K H A O SAT KHA .NANG D O I KH.ANG CUA C A C C H U N G X . \ KHU.AN DOI VOI \ I K H U . W Xattthomonas oryzae pv. oryzicola
GAY BENH S O C T R O N G T R E N LUA
Tang Kim'. IVAn Van Dung-. Le \Unh 1 ii<"^^
TO.M TAT
Nghien cflu dupc thUc hien tai phdng thi nghiem thupc Bd mdn Bao v? Thflc vit. Trudng D41 hpc Can !ho nham tim ra chung xa khuan ed khi nang ddi khing vdi vi khuan Xanthomonas orvzae pv orvzicota s.a\ benh ••oe trong tren lua Cd 18 trong long so 87 ehujig xa khuan thi nghiem dflpc xac dinh ed kha nang doi khing voi vi khuan gay b?nh spe trong tren lfla trong dieu kien phdng thi nghiem, Thi nghiem ve khi nang ddi khang cua 18 chuni;.\a khuan dflpc bo tri theo kieu khoi hoin loan ngau nhien vdi 5 lan lap lai Kel qua cho thay 4 chiing CT4. DT24,T\ 4vaDT12 the hien khi nang ddi khang eao vdi vi khuan A', oryzae pv. oryzicola den thdi diem 7 ngay sau khi nudi cav \oi bin kinh vdng vo khuan la 5.0 mm; 4,8 mm; 4,6 mm vi 4,8 mm. Ben canh dd, kha nang phan giii lipid eua 4 chimg ^^
khuan Iren cung dfldc bd tri iheo kieu hoan loan ngau nhien vdi 5 lap lai. Ket qua eho thay tat ci 4 ehung xa khuan thi nghi?m deu cd khi ning tiet enz>'me lipase va 3 chiing DT24,CT4va DT12 ihehien kha nang phin giii lipid cao vdi bin kinh vdng phan giii lan Iflpt la 14,00 mm; 14,90 mm \a 15,20 mm d thdi diem 9 ngay sau kht nudi eay Mat khae. kha nang phan giai protein eua 4 chflng xa khuan tren ciing dupe bd tri theo kieu hoan toan ngau nhien vdi 5 lan lap lai. Kel qui eho thay lal ea eae ehiing xa khui'n thi nghiem deu cd kha nang tiet en/\ nie pioU'.i-.e va chung DT24 the hi?n khi nang phan giii protein cao nhal vdi ban kinh vdng phan giii la 17,58 mm o ihdi dicm ^ ngay sau khi nudi eay.
Tfl khda' B^nh spc trong Iren lua, lipid, protein, Xanthomonas oryzae pv. oryzicola, xa khuan I.DATVANDE
Benh ,sne trong la lua do vi khuan Xanthomonas oryzae pv. oryzicola (Xoc) li benh hai quan trpng tren lua. b?nh gay ihiel hai nang suit dang ke trong khoang 17,5 - 30"() vi ghi nhin phd bien d eie nfldc Chau A (Wunni et al, 2014), Bien phip phdng tri benh chu yeu bi^n nay la sfl dung cie loai thudc hda hpe. Tuy nhien. bien phap hda hoc eo tie dong xau nhfl inh hiidng den sflc khde con ngfldi, giy d nhiem moi trfldng, lflu ton tren sin pham va tao ra tinh khing thudc cfla mam benh. Nh.ini hfldng den mdt nen ndng nghiep ben vflng, phdng trfl sinh hoc la mdt hfldng di mang tinh hieu qui va than thien vdi mdi trfldng. Trong dd, xa khuan IJ nhdm \ 1 sinh vai dfldc nghien eflu ed nhieu liem ning Ion trong phdng trfl sinh hpe benh eay chang ban xa khuan eu the fle che mam b?nh vdi nhieu cP che nhfl. tiei khang sinh, cpng sinh vd ky sinh .. Nguai ra. xa khuan eon ed kha nang tiet ra c^c enzyme ngoai bio (lipase, protease, chitinase, glueanase,. ) giup phan buy vieh te bao VI sinh vai ga\' benh. Tlieo nghien cflu cua Van-.\hn va cdng tac vien (2000), da cho thay hoat tinh doi khang ciia 26 chung Streptomyces sp. chdng lai vi khuan fnriNiii carotorora tren eai bap d Trung Quoc Li chil khang smb. Gan da\, trong nhieu nghien cflu di edng bd cung cho ring xa khuan cd kha nang quin ly benh do vi khuan ga\ hai ea\ trdng nhfl vi khuan Ralsloma solamiccarum ga\ benh heo xanh tren eay khoai lang (Huynh Trfldng Giang. 2017i,
vi khuan Xanthomonas oryzae pv. oryzae gay benh chiy bia li lua (Nguyen Thi My Ngan, 2014), vi khuan Xanthomonas campeslris pv. citri gay benh loet tren cam, quyt (Huynh Hao Quang, 2018),
\i khuan Erwima sp. gay benh thoi cu khoai mdn (Le Minh Phfltfng va ctv , 2019). Do do, viec nghien cflu xa khuan trong phdng tri benh soe trong tren lua li mdt trong nhflng bien phap sinh hpc day tiem ning, hfldng den nen ndng nghiep an toan ben vflng.
