DANH GIA DAC DIEM NONG SINH HOC VA KHA NANG KET HOP ci'A M O T S O DONG NGO THUAN MOfl CHON TAO
Luong Thai Ha', Nguyen Xuan Thing' Pham Duy Dde', Dd Thi Van', BCii Thj Hoa' TOM T . I T
Danh gid cac dae diem ndng sinh hoe va kha nang ket hop cua 11 ddng ngd bang phUdng phap lai dinh. Hai cay :hd dugc sd dung trong thi nghiem la ddng P4097 va B67. Qua danh gia da xac dinh dUgc ddng DT30, DT51, DT59 cd khd nang ke't hpp chung cao ve nang suat. Nam to hop lai DT24 x CTl: DT23 - CT2; DT30 . CT2; DT51 =< CT2;
vd DT59 X Cr2 eho nang suat eao tUOng dUdng dat 76.5 ta/ha. 77.5 to. ha, SO.l ta/ha, 77,9 ta/ha va S1 ta/ha eao tUOng duong doi chflng DK9901.
Td khda: Ngd {Zea mays L.), kha nang ket hpp (GCA). lai dinh I. DAT VAN DE
Ngd da trd thanh eay trdng ndng nghiep dan dau trong ede eay ngu ede quan trgng tren the gidi, fc dugc sd dyng Idm luong thUe, thflc an chan nudi.
ndng lugng vd cdng nghiep khde. 6 nude ta, theo ifl sd lieu thdng ke nam 2018, tdng dien tich trdng ngd ' tren ca nUdc la 1,039 trieu ha, ndng suat trung binh I d?t 4,72 tan/ha, vdi tdng san lugng 4,91 trieu tan I (Tdng eye Thdng ke, 2018). Tuy nhien, san lugng
;, ngd hdng nam khdng du dap flng nhu cau lieu I thu trong nUdc. Ndm 2018. \'iet Nam phai nhap
! 10,2 trieu tan vJ trong 7 thdng dau ndm 2019 tdng khdi lugng ngd nhap khau la 5.34 trieu tan vdi gid tri dat 1.11 tyUSD (Tdng eye Hdi quan, 2019). De dap dng nhu eau ngd trong nude, trong vdi nam tdi viec
|tSng nang suat, sdn lUgng ngd trong ndde dang rat P dupe quan tam. Trong dd, tap trung vdo tao ddng,
0 gidng mdi ed nang suat eao, ehdng chiu tdt, thich dng vdi bien ddi khi hau. Tao ddng thuan tuy ddi hdi nhicu thdi gian nhUng khdng phai la \'it:e khd, viec khd la xac dinh diigc gid trj sfl dung eda ddng thuan vdo cdng tdc lai tao gidng mdt cdch ed hieu qua. Gia tri sd dung cua ddng thuan phu thugc chd yeu vao kha nang ket hgp cua chflng.
n . VAT Ll£U VA PHLfONG PHAP NGHIEN C0U 2.1. Vat lieu nghien cdu
- 11 ddng ngd the he S4 - S6 ddgc chpn tao bdi Vien nghien cdu Ngd bang phUdng phdp tu phdi ket hgp sib DTI. DT6, DTS, DT12. DT23, DT24, DT30, DT45. DT51. DT59, DT61 cd ngudn gdc tU cic gidng lai thddng mai. Hal ddng B67 vd P4097 (kv hieu CTl va CT2) la hai ddng ngd Uu tfl cd khd nang ket hcfp chung cao ve nang suat dfldc sfl dung lim ddi chflng va ea\ thd. Gidng ddi chdng DK9901 dang duge trdng rdng rai d cae ^ n g sdn xuat ngd.
2.2. PhUdng phdp nghien cdu
- Danh gid dac diem ndng sinh hpc eua eac ddng va lai tao to hgp lai dinh theo hudng dan CIMMYT va \'icn Nghien cflu Ngd. Thi nghiem dflpc bo tri theo khdi ngau nhien hoan chinh (RCBD), 3 lan nhdc lai, moi cdng thflc gieo 4 hang, hdng ddi 5m.
khoang each 65 cm x 25 cm. Theo ddi cdc chi tieu cO ban theo quy chuan QCVN 01-56:2011/BNNPTNT.
- Xfl ly so lieu: Sd lieu ddgc tdng hgp va phdn tich thdng ke sd dyng chddng trinh Excel 2013 va IRRISTAT 5.0. Phan tich kha ndng ket hgp theo Ngd Hflu Tinh va Nguyen Dinh Hien (1996), Nguyen Dinh Hien (1999).
