全 文 ：第 27 卷 第 6 期 作　物　学　报 V o l. 27, N o. 6
2001 年 11 月 A CTA A GRONOM ICA S IN ICA N ov. , 2001
A System of Ovule Subculture for Cotton (Gossyp ium h irsu tum L. )
F iber D evelopm en tΞ
YAN G You2M ing1　XU Chu2N ian1ΞΞ　J IA Jun2Zhen2
(1 Colleg e of C rop S cience, Ch ina A g ricu ltu ra l U niversity , B eij ing , 100094; 2 Colleg e of B asic S cience and T echnology ,
Ch ina A g ricu ltu ra l U niversity , B eij ing , 100094, Ch ina)
Abstract　　To overcom e the lim ita t ion s of the m ethod of co t ton ovu le cu ltu re developed by
Beasley and T ing, a system of ovu le subcu ltu re fo r co t ton fiber developm en t (SO SCFD ) has
been estab lished, includ ing the fo llow ing m ain po in ts: T he ovu les in 2nd developm en ta l sta te
determ ined by the characterist ics of co ro lla and st igm a w ere u sed as exp lan t. Cu ltu red co t ton
ovu les w ere successively tran sferred to fresh m edia w ith 14 cyclic days each subcu ltu re. In
subcu ltu re m edia act iva ted charcoa l (5 g·L - 1 ) w as supp lem en ted and the con st ituen t of
p lan t grow th regu la to rs and its concen tra t ion w ere changed to acco rd w ith the dem ands of
fiber developm en t in d ifferen t phases. T he specif ic st reng th, cell w all th ickness and length
of fiber grow n in SO SCFD , exh ib it ing a developm en ta l schedu le sim ila r to fiber grow n in
p lan t, reached o r app roached tho se grow n in p lan t. T herefo re, SO SCFD can be u sed as a
new experim en ta l too l of studying the characterist ics of each stage and w ho le p rocess of fiber
developm en t, especia lly the fo rm at ion of secondary cell w all th ickness and streng th of
fibers.
Key words　　Co tton; O vu le cu ltu re; F iber developm en t; F iber qua lity
Abbrev ia tion s　　DA C: D ays after cu ltu re; D PA : D ays po stan thesis; DW : D ry w eigh t;
SO SCFD: A system of ovu le subcu ltu re fo r co t ton fiber developm en t
棉胚珠继代培养纤维体系的建立3
杨佑明1　徐楚年13 3 　贾君镇2
(1中国农业大学作物学院, 2中国农业大学基础科学与技术学院, 北京, 100094)
提　要　针对传统的棉胚珠培养方法因纤维在发育中途夭亡而不能用于研究次生壁增厚和强度形成的
机理, 本文建立了棉胚珠继代培养纤维体系, 即根据花铃的形态特征选取Ê 类发育状态的胚珠作外植
体, 以 14d 为周期连续 3 次继代, 在继代培养基中添加 5 g·L - 1活性碳, 并根据纤维发育不同阶段的
特点调整植物生长物质的种类和浓度。结果使纤维重现了植株条件下的发育历程, 其比强度、长度和
细胞壁厚度等品质指标达到或接近植株条件下发育的纤维, 为研究棉纤维发育和品质形成的机理提供
了一个新的实验体系。
关键词　棉花; 胚珠培养; 纤维发育; 纤维品质ΞΞΞ To w hom co rrespondence should be addressed
Received on: 2000206216, A ccep ted on: 2001203215T h is study w as suppo rted by the N ational Science Foundation of Ch ina (Grand NO. 39800097).

Co tton fibers are sing le2celled trichom es tha t develop from certa in ep iderm al cells of the
ou ter in tegum en t of ovu le. T he developm en t of fiber can be divided in to fou r phases:
in it ia t ion, elongat ion, secondary cell w all th icken ing and m atu ra t ion. T he p ropert ies of
co t ton fiber are fo rm ed du ring fiber developm en t. Fo r exam p le, f iber st reng th is determ ined
by the specif ic characterist ics of secondary cell w all w h ich are fo rm ed du ring its th icken ing.
T herefo re, the developm en t of co t ton fiber is a sign if ican t area of research. D evelop ing
co t ton fiber has a lso been a good m odel system fo r the stud ies of severa l fundam en ta l
p rob lem s in p lan t cell b io logy such as cell d ifferen t ia t ion, elongat ion, w all syn thesis, and
o rgan iza t ion, etc.
