Crops
China is
one of the main centers for crop varieties and diversity distribution centers
in the world. China is rich in genetic resources. More than 300,000 of crop
genetic resources have been collected, and include 200,000 grain crops, 55,000
legumes, and 31,000 cotton, fiber, oil, sugar, tobacco and other cash crops,
18,000 vegetables, 11,000 fruit trees and over 15,000 forage, green manure
crops and others, This section focuses on the protection of genetic resources
and the utilization of crops, vegetables and forage.
(1) The diversity of genetic crop resources and
its utilization in China
Cultivated
herbaceous crops include grains, legumes, potatoes, vegetable oils, fibers,
sugar, tobacco and green manure.
a. Grain
crops
Over
100,000 grain crop species have been collected, including Rice, Foxtail millet,
Broomcorn millet (Panicum milliaceum),
Naked barley, Naked oats (Avena nuda),
Waxy corn (Zea mays) and Black wheat
(Fagopyrum), all of which originated
in China. China is also the secondary centre of origin for Wheat (Triticum) and Sorghum (Sorghum bicolor g. kaoliang). The crop genetic resource of China is large. For
example, Foxtail millet and Broomcorn millet (Panicum milliaceum) are preserved perennially in the National Crop
Gene Bank, with as many as 25,000 and 7,200 accessions, respectively. These are
more than the total numbers preserved by all other countries in the world. More
than 16,000 accessions of corn (Zea mays)
genetic resources have been collected. This is probably the most of all seed
banks in other countries and international institutions. The collections of
rice and sorghum are next to the International Rice Research Institute (IRRI)
and the International Crops Research Institute for Semi-arid Tropics (ICRISAT),
respectively, being second in the world. The collection of wheat (Triticum) is a little less than that in
the Varilor All-Union Institute of Plant Industry of Russia (VIR), the National
Seed Storage Laboratory (NSSL) of the USA and the Centro Internacinal de
Mejoramiento de Maizy Trigo (CIMMYT).
Rice (Oryza)
Cultivated
areas of rice in China make up one fourth of the world total and its yield is
the highest. Its distribution is extensive, ranging from 18o59/
N to 53o36/ N, and from sea level to 2,670 m. This
diversity of natural conditions in addition to the multiple-pattern of
cultivation has resulted in a great richness of local varieties, i. e., as many
as 40,000. Indica and Japonica rice have early, medium and late season
varieties. According to cultivating conditions, various varieties all have
paddy and dryland rice, and on the basis of grain patterns, they can be divided
into non-glutinous and glutinous rice varieties. Of the glutinous rice, black
and dark purple varieties have a very high nutrient value. For example, the
Dehong purple rice of Yunnan Province and the Hui Shui black glutinous rice in
Guizhou Province contain over 11% protein, over 0.33% lysine and over 0.25%
riboflavin, which are much more than normal rice. Similar varieties are Donglan
black rice in Guangxi Province, Shaoguan black glutinous rice in Guangdong
Province, Changshu duck-blood glutinous rice in Jiangsu Province and Yangxian
black rice in Shaanxi Province. In addition, Simiao, in Guangdong Province, is
traditional high quality rice, famed in the international market for its long,
cellophane, grain and softness. The grain of Babao (Eight treasures) rice in
Guangnan, Yunnan Province is greenish and tasty. Zhongzi and Huangke (Yellow
husk) glutinous rice in Jingtan, Jiangsu Province, are favorite varieties in
the wine making industry. The varieties of Huaihua glutinous rice are good for
pastry-making. There are three wild rice species in China, Oryza rufipogon, O. officinalis and O. meyeriana. The first one is distributed in the
provinces to the south of 28o14/ N, such as Jiangxi,
Hunan, Fujian, Yunnan, Guangxi, Guangdong, Hainan and Taiwan, while the other
two are distributed in Yunnan and Hainan Provinces.
