Grain quality changes and responses to nitrogen fertilizer of japonica rice cultivars rele

Gra in q u a lity ch a n g e s a n d re sp on se s to n itro ge n fe rtiliz e r o f ja pon ica rice cu ltiva rs re le a se d in th e Ya n gtz e Rive r Ba s in from th e 1950s to 2000s
Junfei Gu,Jing Ch en,Lu Chen,Zhiqin Wa ng,Ha o Zha ng,Jia ncha ng Ya ng
Key L a bora tor y of Crop Gen etics and Phys iology of J iang su Provin ce,Co-Inn ova tion Cen ter for Modern Pr odu ction Tech n ology of Gra in Crops ,Ya ngzh ou Univ er sity,Ya ngzh ou ,Ch ina
A R T I C L E I N F O
A B S T R A C T
Art icle his tory:
Received 23Oct o ber 2014Received i n rev is ed fo rm 21Mar ch 2015Accep t ed 4May 2015Av ail abl e on l in e 9May 2015W h ile th e yield p ot en t ial of rice h as i ncreas ed but lit tle is kn ow n abo ut t h e i m pact o f breedin g on grain qu alit y,esp ecia lly un d er d ifferen t levels o f N ava ilabili ty.In order t o inv est igat e t h e in t egrat ed effect s of breed in g an d N levels o n rice qu ali ty 12japonica rice cul tiva rs bred i n t he pas t 60years in th e Yan gt ze River B as in w ere u sed wit h t h ree lev el s of N:0kg N h a 1
,240kg N h a 1
,an d 360kg N h a 1.Durin g th e p eriod ,m illi ng qu alit y (b ro wn rice p ercen t age,m illed rice p ercen t age,an d h ead rice percent age),app earan ce qu alit y (cha lky kernel s percen tage,ch alk y s ize,an d ch alkin es s),an d eat in g an d cooki ng q uali ty (am ylos e con t en t,gel con s ist en cy ,p eak vi scos ity ,breakd own ,and s et back)were s ign ifi can t ly im p ro ved,but th e n ut rit ive v alue of t h e grain h as declin ed du e to a redu ctio n in prot ein con ten t.Mi cron u t rient s ,su ch as Cu ,Mg,an d S con t ent s ,were decreased ,an d Fe,Mn ,Zn ,Na,Ca,K,P,B co nt en t s were i ncreas ed.Th es e cha nges in grai n q u alit y im p ly t h at s im ult an eou s i m pro vem en ts in grain yield an d grain q ua lit y are p os sibl e t h rou gh s electi on.Overall,ap plicat ion of N ferti lizer d ecrea sed grai n q u alit y,es peciall y in term s of eat in g an d co okin g qu alit y.Und er h igh er N levels,h igher pro tein con t en t was t h e m ain reas on for det eriorat ion of grain qu alit y,alt ho ugh lower am ylo se co n ten t m igh t co n tribu t e t o im p rovin g st arch p as tin g pro pert ies.Th ese resu lt s s ugges t t h at furt h er i m pro vem en t in grain q ua lit y wil l dep en d o n bot h breedin g an d cult ivat io n practi ces ,esp eci ally in regard t o n it rogen an d wat er m an agem en t.
2015Crop S ci en ce So ciet y o f Ch in a an d In s t it u t e o f Crop S cien ce,CAAS.Pro du ct io n an d h os t in g by Els evi er B.V.Th i s is an op en acces s art icl e u n de r t h e CC B Y-NC-ND l icen s e
(h t t p://creat iv ecom m on s.o rg/licen s es /by-n c-n d /4.0/).
Keywords :Breed in g
Cu lt iv at ion t ech n iq ue Gra in q u ali t y J aponica rice
Nit ro gen ou s fert il izer
1.In tro d u ctio n
Rice (Oryza s ativ a L.)is th e m os t im p o rta n t s ta ple fo od in th e w or ld ,p r ov id in g m o re th an 21%o f th e ca lo rific n e ed s of th e w or ld p o p u la tio n ,b u t u p to 76%o f th e ca lo rific in tak e o f th e p o p u la tio n in So u th E a s t As ia [1].In Ch in a ,n ex t to yield ,im p r ov em e n t in gra in qu alities is b eco m in g a p rio rity,alon g
w ith im p r ov em e n ts in eco n o m ic an d livin g s tan d ar d s.Dev el-o p m en t of bo th h ig h y ield an d h igh q u ality in r ice v arieties is es s e n tial [2].
Gr ain q u ality tra its dicta te m ark et valu e an d h av e a p iv otal ro le in th e ad op tio n
o f n e w v arie ties.Rice q u ality tra its
en co m pa s s m illin g re co ve ry,p h ys ica l ap p eara n ce,coo kin g a n d ea tin g qu a lities ,a n d n u trition a l valu e [3,4].Th e ev alu atio n
T H E C R O P J O U R N A L 3(2015)285–297
Corres ponding aut hor.
E-m ail ad dre ss :j cy an g@yzu.ed (J.Yan g ).