A m ethod of co t ton ovu le cu ltu re w as developed by Beasley and T ing (1973, 1974) [ 1, 2 ].
T he m ethod has been u sed as a m odel fo r stud ies on the effects of nu trit ion, chem ica l such as
p lan t grow th regu la to rs, and low air tem pera tu res on fiber developm en t [ 3～ 7 ]. How ever,
f ibers grow n in cu ltu re exh ib ited a com p ressed schedu le of developm en t so tha t the fina l
leng th of fibers grow n in cu ltu re is abou t ha lf of the fibers grow n on the p lan t and the ex ten t
of secondary w all depo sit ion of fibers grow n in cu ltu re is very low [ 3, 8 ]. T he p resen t study
w as carried ou t to im p rove the m ethod of co t ton ovu le cu ltu re.
1　M a ter ia ls and m ethods
Experim en ts w ere conducted from Ju ly th rough Sep tem ber of the years 1996～ 1999 in
Ch ina A gricu ltu ra l U n iversity, Beijing. Gossyp ium h irsu tum L. cv. Zhongm ian suo12 p lan ts
w ere grow n in the field. T he ovu les w h ich w ere su itab le fo r in v itro cu ltu re w ere determ ined
by the characterist ics of co ro lla and st igm a. Ow ing to the d ifference of field tem pera tu re in
the flow ering stage, the ovu les on 2days po stan thesis (D PA ) m igh t be in one of the th ree
k inds of developm en ta l sta te: (É ) each ovu le tha t w as easy to be sunk in liqu id m edium and
the su rface of ovu le w as sm oo th to the naked eye, a t the sam e tim e the co ro lla becam e
pu rp lish red, the upper of co ro lla is w ilt ing bu t the st igm a is fresh; (Ê ) each ovu le on
w h ich fibers had a m ean length of 0. 2～ 0. 4 mm w as easy to separa te and floa t on the su rface
of liqu id m edium , co rresponding ly, the upper of w ilt ing co ro lla becam e dried2up and the
st igm a began to b row n; (Ë ) each ovu le on w h ich fibers elongated to m o re than 0. 5 mm w as
diff icu lt to separa te and handle ind ividua lly, hom o logica lly, the co ro lla and st igm a w ere
dried up. Bo lls w ere co llected a t the sam e tim e ovu les in 2nd developm en ta l sta te un less
g iven an exp lana t ion especia lly.
Bo lls w ere su rface2sterilized in a so lu t ion of H gC l2 (100 g·L - 1) fo r 12 m in. A fter being
rin sed in sterile d ist illed w ater, ovu les w ere asep t ica lly rem oved and floa ted on the su rface of
50 m l of liqu id m edium in 100m l cu ltu re flask s. T he m edium w as a m odified Beasley and
T ing m edium (nam ed N G23) w h ich con ta ined the ino rgan ic sa lts, n ico t in ic acid, pyridox ine
hydroch lo ride, th iam ine hydroch lo ride, m yo ino sito l and D 2gluco se as in Beasley and T ing [ 1 ] ,
bu t added NAA 5 Λm o l·L - 1 and GA 3 1 Λm o l·L - 1, and sucro se in stead of fructo se.
O vu les w ere cu ltu red in the dark a t 32℃ and tran sferred to a subcu ltu re m edium w ith 14
cyclic days each. T he subcu ltu re m edium w as like N G23 m edium bu t tha t act iva ted charcoa l
( 5 g ·L - 1 ) w as added. Experim en ts described herein w ere conducted excep t on ly one
5966 期　　　YAN G You2M ing et a l: A System of O vu le Subcu ltu re fo r Co tton ⋯⋯　　　　

condit ion fo r t rea tm en t varied. Each trea tm en t con sisted of a t least ten flask s w ith 20 ovu les
from one ovary per flask.
F iber leng th w as determ ined acco rd ing to Gip son and Joham [ 9 ]. Tw en ty seeds w ere
exam ined in each trea tm en t.
Six flask s of each trea tm en t w as exam ined and ten seeds from one flask w ere p icked at
random. T he seeds w ere w ashed severa l t im es w ith d ist illed w ater, then the fibers w ere
m anually rem oved from the seeds. T he fibers and seeds w ithou t fibers w ere w eighed after
oven drying to a con stan t w eigh t a t 70℃. A ll w eigh t da ta w ere exp ressed in term s of dry
w eigh t (DW ) per seed.