2.3. Thdi gian va dia diem nghien cdu Thdi gian nghien cdu: Ddnh gia ddng va tao THL dinh trdng vu Xudn 2019; Khao sat THL trong vu Thu Ddng 2019.
- Dia diem: Nghien cflu dUpe thdc hien tai Vi^n Nghien cflu Ngd - Dan Phdgng, Hd Ndi.
III. KET QUA VA THAO LUAN
3.1. Ket qua ddnh gia dac diem ndng sinh hgc cua 11 ddng ngd mdi chgn tao
Trong \'y Xuan 2019, ede ddng ed thdi gian til gieo - tung phan dao ddng tfl 63 - 74 ngdy. Chenh lech tung phan - phun rau la mdt dac diem cd y nghia ndng cao nang suat hat nhan ddng bd me va bd tri gieo trdng bd me trong san xuat hat lai, thdi gian chenh lech dao dgng tU 1 - 3 ngay, trong do ba ddng cd thdi gian chenh lech 1 ngdy la DT12 vd 2 eay thfl. Thdi gian td gieo den chin eua eac ddng lii 110 - 120 ngdy, thich hop sfl dyng cho chgn gidng ngd lai ngdn ngay Cac dong dupe ddnh gid cd sd la dao ddng tU 16,3 - 17,7 la/cay Chieu eao cdy dao ddng td 130,2 - 154,7 cm, hai ddng DTS, DT30 va ' \'K'n Nchien edu Ni;d
TOD chi Khoa hoc Cong nghe i'lorg nghiep Vie' \ohi- So 4(113)72020 2 cay thil cii chieu cao cay tren 150 cm. Chieu cao
dong bJp dao dgng til 50,8 - 78.5 cm. Phan tram dong bjp tren than cung Wong doi phii hgp, tii 37,3 - 52, 7 %. Nhin chung, chieu cao dong bap ciia cac dong la thuan Igi cho qua trinh san xuat hat lai (Bang 1).
Chieu dai bSp cua cac dong ngan hon 2 cay thil (CTl: 14,2 cm; CT2: 14,4 cm), dao dgng til 11,5 - 13,6 cm. Nam dong (DT6, DT12, DT23, DT24, DT45, DT51, DT59) co dudng kinh bSp til 3,5 - 4,1 cm Ion hon 2 cay Ihii (CTl: 3,2 cm;
CT2: 3,3 cm). So hang hat dao dgng tii 10,8 - 15,6
hang/bdp; so hat/hang tii 10,6 - 24.S hat; khgi lugng 1000 hat til 175 - 243,3 g. Dgng DT30 (30,5 ta/ha) dat nang suat cao han 2 cay thii (CTl: 26,9 ta/ha;
CT2:29,3 ta/ha) nhUng chUa \iigt mifc sai khac nho nhat CO y nghta LSD^j g-. Sau dong co nang suat tuong duong hai cay thil la DT12, DT30, DT45, DT51, DT59 va DT61, cac dong con lai c6 nang suat thap hon hai cay thil 6 mifc xac suat 95%. (Bang 2). Theo Muhammad va cong tac vien (2002) thi dac diem nong sinh hgc, nang suat va cac yeu to cau thanh niing suat ciia cac dong nay phii hgp de dUa vao lai U6c lugng kha nang ket hgp.
Bang 1. Mgt so dac diem nong sinh hpc ciia cac dong vu Xuan 2019 Tung
phiin (ngiy)
67 63 72 70 72 70 73 68 66 74
P h u n r a u (ngiy)
70 66 74 71 74 72 75 70 68 76 70 68 69
ASI (ngiy)
3 3 2 1 2 2 2 2 2 2 2 1 1 CV(%) LSD„
C h i n S L (ngiy)
115
no
120 115 120 120 120 120 110 120 115 115 118
Tong so la 16,3 17,0 16,3 16,3 17,0 17,0 17,0 17,7 16,7 16,3 17,0 17,7 16,7
Chieu cao cay (cm)
136,0 136.3 151.2 130,2 134,7 144,5 154,7 146,8 141,3 148,9 143,7 150,3 154,3 6,4 15,8
Chieu cao dong b i p (cm) 50,8 58,0 64,9 56,0 60,0 70,0 77,0 65,2 61,5 78,5 72,6 73,7 71.0 9,9 11,5
% d 6 n g bap 37,3 42,6 42,9 43,0 44,5 48,4 49,8 44,4 43,5 52,7 50,5 49,0 46,0 Ten d6ng
DTI DT6 DTS DT12 DT23 DT24 DT30 DT45 DT51 DT59 DT61 CTl CT2
Ghi chu: Chin SL - Chin sinh ly: ASI: Chenh lech tung phdn phun rdu.
