全 文 ：第 28 卷 第 4 期 作　物　学　报 V o l. 28, N o. 4
2002 年 7 月　 475～ 479 页 A CTA A GRONOM ICA S IN ICA pp. 475～ 479　 Ju ly, 2002
Study on F ield-grown M a ize In troduced in to T ibetan Pla teau: Som e Character-
ist ics of D iurna l Var ia tion of Photosyn thes is
YAN G J ia2D ing3 　L IU Zh i2M in
(Cold & A rid R eg ions E nv ironm en ta l and E ng ineering R esearch Institu te, T he Ch inese A cad emy of S ciences, N o. 260 D ong g ang W est R oad ,
L anz hou 730000, Ch ina)
Abstract　T he diu rna l pa t tern of net pho to syn thet ic ra te in field2grow n m aize in troduced in to T ibetan
P la teau w as an one2peak cu rve and the m ax im um value w as 39. 03 Λm o l CO 2·m - 2·s- 1 a t 15: 00 du ring
the jo in t ing stage, com pared to a tw o2peak cu rve, the m ax im um 20. 03 Λm o l CO 2·m - 2·s- 1 a t 12: 00 in
the sam e cu lt ivar grow n in in terim of arid and sem iarid p la in repo rted by som e researchers. T hese ind ica ted
an increase in leaf pho to syn thet ic ra te as m aize w as in troduced from the low eleva t ion reg ion to the h igh.
Op tim al day tem pera tu re, p len ty of so la r rad ia t ion and sufficien t w ater supp ly shou ld be respon sib le fo r
the d ifferences. Fu rtherm o re, bo th ligh t sa tu ra t ion and com pen sa t ion po in t w ere h igher in in troduced
m aize, im p lying an adap ta t ion to p la teau environm en t of in ten se rad ia t ion. T he in tercellu la r CO 2 concen2
t ra t ion of m aize leaves fluctua ted in the day cou rse, no t m ain ta ined con stan t as suggested by som e re2
searchers.
Key words　M aize, Pho to syn thesis, T ibetan P la teau
引种于青藏高原的大田玉米研究: 光合作用日变化的特点Ξ
杨甲定3 　刘志民
(中国科学院寒区旱区环境与工程研究所, 甘肃兰州 730000, 中国)
摘　要　引种于青藏高原的大田玉米, 在拔节期其净光合速率 (Pn) 日变化为一单峰曲线, 最大值 39. 03 Λmo l CO 2·
m
- 2·s- 1出现在 15: 00; 而文献中生长在干旱半干旱交错平原区的同品种玉米, Pn 日变化为双峰曲线, 最大值 20. 03Λmo l CO 2·m - 2·s- 1出现在 12: 00。表明玉米从低海拔平原引种到高海拔地区使叶片净光合速率变大。适宜的白天高
温、充足的太阳光能和水分供应是出现这一变化的主要原因; 而且引种玉米叶片的光饱和点与光补偿点均增大, 认为
这是对高原环境强烈光照的一种适应。另外, 玉米叶片细胞间隙CO 2 浓度并非象某些文献所报道是保持不变, 而是在
全天进程中有起伏波动。
关键词　玉米; 光合作用; 青藏高原
中图分类号: S513, Q 945　　　文献标识码: A
　　M aize (Z ea m ay s L. ) is a therm oph ilou s crop
belonging to gram inea fam ily. It has h igh pho to2
syn thet ic capacity and h igh adap tab ility to arid en2
vironm en ts[ 1 ]. W hen in troduced from low eleva t ion
p la in s to the T ibetan P la teau w ith an eleva t ion
abou t 3800～ 3900m , th is crop has reached the
m ax im um eleva t ion of u sua l d ist ribu t ion [ 2 ]. A s a
resu lt of specia l environm en ta l facto rs of the T i2
betan P la teau, e. g. h igh eleva t ion, low air p res2
su re ( low den sity of CO 2 and O 2) , in ten se so lar ra2
dia t ion, low m ean annual tem pera tu re and large
da ily tem pera tu re range, d ist inct ra in and arid sea2
son etc. [ 2, 3 ] , in t roduced m aize is expected to ex2
h ib it som e co rresponding varia t ion s in pho to syn2Ξ 中国科学院 1996 年度“西部之光”资助。
Foundation item: the p ro ject‘the W estern L igh t’(1996) , T he Ch inese A cadem y of Sciences.3 3 通讯联系人 A utho r fo r co rrespondence.