T he so lub le sugar con ten t of fiber w as assayed u sing the an th rone2co lo rim etric m ethod
m odified by L in [ 10 ]. T he cellu lo se con ten t of fibers w as determ ined as described by
U pdegraff [ 11 ]. T he ca llo se con ten t of fibers w as determ ined by the m ethod described by
P illonel et a l[ 12 ]. T he fineness and th ickness of fiber w ere m easu red as described by J ia et
a l[ 13 ].
T he average and standard devia t ion of each set of da ta w ere ca lcu la ted. Sho rtest
sign if ican t ranges com parison test w ere conducted to iden t ify w here these d ifferences
occu rred. T he com b ina t ion s of naph tha lene acet ic acid (NAA ) , g ibberellic acid (GA 3) and
ab scisic acid (ABA ) du ring the fo rth subcu ltu re stage w ere designed by u sing a tab le of
o rthogonal arrays and analyzed by u sing ranges m ethod.
2　Results
2. 1　D ura tion between two subcultures
Since 14 days after cu ltu re (DA C) , the so lub le sugar concen tra t ion of con tro l (w ithou t
subcu ltu re) m edia w as low er than tha t of succeed ing subcu ltu res w ith 7, 14, o r 21 cyclic
days each (T ab le 1). A t 28 DA C, the so lub le sugar concen tra t ion of con tro l w as 10. 5 g·
L - 1 and abou t ha lf of tha t of succeed ing subcu ltu res w ith 7, 14, o r 21 cyclic days each. A t
35 DA C, the so lub le sugar concen tra t ion of con tro l w as reduced to 2. 4 g·L - 1 w h ich w as
less than one2f if th of tha t of succeed ing subcu ltu res w ith 7, 14, o r 21 cyclic days each.
Co rresponding ly, the so lub le sugar con ten t of con tro l f iber w as a lso low er than tha t of
succeed ing subcu ltu res w ith 7, 14, o r
Table 1　　Changes in soluble sugar concen tration of media for succeeding subcultures with 7, 14,
or 21 cycl ic days each and without subculture (g·L - 1)
D ays after
cu ltu re
Subcultu re w ith
7 cyclic days
Subcultu re w ith
14 cyclic days
Subcultu re w ith
21 cyclic days
W ithout
subcultu re
0 24. 9 24. 9 24. 9 24. 9
7 28. 9a 28. 9 28. 9 28. 9
14 26. 8a 23. 8a 23. 8 23. 8
21 25. 2a 24. 0 18. 9a 18. 9
28 24. 0a 20. 8a 22. 8 10. 5
35 20. 8a 15. 2 16. 1 2. 4
42 16. 8a 6. 4a 6. 8a 2. 2
49 15. 4a 16. 1 20. 1 2. 1
　　a T he so lub le sugar concentration of used m edia. O n the sam e day cultu red ovules w ith adhering fibers w ere transferred
to fresh m edia in w h ich the so lub le sugar concentration w as 24. 9 g·L - 1.
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21 cyclic days each (T ab le 2). A t 35 DA C, the so lub le sugar con ten t of con tro lw as 68. 0 m g
· (g DW ) - 1. A t 56 DA C, the so lub le sugar con ten t of succeed ing subcu ltu res w ith 7, 14,
o r 21 cyclic days each w as 194. 7, 129. 2 and 192. 3 m g · ( g DW ) - 1, respect ively.
O bviou sly, co t ton ovu les cu ltu red fo r a few w eek s m u st be tran sferred to fresh m edia in
o rder to add gluco se and sugar.
Table 2　　Changes in soluble sugar con ten t of f ibers for succeeding subcultures with
7, 14, or 21 cycl ic days each and without subculture [mg· (g DW ) - 1 ]
D ays after
cu ltu re
Subcultu re w ith
7 cyclic days
Subcultu re w ith
14 cyclic days
Subcultu re w ith
21 cyclic days
W ithout
subcultu re
7 312. 5±12. 6 312. 5±12. 6 312. 5±12. 6 312. 5±12. 6
14 263. 4±13. 1 218. 6±8. 9 218. 6±8. 9 218. 6±8. 5
21 258. 9±12. 9 226. 8±13. 7 183. 7±6. 4 183. 7±6. 4
28 252. 8±12. 6 145. 8±5. 9 244. 7±12. 4 138. 9±5. 4
35 231. 1±10. 2 203. 7±7. 5 181. 3±6. 3 68. 0±3. 7
42 219. 1±9. 2 80. 2±3. 1 108. 7±5. 2 38. 0±1. 8
49 201. 9±8. 4 191. 6±7. 8 231. 6±12. 2 32. 0±1. 5
56 194. 7±7. 1 129. 2±6. 6 192. 3±7. 0 30. 0±1. 4
F ig. 1　　Changes in DW of fibers under succeeding subcultu res w ith 7, 14, o r 21 cyclic days each.