Bang 2. Nang suat va yeu to tao thanh nang suat ciia cac dong trong vu Xuan 2019 Ten
d6ng D T I DT6 DT8 DT12 DT23 DT24 DT30 D T 4 5
C D B (cm) 13,1 12,1 11,5 12,6 12.3 13,4 13,4 11,9
D K B (cm) 3,3 3,5 2,9 3,9 3,5 3,5 3,1 3,8
S H H / bip 12,8 1.3,2 10,8 12,0 12,4 12,0 12,8 14,0
S H / h i n g 20,2 14,2 10,6 19,4 24.8 1 8 4 24,1 24,4
KL 1000 h a t (g)
193,0 176,3 175,0 211,0 186,3 213,3 243,3 211,7
N S T T (ta/ha) 23,4 19,7 22,7 27,4 23,3 22,7 30,5 27,3
Ten d o n g DT51 DT59 DT61 C T l CT2 CV(%) LSD,,,
C D B (cm) 12,1 12,1 13,6 14,2 14,4 2,0 0,5
DKB (cm) 4,1 4.0 3.2 3,2 3,3 1,4 0,1
S H H / b a p 15,6 13,2 12,0 12,4 12,8
S H / h a n g 23,5 20,4 18,8 21,2 22,5
KL 1000 hat (g)
237,3 201,0 213,3 210,0 207,0 7.6 27,0
N S T l (ta/ha 29,0 28,0 27,3 26,9 29,3 9,2 4,1
Chi chii: CDB: Chieu ddi bdp: DKB: DUdng kinh bdp: SHH: Sd hdng hat; SH/H: So hat/hdng; PIOOO: Khdi lUdng 1.000 hat: NSTT: Ndngsiidt thilc thu.
ngne \6r.g nghi-:.
3.2. Ket qud danh gia cac to hop lai dinh vu Thu Dong 2019 tai Vien Nghien cuu Ngo
Trong dieu kien ™ Thu • Dong 2019. cac to hgp lai (THL) CO thdi gian chenh lech tung phan - phun rau ngin til 0 - 3 ngay. tril THL DTS x CT2 chenh
lech 4 ngay. Thdi gian sinh tracing ciia cac to hgp lai dinh dao dgng til 102 - 109 ngay (Bang 3). 10 THL dinh CO ti le dong bap thap hdn doi chilng DK9901 (48.6'^), bien dgng til 35,1<',. - 48,3% (Bang 3).
Bang 3. Mgt so die diem nong smh hgc ciia cac to hgp lai dinh t r o n g ^ Thu Dong 2019 To h g p lai
DTI « C T l 1 ) I 6 » C T 1 DTS X C T l D T 1 2 » C T 1 D T 2 3 « C T 1 D T 2 4 « C T 1 D T 3 0 x C T l D T 4 5 x C T I DT51 x t : r i D T 5 9 » C T 1 DT61 « C T 1 DTI x C T 2 DT6 K CT2 DTS « CT2 D T 1 2 x C n DT23 X CT2 DT24 X t:T2 DT30 X CT2 DT45 X CT2 DT51 x C T 2 D T i 9 X CT2 DT61 x C T 2 DK9901
Tung p h a n (ngay)
55 55 60 56 57 55 55 48 55 51 56 52 56
^ . • ^
55 54 55 52 55 54 52 55 55
P h u n rau (ngay)
56 56 60 58 57 55 55 48 55 52 56 53 56 52 55 54 56 53 55 54 53 56 37
ASI ( i ^ ) 1 1 0 2 0 0 0 0 0 1 0 1 0 1 0 0 1 1 0 0 1 1 2 CV(%) i S D „
C h i n S L (ngiy)
107 107 108 109 108 105 108 102 105 104 105 104 105 102 105 104 107 105 105 106 105 105 107
Tong so la 19,3 19.2 19.9 19,5 19,9 19,7 19,6 17.5 19.2 17.1 17,5 17.2 18,4 17,9 17,9 17,1 17,7 17,8 17,8 17,8 17,3 184 19,5
c n i e u cao cay
_(m)_
192,4 180,9 188,0 195,0 186,5 170,0 206,3 200,1 174,6 192,9 189,9 175,9 261,1 203,7 179,5 184,9 186,0 185,7 184,5 190,9 172,3 169,6 173,1 12,4 38,5
t..meu cao dong b^p (cm) 91,9 S7.4 104.4 101,3 94,7 90,9 105,9 112,1 78,3 107,1 85,9 86,2 91,6 102,2 77,3 90,8 89,1 91,3 88,9 99,8 75,1 75.8 8 4 1 5,4 8,1
%d6iig b i p 47.8 48.3 55.5 51,9 50.8 53,5 51,3 56,0 44,8 55,5 45,2 49,0 35,1 50.1 43,1 49,1 47,9 49,2 48,2 52,3 43,6 44,7 48,6
Ghi chu: Chin SL - Chin sinh ly; ASI: Chenh lech tung phdn phun rdu.