Wheat (Triticum)
Wheat is
the second most important crop in China, being grown all over the country, from
the Tulufan Basin of the Xinjiang Uygur Autonomous Region, 150 m below sea
level to the Qingzang Plateau, 3,400m above. Wheat is cultivated in a great
diversity of climates, explaining its large number of varieties. There are two
characteristics of Chinese native wheat varieties: early maturity and
multigrained spikelets. Many varieties mature earlier and milk quicker to avoid
the dry-hot windy summer. Some varieties have many flowers and grains, e. g.,
6~7 grains in every spikelet on the middle part of the ear. China is one of the
centers for short stem mutants. Southwestern China is also a source of
crossable wheat genes. ¡°Chinese Spring¡±, a native variety in Sichuan Province,
has been used widely for hybridization between genera in many countries. Common
wheat (Triticum aestivum) has three
subspecies in China, i. e., subsp. yunnanense, subsp. petropavlovskyi and subsp. tibetanum, distributed, respectively, 1,500~2,500
m above sea level in the lower reaches of the Lancangjiang River, at the oasis
to the south of the Tianshan Mountains, and in the mountain ous area
1,700~3,540 m above sea level in Tibet.
Corn (Zea mays)
Corn was
introduced into China only some 400 years age, but has become the third
important crop in China. There are more than 13,000 native varieties and waxy
varieties. Although some Chinese corn varieties have traces of the American
Corn Belt species and the deformed ears of European corn, many others are
Chinese specialties, e. g., the tasty, early-maturing orange hard-grain
varieties, and the middle-maturing white hard-grain varieties which are
tolerant of drought and infertile soils. The waxy corn, a natural genetic
mutant in southwestern China, is also known as glue corn, and has about 500
varieties with different grain colors including white, yellow, red, dark purple
and mixed.
Foxtail millet (Setaria italica)
Foxtail
millet, one of ancient crops of China, has a short life cycle, is tolerant of
drought and infertile soils, and stores well. Millet has many varieties, over
2,500 having been collected. Their chaff colors are yellow, white, red, black,
blue-grey, light yellow and light brown; the kernel has more than 10 colours
such as yellow, white, blue-grey and dark green, It has nonglutinous and
glutinous patterns. The early-maturing varieties are Beijing Xiao Zao Gu, Hebei
Lou Li Xiu. The valuable varieties are Shanxi Qinzhou Huang, Shandong Qi Tou
Huang, Yugu No. 1, Shibing Hong Xiao Mi and Lingyi Bai Nian Gu.
Broomcorn millet (Panicum miliaceum)
Broomcorn
millet is another ancient Chinese crop characterized by its early-maturity, and
tolerance of drought and infertile soils. These characters enable it to be used
as a crop sown after natural disasters. Its grain has nonglutinous and
glutinous patterns. The nonglutinous one is called Ji, or Mi, and the glutinous
one is called Shu. More than 7,500 genetic resource accessions have been
collected, of which 97% are Chinese natives. The varieties of Broomcorn millet
are highly diverse, e. g., ear patterns are differentiated into dispersed, side
spreading and closed, and the grains have more than 10 colors, such as white,
yellow, red, ribbon-grey, brown and bi-colours. The valuable varieties are Long
Shu No. 16, No. 18 Nei Mi No. 2, Yi Mi No. 5 and No. 7619 Mi. Drought-tolerant
varieties are Gansu 74-132, Dongshen Er Huang Mi and Huang Mi No. 13 in Inner
Mongolia. Saline-tolerant varieties are Huang Mi No. 580 and Nei Mi No. 3 in
Inner Mongolia. Wild species, e. g., P. miliaceum spp. ruderale, are widespread
in northern China.
Sorghum (Sorghum bicolor g. kaoliang)
Sorghum has
a long history of cultivation and rich genetic resources, with about 10,000
varieties, and many patterns, occurring in China. Based on use, the varieties
are divided into four patterns: grain-using varieties for food and wine-making,
sugar using varieties for sugar resources, other varieties for green forage and
ensilage, and other varieties for craft making, such as mat weaving.
Barley (Hordeum vulgare)
Barley is
an ancient Chinese crop. It is widely distributing from low-lying plains to
plateaus up to 4,750 m above sea level (Sage County, Tibet), but is cultivated
as a main crop only in the Qingzang Plateau. Over 9,000 varieties have been
collected in China. Most of them are poly-rowed and have naked seed patterns, a
few varieties have a seed skin, and hulled two-rowed varieties are rare. There
are many valuable varieties, e. g., the endemic variety Hong Qing Ke in Yunnan
and Sichuan Provinces, dwarf varieties Jiajiu and Ali Zi Qing Ke in Tibet, and
the early-maturing varieties Hong Yuan Bai Qing Ke, Ding Ri Zao and Hai Men Zao
Da Mai. Two indigenous semi-wild subspecies are found in Tibet, i. e., H.
vulgare ssp. Spontaneum and H.
vulgare spp. Agriocrithon. These occur extensively in Tibet as
weeds in barley and wheat fields. There are also perennial species, e. g., H.
brevisubulatum, H. bogdanii. H. jubatum and H. violaceum.