V ertical bars rep resen t±SD.
T he difference of fiber leng th am ong succeed ing subcu ltu res w ith 7, 14, o r 21 cyclic days
each w as in sign if ican t (da ta no t show n ). How ever, T he DW of fibers under succeed ing
subcu ltu res w ith 14 cyclic days each w as increased m o re qu ick ly than tho se under succeed ing
subcu ltu res w ith 7, o r 21 cyclic days each (F ig. 1). A t 56 DA C, the DW of fibers under
succeed ing subcu ltu res w ith 14 cyclic days each w as 8. 7 m g and sign if ican t ly w eigh t ier than
7966 期　　　YAN G You2M ing et a l: A System of O vu le Subcu ltu re fo r Co tton ⋯⋯　　　　

tho se under succeed ing subcu ltu res w ith 7, o r 21 cyclic days each. T hese w ere sim ila r to the
d ifference of DW of seed am ong succeed ing subcu ltu res w ith 7, 14, o r 21 cyclic days each
(F ig. 2). T herefo re, it is su itab le fo r co t ton ovu le cu ltu re succeed ing subcu ltu res w ith 14
cyclic days each.
F ig. 2　　Changes in DW of seed under succeeding subcultu res w ith 7, 14, o r 21 cyclic days each.
V ertical bars rep resen t±SD.
2. 2　Suitable developm en ta l sta te of ovule for culture
T he in v itro developm en t of ovu le w ith adhering fibers w as influenced by its
developm en ta l sta te w hen it w as co llected fo r cu ltu re (P la te É 21). D u ring co t ton ovu le
cu ltu re, m any ovu les in 3rd developm en ta l sta te becam e b row n, and the percen tage of
b row ned ovu les w as 18. 5. In con trast, the percen tage of b row ned ovu les in 1st o r 2nd
developm en ta l sta te w as sign if ican t ly low. T he length of fibers from 1st, 2nd o r 3rd
developm en ta l sta te w ere 16. 5, 26. 1 o r 14. 4 mm , respect ively. N o m arked difference w as
ob served in cellu lo se con ten t of fibers from 1st, 2nd and 3rd developm en ta l sta te. T he fiber
leng th, DW of fibers and seed in 2nd developm en ta l sta te w ere obviou sly superio r to the
o thers (T ab le 3). Fo r co t ton ovu le cu ltu re, it is su itab le to u se ovu les in 2nd developm en ta l
sta te.
Table 3　　Var ious developmen ta l state of cotton ovules af ter 56 DAC
D evelopm ental
state of ovule
Percen tage of
brow ned ovules F iber length DW of fibers
Cellu lo se conten t
in fibers DW of seedÉ 2. 8 16. 5±1. 7 7. 3±0. 6 914. 1±44. 6 21. 4±0. 8Ê 3. 7 26. 1±2. 1 8. 7±0. 4 911. 4±43. 8 23. 7±0. 9Ë 18. 5 14. 4±1. 8 6. 8±0. 3 871. 5±41. 3 20. 9±0. 5
896　　　　　　　　　　　　　　　　　作　　物 　　学　　报　　　　　　　　 　　　　　　　　27 卷

2. 3　Com bina tion s of NAA and GA 3
T he com b ina t ion s of NAA and GA 3 w ere determ ined acco rd ing to fiber leng th, becau se
the fibers w ere elongat ing du ring 1～ 28 DA C. A t the end of the first stage (14 DA C ) of
co t ton ovu le cu ltu re, the fiber leng th of N G21 ( con tro l) w as 2. 0 mm and sign if ican t ly
sho rter than tho se of the o thers. T he fiber leng th am ong N G23, N G27 and N G28 w as
in sign if ican t ly d ifferen t, bu t obviou sly longer than tho se of N G22, N G24, N G25, N G26 and
N G29. A t the end of the second stage (28 DA C) , the fiber leng th of N G21 w as 17. 8 mm and
obviou sly sho rter than the o thers. T he fiber leng th of N G23 o r N G29 w as sign if ican t ly longer
than tha t of N G22, N G25, N G26, N G27 o r N G28 (T ab le 4). It is eviden t tha t N G23, N G27
and N G28 w ere m o re su itab le than the o thers fo r the first stage of co t ton ovu le cu ltu re. So
w ere N G23 and N G29 fo r the second stage.