作者简介: 杨甲定 (19712 )甘肃甘谷人, 理学硕士。
Received on (收稿日期) : 2001204209, A ccep ted on (接受日期) : 2001211219

thesis com pared w ith m aize grow n in low eleva t ion
reg ion.
D ue to the lim ita t ion s of geograph ica l condi2
t ion s and cu lt iva t ion techn iques in the past, there
have no t yet been any repo rts abou t pho to syn thesis
of m aize w h ich w as in troduced in to the T ibetan
P la teau. So the ob ject ives of th is study w ere to in2
vest iga te the d ifferences of d iu rna l pho to syn thet ic
varia t ion betw een m aize grow n in the T ibetan
P la teau and tha t in the low lands, and to ana lyze
the po ssib le facto rs lead ing to these d ifferences.
1　M a ter ia l and m ethods
1. 1　Growing cond ition s and plan t ma ter ia l
M aize p lan ts (Z ea m ay s L. cv“Zhongdan2”)
w ere grow n in an experim en ta l f ield (29°N , 89°E)
in the m iddle va lley of the Yarlungzangbo R iver,
w here the eleva t ion is 3860m , the m ean tem pera2
tu re of grow th season (M ay to Sep tem ber) is 13.
1℃, and the so il type is sandy so il. T he m aize
seeds w ere sow ed in an irriga ted field by the end of
A p ril and covered w ith a layer of p last ic f ilm to
keep the so il w arm. A fter em ergence, seed lings
grew under en t irely na tu ra l condit ion s. T he exper2
im en ts w ere carried ou t in the last ten days of June
w hen m aize p lan ts w ere exact ly a t the jo in t ing
stage and abou t one m eter h igh.
1. 2　Ga s exchange m ea surem en ts
R ates of pho to syn thesis and tran sp ira t ion
w ere assayed w ith C I2301 CO 2 ana lyzer (C ID. Inc. ,
U SA ) , w h ich w as ca lib ra ted once every day befo re
m easu rem en ts w ith standard CO 2 gas (400 ΛL öL )
m ade in Beijing Gas A nalysis Facto ry.
By m ean s of an open gas ana lysis system , the
PA R 1, TA , RH , R s, Pn, E and C iw ere m easu red
successively w ith an in terva l of 1 o r 2 hou rs in a d i2
u rna l cou rse and all va lues w ere reco rded in the an2
a lyzer. Ca w as sim u ltaneou sly m easu red by u sing
the a ir pum ped from alm o st 3 m eters above the
p lan t comm un ity. Every reco rd w as taken du ring
20 m inu tes on the upper parts of th ree m iddle2top
leaves w h ich w ere a t the sam e heigh t of th ree d if2
feren t p lan t seed lings respect ively.
To determ ine the ligh t respon se cu rve of pho2
to syn thesis, layers of w h ite m esh clo th w ere u sed
to change PA R reach ing the sam p led m aize leaves.
Choo sing the period of 13: 00 to 17: 00 on fine days
w hen am b ien t tem pera tu re w as nearly stab le
around 35℃, the ligh t respon se cu rve of Pn w as
genera lized based on pho to syn thet ic ra te a t d iffer2
en t PA R on a sing le leaf. L CP and L SP of in tro2
duced m aize w ere est im ated from these raw data.
A ll m easu rem en ts w ere taken on ly on clear
days. A ll t im e ind ices w ere fo r Beijing t im e.
2　Results
2. 1　D iu rna l varia t ion s of PA R , TA and Pn
A s show n in F ig. 1a, PA R increased sign if i2
can t ly from 8: 00 to 11: 00, then leveled off w ith
som e rise and fa ll un t il 19: 00, and decreased
m arkedly after 19: 00. TA exh ib ited a sim ila r
cu rve w ith its m ax im um (37℃) a t 15: 00.
Pn of leaves (F ig. 1b) increased from 2. 45 to
35. 83 (Λm o l CO 2·m - 2·s- 1) in pace w ith increas2
ing PA R and TA over the period from 8: 00 to 13:
00; then fluctua ted sligh t ly from 13: 00 to 19: 00.
