CONG NGHIEP RLTNG
HIEU LIJC PHONG M 6 | GAY HAI LAM SAN CUA DjCH CHIET
N H A N H A T C O C H A N H
{Azadirachta excelsa Jacob)
Nguyen Thj Bich Ngoc, Nguyen Duy Virvng, Nguyen Thj Hang Phong Nghien cuu Bao quan Lam san
Vien Khoa hoc Lam nghiep Viet Nam
TOM TAT
Dich chict bang dung mdi etanol va can chict bdi mgt so dung mdi hiru co cua nhan hat Cdc hanh da dugc khao nghiem hieu luc phdng mdi nhi Coptotermesformosanus Shiraki gay hai lam sin tren trong phdng thi nghiem bang cac phuang phip ding tin cay. Ket qui thir hieu lire cho thay hieu luc phdng moi tdt d gan nhu tat ca cac ty Ic khdi lugng giiia nhan hat va dung mdi dugc lua chgn. Ty Ic niy cang nhd (lugng nhan hat Cdc hanh cing nhd), cac mau khao nghiem cang bi tan cdng manh, sd lugng mau hi mdi tac dgng tang len vi khdng chi hi tic dgng theo chieu rgng ma cdn bi theo chieu sau. Ket qua thir so bd tren dia petri cho thay trong nhan hat khdng chi chiia mgt sd hgp chat gay ngin an ddi vdi mdi ma cdn chua mgt sd hgp chat cd kha nang gay dgc. Cac ket qua thu dugc cung cap them dir lieu khoa hgc tin cay tao tien dc cho nhiing nghien Cliu sau hon.
Tfr khoa: Phdng mdi, Cdc hanh, Phep thir, Mo\ Coptotermes formosanus Shiraki MO'OAU
Go, tre nira, song may li nhiing vat lieu tu nhien da dugc sir dung dc che tic nhieu vat dung phuc vu ddi sdng thudng ngay cua con nguai. Gd vi cic sin pham lam sin dugc img dung rgng rai nhu vay li nhd nhiing tinh ning ma nhieu vat lieu khac khdng the thay the dugc. Ben canhuu diem dien hinh li cd the tai sinh dugc thi gd va nhieu loai lam sin, do ban chat la cic vat lieu sinh hgc, ciing cd nhugc diem ldn li dc bi pha hoai khi chiu tie dgng cua cac yeu td tu nhien nhu inh sing, lira, cic sinh vat gay hai (nam, cdn trimg...). O Vict Nam, vdi die thii khi hau nhiet ddi, la mdi trucrng thuan lgi cho nhieu sinh vat phi hoai lam sin sinh trudng va phat trien, nen viec bao quin lam sin de keo dai tudi thg sir dung chimg la mgt yeu cau thuc tc.
Cdng tic bio quan lam sin hien nay chu yeu dua tren vice ngam tam cic loai hda chat tir cic mudi vd co hoac cic hgp chat hiru co tdng hgp bing con dudng hda hgc. Nhirng hgp chat dugc dua vio img dung trong thuc te cd uu diem ldn la cd hieu luc phdng tru sinh vat gay hai cho lam sin rat tdt, sin xuat lugng ldn va chii ddng nhung do sir dung tren dien rgng mgt sd hda chat cd do dgc hai cao nen da anh hudng nghiem trgng len mdi trudng sdng cua con ngudi. Vdi tieu chi an toin cho con ngudi va mdi trudng sdng, nhieu loai hgp chat hda hgc da bj cam san xuat hay dugc khuyen cao ban che sir dung d nhieu qudc gia tren the gidi. Ben canh dd, nhiing
nghien ciiu thiic day vice sir dung cic hgp chat it gay hai cho mdi trudng cd ngudn gdc vi sinh vat va thuc vat khdng ngimg dugc khuyen khich.