Peer revie w u n d er re sp on s ib ili t y o f Crop S ci en ce So ciet y of Ch in a an d In s t it u t e o f Crop S cien ce,
CAAS.
x 6j j 5355S S y f I f S ,S y B V T BY N ND (y
)A v a ila b le o n lin e a t w w w .s c ie n c e d ir e c t .c o m
ScienceDire ct
h t t p://d .d oi.o rg/10.101/.c .201.0.007
2214-141/201Crop cien ce ociet o Ch in a an d n s t it u t e o Cro p cien ce C AA .P rod u cti on an d h os t in g b Els evi er ..h is i s an op en a cces s ar ti cle u n d er t h e C C -C-licen s e h t t p://cr eat ive com m on s.or g/l icen s es /b -n c-n d /4.0/.
criteria fo r m illin g q u ality m ain ly in clu d e bro w n r ice p ercen ta ge,m illed rice p ercen tage,a n d h e ad r ice p ercen ta ge,wh ich reflect th e p ro p ortion o f w h o le k ern els (h ea d rice or h ea d mille d rice)a n d bro ke n kern els p ro du ced d u rin g m illin g o f rou gh
rice.
Ap p eara n ce q u ality is m ain ly d e te rm in ed b y g rain s ize,tra n s lu -cen cy ,ch alky gra in p ercen ta ge,ch a lk y a rea a n d d egre e of ch a lk in es s.Starch g ran u les in ch alk y area s of th e gra in a re s m aller an d le s s d en s ely p acke d th a n th e large r tigh tly pa cked g ran u les in tran s luce n t area s o f th e grain [5].Coo kin g an d ea tin g q u alitie s a re m os tly s pe cified by am ylos e co n ten t,gelatin izatio n tem p era tu re,a n d g el co n s is ten cy o f th e gra in s tarch [6–8].Nu tritio n al va lu e is es s en tia l b ecau s e rice is a m ain s ou r ce of d ie tary p rotein a n d m icron u trien ts fo r m os t o f rice gro w in g co u n trie s.In o rd er to im p rov e q u ality tra its alo n g w ith yie ld it is n e ces sa ry to u n d ers tan d th e im p orta n t qu a lity traits ,to s elect fo r th em in a b reed in g p rog ram ,a n d to co n trol th em th ro u gh a p pro p ria te n itr oge n an d w a ter m an a gem en t.
His to ric ally ,m a n y b re ed in g p ro gr am s to ok yield p o te n tia l a s th e p rior ity ta rge t,p a rticu la rly in Ch in a.Rice yields h av e in cre as e d fr om 2.0t h a
1
in th e 1950s to 6.6t h a
1
in th e 2000s
[9,10].In 2006,th e a ve rag e r ice gr ain y ie ld in Ch in a w a s m o re th an 50%h ig h er t h an th e w o rld a ve ra ge [11].Th e Yan g tze Rive r Bas in is th e m a in r ice p lan tin g ar ea in Ch in a ,an d
r ep re s en ts 51.2%o f th e to tal rice g ro w in g a rea an d 51.3%o f th e tota l rice p ro d u ctio n in th e co u n t ry [12,13].Du rin g th e p e riod ,th e y ield p o ten tial h a s s ig n ifican tly im p ro v ed [2,12].Far m ers o ften u s e ex ces s ive N fe rtilizer to m ax im ize g ra in y ie ld.Fo r e xa m p le,Ch in a 's n ation al av er ag e N ap p lica tio n fo r r ice in 2006wa s 193k g h a 1
,m or e th a n 90%a b ov e th e w o rld
a ve ra ge [11].In Jia n gs u p ro v in ce th e a ver ag e N ap p lica tio n is
m o re th an 300k g h a
1
in s o m e h igh yield in g cou n tie s [12].
Ov er -u s e o f N fer tilize r als o co n tr ib u tes to p o o r ea tin g an d co o kin g q u ality o f th e gra in [2,12].Ho w ev er ,little is kn ow n a b ou t th e im pa ct o f br eed in g s e le ctio n o n g ra in q u a lity o f rice,e s p ecially u n d e r d iffe re n t N le ve ls.Un d ers ta n d in g th e ch a n g-e s in g rain q u a lity o f th e r ice cu ltiva rs b red in d iffer en t d e cad e s a n d th e ir lev els of re s p on s e to o f N fer tilize r s h o u ld b e b en eficial for im p ro v in g rice q u a lity in bo th r ice br eed in g a n d cu ltiva tio n.
In th is ex p erim en t w e s elected twe lve rep res en tative ja ponica rice cu ltiv ars b red in th e a rea du r in g th e las t 60y ear lin g ch a racteristics ,ap p ea ran ce,co ok in g an d ea tin g q u ality,an d n u trition al v alu e of th es e cu ltivar s w ere s tu d ie d.Su ch a stu d y s h o u ld p rov id e u s efu l in fo rma tio n fo r ach ievin g a h igh -q u ality a n d h igh -yield rice p rod u ctio n sy s te m w ith in p u ts fro m b oth a gro n om y an d br eed in g.