Table 4　　The effect of combination of NAA and
GA3 on f iber elongation
　
Code
Com binations of
NAA and GA 3
NAA + GA 3
F iber length
14 DA C 28 DA C
N G21 0+ 0 2. 0±0. 2 17. 8±1. 8
N G22 5+ 0. 5 13. 5±1. 7 23. 2±1. 8
N G23 5+ 1 16. 4±2. 2 26. 7±1. 5
N G24 5+ 5 14. 8±1. 8 25. 5±1. 4
N G25 5+ 10 15. 5±1. 3 23. 7±1. 5
N G26 10+ 0. 5 14. 6±1. 7 23. 2±1. 8
N G27 10+ 1 16. 4±1. 7 22. 8±2. 1
N G28 10+ 5 16. 6±1. 9 24. 8±1. 8
N G29 10+ 10 15. 5±2. 2 26. 8±2. 02. 4 　Com bina tion s of NAA , GA 3and ABASince co t ton ovu les w erecu ltu red in the sam e condit ion sdu ring the first and second stages,the fiber num ber and length of eachovu le had been fixed and w ere in2sign if ican t d ifferences a t thebeginn ing of the th ird stage.T herefo re, a t the end of the th ird o rfo rth stage, the d ifferences of fiberDW am ong com b ina t ion s of NAA ,
GA 3 and ABA w ere due to the d ifference of secondary w all th ickness of fibers.
A t the end of the th ird stage (42 DA C) , f iber DW of CT 215 w as 9. 0 m g (T ab le 5). T he
fiber DW of CT 215 w as the heaviest am ong the com b ina t ion s of NAA , GA 3 and ABA and
obviou sly heavier than the o thers. T he cellu lo se and ca llo se con ten t in fibers of CT 215 w ere
837. 36 and 7. 5 m g· (g DW ) - 1, respect ively. It w as no ted tha t CT 215 had a beneficia l effect
on cellu lo se syn thesis and secondary th icken ing of fibers and w as the m o st su itab le
com b ina t ion of NAA , GA 3 and ABA fo r the th ird stage of co t ton ovu le cu ltu re.
In o rder to acqu ire the op t im ize the com b ina t ion of NAA , GA 3 and ABA fo r the fou rth
stage, an experim en t w ith an o rthono rm al design had been carried ou t. A t the end of the
fo rth stage (56 DA C) , the DW and cellu lo se con ten t of fibers am ong com b ina t ion s of NAA ,
GA 3 and ABA w ere sign if ican t ly d ifferen t m u tua lly ( T ab le 6 ). T he data w ere ana lyzed
acco rd ing to the o rthono rm al experim en ta l design. Based on the ana lysis, ABA had a m o st
beneficia l effect on cellu lo se syn thesis and secondary th icken ing of fibers du ring the fo rth
stage, NAA the second, and the m o st su itab le com b ina t ion of NAA , GA 3 and ABA fo r the
fou rth stage con ta ined 1 Λm o l·L - 1 NAA , 0 Λm o l·L - 1GA 3 and 5 Λm o l·L - 1ABA.