II. V.\T LIEU vA PHUONG PHAP NGHIEN Ct/U 2.1. \ a l lieu nghien cflu
Ngudn xa khui'n: Thu mau dat tren nhflng rupng trdng lfla cd dien tich Idn htfn 1,000m- chpn dat d nhflng goc lfla khde va thu d dp sau tfl 10 - 25 cm.
Cie mau dat d nhflng rudng khae nhau dflpc cho vao tflng tui nilon rieng va mang ve phdng thi nghiem lien hanh phin lap theo phfltfng phip cua Hsu va Lockwook(1975).
Ngudn vi khuan Xanthomonas oryzae pv. oryzicola la chung vi khuan nhin tfl Bd mon Ban ve Thflc vit, Khoa Ndng nghiep, Trfldng Dai hoe Can Thtf.
Chflng vi khuan niy di dflPc ghi nhan eo die diem hinh thai, mau sic khuan lac, die diem sinh hda va tneu ehflng dien hinh cua vi khuan gay benh soc Irong tren Ifla tfl huyen Vi Thuy, tinh Hiu Giang va cd kha ning xim nhiem vi gay hai ning nhat tren Ifla trong sd 8 chflng vi khuan thu thip duoc ' Hpe vien eao hoe nganh B.io ve thuc vat, Trfldng Dai hi.c (..i;i Ifio
• Khoa Nong nghiep. Trfldng Dai hoe Can Tho
Tap chi Khoa hoc Cong ngne \6ng nghiep Viet T in -SoSi' M)/2cV(l 2.2. Phflong phap nghien ciifu
2.2.1. Ddnh gid khd ndng dot khdng cua cdc chung xa khudn ddi vdi Xanthomonas oryzae pv. oryzicola trong dieu kien phong thi nghiem
a) VIU Ihap vd phdn lap xa khudn
Thu mau dat tren nhflng rudng trdng lua cd dien tich ldn hon 1.000 m- 6 mdt so tinh DBSCL nhfl: Can Thd, Tra Vmh, Hau Giang va Dong Thip. Chpn dat 6 nhflng gdc cay Ifla khde va thu d dp sau tfl 10 - 25 cm.
Cac mau dat dflpc phan lap theo phflong phap cfla Hsu vi Lockwook (1975) nhfl sau: Hda 4 gram di't vao 40 mL nfldc cat thanh trung cho vao ong Falcon 50 mL. Lac trong 30 phut. Pha loang d 4 nong dp:
10'.10^ \0\ lO-\ Rut 50 pL huyen phfl d nong dp 10 ^ vi 10 ^ cho vao dia petri chfla mdi trfldng ISP4 vi chi dia. Dia dflpc fl trong 2 - 3 ngay, sau dd tach rdng xa khuan tren mdi trUdng MS. Cic chung xa khuan phin lap dflpc ton trfl d d S^C de sfl dung cho cic thi nghiem.
b) Chudn bi thi nghiem
Nhflng chflng xa khuan dfltfc nudi cay trong mdi trfldng MS trong 6 ngay, xac dinh mat sd vi chuyen ve huyen phu xa khui'n la 10^ cfu/mL. Vi khui'n .V oryzae pv. oryzicola (Xoc) dflpc nudi cay tren dia petri chfla mdi trfldng King's B trong 48 gid, cho 5 niL nfldc ci't thanh trung vao dia, xdc dinh mat sd va chuyen ve huyen phu vi khuan cd mat so 10** cfu/mL.
c) ThUc hien thi nghiem
Hda 50 mL huyen phu vi khuan Xoc {mat sd 10" cfu/mL) cflng 10 mL mdi trfldng King'B long (Khoang 50''C) vao dia Petri, lac deu, de ngudi. Sau dd tao gieng tren dia petri bing dung cu due trdn cd dudng kinh 5 mm, dung micropipet hut 10 pL huyen phu xa khui'n (mat so lO^cfu/mL) cho vao gieng vfla due, moi gieng la 1 chung xa khuan khac nhau.