A fter 19: 00, Pn declined sharp ly as PA R and TA
decreased. T he m ax im um Pn (39. 03 Λm o l CO 2·
m
- 2·s- 1) occu rred a t 15: 00. T hese ind ica ted ob2
viou sly tha t the Pn vs t im e cu rve had a sing le peak
and noonday dep ression of pho to syn thet ic ra te d id
no t occu r.
2. 2　D iurna l var ia tion s of RH, Rs and E
RH declined from 58% (8: 00) to 28% (9: 00)
and leveled off around 22% , then increased after
17: 00 and reached 65% at 21: 00. E increased sig2
n ifican t ly from m o rn ing to noon, reached an obvi2
ou s m ax im um at 15: 00, then declined m arkedly af2
ter 15: 00 (F ig. 2). R s of m aize leaves w as stab le
w ith a lit t le decrease du ring 8: 00 to 19: 00. A fter
19: 00, R s increased sharp ly.
　　1 Abbrev iation s: PA R , pho to synthetically active radiation;
TA , temperature of air; RH , relat ive hum idity; R s, stom 2
atal resistance; Pn, net pho to synthetic rate; E, rate of
transp iration; C i, in tercellu lar CO 2 concentration; Ca,
CO 2 concentration in the air 3m above; Ce, CO 2 concentra2
t ion exactly around leaves; L CP, ligh t compensation
po in t; L SP, ligh t saturation po in t.
674　　　　　　　　　　　　　　　　　　　　　作　　物 　　学　　报　　　　　　　 　　　　　　　　　　　　28 卷

F ig. 1　　D iurnal variat ions of PA R and TA (a) , and Pn of
in troduced m aize leaves (b) in the field condit ions. Every
po in t rep resen ts a m ean value of 15 reco rds from th ree
leaves. V ertical bars indicate standard erro rs. (PA R ,
pho to synthetically active radiation; TA , temperature
of air; Pn, net pho to synthetic rate. )
F ig. 2　D iurnal trends of RH , E and R s of in troduced
m aize leaves in the field condit ions. V ertical bars
indicate standard erro rs of the m eans (n= 15). (RH ,
relat ive hum idity; E, rate of transp iration; R s,
stom atal resistance. )
2. 3　D iurna l var ia tion s of CO 2 concen tra tion
A s show n in F ig. 3, Ca w as app rox im ately
con stan t th roughou t the day and w as abou t 300Λm o löm o l w ith a sm all t rough at 15: 00. How ever,
C i exh ib ited la rge undu la t ion. A round sun rise
(8: 00) , it w as very clo se to Ca, then declined ap2
paren t ly. T he m in im um value appeared a t 15: 00.
F rom 15: 00 to 19: 00, C i increased gradually; after
tha t, it ascended so sharp ly tha t it even exceeded
Ca and reached 462 Λm o löm o l a t 21: 00.
F ig. 3　　D iurnal trends of Ca and C i. Every po in t in figure
rep resen ts a m ean value of 15 reco rds from th ree differen t
leaves. V ertical bars indicate the standard erro rs. (Ca,
CO 2 concentration in the air 3m above; C i,
in tercellu lar CO 2 concentration. )
2. 4　L ight respon se curve of leaf photosyn thesis
T he ligh t respon se cu rve of Pn in in troduced
m aize leaves w as determ ined as F ig. 4. O bviou sly,
Pn increased a long w ith increasing PA R in a cu rvi2
linear m anner. In a low PA R range, there w as an
a lm o st linear respon se of Pn to PA R.
F ig. 4　Pn of in troduced m aize leaves versus PA R in the field
condit ions. Every po in t rep resen ts a m ean value of 20
reco rds from four leaves (June 22 and 23, 1999). T he
arrow A and B indicate L CP and L SP respectively. (Pn,
net pho to synthetic rate; PA R , pho to synthetically
active radiation; L CP, ligh t compensation
po in t; L SP, ligh t saturation po in t. )
7744 期　　　　　　　　　YAN G J ia2D ing et al. : Study on F ield2grow n M aize In troduced in to ⋯⋯　　　　　　　　　

3　D iscuss ion s
3. 1　Specia l d iu rna l t rends of Pn and E of in tro2
duced m aize leaves
Con trary to a sing le peak in in troduced m aize
( F ig. 1b ) , the Pn vs t im e cu rve had tw o peak s
w ith a noonday dep ression abou t a t 14: 00, and the
m ax im um Pn w as 20. 03 Λm o l CO 2·m - 2· s- 1 a t
12: 00 in m aize grow n in in terim of arid and sem i2
arid p la in zone (eleva t ion 1250m ) [ 4 ]. T hese ind i2
ca ted tha t in troduct ion from low eleva t ion p la in to
h igh eleva t ion T ibetan P la teau resu lted in increas2
ing of the net pho to syn thet ic ra te and p ro longat ion
of the t im e w hen m ax im um Pn occu rred in m aize.
