全 文 ：A PRIMARY STUDY ON MUTATION
IND UCTION OF IN2VI TRO
CUL TURED GARL IC SHOOTS
BY 60Coγ2RAY IRRAD IATION
Xu Peiwen 　Sun Huisheng 　Yang Yuanjun 　Liu Hengying
( Instit ute f or Vegetable Research , S handong Academy of A gricult ural Sciences , Jinan 　250100)
Sun Shouyi
( Instit ute f or A pplication of A tomic Energy in A gricult ure ,
S handong Academy of A gricult ural Sciences , Jinan 　250100)
In vit ro cultured shoots of four garlic cultivars were used to estimate radio2sensitiv2
ities and mutation rate by 60Coγ2ray. LD50 of the tested materials was around 7～9 Gy
with a mutation rate of 5 %. Two mutants , Tai2R1 and Cang R2 were proved to be ge2
netical variants by the investigation on agronomical characters and the analysis of peroxi2
dase isozyme.
Key words : LD50 , peroxidase isozyme , mutation , sensitivity
本文于 1998 年 3 月 29 日收到。
Garlics ( alli um sativ um L . ) is one of the important vegetables in the world. To improve
yield and quality of garlics many researches have been carried out and a great deal of achievements
have been made. However , variety improvement of garlics by sexual cross can be hardly done
since the garlics propagate mainly by bulbs vegetatively. Therefore , induction of mutation by
physical or chemical agents is important way in garlic breeding. Works on irradation of garlic
bulbs and culture of callus have been done by several authors , however , little success in obtaining
useful mutants has been reporte[1 ,2 ] . There is no report on experiment with irradiation of i n vit ro
cultured garlic shoots. The aim of this research was to find out the radiosensitivities and mutation
rate of i n vit ro cultured garlic plantlets induced by 60Coγ2ray irradiation.
11Material and methods
111 　Cultivars
Garlic cultivars of Cangshan Puke , Cangshan Cao , Caohe Za , and Taicang White Skin from
the original collection of Cangshan and Yanzhou County of Shandong Province and Taicang Coun2
241 　核 农 学 报　1999 ,13 (3) :142～146Acta A gricult urae N ucleatae Sinica
ty of J iangsu Province were propagated in the farm of the Institute for Vegetable Research of
Shandong Academy of Agricultural Science (SAAS) .
112 　Materials for isozyme testing
The garlic materials for isozyme testing include Jix Xiang Red Skin (virus2f ree) , J ia Xiang
Red Skin (virus2infected) , Cangshan Gaojiao (virus2f ree) , Cangshan Gaojiao (virus2infected) , Tai2
R1 , Taicang White Skin (virus2f ree) , Cang R2 and Cangshan Cao (virus2f ree) .
113 　Dosage of irradiation
Plant materials were irradiated at 1 ,3 ,5 ,7 ,9 ,15 ,40 and 80 Gy with a dosage rate of 55 Gy/
h at the Laboratory for Irradiation of the Institute of Atomic Energy Application in Agriculture of
SAAS.
114 　Treatments and investigations
Experiments were carried out partialy at the Institute for Vegetable Research and partialy at
the Yanggu Station for Virus2f ree Seed Garlic Development f rom 1991 to 1996. Shoots f rom i n
vit ro cultured meristems of the 4 garlic cultivars at 015 cm height were irradiated , then trans2
ferred to the test tubes filled with new medium and subcultured for 5～6 weeks. Growth and de2
velopment of the plantlets were investigated. Isozyme of the plants was analized using a method of
polycrylamide2del electrophoresis ( PA GE)
21Results
211 　LD50 of the in vit ro cultured garl ic buds
In the experiment of 1991 , plantlets developed from the irradiated shoots of the garlic culti2
var Cangshan Puke , Cangshan Cao and Taicang White Skin with treatment of 40 and 80 Gy 60Co
γ2ray grew very slowly at the early stage after the irradiation , then all got yellow and died eventu2
ally. Most of the plantlets with 15 Gy dose were stunted and only 10 %～30 % were survived. In
1992 , growth of the plantlets developed from the irradiated buds of the cultivars Caohe Za , Cang2
shan Cao and Taicang White Skin with 1 Gy dose were normal with a plant height of 5cm on aver2
age. 17 %～30 % of plantlets with 3 Gy and 5 Gy were getting yellow with plant height of 3～4cm
and died afterwards , and the others grew normally. 50 %～60 % of plantlets with 7～9 Gy were
getting yellow with the plant height of 115～2cm and died eventually , however , the rest grew
normally( Table 1) . Therefore , 7～9 Gy was considered to be the LD50 of the i n vit ro cultured
garlic shoots. Differences in radiosensitivities among the cultivars were not observed.