Dia Petri thi nghiem dflpc dat trong dieu kien nhiet dp phdng.
d) Chi lieu theo doi
Tien hanh do ban kinh vdng vd khuan d cac thdi diem 1, 3, 5 va 7 sau ngay sau khi nudi cay.
2.2.2. Kiido sdt khd ndng tiet enzyme protease cua cdc chung xa khuan tren moi trUdng thach a) Bo tri thi nghiem
Thi nghiem dflpc bo tri hoin toin ngiu nhien vdi 5 lap lai, moi nghiem thflc li 1 chung xa khuan tbi nghiem. Thi nghiem dflpc thflc hien theo phflpng phap cfla Mitra va Chakrabartty (2005): Xa khuan sau khi dflpc nudi cay trong dia petri 6 ngay tren moi trfldng MS. xac dinh mat so vi chuye'n ve huyen phfl
xa khuan la 10' cfu/mL. Khoanh giay tham (dfldng kinh 5 mm) cd tam xa khuin (mat sd 10* cfWmL) dflpc eay thinh 3 die'm tren mdi trfldng chfla cP chal casein. Xic dinh hoat tinh protease do xa khuan lict ra tren moi trfldng thach bing each trin dung dich TCA (Tricloro acid) 10% len dia petri trong 30 giiy.
b) Chi tieu theo ddi
Tien hinh do ban kinh vdng phan giai protein sau 3, 5, 7 va 9 ngiy sau khi nuoi cay la vung khdng an miu vdi thudc nhudm TCA.
2.2.3. Khdo sdt khd ndng tiet enzyme lipase cua cdc chung xa khudn tren mdi trUdng thach a) Bo tri thi nghiem
Tbi nghiem dflpc bd tri hoin toin ngau nhien vdi 5 lap lai, mdi nghiem thflc li 1 chflng xa khuan thi nghiem.Tbi nghiem dflpc thflc hien theo phfltfng phap eua (Ertugrul el ai, 2007): Xa khuan sau khi dflpc nudi cay trong dia petri 6 ngiy tren mdi trfldng MS, xic dinh mat sd va chuye'n ve huyen phfl x^
khuan la IO** cfu/mL. Khoanh giay tham (dfldng kinh 5 mm) cd tam xa khuan (mat so 10" cfu/mL) dflpc cay thanh 3 diem tren mdi trfldng cd chfla Tween 80 agar.
b) Chi lieu theo doi
Tien hanh do ban kinh vdng phin giii lipid d cic thdi diem 3, 5, 7 va 9 ngiy sau khi nudi cay li vflng trong suot.
2.2.4. Xd ly sd lieu
Sd lieu dutfc long hpp, xfl ly stf bd bing phan mem Excel. Thong ke phan tich ANOVA vi so sanh sfl khac biet gifla cac trung binh nghiem thflc theo tflng each bd tri thi nghiem bing phan mem MSTATC.
2.3. Thdi gian v i dia diem nghien cflu Nghien cflu dflpc thflc hien tfl thing 8 nam 2019 den thing 02 nam 2020 tat phdng thi nghiem benh ciy va nha Ifldi thudc Bd mdn Bio ve thflc vit, Trfldng Dai hpc Can Tho, thanh phd Can Thd.
III. KET QUA VA THAO LUAN 3.1. Phan lip xa khuan
Ket qui phan lip dflpc 87 chflng xa khuan tfl dat trdng Ilia, dUa vao dac diem hinh thai cua khuan lac va die tinh sinh hda nhfl hinh dang khuan lac, mau sac khuan ty cd chat, mau sac khuan ty khi smh, sic to khuech tan tren mdi trfldng nudi eay.. da xac dinh cac chung xa khuan phan lip thudc chi Streptomyces (Nguyen Lin Dung va ctv., 2002),
rnanj'-^ '.L-j •-J-tT . f 3.2. Kha nang doi khing cua cac chung xa khuan doi vdi vi khuan Xanthomonas oryzae pv. oryzicola trong dieu kien phong thi nghiem
Ket qui dinh gia nhanh kha nang ddi khang ciia cae chflng xa khuan ddi vdi vi khuan .V oryzae pv. oryzicola (Xoc) giy b?nh spc trong tren Ifla cho thay cd 18 chung xa khuan thflc sfl cd kha nang doi khang trong tdng sd 87 chflng xa khuan phin lap.