Deca d e
Cu ltiv ar
Gro wt h d u r ation (d a ys )
Pla n t h eigh t
(cm )
Gra in w eigh t
(m g g rain 1
)
L a rg es t a re a of cu ltiva tio n
(×104
h a )
1950s Hu a ngke z a o 138121.221.6>22Guih ua q iu 152125.427.1>251960s Jin na n fe n g 15293.524.5>120Guih ua h u a ng 15494.824.6>1501970s Xuda o 214198.623.8>45Lim ing 13097.824.2>201980s Sida o 8145102.524.3>42Ya nji ng 2148101.623.7>751990s Zh e nd a o 88144110.425.9>60Hu a ida o 5151108.926.7>80Sin c e 2000
Hu a ida o 9151108.528.9>20Lia nj ing 7
147
110.3
27.9
>
120
F –
G y ()x (B)f 5,6,,,,N (N),N (N),36N (36N)D f y ±S ()286
T H E C R O P J O U R N A L 3(2015)285–29
ig.1ra in ie ld A a n d h ar ve s t i n d e o r ice cu lt i v ar s re le as ed i n t h e 190s 190s 1970s 1980s 1990s an d 2000s u n d er 0k g h a
1
0240k g h a
1
240a n d 0k g h a
1
0a p p li ca t io n le ve ls .a t a ar e av e ra ge s o t w o e a rs 1.E.
ve rt i cal b a rs .
2.Ma teria ls an d m e th o d s
2.1.Pla nt ma ter ia ls a nd cultiva tion
Th e exp e rim en ts w e re co n d u cted at th e res ea rch far m o f Ya n g zh ou
Un iver s ity,
Jia n gs u
p rov in c e,
Ch in a
(32°30′N,
119°30′E )d u rin g th e rice gro win g s e as o n (M ay to Octo be r)in 2012,a n d re pe ated in 2013.Th e p r eced in g cro p w as w h e at (Triticu m aestivu m L .)in bo th yea rs.T h e s o il u s ed in th e
ex per im en ts wa s a s an d y loa m (typ ic flu v aq u en ts,en tis ols)with
20.4g kg
1
o rgan ic ma tter,106.2m g kg
1
a lka li-h y dr oly s able N,
28.5m g kg 1
Olse n -P,an d 93.6m g kg 1
ex ch an gea ble K.Tw elv e
japonica rice cultiva rs,
Hu an gk ezao ,HKZ;Gu ih u aq iu,
GHQ;
J in n an fen g,J NF;Gu ih u ah u a n g,GHH;Xu d ao 2,XD2;L imin g,L M;Sida o 8,SD8;Yan jin g 2,YJ 2;Zh en gd ao 88,ZD88;Hu a id ao 5,HD5;Hu aid a o 9,HD9;an d L ia n jin g 7,L J 7,gro w n in th e Yan gtze Rive r Bas in d u rin g th e la st 60ye ars wer e ch o s en ,an d clas s ified in to s ix y f T y (>66×)T f T T ff cu ltiv ars ,s ow in gs w ere at d ifferen t d ates fro m 8to 25Ma y.Tw en ty-d ay -old s ee dlin gs w ere m an u ally tran s p la n te d in to a p ad d y field w ith a h ill s p acin g o f 13.3cm ×25.0cm an d two s eed lin gs pe r h ill.
Th e field ex p erim en ts w er e a s p lit-block de s ign w ith 3
rep licates ,w ith n itr oge n a s th e ma in treatm en t an d cu ltiva rs
as s u b -plots.Th r ee m ain p lots ,n a m ely low N leve l (0k g N h a 1
,
0N),me diu m N le vel (240k g N h a 1
,240N),a n d h ig h N leve l
(360kg N h a 1
,360N),w ere a p p lied in each b lo ck,leav in g a
1.5m s pa ce be tw ee n plots.A dr ain a ge d itch 0.5m w id e w as d u g
to a d ep th
of ab ou t 30cm all ar ou n d th e m ain p lo t,a n d
con n ected to th e cen tra l d rain age ch a n n els o f th e field.Pla s tic film w as in s e rted in to th e s oil betw ee n p lots to a d ep th of 50cm to fo rm a b arrier.Su bp lo ts fo r cu ltivar s w er e as s ign ed in ea ch m ain p lo t.Th e s ub p lo ts w ere 16.0m 2
.Fo r me diu m a n d h igh N fertilizer tr eatm en ts ,u re a as th e N s ou rce wa s ap p lie d at p re-tra n s plan tin g (1d ay b efor e tran s p la n tin g),early tillerin g (7d ay s a fter tran s p la n tin g )an d p an icle in itia tio n (ab ou t 35d a ys f )5%,%,%,y F ,(3)(K )f z y f Qu ality tra its
Y D C(D)N Y ×D Y ×N D ×N Y ×D ×N
Milling qu alit y
Brow n ric e pe rce n t a ge (BRP,%)n.s.n.s.n .s.n .s.n le d ric e pe rce n t a ge (MRP ,%)n.s.n .s.n.s.n .s.n .s.n .s.He a d ri ce p erc e nt a ge (HRP,%)n.s.
n .s.
n.s.
n .s.
n .s.
n .s.
