich trich co cut heo 4% giiip hinh thanh polyphenol nhi^u hon tai cac vi tri bao tii Curvularia xam nhi§m tren la liia a cac thoi di^m 6,24 va 48 gio sau khi lay nhiim, so voi nghiem thiic doi chiing phun niroc cat.
Tii kh6a; Benb vdt nau (Curvularia sp.), co cdt heo (Ageratum conyzoides), kich khang, lua. tich tu polyphenol
1 . OAT VAN BE
Hien nay, tinh hinh khi hau co nhieu thay doi, cac mam henh gay htti cho cay trOng cQng din thich ling, ton tai va phat trien. Benh vet nau do nam Curvularia sp. xu^t hien ngay cang pho bi^n hen liia g ^ day, gay anh hirong den nang suat liia. D^ bao ve cay trong va giam 6 nhi^m moi truang, each quan ly benh bSng thuoc bao ve thuc vat can thay doi [1].
Nguyen ly quan ly dich hai bang ca chfi' kich thich tinh khang luu din da dupc thu nghiem tren nhi^u dich hai va nhieu loai cay hong [2]. Cac hoa chat dugc su dung de kich khang co hieu qua tren Ilia nhu sahcylic acid (SA), clorua dong, benzoic acid, chitosan [1] Ngoai nhimg hoa chat fren, nhieu loai dich trich thuc vat cung co tac dung kich khang nhu CO hoi, song doi, neem, toi [3]. Dich trich tho tir cay Eucalytus citiiodora va Ageratirm comzoides cho hifiu qua cao han hong viec uc chS su phat hien cua soi nam Didymella bryoniae so voi Achilliea mellifohum, Cymbopogon citiatiis (4]. Dich hich la cua cay Datiira metel (ti le 1:1 khoi tupng/the tich) lam nam Rhizoctonia solanivk Xanthomonas oryzae giam phat frien trong dieu kien phong thi nghiem va lam giam fri^u chung benh dom vSn, chay bia la liia trong di^u kien nha luoi. Ngoai ra, dich trich nay con
' Khoa Nong nghiep, Trucmg Dai hoc Can Tha Email: [email protected]
lam tang hoat tinh enzyme chitinase, p-1,2 glucanase, peroxidase, phenylalannine, amonia-lyase [5].
Yasmin etal [6] da nghidn cuu dich trich cua 55 loai thuc vat anh huong den n^m Fusarium moniliforme Sheldon, frong do co 17 loai dich trich thuc vat lie che phat trien cua nam. Dich trich la Lawsonia inermis (60,6%) va dich trich r l Asparagus racemosus (50,6%), voi ty le 1:2 w/v, co kha nang uc che cao nhat San pham chiet xuat tii hgt cua cay neem co the lie che sinh truong vai nam benh Rhizoctonia solani, Sclerotium rolfsu va nam Fusarium oxyporum [71. Theo Le Tuy^n Vo [8], khi phun kich khang bang dich trich co hoi hoac song dai nong do 4% b 25 ngay sau khi gieo, cho chieu cao tuong doi v^t benh d6m van thap han so vai doi chiing va hieu qua den 21 ngay sau khi lay nhi§m henh fren liia. Phan Thi H6ng Thiiy [9] cho bi^t ha loai dich trich la co hoi {Eupatorium odoratum), song dai {Kalanchoe pinnata), co cut heo {Ageratum conyzoides} cb kha nang giam dien tich la nhi^m benh chay la tii 35-45%. Theo Nguyen Van Phuoc
|10], khi ngam hat va phun tan la lua vai than cay co cut heo 4% cho hieu qua giam h&nh cao fren 80%, lic che dupc su hinh thanh bao tu nam, th^ hien kha nang kich thich tinh khang benh chay la som, cao va ben thong qua su tich tu HjOv, phat huynh quang te bao, polyphenol, dong thai lam tang chifeu cao cay Ilia.