Chieu ddi bap eua cae THL bien ddng tfl 14,1 - 19 em (Bang 4). Cd 7 THL cd chieu dai bap dai hdn ddi chflng. DT5I x CT2 (19 em) va DT59 x CT2 [ 1 S.3 cm) ed chieu dai bdp cao hon ddi chflng d mflc V nghia 95"i!. So hdng hat eda cac THL dao ddng ifl 11,5 -14.S hang; sd hat/hang td 2S,9 - 38,5 hat va khdi lugng 1.000 hat bien ddng td 34S - 453.3 gam (Bang4).
Nang suat thdc thu eua eac THL ed sd chenh lech rd ret, bien dgng tfl 59,0 - 81,0 ta/ha. 5 THL cd nang suat thuc thu cao hdn doi chdng la DT24 x CTl (76,5 ta/ha), DT23 « CT2 (77,5 ta/ha). DT30 x CH (80.1 ta/ha), DTS 1 x CT2 (77,9 ta/ha) va DT59 x C T : (81 ta/ha) nhUng chfla vUdt mdc sai khac nhd nhS cd y nghia LSD^^^^. Cdc td hgp lai cdn tai cd nang suit thap hon ddi chdng.
Bang 4.
T6 h g p lai DTI x C T l DT6 X C T l DTS X C T l D T 1 2 x C T l DT23 X C T l DT24 X C T l DT30 X C T l DT45 X C T l DT51 x C T l DT59 X C T l D T 6 1 x C T l D T l x C T 2 DT6 X CT2 DTS X CT2 DT12 X CT2 DT23 X C T 2 DT24 X C T 2 DT30 X CT2 DT45 X CT2 DT51 x C T 2 DT59 X CT2 DT61 X CT2 DK9901 CV(%) LSD,„
N i n g suat va cac yeu to cau t h i n h CDB (cm) DKB (cm)
15.8 14,9 H.2 15,2 15.2 16,6 16,4 16,1 18,4 15,5 14.1 15,2 15,0 14,8 15,0 16,6 15,9 16,9 16,0 19,0 18,3 15,9 16,2 4,4 1,1
4.7 4,4 4,5 4,5 4,3 4,4 4,6 4,3 4,3 4,4 4,6 4,5 4,3 4,3 4.2 4,3 4,3 4,3 4,2 3,9 4,3 4,3 4,5 1,7 0,1
nang suit cua cac to hgp lai S H H / b i p
14.0 12,S 12.9 12,0 13,2 13,7 14,8 13,1 14,0 13,6 14,0 13,1 11,7 11,7 11,5 11,6 12,1 13,1 12,3 13,5 13,3 14,3 14,7
SH/hing 36,1 32,7 30,7 35,1 33,2 33,9 33,9 33,9 34,3 32,9 28,9 33,1 32,3 33,2 35,2 36,5 35,1 36,3 35,5 38,4 38,5 33,5 35,1
dinh dinh \'u Thu E KL 1000 hat (g)
403.3 406.7 416,7 426,7 416,7 423.3 416,7 403,3 403,3 388,0 423,3 406.7 446,7 453,3 426,7 450,0 403,3 420,0 403,3 348,0 383,3 386,7 366,7 5,9 39,7
III - J L / T l / 1 J / / z L/-: 1/
dng 2019 NSTT (la/ha)
66,8 59,0 65,9 71.3 61.1 76,5 75,1 72,9 71,0 68.1 71,8 68,0 71,9 61,1 75,2 77,5 66,1 80,1 71,0 77,9 81,0 70,5 76,0 8,8 10,3
Ghi chu: CDB- Chieu ddi bdp; DKB: DUdng kinh bdp; SHH: Sd hdng hat; SH/H: So hat/hang; PIOOO: Khoi lUdng 1.000 hat; NSTT: Ndng sudt thUc thu.