Tiep tuc sfl dung 18 chung xa khuan nay de danh gii kha nang ddi khing vdi vi khuan A'oc trong dieu kien phong thi nghiem vdi 5 lan lip lai. Ket qua dfltfc ghi nhin thdng qua ban kinh vdng vd khuan (BKWK) d cac thdi die'm 1, 3, 5 va 7 ngay sau khi ciy (NSKC) vi dflpc trinh bay d bang 1.
d thdi diem 1 NSKC, da so cac chung xa khuan deu cd khi nang fle che sU phat trien cfla vi khuan X. oryzae pv. oryzicola d cic mflc dp khac nhau.
Trong dd, 4 chung CT4, DT24, DT12 va TV4 the hi?n kha nang fle che vi khuan Xoc cao vdi BKWK lan Iflpt 5,0 mm; 4,6 mm; 4,6 mm vi 4,4 mm va cd khic bi?t y nghia so vdi cac chflng cdn lai. Den thdi diem 3 NSKC khi nang fle che sU phat tnen cua vi khuan giy benh cua cac chflng xa khuan deu cd xu hfldng tang len vdi BKWK dao ddng trong khoing 0,2 - 5,2 mm. Trong dd, chung CT4 van cd BKWK cao nhat la 5,2 mm, ke den la chung DT24 va TV4 vdi BKWK 4,8 mm, tiep iheo la chung DT12 vdi BKWK la 4,6 mm va cd sfl khic biet y nghia vdi cic chung cdn lai. Den thdi diem 5 NSKC kha nang ddi khang vdi vi khuan Xoc cua cic ehflng xa khuan cd xu hfldng giam. Tuy nhien, 4 chflng CT4, DT24, TV4 va DT12 van duy iri dflpc kha nang ddi khang cao nhit vdi BKVVKli 5,6 mm; 5,3 mm; 5,1 mm vi 4,9 mm khic biel cd y nghia \di cie chflng cdn lai.
Den tbdi diem 7 NSTN, 4 chflng t:T4, DT 24, TV4 va DT12\'an duy tri dflpc kha nang doi khing eao nhat vtfi BK\'\'K Kl 5,0 mm; 4,8 mm; 4,6 mm va 4.8 mm
\'a kliie biet cd y nghia vdi cic chung cdn lai.
Nhin chung, IS chflng xa khuan deu cd khi nang ddi khang vdi vi khuan Xoc gay benh soc trong tren lfla d nhflng mflc dp khic nhau qua cic thdi diem
khao sal Ndi bit nhat li 4 chflng xa khu.in *-'!•*•
D T : 4 . TV4 va DT12 the hi?n kha ning d.-- ^^^-'^f vdi \i khuan Xoc tot nhat vdi BK\\K cao va thdi gian duy tri khi nang doi khang ben \fln,^ den thdi diem 7 ngiy sau thi nghiem.
Bang 1. Bin kinh vdng vd khuan (mini cua cic chflng xa khuan d6i vdi vi khuan .Viini'i'" "'""''•
oryzae pv. oryzicola d cic thdi diem 1. 3. 5 va " nga\
sau khi nudi cay (NSKC)
STT
1 2 3 4 5 6 7 8 9 10 II 12 13 H 15 16 17 18
Chung xa khuSn
I : T 4 DT24 TV4 D T I 2 CT3 CT7 C T l 2 DT5 DT31 DT27 DT30 DT32 H G I 3 HGI I HG20 TVS TV6 TV15 Mdc y nghia CV(%)
Bdn kinh vong '6 Ichuan qua cac thdi diem 1 3 5 NSKC
5,0 a 4,6 ab 4.4 b 4.6 ab 3,6 c 2,6 d 2,6 d 3,6 c 2,1 de
2,6 d 2,8 cd 2,1 de 0,8 e 0,6 ef 0,6 ef 0,2 fg 0,1 g 0,0 hi
i 9 , 7 i NSKC
5,2 a 4,8 b 4,8 b 4,6 be 2,8 cd 1,1 f 1,2 e 2,9 c 2,8 cd
2,9 c 2,9 c 1,6 de 1,5 d 1,1 f 1,4 de 0,5 g 0,5 g 0,2 gh
16,38 .VSKC
5,6 a 5,3 ab 5,1 b 4,')b 2,2 c M d e 1,1 de 2,2 c 3,1 be
2,2 c 3,1 be
1,2 d 1,0 e 1,0 e 1,1 de 0,7 cf 1,0 e 0,7 ef
22.40 (mm) j
7 SSKC
5,0 a 4-8 ab 4,6 b 4,8 ab 1,5 c 1,1 d 1,1 d 1,5 c 1,5 d 1,5 d 1,1 d 0,9 e 0,7 ef 0,9 e 0,5 fg 0,3 gh 0,5 fg 0,1 h
26,62 Ghi chu: Cdc gid tri trung binh trong ciing mot col dUdc theo sau hdi mot hodc nhieu chU cdi giong nhau thi khdc biet khdng co y nghia thong kc irong phep thU Duncan. *'khac biet d mdc y nghia 5%.