Viet Nam li mgt qudc gia cd ngudn tai nguyen thuc vat phong phu. Tir xa xua, ngudi dan Viet Nam da biet sii dung nhieu loai thuc vat dc phuc vu nhu cau dan sirih, dien hinh nhat li chiia benh, phdng trir cic sinh vat gay hai trong san xuat ndng nghiep. Vai thap ky trd lai day, mgt sd loai cay da dugc quan tam nghien ciru img dung, nhieu die tinh mdi dugc phit hien, nhd dd nhieu cay da dugc nhan gidng trdng d dien tich ldn dc phuc vu san xuat quy md cdng nghiep, tieu bieu nhat la cay neem {Azadirachta indica), dugc nhap ngi vao Vict Nam va gay frdng tai mgt sd viing khd han thudc duyen hii mien Trung. Li va hat ciia cay nccm cd thanh phan hoat chat chinh la azadirachtin va cac dan xuat ciia nd, da dugc ndng dan d mgt sd qudc gia nhiet ddi sir dung nhu mgt loai thudc trir sau frong ndng nghiep. Qua tim hieu, chiing tdi ciing dugc biet cay Cdc hanh Azadirachta excelsa lacob, la cay ban dia thudc hg xoan Meliaceae, cd nhieu die tinh gidng cay nccm, dang dugc khuyen khich trdng tai cic tinh Ninh Thuan va Binh Thuan, da dugc mgt so nha khoa hgc trong nudc nghien cuu img dung cong nghe sinh hgc dc chgn gidng (Nguyen Vict Cudng, Pham Diic Tuan, 2007) vi tren the gidi nghien ciiu xic dinh thanh phan trong hat va li (Kohsuke Kurose, Mitsuyoshi Yatagai,
2005, Nor Aini Ah. shukor and Loo Keang Scong, 2006). Cay Cdc hanh ciing dugc xem la mgt ngudn cung cip cic hgp chat dieu khien sinh trudng v i phit trien cdn trung gay hai cho mua mang frong ndng nghiQp(H.Shmuterrer and M.Doll, 1993).
De gdp phan bd sung vao cdng tic nghien ciiu tim kiem, sir dyng ngudn thyc vat tao thudc bao quan lam sin d Vict Nam, chiing tdi da tien hanh dinh gia hi?u lyc phdng moi ciia dich chiet va can chict cua mgt so dung mdi hiiu co la diclometan, metanol va n-hcxan nhan hat Cdc hinh.
Ngi dung bii bio nay trinh biy mgt sd ket qui khio nghiem hieu luc vdi loai moi Coptotermes formosanus Shiraki d quy md phdng thi nghigm de
dinh gii budc dau viec sii dung hat Cdc hinh frong cdng tie bao quin lam san d nudc ta va cung cap co sd khoa hgc cho nhiing nghien cuu sau han ve tao thudc bao quan lam sin tir nguyen lieu hat Cdc hanh.
VAT UEU VA PHUOMG
PHAP N G H ! ^CUU
Vat lifu: Qua Cdc hanh dugc thu hai tai huygn Ninh San, tinh Ninh Thuan
- Qua sau khi thu hii dugc de kho so bg, tich bd vd de lay nhan hat. Phan nhan hat dugc nghien nhd va ngam frong dung mdi etanol theo cic ty Ig khdi lugng: Cdc hanh/ctanol Ii 1:2; 1:3, 1:4, 1:5, 1:6 tuong ling vdi 5 cdng thiic dugc dat ten Ii CTI, CT2,CT3,CT4,CT5.
