Cistanche is a perennial herbaceous plant belonging to the genus Cistanche in the Lidanaceae family, which mainly includes desert cistanche and cistanche tuber. Cistanche is parasitized on the roots of sand plants such as Haloxylon and Tamarix. It has the reputation of “desert ginseng” and has extremely high medicinal value. Historically, it was a treasure of tribute to the court of the Western Regions.
Geographical distribution coincident with host plant
Cistanche is mainly distributed in dry areas such as warm deserts and gravel deserts in the northern hemisphere. It cannot live independently and must attach to the roots of the host plant to obtain nutrients and water. Therefore, the geographical distribution of Cistanche and its host plants coincide.
Desert Cistanche is parasitized on the roots of Haloxylon and Haloxylon plants of the Chenopodiaceae family. They are mainly distributed in Alxa Left Banner, Ejina Banner and Urad Rear Banner in central and western Inner Mongolia, Zhangye and Wuwei in Gansu, and Northern Xinjiang in Xinjiang. And Qinghai and other places. Among them, the quality of medicinal materials produced in the Alxa region of Inner Mongolia is particularly good, which is known as the “Hometown of Cistanche.”
Medicinal materials made from Cistanche
Cistanche cistanche is parasitic on the roots of Tamarix, a plant of the genus Tamarix, and is widely distributed in northern Africa, the Arabian Peninsula, Central Asia and South Asia. In my country, it is mainly distributed in the southern Xinjiang regions around the Taklimakan Desert such as Hotan and Bazhou in Xinjiang. The yield of Cistanche cistanche in Hotan is the largest and the quality is the best. In recent years, introduction experiments have shown that Cistanche cistanche can also be grown in northern Hebei and the Yellow River Delta in Shandong. Due to the high value of Cistanche, the phenomenon of wild pirate excavation is very serious, resulting in a sharp decline in the number of wild Cistanche, and the distribution area is gradually shrinking.
Living habits of taking desert as home
The living habits of the desert Cistanche are very peculiar. They mainly grow in the desert areas where Haloxylon ammodendron and Haloxylon ammodendron are distributed. Wild Cistanche prefers to grow on soft sandy ground with mild salinization, and is often distributed in lowlands such as semi-fixed dunes, dry river beds, and lake basins. The distribution area of desert Cistanche is usually characterized by arid climate, low rainfall (≤250 mm), large evaporation, long sunshine time, and large temperature difference between day and night. The soil is mainly gray brown desert soil and brown desert soil.
The unearthed Cistanche has thick fleshy stems and pale yellow or flesh-colored scaly leaves. Cistanche cistanche is unearthed from April to May every year. After being unearthed, Cistanche will bloom and bear fruit within about a month. Even if it leaves the soil, it can bloom and bear fruit even if it leaves the soil. Due to the harsh desert environment, in order to increase the parasitic rate, one plant of Cistanche can produce tens of thousands to hundreds of thousands of tiny seeds.
The living habits of Cistanche cistanche are similar to those of the host Tamarix. It usually grows in Gobi deserts above 1,000 meters above sea level, on the edge of sand dunes, and low-lying desert areas with sufficient water content.
Cistanche cistanche is suitable for growing in sandy soil with good permeability and water permeability, and does not require high soil organic matter content; it prefers sufficient light and has strict temperature requirements. Too high or too low temperature will inhibit its growth. Cistanche tubulosa is not tolerant to severe cold, the suitable growth temperature is 5-28 ℃, and the best temperature for flowering and fruiting is 15-25 ℃. The soil moisture content for its growth in winter should be maintained below 10% to avoid frostbite deaths of Cistanche cistanche due to low winter temperatures in the introduction area.
Difficult and slow parasitic process
Cistanche is a typical pan-parasitic plant, and all the nutrients needed for its growth are taken from the host. The parasitic rate of Cistanche in nature is relatively low. In order to increase the survival probability, Cistanche usually produces a large number of seeds, which are spread by external forces such as wind and water. These mature seeds after falling into the sandy soil have been in a dormant state (the dormancy period can reach 10 years) before they receive the chemical signal released by the host plant. Once these seeds feel the chemical signal substances released by the host plant and the suitable growth environment, they immediately start the germination process.
Usually under the action of the stimulus secreted by the host plant roots, the seeds of Cistanche germinate and form radicle-like bodies, which produce haustorium at the end of the rhizome. The haustorium contacts the host root and penetrates the epidermis and cortex of the host root to reach the vascular bundle. The sieve tube is connected with the host catheter and the sieve tube to form a “physiological bridge” for the transportation of nutrients. Since then, Cistanche has continuously obtained nutrients from the host to complete the parasitism and growth process.
Key substances that affect parasitism
Stimulating substances for seed germination are one of the key factors for parasitic plants to complete the parasitic process. Studies have shown that mature parasitic plant seeds will not germinate without the effect of germination stimulating substances, even if the external environmental conditions are suitable. In recent years, with the continuous deepening of research, some substances that can stimulate the germination of parasitic plants have gradually been understood. For example, strigolactone hormones are the key substances that stimulate the germination of strigaton seeds. However, the key substances that stimulate the germination of Cistanche seeds have not been isolated yet.
Suction organs are the basis for the establishment of the parasitic relationship between parasitic plants and their hosts. As early as 1875, German Professor Hermann conducted in-depth research on the haustorium of parasitic plants. In addition to seed germination, parasitic plants require the host plant to secrete effective chemical substances, the formation of their haustorium also requires the host plant to release another type of chemical signal substance. This type of signal substance is often referred to as a “spirator-inducing factor”. As a perennial herbaceous sand plant, Cistanche cistanche is far behind other annual parasitic plants in the study of its haustor inducing factors, which is related to the difficulty of indoor cultivation in desert areas.
Cistanche has a long history of application in my country, and it is safe, non-toxic and side-effects. It has broad development prospects in strengthening physical strength, anti-fatigue and delaying aging, and the market demand is huge. Since the National Health Commission included Cistanche in the “Medicinal and Food Homologous” catalog in 2018, the demand for Cistanche in the market has continued to increase. Today, medicated diets, teas, medicinal wines and health foods made from Cistanche are widely popular in China, Japan and some Southeast Asian countries.