9966 期　　　YAN G You2M ing et a l: A System of O vu le Subcu ltu re fo r Co tton ⋯⋯　　　　

Table 5　　The effects of combination of NAA , GA3 and ABA on secondary cell wall th icken ing
of f ibers dur ing the th ird stage
Code
Com binations of NAA ,
GA 3 and ABA
DW of fibers Cellu lo se conten t Callo se conten t
CT 21 0+ 0+ 0 6. 2±0. 4 811. 0±38. 6 13. 2±0. 5
CT 22 0+ 0. 5+ 15 7. 1±0. 2 819. 2±40. 0 11. 8±0. 5
CT 23 0+ 1+ 75 6. 3±0. 5 910. 9±43. 5 15. 4±0. 6
CT 24 0+ 5+ 3 4. 9±0. 5 882. 7±42. 1 17. 6±0. 7
CT 25 1+ 0+ 15 5. 9±0. 5 817. 4±37. 9 15. 9±0. 6
CT 26 1+ 0. 5+ 75 5. 8±0. 6 879. 3±42. 0 16. 9±0. 6
CT 27 1+ 1+ 3 6. 8±0. 5 878. 8±41. 9 15. 4±0. 6
CT 28 1+ 5+ 0 7. 3±0. 7 574. 7±26. 7 15. 4±0. 5
CT 29 5+ 0+ 75 5. 9±0. 3 843. 1±40. 2 15. 6±0. 6
CT 210 5+ 0. 5+ 3 7. 4±0. 5 682. 2±31. 1 12. 9±0. 4
CT 211 5+ 1+ 0 8. 1±0. 4 724. 6±33. 3 10. 6±0. 4
CT 212 5+ 5+ 15 6. 5±0. 4 701. 0±32. 5 12. 0±0. 4
CT 213 10+ 0+ 3 7. 5±0. 5 819. 4±39. 0 8. 6±0. 3
CT 214 10+ 0. 5 + 0 8. 4±0. 4 722. 3±32. 2 19. 0±0. 8
CT 215 10+ 1+ 15 9. 0±0. 5 837. 4±39. 9 7. 5±0. 3
CT 216 10+ 5+ 75 8. 0±0. 4 855. 2±40. 8 9. 9±0. 4
Table 6　　The effects of combination s of NAA , GA3 and ABA on secondary cell wall
th icken ing of f ibers dur ing the fourth stage
Code
Com binations of NAA ,
GA 3 and ABA
DW of fibers Cellu lo se conten t Callo se conten t
CH 21 0+ 0+ 0 10. 2±0. 3 744. 3±32. 2 11. 8±0. 6
CH 22 0+ 0. 5+ 1 8. 1±0. 4 747. 2±34. 7 11. 1±0. 5
CH 23 0+ 1+ 5 9. 2±0. 2 850. 5±41. 3 11. 1±0. 5
CH 24 0+ 5+ 50 9. 5±0. 4 759. 1±35. 1 6. 2±0. 3
CH 25 1+ 0+ 1 10. 1±0. 3 897. 2±39. 7 10. 5±0. 4
CH 26 1+ 0. 5+ 5 9. 9±0. 3 750. 2±34. 9 2. 8±0. 1
CH 27 1+ 1+ 50 10. 8±0. 5 805. 4±37. 5 9. 1±0. 4
CH 28 1+ 5+ 0 8. 0±0. 3 752. 8±35. 0 8. 1±0. 3
CH 29 5+ 0+ 5 10. 5±0. 4 954. 7±45. 5 6. 3±0. 3
CH 210 5+ 0. 5+ 50 9. 2±0. 3 754. 4±31. 7 6. 1±0. 3
CH 211 5+ 1+ 0 9. 4±0. 4 940. 4±46. 2 5. 0±0. 2
CH 212 5+ 5+ 1 9. 2±0. 4 896. 9±37. 3 8. 2±0. 4
CH 213 10+ 0+ 50 8. 9±0. 3 823. 1±35. 2 13. 3±0. 6
CH 214 10+ 0. 5+ 0 9. 1±0. 2 806. 7±32. 6 12. 1±0. 6
CH 215 10+ 1+ 1 8. 8±0. 4 850. 5±33. 8 12. 6±0. 6
CH 216 10+ 5+ 5 10. 1±0. 1 826. 2±32. 4 10. 4±0. 4
2. 5　Results of SOSCFD
T he cell w all th ickness of fibers grow n in cu ltu re w ith the m ethod of Beasley and
T ing [ 1, 2 ] w as no t m easu red, becau se the th ickness of the fiber w as very low (P la teÉ 23) so
tha t few in tact cro ss sect ion s of these fibers w ere ob ta ined. T he length and th ickness of
fibers grow n in SO SCFD w ere 26. 7 mm (P la te É 22) and 3. 87 ± 0. 45 Λm (P la te É 24) ,
007　　　　　　　　　　　　　　　　　作　　物 　　学　　报　　　　　　　　 　　　　　　　　27 卷

respect ively. T he specif ic st reng th of fibers grow n in SO SCFD w as 21. 9 gf· ( tex) - 1 ( tested
by Supervision, In spect ion & T est Cen tre of Co t ton Q uality; M in ist ry of A gricu ltu re of P.
R. Ch ina). T he length, th ickness and specif ic st reng th of fibers grow n in p lan t w ere 28. 2
mm , 4. 02±0. 34 Λm (P la teÉ 25) , and 22. 1 gf· ( tex) - 1, respect ively. It w as show n tha t
f ibers grow n in SO SCFD exh ib ited a developm en ta l schedu le sim ila r to fibers grow n in p lan t.