Appea rance
Cha lk y kern e ls pe rce n t a ge (CKP,%)n.s.n.s.n .s.n .s.n .s.Cha lk y siz e (CS,%)n.s.n .s.
n.s.n .s.n .s.n .s.Cha lk ine s s (CK,%)n.s.n.s.n .s.n .s.n .s.Le ngt h/w id th ra t io (LW R)n.s.
n .s.
n.s.
n .s.
n .s.
n .s.
Cooking a nd ea ting qua l it y Am ylos e con t e nt (AC,%)n.s.n.s.n .s.n .s.n .s.Ge l c ons is te n cy (GC,m m )n.s.n .s.
n.s.
n .s.
n .s.
n .s.Pe a k vis cos it y (PV,cP)n.s.n .s.Hot vis co sit y (H V,cP)n.s.n .s.Cool vis co sit y (CV,cP)n.s.n .s.
Bre a kdow n (BD,c P)n.s.n.s.n .s.n .s.n .s.Se tb a ck (S B,cP)n.s.n .s.
n .s.Cons is te n cy (CT ,c P)n.s.n .s.
n.s.n .s.n .s.n .s.Ove ra ll p a la t ab ilit y (OP)n.s.
n.s.
n .s.
n .s.
n .s.
Nut rit ive qua l it y
Prot ei n c on te n t (PC,%)n.s.
n .s.n.s.n .s.n .s.n .s.Cu c on ce n tra t ion (m g kg 1)n.s.n.s.n .s.n .s.n .s.Fe con c en t ra ti on (m g kg 1
)
n.s.n.s.
n .s.n .s.n .s.Mn c onc e nt ra t ion (m g kg 1)
n.s.n .s.n.s.n .s.n .s.n .s.Zn c onc e nt ra t ion (m g kg 1
)n.s.n.s.n .s.n .s.n .s.Na c on ce n t rat ion (m g kg 1)
n.s.n .s.n.s.n .s.n .s.n .s.Ca con c en t ra ti on (m g kg 1
)
n.s.n .s.n.s.n .s.n .s.n .s.K con c e nt ra t ion (m g kg 1)
n.s.
n .s.n.s.n .s.n .s.n .s.Mg c on ce n tra t ion (m g kg
1
)
n.s.n .s.n.s.n .s.n .s.n .s.S c onc e nt ra t ion (m g kg 1)n.s.n .s.n.s.n .s.n .s.n .s.P c onc e nt ra t ion (m g kg
1
)
n.s.n .s.n.s.n .s.n .s.n .s.B c on ce n tra t ion (m g k g 1
)n.s.
n .s.
n.s.
n .s.
n .s.
n .s.
n.s.,no t s ign ific a n t;
a n d
,sign ifica n t a t P =0.05a nd P =0.01,re sp e ct ive ly.
287
T H E C R O P J O U R N A L 3(2015)285–29
t p es a cco rd in g t o d ecad e o relea se .h e cu lt iv ars were ch o s en be ca u se t h e h ad large an n u al pl an t in g are as .7104
h a .h e g row t h d u rat io n a n d s om e p la n t t rait s o t h es e cu lt iv ars a re lis t ed in abl e 1.o re du ce d i er en ces in h ea di n g ti m e am o n g th e
a t er t ra n s p lan ti n g i n t h e p ro p ort i on s 010an d 40res p ect iv el .or all t h e t rea t m e n t s ph os p h or u s 0kg h a 1
as
s in gl e s u p erp h o s p h at e an d p ot as s iu m 40k g h a
1
a s Cl wer e
ap p li ed as b as al ert il i er 1d a b e ore t ran s p la n t in g.
2.2.Ha rvesting a nd gr ain qu ality m ea surem ent
Pla n ts w er e h an d -h ar ve s ted o n 12–15Octob e r.Pla n ts in tw o r ow s o n eac h sid e o f th e p lo t w ere d is car d ed to a vo id b or d er e ffe cts.Grain yield w a s d eter m in e d fr om a h ar ves t a re a of 6.0m
2
in ea ch p lo t an d ad ju s ted to 14%m ois tu re.Ab ov e-g ro u n d
biom a s s a n d
yield
co m p on en ts ,
i.e.
n u m b er
of
p a n icle s p er s q u a re m eter ,n u m be r o f s p ike le ts p er p a n icle,p e rcen tag e o f filled gr ain s ,a n d gr ain w eigh t,w e re d e term in ed o n p la n ts fro m 0.6m
2
(ex clu d in g th e b o rd er r ow s )s a m p led
r an d o m ly fr o m ea ch p lo t.Th e p er cen ta ge o f filled gra in s w as d e fin e d as th e filled gr ain s (s p ecific gr av ity ≥1.06g c m 3
)a s a
p e rcen tag e o f th e tot al n u m b er o f s p ik e lets.
