Cucumber Germplasm Resources in Southwest China

Cucurbit Genetics Cooperative Report 15:7-8 (article 3) 1992

Si-Lin Yang
Department of Horticulture, Southwest Agricultural University, CongQing, Sichuan, 60316, People’s Republic of China

The majority of Chinese cucumber cultivars of the outdoor type have been grown for fresh consumption in China for well over 2000 years. Only in recent history were the greenhouse and pickling types introduced into China. In a brief summary of intraspecific variation in economically important Chinese cucurbits (6), Chinese cucumber cultivars were divided into three types (horticultural groups): North China type (NC), South China type (SC) , and Southwest China type (SW). The NC and SC types have long been recognized by Chinese horticulturists in China (1, 6) and Japan (3, 4). It was not until 1989 that the SW type was recognized.

There are diverse cucumber cultivars native to southwest China. Recent investigations in Sichuan (2), Yunnan (Zhang, Y.H., pers. comm.) and Guizhu (Z.Y. Guo, personal communication) suggested that all southwest local cultivars belong to the SC type. However, my field surveys and culture experiments indicate that some of the local cultivars in the southwest are distinct from the SC type with respect to fruit traits and ecological requirements. Plants of these local cultivars are characterized by their large short fruits, vigor, and long growing period (ca. 200 days). They are grown in mountain regions: Yaan and Shanzia Regions in Sichuan, Anlong and Tongxing in Guizhou, and Dehong, Zhaotong, and Zishuanbanna in Yunnan. The SW type is composed of those cultivars.

Table 1 compares the morphology and ecological requirements of the SW, NC and SC types, and Cucumis sativus var. hardwickii. The SW type is closely allied with the SC type and the C. sativus var. hardwickii, and distinct from the NC type (Table 1). To date, phylogenies of Chinese cucumber cultivars are unknown. I propose that the SC and SW cultivars either were domesticated from the native wild type (C. sativus var. hardwickii) in southwest China, or were brought into China from India at prehistoric times via the ancient southwest Silk Road (Yang unpublished). The NC cultivars were introduced, via the Silk Road from middle Asia during the Han Dynasty (2nd century BC; see reference 6 and reference therein).

Compared to North China, little attention has been given to the southwest with respect to breeding and germplasm research of cucumber cultivars (1). From the mid 1980s, NC cultivars and F1 hybrids began replacing the indigenous cultivars in the southwestern provinces. Subsequently, valuable local cultigens in the southwest are disappearing. Southwest China, which is bounded by the Himalayas, has been suggested as the original center of domestication of the cucumber (see reference 5 and references therein). Although it still remains unclear of the exact report, it has been suggested that southwest Yunnan should be included as a center for domestication of cucumber (5). Recently, C. sativus var. hardwickii was observed in southwest China (Chen, J. pers. comm.). Southwest China should be of interest for future research by cucumber breeders and taxonomists.

Table 1. Comparison of the morphology and ecological requirements of the SW, NC and SC types, and Cucumis sativus var. hardwickii.

Trait

NC

SC

SW

hardwickii

Photoperiod day neutral short days induce pistillate flowering short days induce pistillate flowering short days induce pistillate flowering
Ecological requirements Temperate, dry tolerance Temperate, humid warm, humid
Days to 1st harvest 50-60 50-70 120
Growth season all spring to summer spring to fall spring to fall
Plant growth less vigorous vigorous vigorous
Trellis support needed unneeded unneeded unneeded
Stem small large large
Leaves small large very large
Branch number 2-5 2-10 >10 >10
Node of 1st pistillate flower 5-7 5-10 30 >30
Flower location main vine main vine main and branch main and branch
Fruit length 40-6- cm 15-30 cm 10-40 cm
Fruit diameter 4-7 cm 6-10 cm 10-20 cm
L:D ratio 8-15 3-8 1-4 1-4
Fruit wt. 150-400 g 150-500 g 15000-3000 g 30g?
Fruit ridges? yes not obvious no
Fruit skin thin thick thick thick
Fruit warts many some rare no
Fruit spines many, white some, black rare, black no
Immature fruit color dark green light green light green/white light green
Mature fruit color yellow yellow, brown brown or white
Fruit color uniformity Uniform mottled mottled mottled
Mature fruit netting Rare Numerous Numerous
Seed length 0.8-1.0 cm 0.9-1.0 cm 1.2-1.4 cm
Seed width 0.3-0.4 cm 0.3-0.4 cm 0.3-0.4 cm
100-seed wt. 2-2.5 g 2-2.4 g 4.0 g
Typical cultivars BeJing, Cigua, Changchun Mei, Lingyan Daci Wuhan Qingyudan, Di Huanggua, Hanzhou Qinpi Zhaotong Da Huang Gua, Yaan Man Huanggua, Anlong Da Huanggua, Xishuangbanna Gourd

Literature Cited

  1. Cui, H.W. and X.P. Zhang. 1991. Cucumber cultivar improvement in the People’s Republic of China. Cucurbit Genetics Coop. Rpt. 14: 5-7.
  2. Dong, W. and L. Chen. 1991. A study of the local cucumber cultivars in Sichuan. Zuowu Pingzong Ziyuan 1991 (1): 24-25 (in Chinese).
  3. Kalloo, R. 1988. Vegetable breeding, vol. 3. CRC Press, Inc. Boca Raton, Florida, USA.
  4. Yamaguchi, M. 1983. World vegetables, principles, production and nutritive values. AVI Publishing Company, Inc. Westport, Connecticut, USA.
  5. Yang, S.L., H. Pu, P.Y. Liu and T.W. Walters. 1991.Preliminary studies on Cucumis sativus var. xishuanbannanesis. Cucurbit Genetics Coop. Rpt. 14:29-31.
  6. Yang, S.L. and T.W. Walters. 1992. Ethnobotany and the economic role of the Cucurbitaceae of China. Economic Botany (Iin review).