J. Sd. & Devel. 2014, Vd. 1Z No. 4:461-467 Tap chi Khoa hpc va Phat triln 2014, tap 12, so 4:461-467 www.hua.edu.vn
DANH GIA BA DANG Dl TRUYEN NldT SO GIONG LUA NGAN NGAY
Nguyin Quflc Trung'', Le Van Trung', Nguyin Thi Trang', Nguyin Thi Thiiy Duffng' Nguyen Thanh Tung\ Nguyen Van Hoan\ Pham Van Cudug^"^
Khoa Cong nghf sink Hoc, Hpc vien Nong nghiep Viet Nam; ^Du dn DCGV, Hoc vi$n Nong nghiep Viet Nam; ^Khoa Nong hoc, Hgc vien Nong nghiep Viet Nam
Email*- [email protected]
Ngay gui bai: 05.05.2014 Ngay chip nhan: 22.07.2014 TOM T A T
Thi nghiem filn hanh flanh gia thOT gian qua cac giai 3oan sinh fnf&ng va da dang di tmyen cua 23 m l u giong Ilia ngln ngay va mot giong dai ngay (VN10) trong vu xuan 2013 tai Hoc vien Nong nghiep Viet Nam Ket qua nghien ciJu cho thay thai gian tif gieo d i n tr6 cac giong ngan ngay la 74 d i n 107 ngay va 157 ngay a giong doi chCmg.
Trong do thoi gian xuat hien la thtj nhlt den lam dong ciia cac gi6ng lua ngln ngay co bien do bien dpng cao nhat la 25 ngay. Xay du'ng cay da dang SLP dyng 50 chi thi SSR nam tren ca 12 nhilm sic the co the chia vat lieu ngln ngay thanh 5 nhom voi he so di truyen 0,78.
Tir khoa: Cay liia, chi thi SSR, da dang dt truyen, ngan ngay
Evaluation of Genetic Diversity of Early Maturing Rice Varieties ABSTRACT
This study aimed to evaluate the duration at different growth stages and genetic diversity of twenty early maturing rice (EMRV) varieties and one late maturing rice vanety (LMRV) (VN10) as check vanety in 2013 spring season, Vietnam national University of Agnculture. The results showed that the days from sowing to heading in EMRV was in a range of 74 to 107 days and 157 days in LMRV The period from first leaf and second leaf apperance and booting were diverse in which the most diverse stage was from second leaf to booting stage with 25 days difference. Phylogenetic tree was constructed with 50 SSR markers spread over 12 chromosomes and the EMRVs were divided in 5 groups at Polymorphic infonnation content (PIC) = 0.78
Keywords; Early maturing rice varieties, genetic diversity, rice, SSR marker.
1. DAT VAN DE Trong cong tac chon tao giong lua ngan
Nhu cau nang cao gia tri san xuat liia gao "gay, viec thu thap va danh gia nguon gen la dong thdi tang hieu qua sii dung dien tich dat rat quan trgng. Hien nay ci Viet Nam, nguon nong nghiep doi hoi can thiet phai nit ngan thdi gen ngan ngay kha da dang gom cac giong ban vu da.'t trong lua. Tai tiong bang song Hong, sii dia va nhap noi tit nhieu nadc nhU: Nhat Ban, dung cac giong ngan ngay se giup ngifdi nong Trung Quoc, My, Philipin (IRRI)... co ca nhom dan dd vEk't va hdn trong vu Xuan, tranh duac ret japonica va mdica. Tuy nhien, chiia co nghien cho ma va thuan ldi hdn trong canh tac vu ciSu danh gia, phan tich thdi gian cac giai doan Dong. Tai dong bang song C^u Long, canh tac va thdi ky sinh trilclng de danh gia vai tro cac cac giong liia ngfln ngay se giiip tang len 3-4 giai doan/thoi ky tdi tong thdi gian til gieo den vu/nSm hoSc tang thoi gian nghi giQa 2 vu. thu hoach d§ co cac dinh huang sii dung trong tranh dUdc biing phat dich hai nhii ray nau. lai tao. cai tien cac giong liia theti hudng ngdn v&ng liin xoSn la. ngay hOn
461
Oanh gia da dang di tmyen mpt s6 giong liia ngan ngay
Ngoai ra, viec danh gia da dang di truyen cac m^u giong ngin ngay de phuc vu cho cong tac chon tao giong la rat can thiet. Nguon gen da dang la cd s6 rat quan trong de s^ dung cac gen, alen phong phii trong cac phep lai khac nhau, dong thdi, da dang di truyen con la cd sci de tao nen liu the lai. Viec danh gia da dang di truyen CO the dlidc thiic hien diia tren cac dac diem hinh thai, nong sinh hoc va cl miic do phan t i ADN.