3.3. Phan tich kha nang ket hgp (KNKH) chung ve tinh trang nang suat
Ket qua phan tich phUdng sai KNKH chung do ddng va KNKH chung cua eay thfl sai khde ed y nghia ve tinh trang ndng suat d mdc dd tin cay 0,05 (F thdc nghiem > F ly thuyet) (Batig 5). De ddnh gia ty le ddng gdp cua ddng va cdy thd vdo viec hinh thanh tinh trang nang suat eua eon lai F^ ta dfla vao phfldng sai KNKH chung eda ddng va cua cdy thd.
Ket qud phan tich cho thay ty le ddng gdp eua ddng vdo ndng suat eao hdn edy thd.
Cae ddng kliae nhau cd gid tri KNKH chung khac nhau (Bang 6). Ddng DT30 (6,706), DT51 (3,573), DT59 (3,623) the hien KNKH chung dUdng cao ve nang suat d mflc ed y nghia 95%. Cdc ddng cdn lai cd gid tri klid ndng ket hdp chimg thap hdn, vdi gid
tri kha nang ket hgp chung dao ddng tfl 1,073 den -7,411. Kha nang ket hdp chung ve tinh trang nang suat cua hai cay thfl Tl (B67) va T2 (P4097) ed kha nang ket hgp chung tfldng duong nhau vi KNKH chung cua 2 cdy thfl Tl (0,071), T2 (-0,071) khdng ed sy* sai khac khi so sanh d mflc xde .suat 95%.
Bang 5. Bang phan tich phUOng sai trong thi nghiem lai dinh ' Ngudn Bac
bien ddng tu do Khdi 2 I Cap lai 21
Sai sd 42 Todn bp 65
Tdng _
binh ??'"8 Ftn Fit
, bmh phugng220,293 110,147 2,964 3,220 I 2300,918 109,568 2,948 1,813 1560,927 37.165
4082,138
59
-" J ngh 'ep Viet (Vjni - So - Bang 6. Gia iri KNKH chung cua cac ddng
Vd cay ihd irong thi nghiem lai dinh
FT I 2 3 4 5 6 7 8 9 10 11
D6n§
Ten ddng D T I DT6 DTS DT12 DT23 DT24 DT30 DT45 DT51 DT59 DT6I Tons
gi -3,527 -5,461 -7,411 2,373 -1,594 0,423 6,706 1,073 3,573 3,623 0,223 0,000
C a y t h t i Ten cdy
thU ^ T l -1,845 T2 1,S45 Tong 0,000 Edi = 2.489
Ed (di-dj) = 3.520 LSD,,, dong = 5.023
Ecj =1,061 Ec(c]s-cl) = 1,501 i,SD„,„ aiy(liii' = 2.J41
Ghi chii: Edi: Sai so cua K\'KIT chung cua ddng:
Ed(di-dj): Sai sd khi so 2 KS'Kll chung cua 2 dong.
LSD^^^^^ (ddng): Bieu thi do chenh lech nho nlni! co y nghia khi ddnh gid KNKH chung ciia cdc ddng. Ecj: Sat so ciia KNKH chung cua cdy thti; Ed(ck - cl): Sai sd khi so sdnh 2 KNKH chung cua cdy thU; LSD^,^.^ (cdy thU): Bieu thj do chenh lech nho nhdt cd y nghia khi ddnh gid KNKH chung ciia cdy thii. * Bieu thi cdc so Ueu ciia cac dong co KNKH chung cao hdn cac ddng khac d mile P > 0.95.
gi: Gid tri KNKH chung cua dong gj: Gid tri KXKIT chung ciia cdy thii.
IV. KET LUAN VADE NGHI 4 . 1 . K£t l u d n
Tlidi gian sinh t r d d n g c u a ede d d n g td 110 - 120 ngay, c h e n h lech t u n g p h a n p h u n rau td 1 - 3 n g a y D d n g D T 3 0 (30,5 t a / h a ) dai ndng suat cao h d n 2 cay t h d ( C T l : 26,9 ta/ha; CT2- 29.3 l a / h a ) nhUng ehUa v d g t m d c sai khde n h d nhat eo \' nghia LSD^^^j..