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KHOA HOC C 6 N G N G H E
Sau khi cay fr6ng bi mdm benh xam nhifem, hpp chat polyphenol dugc tich luy rat nhanh thong qua su bien doi cua nhom phenylpropanoid. Cac chat polyphenol gay dpc cho mdm henh va hau het cac phytoalexin lai co nguon g6c tii polyphenol n&n polyphenol co vai fro quan frpng frong phan ling tu v $ a c a y frong [11].
Nghidn cuu dupc ti^n hanh voi muc dich danh gia hidu qua giam h^nh va khao sat ca che kich thich tinh khang h$nh vet nau fr6n la liia thong qua viec tich tu polyphenol sau khi xu ly voi SA va djch trich CO cut heo
2. VAT U a i V A PHUONG PHAP
2.1. Ngudn nlm, gidng liia vA dich trich thuc v?t Nguon ndm Curvularia sp., SA (Sigma Aldnch) va giong liia nhiim Jasmine 85 dupc cung cap tir Bo mon Bao v^ thuc vat, Khoa Nong nghiep, Truang Dai hpc Can Tha. Nguon dich trich duoc su dung frong cac thi nghiem la co cut heo {Ageratum conyzoides L.) [9] [10]. Dich frich co ciit heo duoc su dung a nong dp 4% (w/v), cu th6 4 g co cut heo tuoi dupc bo sung 100 ml nuoc, chung each thuy 6 65°C frong 30 phut, Ipc dich ti*ich qua giay AVhatman, bd sung nuoc cat thanh triing cho th^ tich dat 100 ml.
2.2. D^nh giA hi$u qua kich thich tinh k h ^ g cua SA 1 mM v^ dich hich cd a i t heo (CCH) 4% ddi vdi b^nh vdt n i u liia frong didu ki$n nha ludi
Thi nghiem duoc bd tri theo th^ thiic hoan toan ngau nhi6n gdm 6 nghiem thiic (Bang 1) va 5 ldn lap lai, mdi lan lap lai la 1 chau.
Bang 1. CAc nf^gmtfauc dugc sur dung frong ttiin^iigm T6n
nghiem thuc SAI
SA2
CCHl
CCH2
DCl DC2
Cach kich thich tinh khang
Ao hat. phun SA 1 mM a 15 NSKG Ao hat. phun SA 1 mM a 15
NSKG Ao hat. phun dich trich co cut
heo 4% 415 NSKG Ao hat. phun dich trich co cut
heo 4« a 15 NSKG Phun ntr6c cat thanh triing Phun nuoc cat thanh triing
Lay nhiim benh 4 20 NSKG
Co
Khong
Co
Khong
Co Khong Ghi chti: NSKG: ngay sau khi gieo
3 kg dat duoc can va cho vao m6i ch$u n h i « co dirong kinh 30 cm, bon lot tnioc khi gieo. Hat lua Jasmine 85 duoc ngam trong nuoc 3 soi 2 lanh trong 30 phiit Sau do, hat liia tiep tiJC duoc ngam 24 gicr trong nuoc cat, roi u 48 gio trong giay tham uot, d l trong dieu kien toi. Bon hat Ma nay mam tot se duoc gieo vao 4 goc trong 1 chau nhira da chuan bi dat.
Cach bon phan dugc ap dijng cong thirc phan bon 120N - 40P2Os - SOK^O [12]. Khi cay liia co 5 la phat trien day du (ttrong duong 14-15 NSKG) thi danh dau la thir 4 va 5. tien hanh phun dich trich 5 ml/la.
Cham soc cay lua d & 20 ngay tuoi. chuyen vao phong chung benh ti& hanh lay benh. Bao tu nisn Curvularia sp. dugc phim voi mat so 50.000 bao tu/ml. CO them 0,01% Tween 20, vol lieu lugng phun la 3 ml/la. Cac chau sau khi phun nam lay nhi^m benh dugc chuyen vao phong lanh, gift 24 gio trong toi CO tao am d6 (khoang 95+3%) va nhiet do 6 25°C.
Sau do. cac chau liia dirge chuyen ra nha luoi co luoi che hoac nha phun suong (30 phiit/lSn phun) che mat 50% nham giiip cho benh phat triln.