Hinh 1. Kbi nang ddi khang ciia xa khuan doi .o vi khuan Xanthomonas oryzae pv oryzicola d thdi diem 5 nga> sau khi nuoi cay
Tap ChiKhoo noc Cong ngne Nong nghiep Viet Nam -SoSi! M) 2020 Khi ning doi khing ciia xa khuan doi vdi vi
khuan gay benh ciy trong di dfldc nhieu nghien cflu trfldc day chflng minh ch4ng han nhfl Nguyen Thi My Ngin (2014) da phin lap va tuyen chpn 23 trong tdng so 268 chung xa khuan phan lap tfl dat trong lua cd kha nang doi khang vdi vi khuan Xanthomonas oryzae pv. oryzae gay benh chiy bia la lfla. Trong do, 5 chung DT24, ST42, TV4, VL6 va CT45 vdi bin kinh vd khuan cao nhat lan Iflpt li 4,00 mm; 4,00 mm;
4,06 mm; 4,18 mm vi 5,10 mm d thdi diem 6 ngay sau thi nghi?m. Dong thdi 5 chung xa khuan nay cung cd kha nang tiet ra cic enzyme ngoai bao nhfl protease, cellulase, lipase... Theo Pham Minh Ly (2016), cung ghi nhin 6 chung xa khuan LV-DTl, LM-HG6, T0-VL5, TS-AG4, BT-CTl, BT-CT5 cd khi doi khang vdi vi khuan Xanthomonas oryzae pv.
oryzae giy benh chay bia la lua thdng qua ca che tiet enzyme ngoai bao li protease, lipase vi cellulase.
Nhfl viy, 4 chflng CT4, DT24, TV4 va DT12 cd khi ning ddi khing vdi vi khuan gay benh gay benh spc trong tren Ifla cao nhat trong tong so 18 chung xa khuan thi nghiem va 4 chung xa khuin nay se dflpc tiep tyc sfl dung trong cac thi nghiem tiep theo.
3.3. Kha nang tiet enzyme Upase va enzyme protease cua cic chung xa khuan
Khi nang tiet enzyme lipase vi enzyme protease ciia 4 chung xa khuan tren mdi trfldng thach dflpc dinh gia qua cac thdi diem 3, 5, 7 va 9 ngay sau khi nudi cay (NSKC) vi dflpc trinh bay d Bing 2.
3.3.1. Khd ndng tiet enzyme lipase
Kha nang tiet enzyme lipase cfla cac ehflng xa khuan thi nghiem dflpc trinh bay d bang 2. Ket qui cho thay ca 4 chung xa khuan thi nghiem deu the
hien kha nang tiet enzyme pilase phan giai lipid.
Thdi diem 3 NSKC, tat ca cic chflng xa khuan deu the hien kha nang phan giai lipid vdi bin kinh vdng phan giai dao dpng trong tfl 2,80 - 7,10 mm, trong dd chflng DT24 cd ban kinh phin giii cao nhat la 7,10 mm; ke den li chimg CT4 cd ban kinh phan giai la 4,80 mm va cd sfl khic biet thdng ke vdi 2 chung xa khuan thi nghiem cdn lai. d thdi diem 5 NSKC bin kinh vdng phin giai cua cac chung xa khuan deu gia tang va dao ddng trong tfl 7,63 - 9,88 mm vi 3 chung DT24, CT4 va DT12 cd ban kinh vdng phan giii lan Iflpt li 9,88 mm, 9,88 mm va 9,48 mm khdng khic biet y nghia vdi nhau vi khic biet cd y nghia so vdi cae chung TV4 con lai. 6 thdi diem 7 NSKC, 3 chung DT24, CT4, DT12 tiep tuc cd kha nang phan giai hpid cao va khdng khac biel thong ke vdi nhau vdi ban kinh vdng phan giai lan Iflpt la 13,10, 11, 90 va 12,38 mm va khac biet thdng ke vdi chflng TV4 d mdc y nghia 5%. Thdi diem 9 NSKC, vdng phin giii lipid van tiep tuc tang vi 3 chflng DT24, CT4, DT12 van duy tri khi nang phin giii lipid cao vdi ban kinh vdng phan giii lan Iflpt la 14,00 mm; 14,90 mm va 15,20 mm cao htfn va khac biet thdng ke vdi chung TV4 d mflc y nghia 5%.