Vdi cac thanh tiiu ve giai tiinh tti genome liia, cac bp chi thi SSR phuc vu danh gia da dang di truyen diitJc phat trien rat manh va co tinh iing dung cao. Nam 2002, McCough da cong bo' danh sach tren 2.000 chi thi SSR mdi phat hien. Cho den nay, theo thong ke co tren 18.000 chi thi SSR tren cay liia (Monaco, 2013). Chinh vi vay, muc tieu cua nghien ciiu nay la thu thap va danh gia thcii gian qua cac giai doan sinh tnfcing mgt so' mlu gio'ng lua ngin ngay, dong thcfi xac dinh da dang dl truyen cac gio'ng nay bang chi thi SSR, qua do nang cao viec bao ton va khai thac hieu qua nguon gen qui nay de cai tien cac gio'ng liia theo hiidng ngan ngay hdn.
2. VAT LIEU VA PHU'ONG PHAP 2.1. Vat lieu
23 mau giong ngdn ngay va 1 mau gio'ng dai ngay thu thap tiJf nhieu nguon diidc gieo cay trong
vu Xuan 2013 tai canh dong dii an JICA-DCGV,- Hgc vien Noi^ nghiep Viet Nam (Bang 1).
2.2. Phi^cttig phap nghien ciiu 2.2.1. Bo tri tbi ngbiem
Hat nay mam dildc gieo tren khay dat co tao cac luo'ng each nhau 2cm de trong nha kinh, khoang each giiia cac hat la 1cm. Cay ma 25 ngay tuoi dildc cay r a rugng theo phUdng phap tuan tli khong nhdc lai, m6i 6 5m^, mat do 33 khom/lm".
2.2.2. PhUdng phap theo doi thdi gian sinh tritdng theo tieu cbuan cua IRRI, 2002
ThcJi diem xuat hien la thfi nha't va thti hai dil(3c ghi nhan vao cung thdi diem (16''00) hang ngay. La diidc coi la xuat hien neu hinh thanh ddy du cac bg phan: phien la, cuong la va be la.
Thdi diem phan hoa dong diidc theo doi cl giai doan biidc thif 4 khi bong liia phan hoa nhi diic va nhuy, bong liia non dai 1-1,Scm. Thdi diem tr6 la thdi diem co 10% so' cay trong gio'ng tro thoat khoang Scm khoi be la. Ke't qua difdc xii ly tho'ng ke bang phan mem Excel.
2.2.3. Danh gia da dang di truyen bang chl thi SSR
Tach chiet ADN: m l u la ditdc lay 30 ngay sau khi cay va dfidc lam dong kho bang chan khong trifdc khi tien hanh tach chiS't theo phifdng phap CTAB cua Doyle (1987).