6 14 ngay sau lay benh (NSLB) [9]. 6 hai la da danh dau. chiiu dai, chieu rpng la [13, 14] va so lirong vet benh g timg cap dua vao bang phan cap danh gia cua IRRI [15] da dugc ghi nhan. Dien tich nhiim benh (mm^ dugc tinh theo cong thirc Si = ^ (soao+ Siai+ ... + S5a5), voi S, (i = 0-5) la dien tich vet benh c^p i; a, (i - 0-5) la so vit bSnh thir i [151. Ti le dien tich la nhiim benh (%) dugc tinh theo cong thirc TLDTLNBi = (Si/S) x 100. S, (i = 1-3) la tong dien tich la nhiim benh thir i; S la di^n tich la, dugc tinh S
= dai * rpng * 0,75 [13,14]. Cuoi cung, hieu qua giam b^nh so vgi doi chirng dugc tinh theo cong thuc HQGB (%) [(TLDTLNBij, UDTLNBi) / TLDTLNBijJ * 100% [15].
2.3. KhSo sdt su tich t l polyphenol 6t 14 liia xOt 1^
SA 1 mM v4 djch trich CO ciit heo 4%
Thi nghiem duoc bo tri theo thi thiic hoan toan nglu nhiSn. gom 6 nghiem thiic (Bang 1) va 31 in lap lai. m6i lan lap lai la 1 chau trong 2 cay lua. Chuan bi dat. cay lua, lay nhiim b^nh nhan tao tuong tu thi nghiem tnroc do.
MSu la de khao sat su tich tij polyphenol dugc thu 6 0. 6. 24 va 48 gio sau lay benh (GSLB). U lua dugc tay ditp luc to bang ethanol-acetic acid (3-Tl trong dia petri. thay giay tham va dung dich ethanol- acetic acid mil ngay cho din khi mau la khone ' mau xanh ciia (Uep luc to. Cuoi ciing. niau d
70 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 7/2020
KHOA HOC CbNG N G H £ chuydn vao frong nuoc cat 1 gio va giii frong dung
dich lactoglycerol (lactic acid + glyceryl + nuoc cat theo ty le 1:1:1) den khi quan sat. Mau dupc quan sat voiToluidine blue 0 (0,05%, pH= 6,8) a nhiet do 60''C trong mpt gio va quan sat 6 kmh hien vi quang hoc.
d mdi lap lai, 2 la dugc quan sat, mdi la quan sat ngdu nhien 20 vi tii co bao tii nam. Ghi nhan chi tieu polyphenol tich tu (td bao co mau xanh la cay) theo 3 miic dp (+) td bao mau xanh la cay nhat; (++) te hao mau xanh la cay trung binh; (+++) te bao mau xanh la cay dam [16].
2.4. Xurly thdng ke
Cac thi nghiem dupc bd tri ciing thoi diem va duoc lap lai hai lan vol ket qua tuong tu nhau. Sd lieu duoc xu ly bang phan mdm Excel va chay thdng ke bang phan mem MSTATC va kiem dinh su khac biet qua phep thii Duncan.
S. KET qUAVA THAO LUAN
3.1. Hi^u qua cua SA ho$c dich trich cd cut heo ddi v6i bdnh vdt nka liia trong didu kien nha ludi
0 chi tieu ty 16 dien tich la nhidm benh, nghiem thiic ddi chiing x u ly nuoc cat va co lay nhidm benh cd ty 16 henh a la 4 va la 5 lan lugt la 55,71% va 41,74%, cho thay vi6c lay nhidm benh nhan tao da dat ket qua tdt. Benh vet nau khong xuat hien a cac Bang 2. Ty Id dign tich Id nhidm bdnh va hieu qua giam
nghiem thiic khong lay nhidm, cho thay khong co su xuat hien hao hi vdt nau trong didu kien nha ludi va phong lay nhidm henh. 6 la 4, hai nghiem thiic SAI va CCHl CO ty le dien tich la nhidm benh ldn lugt la 33,91% va 37,34%, thap han co y nghia so vdi nghiem thiic DCl. Ket qua tuang tu dugc ghi nhan d la 5, voi ly le dien tich la nhidm benh DCl cao hon co y nghia so vai con sd tuong ung cua nghifem thiic SAI va CCHl (Bang 2).