Hinh 2. Kha nang phan giai lipid ciia 4 chflng xa khuan d thdi diem 9 NSKC Bang 2. Kha nang phan giai lipid va protein cua 4 ehung xa khuan thi nghiem
qua cic thdi diem 3. 5, 7 vi 9 ngay sau khi nudi cay (NSKC)
DT24 CT4 DT12 TV4
thllc
MUc y nghia CV(%)
Ban kinh vong phan giai lipid 1 3 NSKC
7,10 a 4,80 b 3,10 c 2,80 d
*
25,82 5 NSKC
9,88 a 9,88 a 9,48 a 7,63 b
•
7,41 7 NSKC
13,10 a 11,90 a 12,38 a 10,43 b
•
8,86 mm)
9 NSKC 14,0 a 14,9 a 15,20 a 11,28 b
•
6,85
Ban kinh vong phar 3 NSKC
6,40 a 2,56 c 5,35 b 3,10 c
•
14,37 5 NSKC
12,38 a 7,90 c 9,85 b 9,70 b
•
6,76
giai protein 7 NSKC
14,35 a 11,05 b 11,55 b 10,67 b
*
8,64 (mm)
9 NSKC 17,58 a 14,95 b 14,55 b 11,88c
•
4,58 Ghi chu: Cac gid tri trung binh trong cung mot cot dUdc theo sau bdi mot hodc nhieu chU cdi giong nhau thi khdc biet khong co y nghia thong ke trong phep ihU Duncan: * khdc biel d mUcy nghia 5%.
3.3.2. Khd ndng tiet enzyme protease Kha n i n g tiet enz\Tne protease c u a c i c c h i m g xa k h u a n thi n g h i e m dutfc t r i n h bay a b a n g 2.
Thdi d i e m 3 NSKC, tat ca 4 c h u n g xa k h u a n thi n g h i e m d e u the hien k h a n i n g p h a n giai protein vdi ban kinh vdng p h i n giai d a o d d n g td 2,56 - 6,40 m m , t r o n g dd c h u n g D T 2 4 cd b a n Idnh v d n g p h a n g i i i Idn nhat la 6,40 m m va k h a c biet y nghia t h o n g ke d mflc 5% so vdi c i c ehflng xa k h u a n thi n g h i e m c d n lai. Thdi d i e m 5 NSKC, mflc dp p h i n giai protein cfla cac c h u n g xa k h u a n deu gia l i n g vdi b a n k i n h v d n g p h i n giai d a o d d n g trong k h o a n g 7,90 m m d e n 12,38 m m v i chflng DT24 van cd b i n k i n h v d n g p h i n giai la 12.38 m m cao htfn v i khac biet y n g h i a t h o n g ke vdi cac ehflng cdn lai. Thtfi die'm 7 NSKC, b i n k i n h v d n g p h i n giai dao d d n g trong k h o i n g 10,67 - 14,35 m m v i c h u n g D T 2 4 van cd ban k i n h v d n g p h a n giai c a o nhat la 14,35 m m va khac biel y n g h i a t h d n g ke vdi c i c c h u n g cdn lai. Thdi die'm 9 NSKC, b a n kinh v d n g p h i n giii cua e i e e h u n g xa k h u i ' n van tiep tuc lang va d a o d d n g tfl 11,88 - 17,58 m m va chiing D T 2 4 van d u y tri kha n a n g p h a n giai protein c a o nhal voi ban kinh vdng p h i n g l i i la 17,58 m m va khac biel y nghia t h d n g ke voi cac c h u n g cdn lai.