Buck wheat (Fagopyrum)
The sown
and harvested acreage of Buck wheat in China is second in the world, after the
former Soviet Union. Fagopyrum esculentum
and F. tataricum are the two main cultivated crops. More than 3,000
indigenous varieties have been collected, F. esculentum and F. tataricum making up
50% each. China is one of the originating areas of Fagopyrum. Seven wild
species are found in China: the perennial species F. dibtrys, F.
urophyllum and F. statice. Annual species are F. leptopodum, F. lineare and F.
gracilipes, and an insufficiently
studied species F. gilesii.
Naked oats (Avena nuda)
Avena nuda originated in China as a
mutant of A. sativa and is distributed mainly in a narrow zone in the cold
plateau at the junction of three provinces/autonomous regions, i. e., Inner
Mongolia, Shanxi and Hebei. More than 1,500 native varieties have been
collected, and among which are some well-known varieties, e. g., Shanxi Wuzhai
San Fen San, Yunnan Qiao Jia Xiao Yan Mai and Inner Mongolia Wuchuan Da Yan
Mai. A. fatua occurs widely in China.
In
addition, grain crops, which have been phased out or are rarely cultivated are Echimochloa crusgall, Eleusine coracana, Amaranthus caudatus and Secale cereale.
b. Legume
crops
There are
many legume crops in China. The most important economic species is Soya bean (Glycine max). Originating in China, it
is unique in terms of its richness of genetic resources. Over 20,000 indigenous
varieties of Soya bean occur in China. The patterns of plant, leaf, pod, sowing
period, time of maturity, disease resistance and grain characters are all
highly diverse. There are many valuable varieties, e. g., the large grain
varieties Shanghai Nanhui Da Li Zhong and Chuansha Qingpi; the early-maturing
varieties Muohe No. 1 and Dongnong No. 36; the multipod varieties Jiangsu
Taixing Liu Yue Xian, Yixing Zhong Zi Dou, Heilongjiang Yian Shou Da Hei Dou
and Hailin Da Jin Huang; the high protein varieties Yinyi Ping Ding Huang,
Suqian Du Dou, Jing 783, Sichuan Jinyang Da Bai Dou and Dongbei Hei Qi Ying Ge
Dou; the oil rich varieties Heilongjinang Faku Man Cang Jin and Jilin Gongjiao
5610-2, and the low linolenic acid varieties Liaoning Huang Qi and Jilin Yuan
Jiao No. 4. The wild species G. Soja ia wide spread in China. There are
two perennial species of Glycine in
China: G. tabacina and G. tomentella, which occur in coastal
areas and the offshore islands of Fujian Province.
In addition
to soya bean, there are 17 other legume crops for grain use. Among these, Vigna angularis, V. umbellata, V.
radiata and V. unguicluata originated in China. Six
species, i. e., Vicia faba, Pisam sativum, Vigna rabiata, V. angularis, V. unguiculata var. and Phaseolus vulgaris, are widespread and widely cultiated, with 4,100, 3,400, 4,700,
3,900, 4,000 and 2,800 varieties, respectively. Other relatively abundant
varieties are Vigna umbellata (about
1,400), Lens culinaris (about 800)
and Phaseolus multiflorus (about
180). Other species, such as Cicer
aritinum, Vigna mungo, Phaseolus lunatus, Cajanus cajan, Canavalia
glabiata, Psophocarpus tetragonolcbus, Mucuna pruriens var. utilis and Lablab purpureus, have
dozens of varieties.
c. Potato
crops
Sweet
potato (Ipomoea batatas) and potato (Solanum tuberosum) are two main
vegetable foods. The cultivated areas of Ipomoea
batatas, which was introduced
into China in the 16 century, cover more than 4,500 thousand ha, i. e., more
than 60% of the total cultivated area in the world. Solanum tuberosum was introduced into China in the early 17th
century. The two species are widespread in China and over 1,000 varieties each
have been collected.
d. Oil
crops
Oil crops
in China are soya bean (as mentioned above), rape, peanut, sesame, sunflower,
oil flax, perilla (Perila trutescens),
safflower (Carthamus tinctorius) and
rush-nut (Cyperus esculentus). The
first four species are widely distributed and cultivated in large areas of
China.