Ab ou t 500g o f g rain s h a rv es ted a t p h y s io lo gical m atu r ity f °f f q y y R Q y M S []G f 5D ,g rain s.T h e b ro w n rice r ate,m illed r ice rate ,a n d h ea d rice r ate w er e ex p res s ed a s p e rcen ta ges o f tota l gr ain w eig h ts.Hea d r ice r efers to th e ke rn els th a t rem a in at th ree-fo u rth s or mo re o f th eir n o rm a l len g th [4].T h e len gth s a n d br ead th s of 10m illed g rain s fro m ea ch s a mp le w er e m ea s u red u s in g a v ern ier m icrom e ter.Ch alkin es s w as e valu ate d vis u a lly o n 100m illed g rain s p er p lo t.Gr ain s c on ta in in g 20%o f m o re o f wh ite b elly,w h ite cen ter ,w h ite b ack,o r a co m bin ation o f th es e w ere co n s ide red ch a lk y ker n els.Ch a lk in e ss a rea w as exp re s s ed a s p er cen ta ge o f th e to tal a rea o f a k ern el.Th e d eg ree o f ch a lk in e s s w a s ca lcu la ted from ch a lk y ke rn e ls an d ch a lky s ize,i.e.th e d eg ree of ch alk in es s (%)=ch a lky k ern e ls ×ch a lky s ize.
Re pr es en ta tiv e m illed rice s am p les we re o ven -d ried
to
co n s ta n t w e igh t a t 60°C,an d w ere th e n gro u n d with a s tain le s s (FW ,)5[5]f f q y ,z ,y ,,y T y ,
f Fig.2–Br ow n r ice p e rce n ta ge (A),m illin
g r ice p e rce n tag e (B)a n d
h e ad rice p er cen tag e (C)o f rice cu ltiv ar s fro m th e 1950s (Hu a n g k ez ao ,HKZ;Gu ih u aq iu ,GHQ),1960s (Jin n a n fen g ,JNF;Gu ih u ah u a n g ,GHH),1970s (Xu d a o 2,XD2;Lim in g ,LM ),1980s (Sid a o 8,SD8;Yan jin g 2,YJ2),1990s (Zh en gd a o 88,ZD88;Hu aid a o 5,HD5),an d 2000s (Hu a id ao 9,HD9;Lia n jin g 7,LJ 7)u n d er 0k g N h a
1
(0N),240k g N h a
1
(240N),a n d 360k g N h a
1
(360N)a p p lica tio n le ve ls .Da ta ar e av e ra ge o f tw o y e ar s w ith ±1
S.E .(v er tica l ba rs ).
288
T H E C R O P J O U R N A L 3(2015)285–29
ro m each p l ot w as d ried a t 40C in a o rced -a ir o ven o r u ali t a n al s i s acco rd in g t o t h e ice u al it ea s u rem en t t a n d ar ds 14.ra in s a m pl es o 10g we re t w ice p a s s ed t h rou gh a eh u s ke r p o lis h e d an d s ep ar at ed i n t o br ok en an d u n br ok en
s t ee l g rin d er -100Ch i n a w it h a 0.2m m s iev e 1i n o rd er t o u rt h er p re p are t h em o r s u b s e u en t an a l se s vi .a m lo s e co n t en t p ro t ein con te n t s t a rch vi s cos i t a n d el em en t a l co n -ce n t rat i o n s.o d et e rm in e a m lo s e co n t en t l ou r s a m p l es w ere
gelatin ize d u sin g 1m o l L
1
Na OH.Am y lo se wa s d eterm in ed color im etr ically u sin g th e am y lo se –io d in e r eaction .Am y lo s e con ten t w a s calcu lat ed by u s in g a m ylo s e/a my lo p ectin m ix ed s tan d a rd s [16].Pr ote in co n te n t w as m e as u re d w ith a g rain an aly zer (In frate c 1241,Fos s ,Den m a rk).
As s ta rch p a ste p ara me ters gen erate d fr om a Rap id Vis co -An alyzer (RVA)re flect s tarch ge latin ization ,d isin tegra tio n ,
s we llin g a n d gellin g ab ility,th e y a re o ften u s ed to ev alu a te
q u ality [17,18].
In
th is ex p erim en t,
rice
sta rch
v is cos ity
RV (M RV 3D;N S f ,Sy y,)y [3]V y ()T f
y
visco s ity,h o t v is cos ity ,a n d co ol (fin al)vis co sity.Seco n d ary com p o n en ts ,s u ch as bre ak do w n an d s etb ack,w ere calcu lated from th e o rig in a l com p on en ts.A b rea kd o wn v alu e wa s ca lcu la t-ed by s u b tractin g th e h ot vis co s ity fro m p ea k v is cos ity ,a se tback va lu e w as calcu lated by s u b tractin g p ea k v is cos ity fro m co ol visco s ity,a n d a co n s is ten cy valu e w as calcu late d by su b tractin g h o t vis co s ity fro m coo l v is cos ity.