- Nhan hat Cdc hinh cdn dugc nghien nhd va chiet boat chat bang cac dung mdi: Di-clo metan, metanol va n- hecxan. Dich chiet dugc cd quay chan khdng de tach dung mdi, thu dugc can chiet chiia boat chat cua nhan hat Cdc hanh
Phiromg phap khao nghidm hi^u lyre
- Thu frong mdi trudng cd mdi hoat dgng manh:
Mdi (Isoptera) dugc dinh gia la ddi tugng cdn trimg gay hai lam sin chii yen d nudc ta. Trong dieu kipn phdng thi nghigm, loai mdi nha (Coptotermes formosanus) dugc gay nudi phuc vu nghien cuu sinh hgc va khao nghigm higu l\tc thudc bio quan lam sin. De xic dinh hieu luc ban dau cua dich chiet tir hat Cdc hanh, chung tdi ip dgng qui trinh khio nghiem hieu luc vdi mdi do Phdng Bao quan Lam san xay d\mg thinh tieu chuan nganh (Tieu chuan 04TCN 106:2006)
- Qui trinh khio nghiem hieu luc cua thudc bio quan lam san vdi mdi.
Quy trinh gdm cac budc: Miu gd (Bd de. Trim
frang) dugc tam dung dich thuoc bao quin can khao nghiem hieu luc theo phuong phip nhiing 10 phut v i ngam thudng vdi thdi gian 24 gid. Mau doi chiing cua moi cdng thiic thi nghiem dugc tam bang dung mdi tuomg iing. Mau sau khi idi ly dugc de khd tu nhien frong didu kien phdng thi nghiem.
Dat mlu khio nghigm vao mdi trudng dang cd moi hoat dgng manh. Sau thdi gian mgt thing, ga mau va danh gia ket qua thi nghiem.
- Danh gii hieu luc cua dich chiet can cii vao cac chi so sau:
Ty Ig % sd mau cd vet moi an (X%)
Ty Ig % sd mau cd vet mdi an rgng bang v i hon Icm'(Y%)
Ty Ig % sd mau cd vet mdi an sau bang hoac han Imm(Z%)
Ket qua dugc qui dinh:
X%, Y%, Z% tfr 0% ddn 30% dat 3 didm X%, Y%, Z% Idn hom 30% ddn 60% dat 3 didm X%, Y%, Z% Idn hon 60% ddn 100% dat I dilm Tdng hgp sd didm cua 3 chi tieu fren, neu cdng thiic nao dat 3-4 diem la cd higu lyc tdt vdi mdi, dat 5-7 diem la cd hieu luc trung binh, neu dat fren 8 diem Ii cd higu lyc kem vdi mdi.
Dieu kign cua phep thu: 70% mau ddi chiing bi mdi an
- Thii fren dia petri: Can chiet nhan hat dugc pha frong dung mdi etanol ndng do 10% vc khdi lugng. Tam dung dich da pha che vio mieng giay lgc cd dudng kinh 40mm theo nhiing lugng the tfch 0,2 ml, 0,5ml va Iml. De dung mdi bay hai tir nhien d nhiet do phdng frong 24 gid. Cho moi mieng giay Igc vao 01 dia petri va tha vao do 100 con moi (90 moi thg, 10 moi linh), bo sung vao dia mgt lugng bdng tham nudc de tao ngudn am cho mdi hoat dgng binh thudng. Mau ddi chiing, giay Igc dugc tam dung mdi etanol. Hoat dgng cua moi dugc theo ddi frong thdi gian 7 ngay, ghi chep lugng mdi chet theo thdi gian.