Nhin chung, trung binh hieu qua giam bfenh ciia SA va dich trich co cut heo ddi voi benh vet nau la liia khoang 30-40%. Cac nghiem thiic khong lay nhidm benh deu khong co benh xuat hien, chiing td khong CO ngudn bao tu Curvularia trong khong khi.
Dieu nay rat quan trong giiip dat ket qua chinh xac khi khao sat sir tich tu polyphenol (Bang 2). 6 thai diem 14 NSLB, cac nghiem thiic SAI va CCHl ddu cho hieu qua giam henh cao hon co y nghia thdng ke ddi voi nghiem thiic DCl d Id thii 4. Hieu qua lie chd benh vet nau cua hai nghiem thiic SAI va CCHl lan lupt la 39,13% va 32,97%. Ket qua tuong tii d la 5, tai thai diem nay, dich trich SAI va CCHl ddu cho hieu qua giam henh, tuy nhien thap hon so voi la 4, chi dat khoang 24. Trong do, hieu qua lie chd benh cua SAI la 24,71% va CCHl la 24,27%, ddu khac biet co y nghia so voi ddi chiing DCl (Bang 2).
benh (%) v6i bgnh vdt n^u liia b 14 ngiy sau lay benh Nghiem thuc
SAI SA2 CCHl CCH2 DCl DC2 Miic y nghia
CV(%)
Ty le dien tich la nhiim benh (%) La 4 "
33,91 b 0,00 c 37,34 b 0,00 c 55,71 a
0,00 c
"
21,69
La 5 "
31,43 b 0,00 c 31,62 b 0.00 c 41.74 a
0,00 c
,.
19,57
Hieu qua giam La 4 "
39,13 a 0.00 b 32.97 a 0.00 b 0.00 b 0.00 b
"
24.36 U 5 "
24.71 a 0.00 b 24,27 a 0,00 b 0,00 b 0.00 b
**
13.42 banh (%)
Trung binh ^' 31.92 a
0.00 b 28,62 a
0,00 b 0,00 b 0,00 b
*•
17,37 Ghi chti: " Trong ciing mdt cdt cac sd tiwig binh
khdng khac bidt y nghia 1% tiong phep thii Duncan.
3.2. Su tich til polyphenol a 14 Ilia sau khi xii ly vdi SA hoSc dich trich co ciit heo
6 thoi diem 0 gig. tat ca cac nghiftm thuc deu giong nhau. chua co su xuat hien t l bao tong hgp chat polyphenol (kit qua khong dugc trinh bay). Kit qua ciia sir tich tu hgp chJt polyphenol qua 3 thoi diem 6. 24 va 48 gio sau khi lay nhiim benh duoc trinh bay trong bang 3. 4. 5 va 6.
theo sau mang mdt hoac nhieu chti cai giong nhau thi
O thoi dilm 6 GSLB, mirc dp tich tu polyphenol a cac nghiem thiic chua co su khac bi6t nhieu. Cac nghiem thirc chii yiu t h i hien miic do "+". khong thsiy nghiem thuc nao t h i hien o miic dp "•*-+" va mirc do "-I-H-" (Hinh 1). Nghiem thirc xu ly SA2 hoSc dich trich CCH2 diu co xuat hien su tich tu polyphenol o muc "*" nhung co ty le rat thfip. chiing to viec xir ly ch4t kich khang da mang lai hieu qua. giiip kich hoat
KHOA HOC CdNG N G H l CO c h i khang va tinh khang ciia cay da bieu hien.
Nghi6m thuc xii ly bang SAI co mirc dO tich tu polyphenol nhilu, o ty le 14,17%, tuong duong voi nghilm thiic CCHl (12,50%). diu cao hgn co y nghia so vol ca 2 nghiem thiic doi chtmg DCl va DC2. Ca hai nghiftm thuc xu ly kich khang va lay b4nh co ty le tich tu polyphenol "-i-" cao hgn co y nghia so vdd hai nghiem thiic xu ly kich khang nhung khong lay
b*nh. Nhu vay. sau khi dugc kich khang, su xam nhap cua bao tu nam benh da lam cho te bao la lua t h i hien tinh khang manh hon, nhanh hon. Nghiem thiic doi chiing khflng lay benh vin the hiSn sir tich tu polyphenol nhung a mac dp rat fliap. Dilu nay chung to CO su ton tai cua cac loai mam benh khac trong mot trudng nha luoi (Bang 3).