212 　Two mutants obtained from the garl ic cultivar
Two mutants , Tai2R1 and Cang2R2 , were found from the nursery2t ray with plants devel2
oped from the irradiated shoots of the garlic cultivar , Taicang White Skin and Cangshan Cao with
15 Gy dose. The growth of the mutants were extraordinary. The plant height , leaf length , leaf
width and the maximum girth of bulbs in Cang R2 increased by 9510 % , 13313 % , 14010 % and
12510 % respectively compared with those of the orginal cultivar and in Tai R1 increased by
9517 % , 13815 % , 20010 % and 28214 % , respectively ( Table 2) . The average weight of both
341　3 期 A primary study on mutation induction of i n2vit ro cultured garlic shoots by 60Coγ2ray irradiation
bulbs and bolts in Tai2R1 and Cang2R2 kept increasing compared with those of their controls in
the trials of 1993 and 1994 , and remained stable till 1996 as shown in Table 3. Furthermore ,
skin of the Cang R2 turned into light purple in contrast to the white control.
Table 1 　Radiosensitivity of the in vit ro cultured garlic plantlets irradiated by 60Coγ2ray
Variety
Dosage
　
　
( Gy)
Number
of shoots
irradiated1
　
Growth3
Plant height 2
(cm)
Normal
( %)
Survivals
( %)
Yellowing
( %)
Died off
( %)
Cangshan Cao 1 26 710 100 0 0
3 26 510 80 6 20 14
5 26 215 63 68 37 32
7 28 210 50 50 53 47
9 26 115 30 32 70 68
154 23 112 13 14 87 86
Taicang 1 26 510 100 0 0 0
White 3 26 410 85 88 15 12
Skin 5 26 210 65 69 35 31
7 28 112 45 45 55 55
9 26 115 40 42 60 58
154 20 110 11 18 89 82
Caohe Za 1 26 510 100 0 0
3 26 315 83 86 17 14
5 26 310 70 72 30 27
7 27 115 50 51 50 49
9 26 115 40 63 60 57
　　11Date of irradiation was March 5th , 1992.
21Plant height was the mean of the plants investigated.
31Date of investigation was April 3 , 1992.
41The garlic was treated in the experiment of 1991.