Ktl QUA VA T H A O LUAN
Miu gd khio nghiem dugc thir thich frong mdi trudng mdi boat ddng manh. Sau thdi gian mgt thing, 100% m i u doi chiing da bi mdi p h i huy. Day la didu kien can de tien hinh dinh gii thi nghiem thanh cdng. Ket qui higu lyc phdng moi ciia dich chidt hat Cdc hanh dugc the hien fa . -i bang sau:
CONG NGHIEP RLfNG
Sang 1. Ket qua khao nghiem hieu luc phong moi Copotermes formosanus Shiraki ciia dich chiet nhan hat Coc hanh bang etanol
Cong thurc
CTI
CT2
CT3
CT4
CT5
Phirong phap
tam Nhiing
Ngam Nhiing
Ngam Nhiing Ngam Nhung Ngam Nhiing
Ngam
Diem danh gia mirc do xam hai ciia moi vdi mau khao nghiem
X%
100 100 100 89 78 78 67 67 57 57
Diem 1 I 1 1 1 1 1 1 2 2
Y%
100 100 100 100 100 100 89 89 78 78
Diem 1 1 1 I 1 1 1 1 1 1
Z%
100 100 100 100 100 78 67 78 67 67
Diem 1 1 1 I 1 I I 1 1 1
Diem tong hgp
3 3 3 3 3 3 3 3 4 4
Ket Luan ve hieu luc
Tot Tdt Tot Tdt Tdt Tdt Tot Tdt Tdt Tdt
Ket qua tai bang I chi ra ranj^ cac hoat chat trong dich chict hat Cdc hanh deu cho hieu luc phdng mdi tdt d ca hai phuang phip tam (nhung, ngam). Q cic dich chict cd cdng thiic CTI, CT2 gan nhu khdng cd mau nao bi mdi tan cdng, hieu lire phdng mdi ciia 2 cdng thiic nay gan nhu tuong duang nhau. 6 cdng thiic CT3 da xuat hien mdt so mau bi mdi gam mdn theo be mat cua mau, cac mau dugc xii ly dich chict cd cdng thirc CT4 va CT5 dii cd hieu luc phdng mdi tdt nhung mgt sd mau khao nghiem khdng chi hi mdi an theo be mat ma cdn bi an sau vao trong. Ket qua phan tram mau bi phi hai cho thay ty le Cdc hinh va dung mdi cang nhd thi sd mau bi mdi hi tan cdng ciing tang len d ca 2 che do xir ly mau, ty le phan tram sd mau gd bi phi hoai khi dugc xir ly thudc bao quan d 2 cdng thirc C^f4 va CT5 la kha ldn (tren 30% va 40% so vdi mau ddi chimg theo thu ty).
Dc cd ket luan chac chin hon vc hieu lyc phdng mdi cua cic hoat chat cd trong dich chict hat Cdc hanh vdi etanol, chung tdi da cho tien hanh cac phep thii lap lai, ket qua thu dugc khdng cd nhieu sy thay ddi.
So sanh cac kdt qui thu dugc vdi cac ket qua ma chung tdi da cdng bo vc hieu lyc phdng radi cho mgt sd hoat chit cd ngudn gdc tir nguyen lieu thyc vat (Nj;uy6n Thi Bich Nggc, Truang Quang Chinh, Nguyen Duy Vugng, Nguydn Thi Hang, Le Bach Dang, 2007, Nguydn Thi Bich Nggc, Nguyen Duy Vugng, Truong Quang Chinh, Hoang Thi 11m, Nguyen Thi Iling, 2008) cho thiy cac boat chat cd trong dich chidt ciia hat Cdc hanh vdi dung mdi
etanol cd hieu lyc phdng mdi tdt ban ban so vdi cic boat chat tannin tach tir cii nau, dau tach tir hat nccm vi thin mit. Die biet, dich chict hat Cdc hanh cho hieu lyc frdi han rat nhieu so vdi cac boat chat tach tir hat xoan ta /cimg tach bang dung mdi etanol). Tuy nhien, neu so sanh vdi cic cdng thiic thudc bao quan ciia tannin va dau hat neem dugc bd sung them phu gia thi hieu lyc ciia dich chict hat Cdc hanh chi cho hieu luc ngang bang d cic cdng thiic CTI vaCT2.