Rape (Brassica)
The main
species of Brassica cultivated in
China are B. napus, B. juncea, B. campestris and B.
chinensis; other species are sporadically cultivated and have only a few
varieties. Over 4,900 genetic resource accessions of Brassica have been collected. The oil-rich varieties are Tibet
Longzi You Cai, Qinghai Men You No. 2 and Shaanxi Hanzhong Ai You Cai (B.
campestris). The linoleic acid-rich varieties are Inner Mongolia San Niu
Wei, Shanxi Hequ Huang Jie and Qinghai Zongzhai Hong Cai Zi (B.
juncea). The low mustard acid varieties are Shanxi Hequ Huang Jie (B.
juncea) and Inner Mongolia Xiao Ri Qi (B. campestris).
Peanuts (Arachis hypogaea)
In spite of
the fact that peanuts have been introduced into China for only about 600 years,
the cultivated area and total production occupies second place in the world.
Currently, more than 4,000 genetic resource specimens have been preserved.
Among these, over 1,900 varieties are native. Four species are most common:
subsp. hypogaea var. hypogaea, subsp. hypogaea var. hirsuta, subsp. fastigiata var. vulgarisehp, and subsp fastigiata var. fastigiata. Among these,
subsp. hypogaea var. hirsuta is now rarely cultivated, but
about 200 varieties of this species are still preserved as genetic resources.
Sesame (Sesamum indicum)
Sesame has
a long history of cultivation in China and, currently, its production is first
in the world. Sesame is widespread in China, but the main cultivated areas are
centralized in the valley of the Yangtze and Hueihe Rivers. Henan Province
makes up one third of the total cultivated area in China. More than 3,100
genetic resource accessions have been collected. Among these, 95% are Chinese
native varieties. Chinese sesame can be divided into 64 types on the base of
single stem, multi-stems, single flower, triflower, flower colour, capsula
rows, capsula length, seed colour and other characters. The most common varieties
are the hybrid ones. Of these, Zhong Zhi No. 7, Ji Zhi No. 1, Zhu Zhi No. 1, and E Zhi
No. 1 are valuable varieties.
e. Fibre
crops
The main
fibre crop is cotton, followed by hemp. Of the many kinds of hemp, those
originated from China are ramie (Boehmerin
nivea), abutilon (Abutilon avicennae),
hemp (Cannabis sativa), jute (Corchorus olitorius) and Apocynum venatum (China is one of the
originating areas of the last three).
Cotton (Gossypium)
Four
species of cotton are cultivated in China. These are (1) G. oreum, introduced into
China in about 1,000¡«500 BC, and was the main cultivated
species before the 1920s; it has a long cultivation history and formed the
unique ¡°race chinese¡± which had 2,000 varieties but has basically been phased
out. (2) G. hirsutum, introduced into China in the late 19th century,
id the main cultivated species now. Stone ville and D.P.L were important
cultivated varieties. The cultivated acreage of D.P.L No.5 reached 3,500
thousand ha at its peak. Currently, the main cultivated varieties are native
hybrid ones. (3) G. barbadense is mainly distributed in
small areas of Hainan Province, Yunnan Province and Xinjiang Uygur Autonomous
Region. In addition, there are two kinds of kapok (Gossampnus malabarica) in Yunnan Province, i.e., var. brasiliense and var. perviamum. (4) G. herbaceum was
cultivated in Gansu Province on a small scale using its varieties An Cao Mian
and Jingta Cao Mian.