Explana tion of Pla tes
　　1. Co tton ovules from 3 k inds of developm ental state on at 28 DA C. 2. L ength of fibers grow n in SO SCFD. 3.
T ransverse section of fiber grow n in cultu re at 58 D PA as Beasley and T ing (1. 6K×). 4. T ransverse section of fiber
grow n in SO SCFD at 58 D PA (1. 6K×). 5. T ransverse section of fiber grow n in p lan t at 58 D PA (1. 6K×).
3　D iscuss
F iber p ropert ies, e. g. st reng th, f ineness and length, requ ire fu rther im p rovem en t to
m eet econom ic p ressu res and to facilita te m o re efficien t sp inn ing techno logy. A n
understand ing of the regu la to ry elem en ts and genes exp ressed in co t ton fibers is necessary to
assist in the im p rovem en t of fiber qua lity. Fo r th is ob ject, an experim en ta l system of in v itro
f iber developm en t is u sefu l, becau se the com p lex ity of the w ho le p lan t system cau ses the
d iff icu lty to elim ina te o r d ist ingu ish the effect of o ther facto rs w h ich influence fiber
grow th [ 14 ]. A s m en t ioned above, the m ethod of Beasley and T ing [ 1, 2 ] has been u sed as a
m odel fo r study on fiber developm en t. Bu t fibers grow n in cu ltu re d ied in m idw ay so tha t
their f ina l leng th w as abou t ha lf tho se of fibers grow n in p lan t and their secondary cell2w alls
d id no t th icken obviou sly [ 3, 8 ]. It is obviou sly ind ica ted tha t the m ethod of Beasley and
T ing [ 1, 2 ] is no t help fu l fo r studying the fo rm at ion of secondary cell2w all and the streng th of
co t ton fibers. U p to now , no repo rt has m en t ioned to tran sfer cu ltu red co t ton ovu les to fresh
1076 期　　　YAN G You2M ing et a l: A System of O vu le Subcu ltu re fo r Co tton ⋯⋯　　　　

m edia to study the fiber developm en t. O u r da ta show tha t the so lub le sugar concen tra t ion of
m edia w as con t inuou sly reduced du ring co t ton ovu le cu ltu re and co t ton ovu les cu ltu red fo r
tw o w eek s m u st be tran sferred to fresh m edia (T ab le 1, 2; F ig. 1, 2). A t first, cu ltu red
co t ton ovu les w ith adhering fibers w ere tran sferred to fresh m edia in w h ich no an t iox idan ts
o r ab so rben ts w ere added. Becau se the pheno lics secreted by cu ltu red co t ton ovu les w ere
ox id ized, the m edia becam e b row n ing abou t 24 hou rs after subcu ltu re and m o re than 90% of
cu ltu red co t ton ovu les w ith adhering fibers w ere b row ned and died a t 5 days after
subcu ltu re. T hen act iva ted charcoa l (5, 10 o r 15 g·L - 1) w as added to subcu ltu re m edia and
p reven ted the b row n ing of m edia and cu ltu red co t ton ovu les w ith adhering fibers. T he effects
of act iva ted charcoa l am ong 5, 10 and 15 g·L - 1 w ere in sign if ican t (da ta no t show n). In
SO SCFD act iva ted charcoa l ( 5 g ·L - 1 ) w as supp lem en ted to subcu ltu re m edia, the
percen tage of b row ned ovu les w as 3. 7 (T ab le 3). It is ind ica ted tha t the subcu ltu re of
cu ltu red co t ton ovu les w ith adhering fibers had succeeded by supp lem en ted act iva ted charcoa l
(5 g·L - 1).