Theo nghien ciru cic nha khoa hgc thudc trudng dai hgc Khon Kacn, Thai Lan (Somdcj Kanokmedhakul, Kwanjai Kanokmedhakul, Thirada Prajuabsuk, Sanha Panichajakul, Piyanan Palyamee, Samran Prabpai, and Palangpon Kongsaerce, 2005), nhan hat Cdc hanh cd chira mgt sd dan xuat cua Azadirachtin, la thinh phan hda hgc chinh cua dau tach lir nhan hat nccm cd cdng thirc phan tir la C^fl^O,,, va cau tao da dugc chuan hda vao nhirng nam 80 ciia the ky trudc, da va dang dugc nghien ciiu tao che pham phdng trir cdn trimg gay hai trong ndng nghiep. Ndng dan d Thai Lan sir dung dich chict hat Cdc hanh nhu la mgt loai thudc diet cdn trimg dc bao vc cai bap vi mgt sd loai rau khdi sy phi hoai cua cdn triing, nhat la mgt sd loai budm dem. Nhan hat Cdc hanh ciing dugc cdng bd cd chira mdt sd limonoid cd hoat tinh sinh hgc gay ngan an va uc che sinh trudng cua cdn trimg (Baoliang Cui va ddng nghiep, 1998). Nhu vay, rat cd the cac hoat chat cd trong dich chict etanol tron^
nghien ciru ciia chimg tdi cd chiia mgt sd hgp chat cd boat tinh gay khang an vdi mdi.
Quan sat die diem phi hoai cua mdi tren cic mlu khio nghiem ciing cho thay mdi chi tan cdng mlu gd d mgt vii diem fren be mat va tit nhiing diem niy mdi se tiep ti^c an sau vio phan ldp gd ben frong khdng tham che pham. Trong khi dd, d cac mau gd ddi chiing, mdi tan cdng d tat ca mgi diem fren be mat va phi hiiy gan nhu hoan toan mau.
Dd danh gia su tie ddng den mdi cua hoat chat tich ra hi nhan hat Cdc hinh bing mdt so dung mdi huu CO khac nhau la: metanol, ^-clo metan va n- hexan, chiing tdi tien hanh mgt so phep thu fren dia petri theo phuomg phip da trinh bay fren day. Ket qua sd mdi chdt theo thdi gian phep thu the hipn frong bang 2:
Bang 2. So lug'ng moi chet theo th&i gian trong phep thu tren dia petri
Thoi gian dem luong moi chet (So ngay sau khi
bat dau thii)
1 2 3 4 5 6 7
Can chiet ciia cac dung moi va lieu lirong tham len giay loc (mL dung djch) Di-clo Metan
0.2 0 0 0 5 8 8 8
0.5 0 0 0 6 11 11 11
1.0 60 100 100 100 100 100 100
Metanol 0.2
0 0 0 0 10 10 10
0.5 0 0 0 0 14 17 17
1.0 20 30 100 100 100 100 100
n- hcxan 0.2
0 0 0 0 4 9 9
0.5 0 0 10 15 18 30 30
LO 0 0 20 25 60 63 63 Bing ket qui cho thay, can chict nhan hat dugc
tich bdi ci 3 dung mdi lya chgn deu cd khi ning lim cho mdi thj nghiem chet. Lugng mdi chet nhieu nhat khi tien hanh phep thir mdi d nhiing dia bd tri giay lgc tam lugng dung dich ldn nhat (1 rnL) cho ca 3 loai can chiet. O nhiing dia ma giay lgc tam dung dich can chiet tich boi dung mdi di-clo metan vi metanol lugng mdi chet dot bien, sau mdt ngay vdi can chict di-clo metan va sau 3 ngay vdi can chict metanol. Tdc do chet cda mdi ldn nhat khi tien hanh thir vdi dung dich can chict metanol d lieu lugng ImL nhung lai ldn nhat vdi dung dich can chict cua n-hcxan khi diing vdi lieu lugng 0.5mL mac dii so lugng mdi chet d lieu lugng nay khdng ldn vi tdc do mdi chet ciing khdng dot bien manh nhu trudng hgp tam ImL dung djch.