Bang 1. Danh sach 23 giong n g a n ngay va 1 giong dai ngay
Ky hi$u S I S2 S3 84 S5 3 6 S7 S8 S9 S I I S12 S13
Ten giong KD18 VN10 IR24 Asominori
AD11 OM5524 IRR1108 IR50 IRRI142 Agaminmi Nonn PL9 RuflL3
NguSn goc Trung Quoc Viet Nam
IRRI Nhat Ban Viet Nam Viel Nam IRRI IRRI IRRI Nhat Ban Nhat Ban Nhat Ban
Ky hieu S15 S16 S17 S18 S19 S20 S21 822 823 S24 827 828
Ten giong IR58 MTL163 HYMST P 6 D B Kim23B Hoa s u a OM1121 OM5930 OM6162 OM6932 RuflL19 OM5964
Nguon goc IRRI Viet Nam Nhat Ban Viet Nam Trung Qu6c
My Vi^t Nam Vi^t Nam Viet Nam Vi^l Nam N h | t B^n V i f t Nam
Nguyin Qu6c Tmng, Le Van Trung, Nguyin Thi Trang, Nguydn Thj Thiiy Dirang, Nguyin Thanh TCing, Nguyin Van Hoan, Pham Van CuOTig Bang 2. Danh s a c h cac chi thi khao s a t t r d n 12 n h i e n i s a c t h e (McCouch, 2002) TT Chi thi SSR NST
MOI ngugc Nhiet (Jg
gan moi RM495
RM1 RM283 RM259 RM312 RMS RM237 RM431 R M I 54 RM452 RM489 0 S R 1 3 RM338 RM55 RM514 RM307 R M I 24 RM507 RM413 R M I 61 R M I 78 RM334 RM133 RMS 10 RM454 R M I 62 R M I 25 RM11 RM455 RM118 RM408 R M I 52 RM25 RM44 RM284 RM433 RM447 RM316 R M I 05 RM215 RM474 RM271 RM171 RM484 RM552 RM536 RM287 RM144 RM19 RM277
aatccaaggtgcagagatgg caacgatgacgaacacaacc gcgaaaacacaatgcaaaaa gcgttggttggacctgac gtctacalgtacccttgttggg cggcatgagagtctgtgatg
tgcaacttctagctgctcga caaatcccg actgctgtcc tcctgcgaactgaagagttg accctctccgcctcgcctcctc acttgagacgatcggacacc catttgtgcgtcacggagta cacaggagcaggagaagagc agattgatctccc attc ccc gtactaccgacctaccgftcac cttaagctccagccgaaatg ggcgattcttggatgaagag tgcagatgagaagcggcgcctc tcgcgtgaaagataagcggcgc gtlcagtgttcagtgccacc ttggatlgttttgctggctcgc aaccggattagtttctcgcc cicaagcttagctgctgctg gccagcaaaaccagggatccgg atcagcagccatggcagcgacc tctcctcttcccccgatc aacaacccaccacctgtctc ccaatcggagccaccggagagc caacgagctaacttccgfcc gaaaccaccacacctcaccg ggaaagaatgatctttlcatgg acgggcaatccgaacaacc atctctgalactccalccatcc tgcgctgaactaaacacagc cccttgtgctgtctcctctc ctagtlgggcatacgatggc gtcgtcgacccalcggagccac caaaatggagcagcaagagc aagatgtacgggtggcattc tcagatctacaatlccatcc aacgcgaggacacgtacttac tctccctcctcaccattgtc cgcagttgtggatttcagtg tctctcctcttgtttggctc ttccctgttaagagagaaalc Igccctggcgcaaattlgalcc caaaaacagagcagatgac cggtcaaatcatcacclgac
aagtcaccg agtttaccttc gcalccgalcttgatggg tgggaagagagcactacagc agagcaaaaccclggticac ctcctcctcctgcgaccgctcc gg g ate aa ace ac gfttctg tcacccatggatgttgtcag agccacagcgcccatctctc ggcaaaccgatcactcagtc Icccggtlattttaaggcg cacgagcatattactagtgg ctgctatgcatgaactgctc catggalcaccgagctcccccc ctcaccctcatcatcgcc tccccaccaatcttgtcttc tgtgtcatcagacggcgclccg galcaccgttccctccgcctgc ggaacacgggglcggaagcgac gtgatcagfgcaccatagcg caaggtcttgtgcggcttgcgg aggggatcatgtgccgaaggcc
cacatcctccagcgacgccgag actgctacttggglagctgacc ccgtagaccttcttgaagtag ctaccatcaaaaccaatgttc tcgggaaaacctaccctacc cctgtacgttgatccgaagc agacaaacctggccattcac acgggcttcttctccttctc acgcttalatgttacgtcaac tgagcacctccttclctglag tcggtgagacctagagagcc acgagatacgtacgccttig tgctgccctctctctctctc tgclcaacgtttgactgtcc acacaccaacacgaccacac gtgtatttggtgaaagcaac gctagaggagatcagatggtagtgcatg ctcaagatggacgccaaga caaggcltgcaagggaag
463
Danh gia da dang di Iruyen mot so giong lua ngan ngay
Ky thuat PCE danh gia da dang di truyen sii dung bo chuan 50 chi thi SSE difdc tham khao tii Chiidng trinh khai thac da dang di truyen trong cai tien gio'ng cay trong (Generation Challenge Program, Consultative Group on International Agricultural Research - CGIAR). Cac chi thi nay difdc phan bo' deu tren 12 nhiim sdc the (McCouch, 2002) (Bang 2). San pham PCR dUdc kiem tra tren gel Agarose 4% va quan sat hkag den chieu UV. Xay diing sd do da dang di truyen bang phan mem NTSYS 2.1: sit dung "He so tifdng dong Jaccard" va phtfdng phap UPGMA trong NTSYS 2.1. He so PIC (Polymorphic Information content ) ciia moi locus SSR difdc tinh theo cong thfic PIC (i) ^ 1 - I Pij^ (Botstein, 1980 ). Trong do, I la so locus SSR tifdng uing; j la so' thil tli aUen cua locus SSR va Pij la tan suat alien thfi j vdi locus SSR thil i.