^^i^P
Hinh 3. Kha nang phan giai protein eua 4 chung x? khuan d thai diem 9 NSKt:
N h i n c h u n g , 4 chflng -\a khua'ii ihi n g h i e m deu cd khA n a n g liet e n z y m e lipase p h i n giai lipid va e n z y m e p r o t e a s e p h i n giai protein vdi nhieu mflc dd k h a c n h a u va c h u n g D T 2 4 ed k h i n i n g liet enz\ me lipase va en/\ m e protease cao va keo dai den thoi d i e m 9 ngay sau khi nudi cay
Theo Nguyen Lan D u n g va c d n g l i c vien (2002), lipid la t h a n h p h a n q u a n t r o n g cua m i n g sinh chat hay m i n g le b a o c h i t ( C ) t o p l a s m i e m e m b r a n e , C M ) va protein la mdt i r o n g n h i i n g t h i n h p h a n cau lao cua vach le b a o d vi k h u a n . Nhfl viy, viec fle che va tieu diet m i n i bi-nh t h d n g qua cP c h e tiet e n z y m e lipase p h i n g i i i lipid va e n z \ ' m e protease p h a n giai protein tren vach te b a o cua m a m b e n h cua xa k h u a n la CO k h i n a n g va d i n g xem xet \ a kel q u a ihi n g h i e m da chflng m i n h rang 4 ehiing xa k h u a n cd kha n i n g
d o i k h a n g \tfi l i e n h a n gav b ? n h spc trv.ic n ^ "
lfla t b d n g q u a cc c h e tiet e n z y m e lipase \ ^ '"'^' p r o t e a s e v i k h i n a n g tiel ra eae e n / v n u - r ^ ua x-' k h u a n c u n g l i m d t hfldng trien v p n g tn>iii: i - i o n g t "
b e n h eay t r d n g d o vi k h u a n gav ra I h e o nghn.'n eflu c u a H u y n h TrUdng G i a n g (2017) e h o r i n g t> ^bung T T 9 , T T 11. T T 15, T T r 4 4 . T D 16 \ a T T 17 deu eo klia n a n g liei e n z y m lipase va e n z ) ' m e protease de dpi k h i n g b e n h heo x a n h tren k h o a i lang d o w k h u a n Ralstonia solanacearum gay ra. TflPng lu, 1 e .Mmh P h f l a n g va c p n g t i c vien (2019) cho rang 4 chiing LV-DT15, C M - A G 2 2 . D H - T \ ' 4 . L\" DT24 cd d d i k h i n g ddi k h a n g cao voi vi k h u a n Eruinia sp. gay b e n h thdi n h u n t r e n k h o a i m d n d e u cd kha n a n g liet e n z y m e lipase va e n z y m e protease.
1\. KET LUAN VA DE NGHI 4 . 1 . Ket l u a n
Bdn (04) c h u n g xa khui'n C T 4 , 1)T24. T V 4 va D T 1 2 cd k h a n i n g ddi k h a n g cao vdi \'i k h u a n Xanthomonas oryzae pv. oryzicola gay b e n h spc t r o n g tren lua d o n g thdi c u n g the hien k h a n a n g tiet e n z y m e lipase va p r o t e a s e c a o t r o n g dieu kien p h d n g thi n g h i e m .
4.2. D e n g h i
K h a o sat k h a n a n g p h d n g tri b e n h s p c t r o n g t r e n lfla c u a 4 chflng xa k h u a n n a y t r o n g d i e u k i e n n h a Ifldi.
T A I L I E U T H A M K H A O
Huynh H i o Q u a n g , 2018. Khdo sdt mot so cd che doi khdng vdi VI khuan Xanthomonas campestris pv. cilri gdy benh loe! tren cam. quyt cda cac chiing xa khudn tnen vong. Luan van tot nghiep cao hpc nganh b i o ve thflc vat, Khoa Ndng nghiep v i Sinh hoc flng dung, Trfldng Dai hoc Can Tho.
HuynbTrfldng Giang, 2017. X/idosflt A:/landfj^p/iOM^tn benh heo xanh tren khoai lang do vi khudn Ralstonia solanacearum cita cdc chiing xa khudn. Luan van tdt nghiep cao hpe chuyen nganh bao ve thflc vat, Khoa Nong nghiep va Sinh hpe flng dung. Trfldng Dai hpe Can Tho
Le Minh PhflOng, Nguyen TrUdng Srtn va Le M i n h Tfldng, 2019. Kha nang doi khang ciia cat chiini' xa khuan doi vdi vi khuan Erwinia sp gay benh thdi nhun cu khoai mdn (Colocasia esculentaj. Tap chi Bdo ve ihUc vdt. 5: 27-34.
Nguyen L i n D u n g , Nguyen Dinh Q u y e n va Pham Van TY.2002. Vl smh Mil ho. \ h d \ u a t b a n ( , •• lu^ Viet Nam Ha Ndi.
Nguyen YhiMy Ngin, 2014. Khdo sdt khd luiii;' ph,,„. ir, itta Aij khudn doi \ ili vi khudn Xanthonwiui ,„,_,.
pv oryzae. Luin van idi nghiep cao h o t UL n I i,
Tap chi Khoa hoc Cong rg'-e \cng nghiep VmNam - So Sji J4)/2020
ve thflc vit. Khoa Nong nghiep va Sinh hpc flng Mitra, P. and P. Chakrabartty. 2005. An extracellular dyng, Trudng D ^ hpc C i n Tho. protease with depilation activity from Streptomyces Ph^m Minh Ly, 2016. Khdo sdt mot so cd che doi khdng nogalator. Journal of Scientific and Industrial
vdi VI kiiudn Xanthomonas oryzae pv. oryzae gdy benh Research. 64(12): 978-983.
