全 文 ：园 　艺 　学 　报 　2007, 34 (1) : 141 - 142
Acta Horticulturae Sinica
Rece ived: 2006 - 09 - 06; Accepted: 2006 - 12 - 18
Thanks for the concretely instruction and help ofW u M ing2zhu who is member of Chinese Academy of Engineering.
D iscovery of W a term elon Gynoec ious Gene gy
J IANG Xiang2tao1 and L IN De2pei2
( 1 X iangfu Seed Co. , L td. , of Heilongjiang, D aqing, Heilongjiang 166300, China; 2 S ichuan A cadem y of A gricu ltura l Sciences,
Chengdu 610066, Ch ina)
Abstract: W atermelon gynoecious was firstly discovered in 1996. Genetic segregation andχ2
test have p roved that watermelon gynoecious was controlled by recessive gene, so it is named as gy
gene.
Key words: W atermelon; Gynoecious; Variation
西瓜全雌基因 gy的发现
姜向涛 1 , 林德佩 2
(1 黑龙江省大庆市向富种业有限责任公司 , 黑龙江大庆 166300; 2 四川省农业科学院园艺研究所 , 成都 610066)
摘 　要 : 1996年在西瓜制种田中发现全雌性突变株 , 经 4年杂交和系统选择 , 于 2000年培育出西瓜全
雌系 ‘全雌 1号 ’。经世代遗传分离的χ2试验证实全雌性由 1对隐性基因控制 , 将该基因命名为 gy。
关键词 : 西瓜 ; 全雌系 ; 突变
中图分类号 : S 651　　文献标识码 : A　　文章编号 : 05132353X (2007) 0120141202
It was reported that gynoecious lines were found in cucumber (Cucum is sa tivus) , Cucu rbita foetid issim a
and ridge gourd (L uffa acu tangu la) from Cucurbitaceae ( Esquinas2A lcazur & Gulick, 1983). No gynoecious
lines were found in 162 genes of Gene list of watermelon of 2003 Cucurbits Genetics Cooperative Report ( Gu2
ner & W ehner, 2003). It was the first time that watermelon gynoecious lines and its gene gy are reported in
p resent study.
1　D iscovery of wa term elon ( C itru llus lana tus) gynoec ious ind iv idua l
The ratio of p istillate and stam inate flower of watermelon was 1∶5 - 8 in normal condition. The author found
the individuals of higher ratio p istillate flower in the watermelon Lüyuan 001 in early 1990s. After several gener2
ations of self2crossing and selection, strong gynoecious lineswith nearly 1∶1 of p istillate and stam inate flowerwas
obtained. Mutant of gynoecious individual with p istillate flower in each node was found in the field of strong gy2
noecious lines. It cannot be selfed for germp lasm conservation due to no male flower in mutant, so by sib2cross
using male flower of sib2p lant of the strong gynoecious lines, one ripen fruit with 138 seeds inside was obtained.
Eighty2eight out of 138 seeds were sown in the next sp ring, and no gynoecious individual was found in survived
p lants, but the ratio of female flower to male flower reached to 116∶1. Strong gynoecious individuals appeared by
continuous self2pollination in p rogenies of mutants from 1998 to 1999, but they were not conserved because of no
male flowers for pollination. In 2000, the male flowers were induced by silver nitrate in mutant gynoecious wa2
termelons generation, and the steady gynoecious lines was obtained and named Gynoecious 1.
Gynoecious 1 watermelon is early2mature with only 70 - 75 days from sowing to fruit maturity. There is
only one female flower on each node of the main shoot and no male flower ( Fig11). The fruit shape is round,
average fruitmass is 4 kg. The pericarp is thin and its color is light2green with dark green striation. The sarco2
carp is red, crisp , sweet and juicy. Soluble solid content is 1216%. A little seeds are yellow, and small.
Acta Horticulturae Sinica Vol. 34
F ig. 1　The gynoec ious wa term elon
2　Results and ana lysis
χ2 test of inheritance of gynoecious gene was con2
ducted at Sanya Academy of Agricultural Sciences in
Hainan Province from December 2005 to Ap ril 2006.
The experiment was laid out in a random ized design
based on generation type. Each generation type con2
sisted of 50 - 100 individuals ( Table 1). Flower sex
form of each generation type was recorded during the
anthesis of p lant.
Table 1　Genetic segrega tion andχ2 test of gynoec ious
Generation
Expectation
Normal∶A ll gynoecious
Observation
Normal A ll gynoecious
χ2
P1 0∶1 　0 59
P2 1∶0 60 0
F1 1∶0 116 0
F2 3∶1 86 18 218442
BC111 1∶1 59 43 215
BC112 1∶0 101 0
　　P0105 = 3184, χ2 < P0105 , P > 0105.
　　Results showed that F1 , derived from the cross of gynoecious line P1 of Gynoecious 1 with monoecious
line P2 of A123, was normal monoecious which is the common sex form ( Table 1). The ratio of normal sex
form to gynoecious form was 86∶18 in F2 , and in p rogeny of backcrosseswas 59∶43. The statistic analysis sug2
gested that difference in the value of observation and the expectation (3∶1 and 1∶1) was not significant ( P >
0105). It means that the gynoecism in watermelon is controlled by one recessive gene.
Three types of flower ( stam inate, p istillate and hermaphrodite) in Cucurbitaceae can form 8 combinations
( Poole & Grimball, 1939) , that are: monoecious, andromonoecious, gynomonoecious, hermaphrodite, trimo2
noecious, gynoecious, androecious and dioecious. One hermaphrodite muskmelon from Hebei Province in
China is a basic germp lasm to p roduce gynoecious muskmelon. In this research, gynoecious watermelon was
discovered from a mutant of strong gynoecious individual with the ratio of female to male flower is 116∶1. So
the genetic background is quite different in these two gynoecious individuals.
Gynoecious 1 can also be crossed with other normal type of watermelon to obtain the same genetic segrega2
tion results as A123. The author had transferred the gynoecism to yellow, black, stripe pericarp and integrifo2
lious watermelon, and got several new gynoecious watermelon lines. The author suggests that the recessive
gene contained in Gynoecious 1 is named gynoecism, and denoted with gy.
The new gynoecious watermelon germp lasm has the characteristics of more female flower, so its habit and
fruit2setting rate are higher than the normal one. In the meantime, it is an efficient system for hybrid p roduc2
tion as it does not need emasculation and manual self2pollination and ensures that most of the seeds harvested
are hybrids.
References
Esquinas2A lcazar J T, Gulick P J. 1983. Genetic resources of Cucurbitaceae. IBPGR Rome: 42 - 50.
Guner N, W ehner T C. 2003. Gene list for watermelon. CGC Rp t. , 26: 75 - 83.
Peterson C E, OwensW , Rowe P R. 1983. W isconsin 998 muskmelon germp lasm. HortScience, 18 (1) : 116.
Poole C F, Grimball P C. 1939. Inheritance of new sex form s in Cucum is m elo L. J. Heredity, 30 (1) : 21 - 25.
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