F rom F ig. 2, it w as clearly show n tha t the d i2
u rna l t rend of E w as a standard one2peak cu rve.
Fu rtherm o re, varia t ion s of E w ere m o re clo sely re2
la ted to TA ( r = + 0. 949 ) than to R s
( r= - 0. 625). So it w as inferred tha t in troduced
m aize d id no t suffer w ater deficit w hen m easu red.
T he diu rna l varia t ion s of R s (F ig. 2) w ere con sis2
ten t w ith ob serva t ion tha t w ith adequate w ater,
leaf R s w as a lm o st con stan t th roughou t the day in
w heat [ 5 ]. T here w ere sim ila r ind ica t ion s in co t2
ton [ 6 ] tha t m idday stom ata l conductance is so h igh
( i. e. stom ata l resistance so low ) tha t it p rovides a
rela t ively sm all lim ita t ion to gaseou s d iffu sion
(CO 2 and H 2O vapo r) in an irriga ted field environ2
m en t.
3. 2　Var ia tion s of CO 2 concen tra tion
T hough it has been suggested tha t som e
species w ou ld m ain ta in a nearly con stan t C i acro ss
varying environm en ta l condit ion s[ 7 ] , th is w as no t
the case in ou r experim en t. A s show n in F ig. 3, C i
had apparen t f luctua t ion and w as less than 200Λm o löm o l from 9: 00 to 19: 00 desp ite rela t ively
con stan t Ca (abou t 300 Λm o löm o l). Con sidering
tha t the R s w as con stan t from 9: 00 to 19: 00 (F ig.
2) , the decreasing of C i m u st resu lt from the h igh
pho to syn thet ic ra te of p lan t comm un ity am ong
w h ich the am b ien t CO 2 w as com peted by all pho to2
syn thet ic leaves. W h ile after 19: 00, increasing of
C i w ou ld be a t t ribu ted to sharp Pn descen t of leaf
itself and accum u la t ion of CO 2 in space su rrounding
leaves in p lan t comm un ity. In addit ion, Berry et
a l[ 8 ] ind ica ted tha t stom ata l appara tu s shou ld re2
spond to changes in environm en ta l facto rs in such a
w ay as to keep the rela t ive stom ata l lim ita t ion,
tha t is , C iöCe shou ld be con stan t. If fo llow ing
th is po in t, the CO 2 concen tra t ion exact ly around
pho to syn thet ic leaves (Ce) w as specu la ted to fluc2
tua te accom panying w ith varia t ion s of C i.
3. 3　L SP and LCP in in troduced ma ize leaves
M aize in troduced to the T ibetan p la teau had a
h igher L SP (900 Λm o l·m - 2· s- 1 ) (F ig. 4) than
low land m aize [ 4 ] , abou t 1. 5 t im es as grea t as tha t
of the la t ter (600 Λm o l·m - 2·s- 1). T h is m ean s a
physio log ica l adap ta t ion occu rred in m aize in tro2
duced to th is environm en t of in ten se so lar rad ia2
t ion. It w as con sisten t w ith view s tha t h igher ele2
vat ion w ou ld cau se a la rger L SP, as repo rted in
M im u lus ca rd ina lis [ 9 ] and som e C3 p lan ts in a lp ine
m eadow [ 10 ]. O n the o ther hand, the L CP of in tro2
duced m aize (90 Λm o l·m - 2·s- 1) (F ig. 4) w as a l2
so m uch h igher than tha t of low land m aize ( 50Λm o l·m - 2 · s- 1 ) [ 4 ]. T h is resu lt d isagreed w ith
the view tha t p lan ts grow n in a h igher eleva t ion re2
gion w ou ld have a low er L CP [ 10 ] , bu t w as sim ila r
to the resu lts of p la teau O ry z a sa tiva [ 11 ]. So th is
m ay ind ica te tha t the rise o r fa ll of L CP along w ith
change in eleva t ion w as rela ted no t on ly to p lan t
species, bu t a lso to d ifferences betw een part icu la r
hab ita ts and to specia l grow ing condit ion s and de2
velopm en ta l stage of the p lan t.