Hemp
Nine hemp crops are cultivated in China,
i.e., ramie (Boehmeris nivea), jute (Corchorus olitorus), jana (C. capsularis), hemp (Cannnabis sativa), abutilon (Abutilon
avicennae), kenaf (Hibiscus
cannabinus), flax (Linum
usitatissimum), sisal (Agave sisalana)
and (Apocynun venatum). Twelve
species, 3 sub-species and over 900genetic resource accessions of Bachmeria have
been collected. The main cultivated variety is white leaf ramie. Valuable
varieties are Guangxi Hei Pi Dou, Hunan Qing Jia Ma, Jiangxi Zhu Zi Bian and
Chuannan Hong Pi Xiao Ma. More than 400 genetic resource accessions of Corchorus
have been collected, the valuable varieties being Yue Yuan No. 5, No. 681 and
No. 716 in Guangdong Province, Mei Feng No.4, and Min Ma No. 407 in Fujian
Province. Linum usitatissimum is the
main fiber crop in North China. The oil variety is Hu Ma, and some varieties
can be used for both oil and fiber. Currently, over 400 genetic resource
accessions of Linum usitatissimum and
100 accessions of Hu Ma have been preserved. The main varieties are: Guang Hua
No. 1 and No. 2, and Hei Ya No. 1, No. 2 and No. 3 (fibre use), and Si Ju Hu Ma
and Meng Ya/No.1 (for both oil and fibre). Cannabis
sativa has a long history of cultivation and is mainly distributed in
northern China, but is also cultivated in the southern provinces of Jiangsu,
Anhui, Yunnan, Sichuang, and Hubei. Over 390 varieties were cultivated in China
but have not been well preserved. The main valuable varieties are Gushi Kui Ma,
Liu¡¯an, Han Ma and Weixian Da Bai Pi. The varieties of Abutilon avicennae, an ancient crop in China, comprised 697
accessions, but most have been lost because of poor preservation. Hibiscus cannabinus is a new crop in
China which was introduced in the twentieth century. The cultivated area is
over 900 thousand ha, all over the country. The main production areas are,
however, concentrated in southern China. Agava
sisalana and Apocynum venatum are
also cultivated in China although their genetic resources need further
collection.
f. Sugar crops
The main sugar crops in China are sugar
cane (Saccharum) and sugar beet (Beta vulgaris).
Sugar cane (Saccharum)
Sugar cane has three cultivated species: S.
officinarum, S. sinense, S. barberi, and two wild
species: S. spontaneum and S. robustum. The main cultivated species
in China are S. chinense and other crossbred varieties. Sugar cane is divided into
two categories according to use, i.e., for sugar and for fruit. The valuable
varieties for sugar use are Tai Tang 134, Yue Tang 63/237, Guangxi No.11,
Sichuan No.3, No.6 and No.10, Jiangxi No.1 and No. 14. The valuable varieties
for fruit are Tanzhou Da Zhe in Guangdong Province, Bai Mei Zhe in Fujian
Province, and Lohan Zhe in Yunnan Province. More than 1,600 genetic resource
accessions of sugar cane have been collected. Among these, there are over 600
native varieties.
Sugar beet (Beta
vulgaris)
Sugar beet was introduced into China less
than 100 years ago but the cultivated area has reached 660 thousand ha mainly
in Heilongjiang, Inner Mongolia and Xinjiang. More than 900 genetic resource
accessions are conserved, mostly introduced from abroad. Good cultivars bred in
China are Shuangfeng No. 5, Xintian No.2 and Tianyan No. 5 and No. 6.
g. Tobacco (Nicotiana)
The cultivated history of Nicotiana in China is about 400 years.
Sun-cured tobacco was cultivated previously. The history of cultivated
flue-cured tobacco is only about 100 years. Now, the cultivated acreage is
about 1,100 thousand ha, i. e., the highest in the world. Currently, two
species are cultivated: N. tabacum, which is the dominant species,
and N. rustica. According to the method of processing and usage, N.
tabacum is divided into five types: sun-cured, flue-cured, Burley and
Aromatic. About 2,000 genetic resource accessions of Nicotiana are preserved, mostly sun-cured and flue-cured.
h. Green Manure
Before the 3rd century BC, the
utilization of wild green plants as manure was recorded in ¡°Lu Shi Chun Qiu¡±
and other books. The record of cultivating green manure appeared in the 3rd
century AD. Today, the total cultivated area in China is over 13,000 thousand
ha.
A great variety of plants, belonging to
nearly 100 species in 9 families, can be used as green manure. In addition to
herbage, some arbors and shrubs can also be used as green manure. A great
number of varieties are cultivated as green manure and over 900 genetic
resource accessions have been collected.