3. KET QUA VA THAO LUAN
3.1. Ket qua d a n h gia cac giai doan sinh trifdng
Dgng thai xuat hien la o cac gio'ng the hien kha da dang, cac mau giong ra la thfi nhat sdm
nh^t la 5 ngay (S13, S23) va 6 ngay (S6, S l l , S12). Tong thdi gian cho cay ma xuat hien 2 la ngSn nhat d m l u giong S13 la 11 ngay; Sl5 va S23 la 12 ngay; dai nhat cl cac m i u giong S2, S9, S20, S21, S22, S24 la 19 ngay. Dgng thai xuat hien la d giai doan ma dai, ngdn co 5 ca cac m l u giong CO nguon goc Nhat Ban (Japonica), IRRI va Viet Nam (Indica).
Giai doan sinh san hat dau tfi liic phan hda dong den liic Ma tr6 bong, giai doan nay keo dai khoang 27-35 ngay. Theo ket qua cl hinh 1, thcii gian tfi gieo den phan hoa dong bifdc 4 co sif dao dgng tifdng doi ldn tfi 60 tdi 81 ngay, neng dai ngay VNIO la 132 ngay. Nha vay, giai doan phan hoa dong co sii dao dong ldn nhat ve thcJi gian sinh tnidng, cac mSu giong ngan ngay bat bugc phai sinh trficing nhanh nhat vao thdi diem nay. Nhom co thdi gian ngan nhat 60-65 ngay (S4, S18, S19vaS20).
Giai doan tr5 bong bat dau khi cac hoa dau tien cua bong nho ra dong den khi long tren cung khong dai ra difdc nila. Do dai giai doan nay dao dpng 8 ngay gifla gio'ng ngSn nhat, 13 ngay (S8, S9 va S12), vai giong dai nhat 22 ngay (S20).
Chu thich Tir gieo den la thir nhat
Tir la tht>
nhat den I3 thiJ2
Ti/la tht>2 den phan hoa ddngbu'crc4
Tir phln hoa dong buac 4 den tro
Hinh 1. Tong hdp cac giai d o a n sinh trfiofng tif gieo d e n t r o ciia 24 m a u giong nghien ciiu t r o n g vu x u a n 2013 tai Hoc vien Nong n g h i e p Viet Nam
NguySn Quoc Trung, Ld Van Tmng, Nguyen Thi Trang, Nguyin Thj Thuy Dipang, Nguyin Thanh Tiing, Nguyin Van Hoan, Pham Van CtFcrng
Tfi ket qua the hien 6 hinh 1, tong do dai, n g ^ cua th6i gian sinh trfidng chu yeu phu thuoc vao giai doan sinh trifdng sinh difdng.
Giai doan phan hoa dong va giai doan chin cac mlu giong khong bien dong nhieu. Toe do ra la nhanh hay cham ciing khong dong nghia vdi mau giong ngdn hay dai ngay. Trifdng hdp hai m&u giong S18 va Sl9 co toe do ra la 1 va !a 2 Cling nam trong khoang gia tri trung binh nhfing thdi gian sinh trifdng sinh dfiSng riit ngan di rat nhieu nen tong thdi gian ngdn nhat trong cac vat lieu nghien cfiu: tfi gieo tdi tro tfidng fing 74-76 ngay trong vu Xuan.