F iber elongat ion dom inates a t 1D PA and con t inues to abou t 30 D PA w hen m ax im um
length is a t ta ined. Secondary cell2w all th icken ing of fiber beg in s a t 13～ 19 D PA , befo re the
cessa t ion of fiber elongat ion [ 15 ]. Based on ou r da ta (T ab le 4～ 6) , the con st ituen t and its
concen tra t ion of m edia m u st be changed to acco rd w ith the dem ands of fiber developm en t in
d ifferen t phase, e. g. one of the N G23 ( included NAA 5Λm o l·L - 1 and GA 3 1 Λm o l·L - 1) ,
N G27 ( included NAA 10Λm o l·L - 1 and GA 3 1Λm o l·L - 1)o r N G28 ( included NAA 10 Λm o l·
L - 1 and GA 3 5 Λm o l·L - 1) fo r 1～ 14 DA C; N G23 o r N G29 (included NAA 10 Λm o l·L - 1 and
GA 3 10 Λm o l·L - 1) fo r 15～ 28 DA C; CT 215 ( included NAA 10 Λm o l·L - 1, GA 3 1 Λm o l·
L - 1 and ABA 15 Λm o l·L - 1) fo r 29～ 42 DA C; the m edia included NAA 1 Λm o l·L - 1 and
ABA 5 Λm o l·L - 1 fo r 43～ 56 DA C. O u r da ta agreed w ith p reviou s op in ion tha t f iber
elongat ion w as st im u la ted by IAA and GA 3 [ 1, 2, 13 ]. In addit ion, ou r da ta a lso show ed tha t
ABA stim u la ted secondary cell2w all th icken ing of fiber.
A cco rd ing to the m ethod of Beasley and T ing [ 1, 2 ], ovu les w ere co llected by the
D PA [ 1～ 8 ]. How ever, ow ing to the d ifference of environm en t tem pera tu re, the ovu les on the
sam e D PA m ay be differen t in developm en ta l sta te. Zheng et a l[ 16 ] and ou r da ta (T ab le 3)
show ed in v itro f iber developm en t w as obviou sly influenced by the developm en ta l sta te of
ovu le. In ou r p resen t study, the su itab le ovu les w ere determ ined by the characterist ics of
co ro lla and st igm a. It is no t on ly easy to opera te, bu t a lso beneficia l to elim ina te the
influence of the developm en ta l sta te of ovu le.
Based on ou r da ta, the leng th, cell w all th ickness and specif ic st reng th of fibers grow n
in SO SCFD w ere 26. 1 mm , 3. 87 Λm , and 21. 9 gf· ( tex) - 1, respect ively, app roach ing o r
reach ing tho se grow n in p lan t. O u r da ta a lso show ed tha t sub stances syn thesized and
accum u la ted in the fibers grow n in SO SCFD w ere m ain ly cellu lo se and ca llo se in no rm al
quan t ity (T ab le 3, 5, 6). A ll of these da ta show fibers grow n in SO SCFD exh ib ited a
developm en t schedu le sim ila r to the fibers grow n in p lan t.
207　　　　　　　　　　　　　　　　　作　　物 　　学　　报　　　　　　　　 　　　　　　　　27 卷

Com pared w ith the m ethod of Beasley and T ing [ 1, 2 ] , the d ist ingu ish ing fea tu res of
SO SCFD w ere as fo llow s: (1) Cu ltu red co t ton ovu les w ere successively tran sferred to fresh
m edia. ( 2) In subcu ltu re m edia act iva tad charcoa l ( 5 g ·L - 1 ) w as supp lem en ted. ( 3)
Cu ltu red co t ton ovu les w ere subcu ltu red succeed ing ly w ith 14 cyclic days each. ( 4) T he
con st ituen t of p lan t grow th regu la to rs and its concen tra t ion of m edia w ere changed acco rd ing
to the dem ands of fiber developm en t in d ifferen t phase. (5) T he ovu les in 2nd developm en ta l
sta te w ere u sed as exp lan t. (6) F ibers grow n in SO SCFD exh ib ited a developm en ta l schedu le
sim ila r to fibers grow n in p lan t. T herefo re, SO SCFD can be u sed as a new experim en ta l too l
to study the characterist ics of each stage and w ho le p rocess of fiber developm en t, especia lly
the fo rm at ion of secondary cell w all th icken ing and streng th of fiber.
References
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4　H aigler C H , N R Rao, E M Robers, et a l. P lan t P hy siol, 1991, 95: 88～ 96
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12　P illonel Ch, A J Buchala, H M eier. P lan ta, 1980, 149: 306～ 312
13　J ia J2Z, Y2M Yang, C2N Xu, et a l. J of Y unnan A g ricu ltu ra l U niversity , 1999, 14 (4) : 21～ 25
14　Ko sm idou2D im itropoulou K. Cotton P hy siology. M emph is: T he Co tton Foundation, 1986. 361～ 374
15　Basra A S, C P M alik. In t R ev Cy tol, 1984, 89: 65～ 113
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3076 期　　　YAN G You2M ing et a l: A System of O vu le Subcu ltu re fo r Co tton ⋯⋯