(2) Present
situation and problems of crop genetic resource protection in China
The significance of crop genetic
resources has long been recognized and great attention to their protection has
been paid by the Chinese government. During 1955-1956 and 1979-1980, nationwide
crop variety collections were organized. After the 1970s, several large-scale
explorations were organized.
Up to 1995, China possessed, through
collection, requisition and introduction from abroad, about 350 thousand
specimens of genetic resources of different crops.
Two national crop gene banks have been
built by the Chinese Academy of Agricultural Sciences in Beijing to preserve
the genetic resource collections. The No. 2 Bank is mainly in charge of the
long-term preservation of crop genetic resources for the country. To date, 300
thousand crop genetic resource accessions are preserved in the bank. In
addition, 25 national crop nurseries have been set up for the preservation of
vegetatively propagated crops and perennial crops.
Many problems in crop genetic resource preservation
demand prompt solution. The conspicuous ones are: the preservation of
cultivated species is fair but quite bad for wild species and relatives; the
collection and preservation of staple crops is fair while quite bad for the
¡°minor¡± crops; the collection and preservation of varieties in accessible areas
are fair while no attention has been paid to remote mountainous, inaccessible
areas. Especially in recent years, the rapid growth of the economy, including
the development of industry and transport and the reclamation of farmland, has
resulted in environmental deterioration and the serious destruction of some
wild resources. For example, there were several thousand ha of Glycine soja around the Yellow River
mouth, Kenli County, Shandong Province, Usually, over 1,000 kg of G.
soja seed could have been collected by farmers in autumn. However, oil
exploitation and agricultural reclamation during recent years has made G.
soja rare. Similar misfortunes have happened to G.soja on the Sanjiang
Plain in Heilongjiang Province. Another example ix the two kinds of wild rice, Oryza rufipogon and O. Meyeriana, in Jinhong
County, Yunnan Province. They were found in 24 areas in 1964, indifferent
niches and at different altitudes. Now, they are nearly extinct because of
rubber cultivation and agricultural development. In Mandan Village, Donger
Township, Yuanjiang County, of the same province, wild rice used to inhabit six
ponds. Currently, wild rice only exists in two ponds and their areas are still
being reduced. In Guangdong and Hainan Provinces, in 1978-1980, wild rice was
found in 1, 182 localities (spread over nearly all the counties of Hainan
Province). By the end of 1994, 13 areas out of 16 in 15 counties in the two
provinces had disappeared and the three left were still decreasing owing to
human and domestic animal activities. It is expected that wild rice in Yunnan,
Guangdong and Hainan Provinces will be extinct in 3 to 5 years if no emergency
protection measures are employed. The wild relative species of other crops face
a similar fate.
As one of the important centers of origin
for crops in the world, China has many wild species and their relatives are
distributed widely throughout the country. At the same time, as a developing
country, China¡¯s economic ability is still limited. There, China urgently
requires international aid to improve the protection of its crop genetic
resources which are indispensable material for the sustainable development of
agriculture and for a common future.
(1) The
diversity of vegetable resources in China
The vegetables resources of
China are very rich. There are more than 229 species in 56 families of edible
vegetables and of which 209 species in 29 families are higher plants (including
varieties). One hundred and thirty-five species of edible vegetables originate
from China, including 50 species of popular vegetables, such as Brassica campestris var. cephacta, var. rosularis, var. tai-tsai, B. juncea var. foliosa, var. tumida, Glycine max, Beninceasa hispida, Allium fistulosum var. giganteum,
var. caespitosum, A.
chinensis, A. tuberosum, Lactuca sativa,
Ipomoea aquatica, Dioscrorea batatas, Zingiberaceae officinale, Colocasia
esculenta, Nelumbo nucifera, Brassica schreberi, Typha latifolia, Malva
verticillata, Toona sinensis, Basella and Chrysanthemum nankingense.
Brassica
campestris is
the premier vegetable of China. It has two main groups: subsp. pekinensis,
¡°coned cabbage¡±, distributed mainly in the north, and subsp. chinensis,
¡°non-coned cabbage¡±, mainly in the south. About 1,500and 1,000 germplasm
resource accessions have been collected, respectively, for these two species.