STT 1 2 3 4 5 6
B4nK 3. Su tich tu oolvohenol trta 14 liia 6 th6i dilm 6 Efilr .sau khi lav nhiim bfnh
Nghidm thuc SAI SA2 CCHl CCH2 BCl DC2 Miic y nghia CV(%)
Gia tri cac cap tich tii polyphenol cap "-"
309 c 339 b 315 c 345 b 351a 357 a
**
14,33
cap "+"
51a 21b 45 a 15 b 9 c 3 c
**
19,54
Ty le (%) cac cap tich tu polyphenol cap "-"
85,83 d 94.17 be 87.50 cd
95.83 b 97.33 ab
98.83 a
*
5,02
cap V 14,17 a 5,83 b
12,50 a 4,17 be 2,50 be 0,83 c
*
22,93
Ghi chu: Cac cbd sd tiong ciing mot cot gidng nhau khong khac biet o mdc y nghia 5% qua phep thu Duncan, *: khac bi$t dmucy nghia 5%
Den thai diem 24 GSLB, ket qua cho thay miic do tich tu polyphenol 6 cac nghiem thiic da co nhidu su khac biet. Miic dp tich tu polyphenol "++" da xuat hien, tuy nhifin voi ty le khong cao, chu ydu vdn la cap dp "+", chua thay cap do "+++". Nghiem thiic CCHl CO ty le tich tu polyphenol d miic "+" cao nhat,
dat 87,50%, ke den la nghiem thiic SAI la 81,67%, cao hon CO y nghia so voi cac nghiem thiic ddi chiing DCl va DC2. 0 miic do "++", nghiem thirc SAI, CCHl va CCH2 co ty le tich tu polyphenol tiJong duong nhau, ldn lugt la 4,17%, 4,17% va 3,33% (Bang 4).
B ^ 4. Su tich tu polyphenol tren lA liia d thdi didm 24 gio sau khi lay nhidm benh STT
1 2 3 4 5 6
Nghiem thiic SAI SA2 CCHl CCH2 S C I DC2 Miic y nghia CV(%)
Gia tri cac cap "-"
51c 144 b
30 c 120 b 312 a 347 a
**
18.59
cap tich tu polyphenol cap "+"
294 a 216 a 315 a 228 a 48 b 13 b
»»
22.82
c4p "-^~^"
15 a Ob 15 a 12 a Ob Ob
**
9.38
Ty le (%) cac cap tich tu polvohennl cap "-"
14.17 d 40,00 c 8,33 d 33,33 c 86,67 b
96,50 a 7,02
*
cap "-(•"
81,67 a 60,00 b
87,50 a 63,33 b 13,33 c 3,33 d
**
9,63
c a p "+-(•"
4,17 a 0,00 a 4,17 a 3,33 a 0,00 a 0,00 a
**
_ _ _ 8 i 3 4 _ _ _ Ghi chii: Cac chu sd tiong cung mdt cdt gidng nhau khdng khac biit d mtic y nghia qua phep thti Duncan, *: khac bidt & miic y nghia 5%, ": khac biet d mtic y nghia IX
a thoi dilm 48 GSLB, su tich hi polyphenol co "^^K- T™ng hai nghiem Uiiic xir ly kich khang va su phan biet ro rang giira cac cap va cac nghiem thiic <=* >^y '^e"'', nghiem thiic CCHl cd ty le w cao (Bang 5 va 6). Mirc do tdng hgp polyphenol o c4p do "^at. dat 11.67% va khong khac biet y nghia thong ke
••-HH^" da duoc ghi nhan 6 cac nghiem fliiic xu ly kich » ™ " g h i t a thiic SAI (7.5%). Tuy „hie„, „ ^ j .