In a d ditio n to p h ys ioch e m ical co m p os itio n a n a lys is ,co ok in g an d e atin g q u ality wa s als o ev alu ated w ith a ric e tas te a n alyze r ST ,f f q y []x y f x f L f NO 3L f O
T Fig.3–Ch alk y k er n e l p erce n ta ge (A),ch a lk y ar ea (B),ch a lk in e s s (C),a n d gr ain le n g th /w id th r atio (D)o f rice cu ltiva rs fro m th e 1950s to 2000s.See ca p tio n to Fig.2fo r oth er d e tails .
289
T H E C R O P J O U R N A L 3(2015)285–29
ch ara ct ers we re eva lu a t ed u s in g a A o d el A-e wp o rt ci en t i ic dn e Au st ra li a as d es crib ed b Han et al..i s co s it v al ue s w ere reco rd ed as ce n t ip oi s es cP .h e o rig in al com p o n en t s
o s t arch
v is co si t ch a ract er s
in clu d e
p eak
A1A w h ich is a con ven i en t an d accu ra t e t o o l o r eva lu a t io n o rice coo ki n g a n d ea t in g u al it 19.
E act l 1g o po w d ered gra in s w as d ecom p o s ed i n a m i t u r e o 8m o H a n d
2m o H 22.h e a s h w a s t h e n
d ec om p o s
e d u sin g a m icro w av e as h in g d e vice (CEM 2000,Kam p ,Lin tfo rt,Germ a n y)a n d d ilu ted in 10m L o
f a qua regia.Cu ,Fe,Mn ,Zn ,Na ,Ca ,K,Mg,S,P,a n d B w er e m ea s u red b y ICP-OE S (Th erm o J a rrell As h ,T race Sca n ,Fr an k lin ,USA).
2.3.St atistica l a na lysis
An a ly sis o f var ia n ce wa s p e rfor me d u s in g th e SAS/STAT s ta tis tica l a n a lys is p ack ag e (ve rs io n 6.12,SAS In s titu te,Ca ry,NC).A GL M an a ly s is o f v arian ce p ro ced u re w as ru n to id e n tify s ign ifican t s ou r ces o f v ar ian ce,wh ich w ere p ar titio n ed be twe en e ffe cts d u e to y ea r (Y),cu ltiv ars r elea s ed in d ifferen t d ecad es (D),cu ltiv ar s n es te d w ith in d ecad es [C(D)],n itro gen fert ilizer (N),an d th eir in tera ctio n s (Y ×D,Y ×N,D ×N,a n d Y ×D ×N)a n d res idu al e rro r.Mea n s w ere te ste d b y lea st s ign ifican t d iffe ren ce at P =0.05(L SD 0.05).
3.Res u lt s
3.1.G r a in yield a nd qua lity differences
Diffe ren ce s in gra in y ield a n d h a rve st in d ex a m on g th e 12cu ltiv ars b red are s h ow n in Fig. 1.Grain yield p ro gre ss ively in crea s ed fr om th e 1950s (3.13t h a
1
)to 2000s (9.44t h a
1
)
a cro ss d ifferen t N leve ls w ith an av erag e y ea rly in c reas e o f 4%.Gra in y ield in crea s ed by 35.7%fro m th e 1950s t o 1960s ,31.2%fro m th e 1960s to 1970s ,17.3%fro m th e 1970s to 1980s ,17.4%fro m th e 1980s to 1990s ,a n d 23.1%fro m th e 1990s to 2000s.Sim u lta n e ou s ly,a ver age p la n t h e igh t d e crea s ed fro m 117.9c m in th e 1950s to 92.56cm in th e 1990s,bu t in crea s ed to 100.6c m in s u p er rice cu ltiv ars (2000s ).H arv es t in d ex in cre as ed from 36.5%in th e 1950s to 48.9%in th e 2000s (Fig.1).N fer
tilizer
Fig.4–Am y lo s e con ten t (A),g e l co n s is te n cy (B),an d ov e ra ll p alata b ility (C)o f rice cu ltiva rs fro m th e 1950s to 2000s.Se e ca p tio n to Fig.2for o th e r d eta ils.
F 5–T f y (),y (B),y (),(D),(),y (F)RV f f f 5S F f 290
T H E C R O P J O U R N A L 3(2015)285–29
ig.h e va lu e o p e ak v is cos it A h ot v i s co s it co o l v i s co s it C br ea k d o w n s et b a ck E a n d co n s is t en c in th e A p ro il e o rice cu lt i va rs ro m t h e 190s t o 2000s.e e ca p t i on t o ig.2or o t h e r d et a il s.
291 T H E C R O P J O U R N A L3(2015)285–29
s ign ifican tly in cre as ed gra in yield a n d h a rv es t in d ex e xcep t th at y ie ld s o f s o m e ear ly d eca d e cu ltiv ars d ro pp ed a t h igh N lev els (i.e.360k g N h a1)d u e to lo d gin g.