The valuable cultivars of subsp. pekinensis are: Tianjin Qingmaye which
has wide adaptability, disease-resistance, and a high storage quality, and
Beijing ¡°Xiaoqingkou Hetaowen¡± which is of good quality, virus-resistant and
also of high storage quality. Valuable cultivars of subsp. chinensis
are: Shanghai ¡°Siyueman¡±, characterised by a wide adaptability, thick leaves
and high yield; and Wuhan ¡°Hongcaitai¡±, characterized by its tender taste.
The
second vegetable is Raphanus sativus with many types. Based on the
patterns of leaves, roots and their colours, it is divided into more than 30
forms with many varieties of each. More than 1,800 germplasm resource
accessions have been collected. The valuable varieties include: Beijing
¡°Xinlimei¡± and Shandong ¡°Weixianqing¡± which could be used as fruit; Beijing
¡°Dahongpao¡± and Taihu ¡°Wanchangbai¡± are good for cooking; Yangzhou (Zhejiang
Province) ¡°Yanzhong¡± and Xiaoshan (Zhejiang Province) ¡°Yidaozhong¡± which are
excellent for making pickled vegetables, known as ¡°Yangzhou Luobotou¡± and
¡°Xiaoshan Luobogan¡±.
Cucumbers
(Cucumis sativus) are cultivated everywhere in any season of the year
using appropriate varieties. Meanwhile, cultivation in protected areas is also
common. More than 1,300 germplasm resource accessions are preserved. The
valuable varieties are: Beijing ¡°Dacigua¡±, the disease- resistant varieties
Tianjin ¡°Jinyan¡± and Shaanxi ¡°Xinong 58¡±. The parthenocarpus cultivars are
Jinan (Shandong Province) ¡°Yue¡¯ersan¡± and ¡°Zhongnong 3¡±.
Eggplant
(Solamum melongena) has a 1,000 year history of cultivation in China.
The fruit forms are:circular, long and egg-shaped with 3 patterns, i.e.,
purple, dark purple, green, and white colours. More than 1,300 germplasm
accessions are preserved. The valuable varieties are: Beijing ¡°Jiuyeqie¡±,
Chengdu ¡°Muoqie¡± and Hangzhou ¡°Hongqie¡±; the high quality varieties are Tianjin
¡°Liangshuiqie¡± and Zhejiang ¡°Shijiemei¡± which is also suitable for food
processing.
Hot
pepper (Capsium) has long been cultivated in China. It is distributed
throughout the country and has very rich germplasm resources, with over 1,500
accessions being preserved. Famous varieties are Yunnan ¡°Qiubei¡±, Shaanxi ¡°Qinjiao¡±,
Henan ¡°Yoncheng¡± and Fujian ¡°Ninghua¡± which are suitable for making dry hot
pepper. Raw varieties are: Hunan ¡°Fudijian¡±, ¡°Beijing 78-9¡± and Jilin ¡°Mala
Sandaojin¡±.
Furthermore,
the preserved germplasm resources of tomato, leaf mustard, pumpkin, kidney bean
and cowpea each comprise more than 1,000 each.
China
is the homeland of aquatic vegetables, having over 300 varieties. All of them
have been cultivated for more than 2,000 years except Nasturtium officinale
which was introduced in recent years. The most commonly cultivated 12 species
are: lotus, taro, wild rice stem, water chestnut, arrowhead, aquatic celery,
Gorgon fruit, water shield, cattail stem, water spinach and Nasturtium
officinale.
(2) Problems with the protection of vegetable genetic resources
Following
population increases and economic development, the cultivated areas of
vegetables are increasing continuously, especially in protected areas around
cities. The total area of vegetables under cultivation in China has doubled
during the period from 1981 to 1991,i.e., from 3,450 thousand to 6,910 thousand
ha. Cultivated areas in the protected areas around cities increased from 30
thousand ha in 1984 to 340 thousand ha in 1994, an 11 fold increment over the
last ten years.
Besides
the growth of cultivated areas, the composition of the varieties has also
changed greatly. Before the 1980s, the main cultivated vegetables were local
and normal varieties. After the 1980s, the popularization of new hybrid
varieties has had an enormous impact on the traditional and local varieties,
some of which are little left; others have disappeared.