72 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 7/2020
KHOA HOC GONG N G H l tich tu polyphenol g mirc "-i"i~i- " ciia CCHl va SAI
cao hon co y nghia so vm ty le tuong ling g hai nghiem tiiirc xir ly kich khang va khong lay benh la SA2 va CCH2. O miic dO tich tu "+-1-". nghiem thiic CCHl c6 sir tich hi polyphenol cao nhat, dat 13.33%, khong khac biet y nghia thong ke so hai nghiSm thiic CCH2 va SAI. Nghiem thiic doi chung khong ghi nhan dugc miic do tich tii polyphenol "+-*•" g 48 gig sau khi lay nhilm benh. 6 cap V . cac nghiem thirc CO ty \& khac biet hoan toan. su khac bifet co y nghia, cao nhat la SAI voi ty le tich tij la 88,33%, fliap
i.s'.i>.f-'- u- rA/--n • ^ ' 1 - . . ' , . , , . . . Ghi chti-Cac chu'sd tiong Cling mdt cdt gidng nhtt la dot chung DC2 co ty le tich til polyphenol la . , , . , , , . . . , . , ' '. .r^,
nhau khong khac biet a mirc y nghia qua phep thir 9.17%(Bang6). Duncan, ': khac bidt & mtic y nghia 5%, ": khac
biet & miic y nghia 1%
Baiig 6. Ty 16 c4c c^p tich tu polyphenol trte 14 lila or th6i dilm 48 gliy sau khi I4y nhilm b^nh 3ang 5. 014 tri c4c d p tich til polyphenol trin 14 liia
g thai dilm 48 gifr sau khi lay nhilm binh
snr
1 2 3 4 5 6
Nghiem thirc SAI SA2 CCHl CCH2 DCl DC2 Miic y nghia
CV(%)
Ty 1^ (%) cac cap tich tu polyphenol cap "-"
Oc 129 b
9 c 93 b 279 a 327 a
».
35.21 cap V '
291a 210 a 301a 243 a 81b 33 b
.»
16.27 cap "-H-"
42 a 18 b 48 a 15 b Oc
0
•*
7,93
cap "-HH-"
27 a 3 b 42 a 9 b Oc Oc
••
22,36
STT 1 2 3 4 5 6
Nghiem thiic SAI SA2 CCHl CCH2 DCl DC2 Miic y nghia CV(%)
Ty le (%) cac cap tich tu polyphenol cap "-"
0.00 35,83 c
2,50 e 25,83 d 77,50 b 90,83 a
*
5,42
cap V 80,83 a 58.34 d 83,61 b 67,50 c 22.50 e
9,17 f
•*
5,53
cap "-H-"
11,67 ab 5,00 b 13,33 a
4,17 ab 0,00 c 0,00 c
**
4,20
cap "-H-i-"
7.5 a 0,83 b 11,67 a 2,50 b
0.00 b 0.00 b
*
16.29
Ghi chu: Cac chd sd trong cung mot cot gidng nhau khong khac biit d mm: y nghia qua phep thu Duncan, *: khac biit o muc y nghia 5%, **: khac biet a muc y nghia 196
thai diem hao tu nam tiep xiic vai la liia, sau do moi bat ddu moc dng mam, tao dia ap de dam thung, xuyen qua lop kutin ciia la cung cdn mot khoang thai gian. Trong khoang thdi gian nay, cay lua cung kip ,,4v thai tao ra ca che tu ve. Su tich tu polyphenol cung la 1 trong nhiing ca che tu ve ciia cay khi bi mam benh tan cong. Polyphenol co tac dung lam thay ddi vach te bao. giiip te bao co kha nang khang lai cac enzyme do mdm benh tiet ra. Ben canh do, polyphenol con gay doc cho mam benh, han che mam benh phat trien. Ke ca khi khong co mdm henh tan cong thi te bao thuc vat vdn co su tdng hop polyphenol, chi la khi mam benh xam nhap, qua trinh nay xay ra nhanh hon, dac biet la d' vi tri mdm benh tdn cong nhu la quanh dia ap cua nam. Sir tich tu nay han chd mam benh tan cong bang phan ling tu chet ciia td bao [ 11 ].