3. 4　Possible factors for h igher Pn in in troduced
ma ize
Con sidering tha t the low CO 2 part ia l p ressu re
in T ibetan P la teau cau sed by h igh eleva t ion is d is2
advan tageou s to p lan t pho to syn thesis, w e suggest2
ed tha t the o ther environm en ta l facto rs m u st po si2
t ively influence Pn in in troduced m aize. A s ap2
peared in F ig. 1a, the a ir tem pera tu re from 11: 00
to 19: 00 fluctua ted betw een 28～ 37℃. T h is tem 2
pera tu re range w as exact ly around the op t im al
tem pera tu re of pho to syn thesis in m aize [ 4 ]. So bo th
the electron tran spo rt and CO 2 f ixa t ion in leaf
ch lo rop lasts w ou ld p roceed a t h igh speed [ 12 ]. T h is
shou ld be one of m ain facto rs fo r h igher Pn in in2
874　　　　　　　　　　　　　　　　　　　　　作　　物 　　学　　报　　　　　　　 　　　　　　　　　　　　28 卷

t roduced m aize.
Fu rtherm o re, the jo in t ing stage of in troduced
m aize (m iddle June to la ter Ju ly) is du ring the ra in
season in the T ibetan P la teau. It often ra in s heavi2
ly a t n igh t and rad ia t ion is h igh du ring the day. So
even at noonday, RH w as no t less than 20% and at
sun rise and sun set RH w as as m uch as 60% (F ig.
2). T he m in im um R s and the sharp peak of E oc2
cu rred a t 15: 00 w hen TA w as the h ighest (F ig. 2,
F ig. 1a ). U nder w ater st ress, R s w ou ld increase
and E exh ib it a decline a t h igh am b ien t tem pera2
tu re [ 13 ] , so ou r resu lts ind ica ted tha t so ilw ater w as
sufficien t and there w as no t w ater deficit fo r f ield
m aize leaves w hen m easu red. T he ab sence of w ater
deficit w ou ld be ano ther im po rtan t facto r fo r h igh2
er Pn in in troduced m aize du ring its jo in t ing stage.
In con trast, in m aize grow n in in terim of arid and
sem iarid p la in zone, the w ater supp ly is a lw ays the
lim it ing facto r fo r crop pho to syn thesis[ 14 ] , i. e. w a2
ter st ress w ou ld reduce bo th gro ss and net pho to2
syn thesis[ 15 ].
Becau se the leaves of in troduced m aize show ed
a h igher L SP (d iscu ssion above) , in ten se so lar ra2
dia t ion m ay strongly p rom o tes its pho to syn thesis.
O n the o ther hand, it has been ob served tha t sho rt
w avelength ligh t, especia lly b lue ligh t, is effect ive
in cau sing stom ata l open ing o r p reven ts stom ata l
clo su re [ 16 ]. A s show n in fig. 2, R s of m aize leaf
w as a lm o st con stan t from 9: 00 to 19: 00 w ith a
sligh t va lley a t noonday. T h is m ean s tha t stom ata l
clo su re d idn′t occu r du ring th is period and m aize
cou ld easily exchange gas w ith am b ien t a ir, m ain2
ta in ing the h igh level of Pn desp ite low CO 2 part ia l
p ressu re. T he h igh in ten sity of so la r rad ia t ion and
h igh con ten t of sho rt w avelength ligh t in the T i2
betan P la teau environm en t shou ld a lso be rela ted
to h igh Pn of in troduced m aize.
Acknowledgm en ts
W e thank the cen tra l L abo ra to ry of T ibetan
A cadem y of A gricu ltu ra l Sciences fo r p rovid ing
som e experim en ta l facilit ies.