chdy bia Id cua cdc chiing xq khudn Inen vong. L u i n Wonni, I., B. Cottyn. L. Delemmerman, S. Dao, L.
van tdt nghiep ky sfl chuyen nganh b i o ve thflc vat, Ouedraogo, S. Sarra and \. Verdier, 2014. Analysis Khoa Ndng nghi?p va Sinh hpe flng dung, Trfldng oi Xanthomonas oryzae pv oryzicola Population Dai hpc Can ThP. in Mali and Burkina Faso Reveals a High Level of Ertugrul, S., G. Donmez and S. Taka^, 2007, Isolation Genetic and Pathogenic Diversity. Phytopathology.
of lipase producing Bacillus sp. from olive mill 104(5): 520-531,
wastewater and improving its enzyme activity. Yan-Min. V., T. Da Quun, T. Shi Min and Z. Ding.
Journal of Hazardous Materials, 149(3): 720-724. 2OOO. The antagonism of 26 strains Streptomyces sp.
Hsu, S., J. Lockwood, 1975. Powered chitin agar as a against several vegetables pathogens. Hebaei Agnc selective medium for enumeration of actinomycetes Univ.. 23: 65-68.
in water and soil. Apllied microbiology, 29(3): 422-426.
Evaluation of antagonistic ability of actinomyces
for Xanthomonas oryzae pv. oryzicola causing bacterial leaf streak disease on rice
Tang Kim, Tran Van Dung, Le Minh Tuong Abstract
The research was conducted in the laboratory of Plant Protection Department, Can Tho University to screen actinomycetes to control bacterial leaf streak disease on rice caused by Xanthomonas oryzae pv. oryzicola. Eighteen of 87 strains in total were able to resist against X. oryzae pv. oryzicola in laboratory condition. The experiments for antagonistic ability of 18 actinomyces strains in controllingX oryzaepv. oryzicola arranged in completely randomized design with 5 replications. The results found that 4 strains CT4, DT24, TV4 and DT12 had high antagonistic ability with a radius of inhibition zones reaching 5.0 m m ; 4.8 mm; 4.6 mm and 4.8 mm respectively at 7 days after inoculation. On the other hand, the lipolytic ability was also checked with 5 replications by completely randomized design. The results indicated that 4 testing strains could produce lipase and 3 strains DT24. CT4 and DTI 2 expressed the lipolytic activity with the lipolytic halo radius of 14.00 mm; 14 90 m m and 15.20 mm respectively at 9 days after testing. Beside, protease activity assay was tested with 5 replications by completely randomized design. The results found that 4 strains could produce protease and the DT24 isolate expressed the highest proteinolytic activity with proteinolytie halo radius of 17.58 m m at 9 days after testing.
Keywords' Actinomyces, bacterial leaf streak on rice, lipid, protein, Xanthomonas oryzae pv, Oryzicola
Ngay n h a n b i i : 13/4/2020 Ngfldi p h a n bien: TS, Tran D i n h Gidi Ngiiy p h a n bien 22/4/2020 Ngay duyet dang: 29/4/2020
NGHIEN ClTU KY THUAT NHAN GIONG NGAI DEN (Kaempferiaparvifiora) BANG CHOI CU
Dao Thiiy Dflong', Nguyen Tbi Thu'. Tran Ngpc Lan', Nguyen Dae Binh Minh', Nguyen Viet Trung^
TOM TAT
Ngat den la mot loai dflpc lieu quy hiem cua Viet Nam, dflpc nhan giong tfl choi cu, khoi Iflpng cu giong tfl 30 g - 40 g/l n h i n h cho ty le nay m a m eao 100%, khi trdng nen chpn loai eu gidng 1 nhanh to khde khdng nen chpn eil nhieu n h i n h nhd. Thanh phan gia the dat ^• trau hun (1 • 1) hoac cat 100% cho ty le nay mam dat 100%, thdi gian fldm ldi khi xuat vfldn 45 - 46 ngay Bo sung ehal kich thich smh trfldng GA3 d ndng dd 150 ppm, N3M h o i c ROOTS NEW (pha theo khuyen eao) deu cho t>' le nay mam eao 100%, thdi gian flOm tdi khi xuat vfldn g i i m tfl 8 - 1 2 ngiy so vdi ddi chflng. Che dp che bong thich h p p la 60 - 70% ciy cd ty le sdng sdt 100%, t i n g khan nang phal trien cay eon.
Tu khda: Ni;a! den (Kaempferia parviflora), chdi eii. k)- thuat nhan giong
' Vien Nghien cflu va Phat irien Vung, Bd Khoa hpc va Cdng nghe; - Trfldng T H P T Thach Ban, Ha Ndi