T ab le2s u m m ar ize s c om p u te d F-v alu es fo r d iffer en ce s in g ra in q u a lity.Diffe re n ces in q u ality tr aits b e twe en th e tw o y ea rs w ere n o t s ign ifican t a n d av er ag e d ata acr os s th e ye ars a re u s ed in th e fo llow in g a n a ly s es.Th e re w e re s ign ifica n t d iffere n ces in a ll q u a lity tr aits am o n g cu lt iv ars(Ta b le2).E v en w ith in th e s a m e d e cad e s ign ifica n t d iffere n ces w ere d et ected a m o n g cu ltiv ar s.Nitr og en fe rtiliz er h a d s ig n ifican t im p ac ts o n g ra in q u a lity t raits ex cep t fo r m illed rice p er cen t age,h e ad rice p e rcen tag e,le n gt h/w id th ra tio,a n d g el co n s is ten cy.Gen e ra l-ly,n o s ig n ifica n t in tera ctio n s w e re o bs e rv ed be tw een y ea r, cu ltiva rs,a n d n itr o gen fer tilize r a p p lica tio n(Ta ble2).
ling qua lity
M illin g q u ality w a s ev alu a ted b y th r ee m illin g tra its:bro w n r ice p er cen tag e(BRP),m ille d rice p erc en ta ge(MRP),an d h ead r ice p er cen tag e(HRP).BRP r es p o n d ed p o sitive ly to n itr og en lev els(Fig.2-A).On av era ge,BRP in crea s ed fr om82.79%at th e 0N lev el to83.81%at th e240N lev el,a n d to84.83%at th e 360N le ve l.N o cle ar ten d e n cy w as attr ib u ta ble to b re ed in g. BRP in cr ea s ed by1.8%p e r ye ar fro m th e1950s to2000s,w ith th e h ig h es t in crea s e in th e1970s(Fig.2-A).
M RP a n d HRP we re n o t in flu en c ed by N fer tilize r a p p lica-tio n(Ta ble2),w h ile s ig n ifica n t g en etic d iffe ren ces w e re o b s erv ed in MRP an d H RP(Fig.2-B,C).Ge n er ally MRP an d HRP w er e im p r ov ed d u r in g br eed in g r ega rd les s o f N le vels.Fo r e xa m p le,HRP in cr ea s ed o n av er ag e by68.7%fro m39.78%in th e1950s to67.11%in th e2000s,w ith m o r e va riatio n in th e e ar ly d e cad e s(Fig.2-C).Co m p a red w it h HRP,th e in cre as e in M RP a ttribu te d t o b ree d in g w as le s s a n d s h o w ed th e h ig h es t v alu e in1980s(Fig.2-B).
3.3.Appea r a nce qua lity
Fig.3s u m m arize s fou r ma in a p pe ara n ce q u ality p ro p erties, in clu d in g ch alk y ker n el pe rcen tage(CKP),ch alky s ize(CS), ch a lkin es s,a n d le n gth/width ra tio(L W R).As s h ow n in Fig.4, CKP,CS an d ch a lkin es s w ere s ign ifica n tly in crea s ed w h en n itrog en fer tilize r w as ap p lied rega rd les s o f cu ltivars.On a vera ge, CKP,CS a n d ch alkin es s in cr eas ed by21.4%,25.3%,a n d39.5% fro m0N to240N,res p ective ly,an d by24.1%,29.5%,a n d56.5% fro m240N to360N(Fig.3).
Cu ltiv ar s b red d u r in g d iffer en t d ecad es s h o we d s u b sta n tial d ec reas e s in CKP,CS a n d ch a lk in e s s.Fo r e xa m p le,CKP w as o n
a ve rag e d ecrea se d fro m51.6%to43.3%,42.5%,29.7%,23.5%,an d
16.3%d u rin g th e1950s,1960s,1970s,1980s,1990s,an d2000s, r es p ectiv ely.For CS a n d ch a lk in e s s,s im ila r ten d en cies we re o bs e rve d rega rd le s s o f N a p plica tio n le vel.Wh en co m p ared w ith m od e rn cu ltiv ars th ere w as m o re g en e tic v ariation in a p p ear an ce q u a lity am on g old cu ltiv ars(Fig.3).No s ign ifican t d iffe ren ces in L WR we re ob s erv ed a cro ss N fertilizer lev els (Tab le2).
3q y
q y y y y
f is,a m ylo s e co n t en t(AC),
g el co n s is ten cy(GC),an d s ta rc
h p a s tin g p ro p er tie s.Th e re w e re s ign ifica n t v ar ia tio n s a m o n g N fe rtiliz er le ve ls an d cu ltiv a rs(Ta ble2;Fig.4).At e ach N le ve l, AC w a s firs t d ecre as e d r ap id ly,a n d th e n s ligh tly in cre as ed w ith th e b ree d in g p r og re ss.AC w as co m p ar ative ly low e r at a h ig h er N lev el w ith a ve ra ge19.1%,16.7%,an d15.3%at0N, 240N,a n d360N le vels,r es p e ctiv ely(Fig.4-A).