Sau d d n g co n a n g suat tUdng dUdng hai eay t h d la
Evaluation of agrobiological characteristics and combining ability of new inbred maize lines
D T i 2 , D T 3 0 , D T 4 5 , D T 5 1 , D T 5 9 vd D T 6 1 . D d n g D T 3 0 (6.706), D T 5 1 (3.573). D T 5 9 (3.6231 t h e hi?n K N K H c h u n g d d d n g ead ve n a n g sudt d m d c eo y n g h i a 95"o.
Da xde d j n h dUdc 5 T H L ed n d n g suat ihUc t h u c a o h d n d d i chflng la D T 2 4 x C T l (76.5 t ^ / h a ) , D T 2 3
* C T 2 (77,5 t a / h a ) , D T 3 0 x C T 2 (80,1 tij/ha). D T 5 I X C T 2 (77,9 tg/ha) va D T 5 9 x C T 2 (81 t ^ / h a ) n h U n g c h u a \aigt mUe sai k h a c n h d n h a t cd y n g h i a LSD^^^^.
4 . 2 . D e n g h j
Tiep tuc ddnh gid va sfl d u n g d d n g D T 3 0 . D T 5 1 , D T 5 9 ed gia tri K N K H c h u n g e a o t r o n g cdc thi n g h i e m lai tao tiep t h e o . D d n g thdi tiep tye d a n h gia 5'td h g p lai trien v g n g ( D T 2 4 x C T l ; D T 2 3 x C T 2 ; D T 3 0 X CT2; D T 5 1 x C T 2 ; va D T 5 9 x C T 2 ) d cdc
\-ung s m h thdi k h a c n h a u d e ed kel q u a tdt n h a t lUa c h g n d e dUa vdo sdn xudt.
T A I L I H U THAM KHAO
Nguyen Dinh Hien, 1999. ChUdng trinh phdn mem Di triiyi-n so lUdng. Dai hgc Ndng nghiep I, Ha Ngi.
Q C \ N 01-56:2011/BNNPTNT. Quy chuan ky thudt qudc gia ve kliao nghiem gia trj canh tac va sd dyng cua gidng ngo.
Ngd H du T i n h vd Nguyen Dinh hien, 1996. CdcphUdng phdp tai thii vd phdn tich khd ndng ket hdp trong cdc thi nghiem ve liu the lai. NXB Ndng nghi?p.
T d n g c u e Hal q u a n , 2019. Nhap khau hdng hoa theo thdng. truy cap ngdy 31 / 8 / 2 0 1 9 . Dja ehi: https://www.custonis.gov.vn/Lists/
'lliongKeHaiQuanLichCongBo.
Tong cue Thong ke, 2018. Sd lieu thong ke Nong nghidp, Ldm nghiep, 'Thiiy sdn, truy cap ngay 02/4/2020. Dja chi: https://www.gso.gov.vn.
M u h a m m a d Saleem, Kashif S h a h z a d , M u h a m m a d Javid a n d Afaq A h m e d , 2002. Gcnnetic analysis for various quantitative traits in maize (Zea mays L.) Inbred lines. International Journal of Agriculture and
"• ' % 4 (3): 379-382.
Luong Thai Ha, Nguyen Xuan Thang, Pham Duy Due, Do Thi Van, Bui Thi Hoa .A total of 11 inbred maize lines was evaluated for agrobiological characteristics and combining ability with 2 testers P4097 and B67. Among the inbred lines, DT30. DTS 1, DT59 were found as desirable agronomic characteristics and good general combining ability for yield trait. Five topeross hybrids DT24 x C T l ; DT23 x CT2; DT30 •< CT2- DT51 X CT2;and DT59 x CT2 showed good important yield components and high yield {7.65; 7.75,8.01; 7.79; and 8 1 tons per ha, ^e^pcell^cl^) as compared lo control lineDK9901.
Ke>'Words: Maize (Zea may L.). combining ability (CA), lopcross Ng.n n h d n bdi: 10/4/2020
Ni;.iv phdn bien: 19/4/2020
N g d d i p h a n bi?n: TS. Le Van D u n g Ngdy duy?t d a n g : 2 9 / 4 / 2 0 2 0