3.2. Ket qua phan tich da d a n g di t r u y e n biing chi thi SSR
Trong 50 chi thi SSR dudc sil dung cd 19 chi thi xuat hi§n vach ddn hinh; 31 chi thi xuat hiSn vach da hinh vdi tong so' 71 alen (trong do co 66 alen da hinh va 5 alen ddn hinh d 0SR13, RM152, RM316, RM334, RM552). Chi thi RM474 co he so da dang cao nhat la 0,61 (Bang 3).
Hinh 2. Ket qua dien di san pham PCR tren gel agarose 4% vofi mot so SSR Ghi cbu: Tii trai qua phai- S}->S28 vit DNA ladder lOObp
Ket qua phan tich khoang each di truyen bdng phifdng phap UPGMA trong NTSYS 2.1.
the hien trong hinh 3. Vdi do tUdng dong di truyen d mflc 0,78 co the chia cac mau gio'ng thanh 5 nhom:
Nhom 1: Gdm cac mau gio'ng Japonica:
Asominori, NorinPL9, IRRI142 va Agamimi.
Nhom 2: Mlu giong IntiicaMTL163 Nhom 3: Gdm cac gio'ng Indica co ngudn goc tfi vien Ilia Ddng bdng song Cfiu Long va mgt so' mlu gidng khac. Trong do, 2 mau gio'ng ngdn ngay nhat la P6DB va Kim23B c6 khoang cac di truydn kha gan nhau. 0 do tadng ddng 0,94 chfia the phan biet dxiOc 2 mau gio'ng la Hoa sfia va OM6932.
Nhom 4: Cac gidng indicaIR24 va 2 dong CSSLs (Chromosome segment substitution lines) RufIL3 va RufIL19 c6 nen gen ciia IR24 mang mgt doan cua nhiem sac the so 1 va 5 tfidng fing tfi Oryza rufipogon do phong thi nghiem Chgn gio'ng cay trdng, Dai hoc Kyushu phat trien.
Nhom 5: Nhom cac gidng Indica deu difdc danh gia co tiem nang nang suat cao, tinh thich nghi rong nhfi: KD18, ADll, OM5524, IRRIIOS va VNIO. Trong do quan he di truyen gifla KD18 va ADll da the hien rat ro qua trinh chon tao mau gidng ADll tfi phep lai ciia KD18.
So sanh sfi phan nhom tren vdi do dai cac giai doan sinh trifdng d hinh 1 nhan thay 2 mau gidng ngan ngay nhat la P6DB va Kim23B deu nam d nhdm 3. Ket qua danh gia da dang di truyen the hien ro nguon goc cac mau giong thuoc Japonica hay Indica, cac mau gio'ng co thdi gian smh tradng ngdn co d ca 2 nhdm:
Japonica (Agamimi, Norm PL9) va Indica (Kim23B, P6DB,..). Vi vay, chifa thay dugc moi lien he ro rang gifia cac phan nhdm theo chi thi SSR va theo thdi gian sinh trifdng. Theo ke't qua danh gia tren, chiing toi nhan thay bg 50 marker SSR su dung trong nghien cfiu da danh gia kha chinh xac moi quan he di truyen gifia cac mau gid'ng nghien cflu.