Khi da dugc tao dieu kien sdng day dii, mdi hi nhiem dgc td chet vi 2 nguyen nhan m i da dugc nhieu nha nghien ciiu xem nhu 2 ca che gay ddc chg mdi: cac dgc td lie che hay lam rdi loan he thdng than kinh (ca che 1) ya cac ddc td lim rdi loan he thdng tieu hda (co che 2). Mdi chet frong thi nghiem dugc bd tri d tren cd the do hi nhiem ddc mgt sd hgp chat tach ra tir nhan hat Cdc hinh cd khi
ning bay hoi nhung bieu hien hi tic ddng len than kinh cua mdi troiig thi nghiem khdng that rd rang.
De lamrd ban chat, co che gay ddc cho mdi theo ca che 1 can bd tri nhiing thi nghiem rat phiic tap, can nhieu thiet bi phan tich hien dai (Pompun Siramon, Yoshito Ohtani, Ilideaki Ichiura, 2009). Quan sat hinh thai mdi sau khi chet ciing cho thay bieu hien chet theo CO che 2 khdng rd ring vi tat ca nhiing giay lgc dugc tam dun^ dich can chidt khdng hi moi tan cdng va sir dung dc lam ngudn thiic an.
Tien hanh theo ddi hoat ddn^ cua mdi hang ngay chung tdi ciing nhan thay rang mdi chi hoat dgng manh xung quanh dia thir frong vii gid dau tien sau khi thi mdi, sau dd co cum lai quanh khu vyc cd phin bdng tham nudc, rieng dTa ddi chiing mdi boat ddng xung quanh dia gin nhu toan bd thai gian 7 ngay quan sit. Ngoai ra, quan sit phin giay lgc ben trong cac dTa cho thiy chi cd phin giiy lgc d dTa ddi chiing la hi mdi sir dung dd lam thiic an, cac dia cdn lai gan nhu khdng cd sy tic ddng nao cua mdi. Hien hrgng nay lim bieu hicn rd hon hoat tinh gay ngin an cua cic hgp chat tach ra tii nhin hat Cdc hinh ma chung tdi da gia dinh d tren
K^T LUAN
CONG NGHIEP RLfNG
Hieu lyc phdng mdi ciia dich chict nhan hat qua Cdc hinh da dugc danh gia d qui md phdng thi nghiem. Ket qua tir phep thir tien hinh frong mdi trudng d nhirng khu vyc cd mdi Coptotermes Formosanus Shiraki boat ddng manh cho thay djch chiet bing dung mdi etanol cho hieu lyc tdt khi xir ly mau gd theo ca 2 cich li nhiing v i ngam frong dung dich chict d tat ca cac cdng thiic khio nghiem.
Ket qua phep thir tren dia petri cho thay trong thanh phan nhan hat Cdc hanh cd chira mdt sd hgp chat cd kha nang gay ddc cho mdi bieu hicn thdng qua hien tugng mdi chet. Tuy nhien, do gidi han ip dung cua phep thir mi chung tdi bd tri, co che gay dgc lam mdi chet khdng bieu hien rd rang, v i khdng the danh gii bing quan sit nhu khi thi nghiem vdi nhieu hda chat tdng hgp hda hgc. Dc dinh gii ca
che gay ddc can phii thiet kc nhirng phep thu phirc tap vi tinh vi vdi nhieu thiet bi hicn dai ma mdt sd nha khoa hgc da cdng bd (Pompun Siramon, Yoshito Ohtani, Ilideaki Ichiura, 2009). Hicn tugng mdi khdng sir dung phan giay lgc dugc tam dung dich cic can chiet ya die diem phi hoai cic mau gd da xir ly dich chict etanol so vdi ddi chimg li bing chimg cho gii dinh hieu iing gay ngan an cua mdt sd hgp chat cd trong nhan hat Cdc hinh.