Su tich tu polyphenol cang nhidu, cang nhanh thi thuc vat chdng lai mam henh cang tdt. Sii dung SA va Hinh 1. Su tich tii polyphenol trong mo Id liia
Ghi chii.- (A) muc do "+": (B) mdc do •'++";
(C) miic do "t-H-"
Nhin chung, qua 4 tiidi diem khao sat, cac nghiem thiic dugc xii ly kich khang co miic dp tich tii polyphenol nhanh va nhieu hon so vdi cac nghiem thiic kh6ng dugc xu ly kich khang (ddi chiing). Tir
73
KHOA HOC CdNG NGHE dich trich cd cut heo lam tang kha nang tich tii
polyphenol ciia cay tii thoi diem 6 gid va keo dai den 48 gia, nghia la tang nhanh va sdm co kha nang chdng lai su xam nhidm cua nam Curvularia, ddn den giam benh vdt nau.
Kdt qua su tich tu polyphenol trong nghien ciiu nay phii hgp nghien ciiu cua Wilson et al. [17].
Polyphenol da dugc chiing minh cho kha nang khang henh la d vay hanh tay tich luy du luong catechol va protocatechuic acid de ngan ngira benh than thu do CoUetotrichum circinansgay ra.
4. KET LUAN VAOE NGHI
Viec ngam hat va phun chat kich khang acid sahcyUc 1 mM giiip gia tang su tich tii polyphenol, hat dau CO hieu qua tdt kha sam, a 6 gia sau khi lay nhidm benh, den thai diem 48 gid, giam vet benh ddm nau voi hieu qua khoang 31,92%.
Xu ly hat va phun dich trich than va la cd cut heo d nong dp 4% cho hieu qua cao tuong duong SA, voi hieu qua giam benh dat 28,62%.
Cac CO che kich khang khac nhu te hao phat hu;ynh quang, tich tu H2O2 ciing nhu hieu qua kich khang trong didu kien ngoai dong se duoc thuc hien d cac thi nghiem tiep theo.
TAI u n THAM KHAO
1. Pham Van Kun, 2002. Ket qua nghien ciiu ung dung su kich khang trong quan ly benh tren liia. Ky yeu Hpi thao kich thich tinh khang benh luu ddn tren Ilia, mot chidn luge than thien voi moi truang de quan ly benh tren liia. Trang 1-6.
2. Sterner U., and Schonbeck R, 1995. hiduced resistance in monocots. In: mduced resistance to disease in plant Spnnger, Dordrecht, pp 87-110.
3. Nguyen Chi Cuong, 2002. Buoc ddu danh gia hieu qua kich khang luu ddn chdng benh chay la liia {Pyricularia grisea (Cooke) Sacc.) ciia mpt sd dich trich tir thuc vat. Tieu luan Tdt nghiep. Truong Dai hgc Can Tha.
4. Fiori A C. G., Schwan-Esti-ada K R. F., Stangarlin J. R., Vida J. B., Scapmi C. A , Cruz M. E.
S., and Pascholah S. F.. 2003. Antifungal activity of leaf exti-acts and essential oils of some medicinal plants against Didymella bryoniae. Joumal of Phytopathology 148: 483-487.
5. Kagale S., Marimuthu T . Thayumanavan B., Nandakumar R., and Ramasamy S., 2004.
Antimicrobial activity and induction of systemic
resistance in rice by leaf extract of Datura metel agamst Rhizoctonia solani and Xanthomonas oryzae pv. Oryzae. Physiological and Molecular Plant Pathology 65:91400.
6. Yasmin M., Hossain K S., and Bshar M. A., 2008. Effects of some angiospermic plant exti-acts on m vitro vegetative growth of Fusarium moniliforme.
Banglades Joumal Botany 37: 85- 88.
7. Vu Van Khanh, Vu Van Dp va Nguydn Tidn Thang, 2007. Khao sat boat tinh lic che mot sd loai nam gay benh cay ciia san pham chiet xuat tii hat xoan chiu han {Azadirachta mdica A. juss) trong tai Viet Nam. Ky ydu Hpi nghi khoa hpc cong nghe 2007. TP. HCM ngay 21 thang 9 nam 2007.