Acr os s N le ve ls,GC s tea d ily in c rea s ed fro m39.65to 59.41m m,with th e h igh e s t va lu e s in th e1970s(70.9m m). Ap p lica tio n o f N s ign ifican tly red u ced GC fr om69.11m m at 0N to60.9m m a t240N an d56.37m m a t360N,a d eclin in g tr en d w ith in crea s in g N lev els.
T h e Rap id Vis co An a ly zer(RVA)is a u s efu l to ol fo r ra p id a s s es s m en t of e atin g a n d co o kin g q u a lity o f rice.T h e s ta rch p a s tin g p ro p er tie s a n a ly zed b y RVA ar e s h o w n in Fig.6, in clu d in g p ea k vis co s ity,h o t v is co s it y,co o l v isc os ity,br ea k-
d o w n,s etb ack,a n d co n s is ten cy.Th
e s e s ta rch p as tin g p ar am-
e ter s re fle cts th e tex tu r e an d s tick in e s s o
f co ok ed rice. Ap p lica tio n o f N fe rtilizer s ign ifican tly d ecre as e d p ea k v is c os-itie s acr os s a ll cu lt iv ars(Fig.5-A).Sim ila r p a tter n s o f r es p o n s e to N fertilizer w er e o b tain ed fo r h o t vis co s ity(Fig.5-B),co o l v is co s ity(Fig.5-C),a n d br ea kd o w n va lu es(Fig.5-D).In co n tr as t,N fe rtiliz er in cre as e d th e va lu e of s etb a ck(Fig.5-E), b u t th er e wa s n o s i
g n ifica n t e ffect of N o n co n s is te n cy.N o o b viou s tren d wa s fo u n d in s tar c
h p a s tin g p ro p ert ies a s a co n s e q u en ce o f b re ed in g.Co m pa re d to1950s cu ltiv ar s p ea k v is co s ity a n d b rea kd o w n v alu es o f m od e rn japon ica cu lt iv ars w e re s ign ifican t ly in crea s ed by5.7%an d130.3%,res p e ctiv ely, a n d se tb ack v alu e w as s ign ifican tly d ecr ea s ed b y141.7%.
In a d dition to bioch em ica l an d b io p h ys ical a n aly s is,co ok in g a n d eatin g qu a lity ca n also be me as u red by se n s ory as s es sm en t.
A rice tas te a n alyzer STA1A w as u s ed to rate th e o vera ll p alatab ility(Fig.4-C).Palatab ility stea d ily imp ro ved w ith b reed-in p ared to1950s cu ltiv ars,ov erall p a lata bility of mo d ern rice cu ltiva rs in crea s ed by20.7%,17.6%,a n d22.9%w ith0N, 240N,an d360N lev els,res p ectiv ely.N a pp licatio n s sign ifica n tly re du ce d o ver all pa lata bility re gard le ss o f cu ltivar s.On a vera ge, o ver all pa lata bility v alu e d ro p pe d fro m73.31a t0N to67.07at 240N an d64.07a t360N.
3.5.Nutr itive qua lity
Re gar d les s o f N ap p lication r ate s,pr otein co n ten t in m ille d r ice w a s s ign ifica n tly red u ce d d u rin g b reed in g p r ogr es s(Fig.6).It d ec reas e d fro m8.8%in th e1950s to7.4%in th e2000s a t th e0N leve l,fro m9.55%in th e1950s to8.35%in th e2000s at th e240N leve l,an d fro m10.35%in th e1950s to9.2%in th e2000s at th e 360N leve l o f fertiliza tio n.Ho w eve r,th e ap p lication of N fe rtilizer s ig n ifica n tly in cre as ed th e p ro tein co n ten t(Fig.6; T ab le2).Th e a ve rag e p r ote in con t en ts w er e7.7%,9.0%,a n d9.7% a t0N,240N,a n d360N le vels,res p ective ly.
Un d er h igh er N le vels,all m icron utrien t co n ten ts w ere low er (Fig.7).Th is m a y d u e to en h an ce d carb on as s im ila tion u n d er h igh N a pp licatio n,a s h igh N w ou ld in cr eas e th e co n cen tra tion o f p h o tos yn th e tic en zym es in leav es,an d th e la rger y ield s w ou ld d ilu te m icr on u trie n t co n ten ts(Fig.7).For Cu,th e av erag e co n ten t
f1N61 N(3%),6536N(%) S f(F)
,
292T H E C R O P J O U R N A L3(2015)285–29
.4.Cooking a nd ea ting ua lit
C oo k in g/ea t in g u al it is la rg el d et e rm in e d b p h s i cal an d ch em i cal ch a ra ct er is t i cs o t h e st arc h i n t h e en d o s p e rm:t h at d ro p pe d ro m2.87m g k g a t t h e0l evel to2.7m g kg at t h e 240l evel.8a n d t o2.m g k g1at t h e0leve l7.7. im ila r re su l t s we re o bt ai n ed or ot h e r m icro n u t rien t s ig.7. Co m p aris o n s be t wee n t h e cu l ti va rs wi t h in d eca de s sh ow ed t h e。