In
addition, no attention was paid to purification and protection, and the mixing
and even loss of varieties is very serious. Furthermore, the increasing
introduction of foreign species and the expansion of their cultivated areas
have made it an urgent task to protect and save ancient, specific, valuable
vegetable varieties and wild vegetable resources.
(1) General situation
of forage crop genetic resource diversity in China
The
cultivation of forage in China has a long history, e. g., Medicago sativa has about 2000 years of cultivated history. Under
different natural condition and cultivation methods, many native varieties have
been formed. The diversity of forage in China is very rich. For seed plants
alone, there are 4,215 species in 879 genera and 127 families which can be used
as livestock forage. Among these, the valuable forage comprises over 180
species which are widespread in temperate steppes, deserts, cold highland
grassland, and tropical and subtropical prairies. The experience of
domestication and breeding of new forage crops in China is very rich. Many wild
herbage species have been introduced and cultivated for livestock farming, for
example, Astraglus adsurgens, Caragana korshinskii, Hedysarum laere, Agropyron cristatum,
Ceratoides latens, Kochia prostrata, Calligonum mongolicum, Artemisia sphaerocephala and Indigofera amblyantha.
Nearly all
famous cultivated forage crops have their wild species or wild relatives in
China. For example, the wild relatives of Medicago
sativa have 13 species in China, e. g., M. susveolens, M. lupulina and M.
alaschanica; the wild relatives of Trifodium
repens and T. pratensis have 3 species, e. g., T. lupinaster; the wild
relatives of Bromus inermis have 25
species, such as. B. ircutensis and B. ciliatus; the wild
relatives of Festuca pratensis have
23 species, e. g., F. alaica and F. rubra; the wild
relatives of Poa pratensis have 70
species, e. g., P. acmocalyz and P. alta. In addition, Dactylis glomerata, Cynodon
daelylon and Phalaris arundinacea also
have wild relatives in China. There are some other endemic species.
Furthermore,
204 species, in 20 genera, of forage crops which were not found in China have been
introduced. This has greatly enriched the forage gene bank. There are today 127
families, 899 genera and 4,419 species of forage in China, which makes it the
richest country for such species.
A group of
wild, landrace, and introduced species for cultivation have been screened. Up
to 1995, 32 wild species, 32 landraces, and 42 introduced species have been
identified and documented. In addition, a group of new hybrid varieties (64)
have been popularized for production.
(2) Current situation of forage genetic
resources in China
Overgrazing,
reclamation and excavation of prairies is very serious and has resulted in
large areas of grassland degradation, desertification and salinization.
According to statistics, the degraded grassland area made up 15% of the total
in the mid-1970s. This increased to over 30% in the mid-1980s. For example, the
degraded grassland area of the Inner Mongolia Plateau accounts for 50% of the
total area of the Autonomous Region. In Hulunber Grassland, a place famous for
its plentiful water and lush grass, 23% of the grassland has been degraded and
the situation is worsening. Some populations of valuable forage grass have lost
their habitats, resulting in a decrease in the number of species and
population. Formerly abundant species have become rare, endangered, or even
extinct.
(3) The protection of forage genetic resources
in China
In 1986, a
national crop gene bank was set up by the Chinese Academy of Agriculture (in
Beijing) for the long-term (50 years) preservation of the crop (including
forage) genetic resources of the country. In 1989, A forage gene bank, with a
capacity of 40,000 accessions, was built in the Institute of Grasslands of the
Chinese Academy of Agriculture (in Huhhot) for medium term preservation and
supply of forage seed. Five perennial forage genetic resource nurseries were
set up in Huhhot, Beijing, Wuhan, Nanning and Kunming, for breeding, species
preservation for farming and seed supply. In this way, a national system of
herbage resource ex situ protection
and seed supply has been established and in which the forage gene bank serves
as the centre and co-operates with the National Crop Gene Bank and perennial
forage genetic resource nurseries.
In view of
the abundant forage genetic resources and the stress on them, the existing
protection measures are, however, far from enough. It is necessary to take
sustainable use as a strategic target to efficiently protect and rationally use
such resources. To date, basic research must be emphasized in order to solve
theoretical and technical key problems in the action plan for the preservation
of the grassland ecosystem, to speed up the pace of identification,
propagation, and entry into the germ gene bank, to enforce the ¡°Grassland Law¡±,
and to strengthen the management and protection of grasslands.