8. Le Tuyen Vo, 2008. Khao sat kha nang kich khang luu ddn ciia rapt sd dich trich thuc vat ddi vai henh ddm vdn do nam Rhizoctonia solam Kuhn tren Ilia bang phuong phap phun la. Luan van tdt nghiep dai hgc. Truong Dai hgc Cdn Tha.
9. Phan Thi Hdng Thiiy, 2009. Khao sat kha nang han che benh chay la va ddm nau tren liia khi xii ly voi ba loai dich trich fhuc vat. Luan van tdt nghiep cao hpc. Truong Dai hpc Can Tho.
10. Nguydn Van Phuoc, 2013. Khao sat kha nang kich khang chdng benh chay la {Pyricularia grisea) cua dich trich cd ciit heo {Ageratum conyzoidesT) va la cay neem {Azadirachta indica) tren khia canh sinh hgc va mo hoc. Luan van tdt nghiep cao hpc.
Truong Dai hoc Can Tho.
11. Nicholson R. L , and Hammerschmidt R., 1992. Phenolic compounds and theu role in disease resistance. Annual Review of Phytopatiiology 30: 369- 389.
12. Mai Nguyet Lan, 2019. Danh gia hieu heu true tidp va luu tdn cua phan bon vo co da luong den nang suat va chat lugng liia cao san tai ddng bang song Cihi Long. Luan an tien si nong nghiep. Vien Khoa hpc Nong nghiep Viet Nam. 233 trang.
13. Pinnschmidt H. 0, Teng P. S., Bonman J. M., and Kranz J., 1993. New assessment key for leaf blast IRRN 18:4&46.
14. Yoshida S., 1981. Fundermental of rice crop science. IRRI. Los Banos, Laguna, PhUippines 269 o
15. IRRI (hitenational Rice Research histitiite) 2012. Standard evaluation system for rice IRRT I ' Banos, Laguna, PhiUppines 56 p.
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16. Huynh Minh Chau, 2003. Sinh hpc ve su xam 17. Wilson C. L. and Wisniewski M. E., 1989.
nhiSm ciia nam Pyricularia grisea h-en liia va kha Biological conti-ol of postharvest diseases of fraits nang kich thich tinh khang benh chay la liia cua and vegetables: an emerging technology. Annual cloarua dong va acibenzolar-s-meUiyl tren khia canh review of Phytopathology 27: 425441.
mo hpc. Luan van tot nghiSp thac sy. Traong Dai hoc Can Tho.
EFFICACY AND POLYPHENOL ACCUMULATION ON INDUCED RESISTANCE AGAINST RICE LEAF SPOT BY SAUCYUC ACID AND AGERATUM EXTRACT
Le Thanh Toan", Luong Thi Kim Y", Tran Van Dat' 'College of Agriculture, Can Tho University Summary
In recent years, beside the outbeaks of major pests, several minor diseases are getting more important in plants. The fiingus of Curvularia sp. is one of the agents of grain discolorahon and a pathogen of leaf spot disease on foliage of rice plants. Now. area of rice cultivation towards the prachce of organic agicuiture is increasing, to limit effect of chemical pesticides to human health and environment. Induced resistance is a safe method of pest management and has achieved some good results. Therefore, research was conducted to evaluate disease reduction and survey a mechanism of induced resistance against leaf spot in nee plants treating by salicylic acid 1 mM or Ageratum leaf extract 4%. The results showed that the disease reduction of treated rice plants was approximately 28.62-31.93%. Moreover, salicyhc acid 1 mM and Ageratum leaf extract 4% helped nee leaves accumulate more polyphenols at infected sites of Curvularia at 6. 24 and 48 hours after inoculation, compared to the water control
Keywords: Leaf spot, Curvularia sp., Ageratum leaf (Ageratum conyzoides), induced resistance, nee, polyphenol accumulation.
NguM phto bien: GS.TS. NguySn Van Tuilt Ngiy nhan bii: 10/4/2020
Ng4y thdng qua phan bi6n: 11/5/2020 Ngiy duyftt dang: 18/5/2020
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