465
Danh gi^ da dgng di tmyen mot s6 giong lua ngan ngay
B a n g 3. He so da d a n g di t r u y e n c u a cac chi t h i SSR v a d i e u kign PCR tU<Aig Ang
TT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Chi thi SSR RM495
R M I RM283 RM259 RM312 RM5 RM237 RM431 RM154 RM452 RM489 0 S R 1 3 RM338 RM55 RM514 RM307 R M I 24 RM507 RM413 RM161 R M I 78 RM334 RM133 RM510 RM454
NST
2 2 3 3 3 3 3 4 4 5 5 5 5 5 6 6 6
T o n g s f alen
2 2 2 2 3 3 2 2 3 2 3 2 2 2 3 2 2 2 3 2 2 2 2 2 2
H^ so da dang S6 aien da hinh 0 0 2 2 3 3 0 0 3 0 3 1 0 0 3 0 0 0 3 2 0 1 0 2 2
PIC*
0,28 0,48 0,23 0.29
0,54 0,53 0,5
0.53
0,53 0,28 0,42 0,50 0,28
TT
26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
Chi thj SSR R M I 62 R M I 25 RM11 RM455 RM118 RM408 R M I 52 RM25 RM44 RM284 RM433 RM447 RM316 RM105 RM215 RM474 RM271 R M I 71 RM484 RM552 RM536 RM287 RM144 R M I 9 RM277
NST 6 7 7 7 7 8 8 8 8 8 8 8 9 9 9 10 10 10 10 11 11 11 11 12 12
T o n g s f i alen
2 2 2 2 2 2 2 2 2 2 2 2 2 3 2 3 2 2 2 2 2 3 2 2 2
H# so da dgng S o alen da hinh 0 2 0 2 0 2 1 2 0 2 0 2 1 3 2 3 0 2 0 1 2 3 2 2 2
PIC-
0.34 0,44 0.34 0.32 0,44 0.42 0,48 0.36 0.49 0,14 0,61 0.28 0,24 0,22 0,56 0,22 0,42 0,38 Ghi chll: *:polymorphic information content
K n i f i A D l l IRRI108 VNIO IR?4 KufILd RuflU.9 IKiO IRS8 PfifiR KiniZ;iB Hoa sua U M b y J O OMD9G4 O M f i l f i ? OM1121 HVMST MT11 fi^
Asominori N o r l n r i o IRRI147 Agamimi
Hinh 3. Stf d6 q u a n he di t r u y e n 24 m^u gio'ng n g h i e n ciiu xac d i n h b a n g chi t h i SSR
Nguyin Quoc Tiung, Lfi Van Tmng, Nguyin Thj Trang, Nguyen Thi Thuy Du'ang, Nguyen Thanh Tiing.
Nguyin Van Hoan, Pham Van Cu-dng
4. K E T L U A N
G i a i d o a n s i n h trifdng s i n h difdng tH xu^'t h i e n 2 l a d e n p h a n h o a d d n g q u y e t d i n h t d n g t h d i g i a n s i n h t r i i d n g ciia cac m a u giong Iiia n g d n n g a y .
M l u gio'ng liia P 6 D B v a K i m 2 3 B co thdi gian sinh t r u d n g sinh dfldng n g a n n h a t 60-62 ngay.
Stl d u n g c h i t h i S S R d a n h g i a d a d a n g di t r u y e n d a t h e h i e n r a t t d t sif tifdng d d n g di t r u y e n v a p h a n b i e t cac m a u gid^ng n g h i e n cflu t h a n h 2 n h o m chfnh Japonica v a Indica, t r o n g do n h d m Indica dUdc c h i a t h a n h 4 n h o m n h d vdi h e sd' di t r u y e n 0,78. H a i m a u gio'ng n g a n n g a y P 6 D B v a K i m 2 3 B co q u a n h e di t r u y e n k h a g i n n h a u " 0,86.
LOI CAM ON
N h d m tac gia xin c a m dn si( h o trd t h i e t hi v a vkt h e u tii d u a n Cai tien m a u gio'ng cay trong cho mien n u i v a t r u n g d u phia Bac (JICA-DCGV).
TAI LIEU THAM KHAO Botstein D, White RL, Skolnick M and Davis RW
(1980). Construction of genetic linkage map in man using restriction fragment length polymorphisms. Am J Hum Genet 32; 314-331.
Doyle, J.J. and Doyle J.L. (1987). A rapid DNA isolationprocedure for small quantities of fresh leaf tissue. PhytochemBuil 19: 11-15.
IRRI (2002). Standard Evaluation of Rice. International Rice Rearch Institute, LosPanos, Philippines.
McCouch S. R.. L. Teytelman, Y. Xu, K. B Lobos, K.
Clare, et. al. (2002). Developmentof 2240 new SSR markers for n e e (Oiyza saliva L.). DNA research, 9( 6): 1 9 9 - 2 0 7 .
Monaco M.K., Stein J., Naithani S., Wei S., Dharmawardhana P., Kumari S , Amarasinghe V , Youens-Clark K, Thomason J, Preece J, Pasternak S, Olson A, Jiao Y, Lu Z, Boiser D, Kerhomou A, Staines D, Walts B, Wu G, D'Eustachio P, Haw R, Croft D, Kersey PJ, Stein L, Jaiswal P, Ware D (2013). Gramene 2013: comparative plant genomics resources Nucleic Acids Res. PMID' 24217918