Ket qua budc dau nay cung cho thay tiem ning sir dung hat Cdc hanh trong cdng tic bao quin lam sin d nudc ta. Cic ket qui thu dugc khdng chi cung cap them nhirng dii lieu khoa hgc cho cay Cdc hanh ma cdn li ca sd cho nhirng nghien sau han sy tic ddng ciia cic hgp chat tich tir nguyen lieu thyc vat len loai mdi Coptotermes formosanus Shiraki
T A I L I E U THAM K H A O
Nguyen Vict Cudng, Pham Diic Tuan, 2007. IJ'ng dung chi thi phan tii (RAPD va AN D lyc lap) trong nghien ciru da dang di truyen va xay dung vudng gidng cay Cdc hinh. Tap chi Ndng nghiep va phat trien ndng thdn, sd
19,pp:69-75.
Nguyen Thi Bich Nggc, Truang Quang Chinh, Nguyen Duy Vugng, Nguyen Thi liang, Le Bach Ding, 2007. Ket qui khio nghiem hieu lyc phdng chdng cdn trimg gay hai lam sin cua mdt sd chat chict tir nguyen lieu thyc vat. Tap chi Khoa hgc Lam nghiep, sd 4, pp: 486-491.
Nguyen Thi Bich Nggc, Nguyen Duy Vugng, Truang Quang Chinh, Hoing Thi Tim, Nguyen Thi Hing, 2008. Hieu lyc phdng mdi gay hai lam sin ciia dau neem vi tanin. Tap chi Kinh te Sinh thai, sd 26, pp: 35-39.
Baoliang Cui va ddng nghiep, 1998. Limonoids from Azadirachta excelsa, Phytochemistry, Vol 47, No 7, pp:1283-1287.
Kohsuke Kurose, Mitsuyoshi Yatagai, 2005. Components of the essential oils of Azadirachta indica A. Juus, Azadirachta siamcnsis Vclton, and Azadirachta excelsa (Jack) Jacobs and their Comparison, Journal of wood science, 51,pp:185-188.
Nor Aini Ab. shukor and Loo Keang Scong, 2006. Azadirachtin variation of six provenances of, 9(5), pp:
833-836.
Pompun Siramon, Yoshito Ohtani, Ilideaki Ichiura, 2009. Biological performance of Eucalyptus camaldulensis leaf oils from ThaiLand againts the subteranean termite Coptotermes Formosanus Shiraki, Journal of Wood Science, 55, PP: 41-46.
ll.Shmuterrer and M.Doll, 1993. The Marrango or Philippine Neem free, Azadirachta excelsa (=A.integrifoliola):
Anew source of insecticides with growth regulating properties, Phytoparasitica, 21 (1), pp: 79-86.
Somdcj Kanokmedhakul, Kwanjai Kanokmedhakul, Thirada Prajuabsuk, Sanha Panichajakul, Piyanan Palyamee, Samran Prabpai, and Palangpon Kongsaerce, 2005. Azidirachtin derivatives from seed kernels of Azadirachta excelsa. Journal of Natural products, 68, pp: 1047-1050.
ANTITERMITIC ACTIVITY OF SOME EXTRACTS FROM SEED KERNELS OF AZADIRACHTA EXCELSA JACOB
Nguyen Thi Bich Ngoc, Nguyen Duy Vuong, Nguyen Thi Hang Forest Product Preservation Division
Forest Science Institute of Vietnam SUMMARY
Ethanol and some organic solvent extracts from the seed kernels of Azadirachta excelsa Jacob were used for the evaluation of antitcrmitic activity based on wood preservation standards (using Abbot's equations) and testing on petri dishes in the laboratory, fhc results of testing on termites calculated by Abbots equations indicate very good effects with most tcnniticide formulas selected. However, the smaller the mass of seed kernel used, the larger the numbers of wood samples damaged and wood samples arc destroyed not only on sides but also at depth, 'fhc testing on petri dish showed that seed kernels contain chemical compounds which have antifeedant activity. Additionally, there arc also some compounds which were toxic to termites in this experiment. The primary results add scientific information and improve research for a better understanding of toxicity mechanisms of compounds extracted from seed kernels of Azadirachta excelsa Jacob
Keywords: Antitcrmitic achvWy, Azadirachta excelsa Jacob, Testing, Coptotermes Formosanus Shiraki