References
[ 1 ]　N asyrov Y S. Genetic contro l of pho to synthesis and imp rov2
ing of crop p roductivity. A nn. R ev. P lan t P hy siol, 1978,
29: 215～ 237
[ 2 ]　T ibetan P lateau scien tific expedit ion team , Ch inese A cadem y
of Sciences (中国科学院青藏高原综合科学考察队). Charac2
terist ics of p resen t clim atic facto rs; M ain traits of crop s cli2
m ate in T ibetan P lateau; C rop and clim ate (m aize). C lim ates
of T ibet (西藏气候). Beijing: Science P ress, 1984, 90～ 132;
225～ 228 and 241～ 244 ( in Ch inese)
[ 3 ]　Hou G2L (侯光良) , L i J2Y (李继由) , Zhang Y2G (张谊光).
A groclim atic resources of T ibetan P lateau. Ch inese A g rocli2
m atic R esou rces (中国农业气候资源). Beijing: Peop le′s U ni2
versity P ress, 1993, 198～ 209 ( in Ch inese)
[ 4 ]　Feng J2C (冯金朝) , J iang T 2R (江天然) , Song Y2X (宋耀
选) , et a l. Effects of environm ental facto rs on pho to synthe2
sis of C3 and C4 p lan ts. J D esert R esearch (中国沙漠) , 1998,
18 (supp l. 4) : 39～ 42 ( In Ch inese w ith English abstract)
[ 5 ]　L u Z2M (卢振民) , N iu W 2Y (牛文元) , Zhang Y (张翼).
F ield studies of the w heat stom ata resistance influenced by
so il w ater conten t. A cta B otan ica S in ica (植物学报) , 1986,
28 (4) : 419～ 426 ( in Ch inese w ith English abstract)
[ 6 ]　Co rnishK, J W Radin, E L T urco tte, et a l. Enhanced pho to2
syn thesis and stom atal conductance of P im a co tton (Gossyp i2
um barbad ense L. ) bred fo r increased yield. P lan t P hy siol,
1991, 97: 484～ 489
[ 7 ]　W ong S C, Cow an I R , Farquhar G D. Stom atal conductance
co rrelates w ith pho to synthetic capacity. N atu re, 1979, 282:
424～ 426
[ 8 ]　BerryJ A , Dow nton W J S. Environm ental regu lation of pho2
to syn thesis. Govindjee ( ed. ) , P hotosy n thesis (V o l. Ê ).
N ew Yo rk: A cadem ic P ress, 1982, 263～ 343
[ 9 ]　M ilnerH W , H ieseyW M. Pho to synthesis in clim atic races of
M im u lus ( I. Effect of ligh t in tensity and temperature on
rate. ). P lan t P hy siol, 1964, 39: 208～ 213
[ 10 ]　Zhang S2Y (张树源) , L u G2Q (陆国权) , W H (武海) , et a l.
Pho to synthesis of m ajo r C3 p lan ts on Q inghai P lateau. A cta
B otan ica S in ica (植物学报) , 1992, 34: 176～ 184 ( in Ch inese
w ith English abstract)
[ 11 ]　X ia M 2Z (夏明忠). Study on pho to synthetic characterist ics of
p lateau O ry z a sa tiva var. jap on ica. P lan t P hy siology Com 2
m unica tions (植物生理学通讯) , 1991, 27: 181～ 184 ( in Ch i2
nese)
[ 12 ]　FarquharG D , Sharkey T D. Stom atal conductance and pho2
to syn thesis. A nn R ev P lan t P hy siol, 1982, 33: 317～ 345
[ 13 ]　Zhang S2Y (张树源) , W u H ( (武海) , Shen Z2X (沈振西) , et
a l. T he response of m idday dep ression of diurnal variat ion of
net pho to synthetic rate of w heat leaves on eco logical facto rs
in the field environm ent of Q inghai P lateau. A cta B ot B orea l2
O ccid en t S in (西北植物学报) , 1995, 15: 212～ 218 ( in Ch i2
nese w ith English abstract)
[ 14 ]　F ischer R A , N C T urner. P lan t p roductivity in arid and
sem iarid zones. A nn R ev P lan t P hy siol, 1978, 29: 277～ 317
[ 15 ]　Perry S W , D R Krieg, R B H utm acher. Pho to synthetic rate
contro l in co tton. P lan t P hy siol, 1983, 73: 662～ 665
[ 16 ]　Sharkey T D , Raschke K. Separation and m easurem ent of di2
rect and indirect effects of ligh t on stom ata. P lan t P hy siol,
1981, 68: 33～ 40
9744 期　　　　　　　　　YAN G J ia2D ing et al. : Study on F ield2grow n M aize In troduced in to ⋯⋯