Table 2 　Agronomic characters of the garlic plantlets irradiated by 60Coγ2ray
Materials
Plant
height
(cm)
Rate
　
( %)
Leaf
length
(cm)
Rate
　
( %)
Leaf
width
(cm)
Rate
　
( %)
Girth
of bublb
(cm)
Rate
　
( %)
Clove
　
number
Tai R1 (mutant from 45 19517 31 23813 115 30010 13 38214 6
　Taicang White Skin)
Taicang White Skin 23 10010 13 10010 015 10010 314 10010 1
　(Control)
Cang2R2 (mutant 39 19510 28 23313 112 24010 9 22510 1
　from Cangshan Cao)
Cangshan Cao 20 10010 12 10010 015 10010 410 10010 1
　(Control)
441 核　农　学　报 13 卷
Table 3 　Comparison in average wieght of bulb and bolt between the mutants and the control 3
Materials Year
Plant
number
Bulb
weight
(g)
Ratio
　
( %)
Bolt
weight
(g)
Ratio
　
( %)
Tai2R1 1992～1993 6 81 13712
(Mutant from Taicang White Skin) 1993～1994 43 98 16016 53 13215
1995～1996 336 87 49
Taicang White Skin 1992～1993 1 59 100
(Control) 1993～1994 6 61 100 40 100
Cang2R2 1992～1993 1 87 14013
(Mutant from Cangshan Cao) 1993～1994 7 106 13412 52 12613
Cangshan Cao 1995～1996 387 102 44
(Control) 1992～1993 1 62 100
1993～1994 6 79 100 41 100
　　3 Bulb and bolt weight were the means of total plants in treatment
Fig. 1 　Banding patterns of the peroxydase
enzyme of the garlic3 11Jia Xiang Red Skin (virus2free)
21Jia Xiang Red Skin
31Cangshan Gaojiaozi (Virus2free)
41Cangshan Gaojiaozi
51Tai2R1
61Taicang White Skin
71Cang2R2
81Cangshan Cao　　Results of peroxidase isozyme assessmentswere shown in Fig. 1. The Tai R1 possessedone more dark and thick band ( PG4) and lackof a weak and thin band ( PG6) when comparedwith control , Taicang White Skin. An addi2tional PG3 band was found in Cang R2 , whilenothings could be seen in the same position ofCangshan Cao. Banding patterns of the virus2f ree and the virus infected garlics are uniquewithin the same garlic varieties. , exept thatthe color of the PG1 bands of the virus2f ree ma2terials were darker than that of the virus2infect2ed ones in spite of that the virus2f ree plantsgrew much more vigorously. It was suggetedthat , to some extent , the Tai R1 and Cang R2were different genotypically f rom their con2t rols.
31Discussions and conclusions
311 　Radiosensitivities
Radiosensitivities of the four cultivars used in the experiments showed little difference , indi2
cating that more garlic genotypes should be used for further study.
312 　LD50 and mutation rate
Although LD50 of the garlic plantlets was found to be 7～9 Gy in the experiment whereas mu2
541　3 期 A primary study on mutation induction of i n2vit ro cultured garlic shoots by 60Coγ2ray irradiation
tations had not been found at this range of dosages. Since mutants were obtained in plants irradi2
ated with 15 Gy , a suiteble dosage for inducing mutation from the i n vit ro cultured garlic plantlets
was 15 Gy. The mutation rate was about 5 % , a further study on techniques for increasing muta2
tion rate is necessary.
313 　The mutants
A good uniformity of the mutant and its progenies were detected and no“Chimarea”was
shown. This could be caused by two factors : 1) The mutation might occur just at the growth
points of the buds ; 2) the radiation was performed at the very early stage of the young shoot de2
velopment so that the mutation occured ealier enough to keep to“Chimarea”f rom being visible.
Acknowledgement :The authors are indebted to Professor Liu Zhenmeng at the Institute for Maize Research of the Shandong
Academy of Agricultural Sciences for his assistance in peroxidase PAGE testing and to Mr. Lu Kuiliang for his management in field
trials.
References
1 　杨宗渠 ,等.γ射线照射大蒜鳞茎对共生长发育的影响 ,河南农业大学学报 ,1987 ,21 (3) :356～361
2 　A. Croci , et al.γ射线对大蒜种瓣效应及外源生长调节剂的修复作用. Envir. Exp . Bot . , 1987 ,27 (1) :1～5
60Coγ射线辐照大蒜离体培养苗诱变研究初报
徐培文 　孙慧生 　杨元军 　刘恒英
(山东省农业科学院蔬菜研究所　济南　250100)
孙守义
(山东省农业科学院原子能应用研究所　济南　250100)
用 4 个大蒜品种的离体培养芽进行60Coγ射线诱变试验。以明确其敏感性和诱变率。供
试材料的致死计量为 7～9 Gy ,诱变率为 5 %。通过农艺性状观察和过氧化物同功酶分析 ,表
明出现的两个突变体 ———Tai R1 和 Cang R2 ,其属遗传型变异。
关键词 :突变 　敏感性 　致死剂量 　遗传型
641 Acta A gricult urae N ucleatae Sinica
1999 , 　13 (3) :142～146