lnfluences of Different Habitats on Asexual Propagation of Wild Gastrodia elata f.glauca being Domesticated in Ganzi

Xueqiang XlE

Department of Environment and Life Science，Sichuan University for Nationalities，Kangding 626001，China

lnfluences of Different Habitats on Asexual Propagation of Wild Gastrodia elata f.glauca being Domesticated in Ganzi

Xueqiang XlE*

Department of Environment and Life Science，Sichuan University for Nationalities，Kangding 626001，China

［Objective］The influences of different habitats on asexual propagation of wild Geg （abbreviation for Gastrodia elata Bl.f.glauca S.Chow）being domesticat-ed in Ganzi prefecture was studied. ［Method］The research trial was carried out in the following three kinds of habitats at the same time：the plastic greenhouses，the birch forest of shady slope and the shrubbery of sunny slope，and the results were analyzed with group data average hypothesis test method.［Result］The overall tuber（the juvenile tuber，the immature tuber and the mature tuber）yield and the mature tuber yield were both very significantly higher in the plastic greenhouses than in the other two types of habitats，and respectively reached 9.52 and 6.70 kg/m2；the ma-ture tuber drying rate was dramatically or very dramatically lower in the plastic greenhouses than in the other two types of habitats，and was 23.84%；the stabilities of the overall tuber yield，the mature tuber yield and the drying rate were all re-duced in the order of greenhouses，birch forest and shrubbery；and the dry mature tuber yield of the plastic greenhouses was the highest in the three kinds of habi-tats，and was 1.60 kg/m2.［Conclusion］A good habitat had to be created or chosen in the domesticating cultivation of the wild Geg in Ganzi prefecture.The preferred choice was the plastic greenhouse，the alternative one was the deciduous broad-leaved forest of shady slope.The imitating wild planting of the wild Geg should be done in the warm moist deciduous broad-leaved forest of shady slope.

Habitat；Gastrodia elata Bl.f.glauca S.Chow；Asexual propagation；Domesticating cultivation；Imitating wild planting；Overall tuber yield sum；Mature tu-ber yield；Drying rate

G astrodia elata is a valuable traditional Chinese medicinal material and a modern health-protection food material，i.e.，it can treat hypertension，giddiness，head-ache，facial paralysis，limb numbness，infant convulsion，etc.，and also can condition and strengthen the function of human body.Wild Gastrodia elata Bl.f.glauca S.Chow （Wild Geg）has good shape，high drying rate and good quality，which is few in wild region and rarely cultivated artificially，and thus is expensive than other types of Gastrodia elata［1］.Wild Geg in Ganzi has been explored excessively due to no pollution and large market demand.In order to satisfy the market demand and effectively protect wild Geg source in Ganzi prefecture，it is necessary to carry outdomesticating cultivation. Habitat conditions can influence the growth and development of any plant. In orderto conductimitating wild planting on wild Geg in Ganzi prefec-ture and to conduct bionics wild culti-vation on Gastrodia elata，asexual propagation of wild Geg being domes-ticated at different habitats was re-searched，aiming at providing certain theoretical basis for asexual propaga-tion of wild Geg.

Materials and Methods

Materials

Preparation of wild Geg'sseed stem （G） Yusaping forest farm in Luding county has an altitude of 1 800 m，and is warm throughout the year generally with rain and fog.The wild Geg produced at this region has flat elliptic mature tuber，a single-tuber weight of 120-760 g，short inflores-cence internode，a lot of flowers，and good quality.The mature tuber thereof was cultivated in a greenhouse in April of the first year，artificial pollination was performed to obtain sexual seeds，which were sown accompanied by the leaves with Mycena dendrobii and tree trunks for growing Armillariella mellea［2］，and the juvenile tuber and im-mature tuber were harvested at the end of March of next year as seed stem designated as G，which was the seed stem of the first sexual genera-tion.

Culture of fungus-growing material Culture of Armillariella mellea mother strains：Tissue isolation was per-formed on tubers of Kangding wild Geg attached with rhizomorph fol-lowed by purification，obtaining the mother strains designated as AmG.

AmG culture on tree branches：Branch sections of Prunus tomentosa Thunb.（with a diameter about 1 cm，and a length of 1-2 cm）were filled in a brown bottle（600 ml），which was then filled with the mixture of corn flour，white sugar and agar（weighed at a proportion of 20，20，and 8 g per 1 000 ml of water）decocted in water to sub-merge the branches； autoclaved sterilization was performed at 121℃for 1 h，and AmG was inoculated after cooling.Above process was began inlate January and finished in later February.

AmG culture on tree trunk：AmG culture was then performed on short-cut wood of Quercus spinosa David ex Fr.by use of the tree branches ob-tained above.The process was con-ducted according to following method：A branch of Quercus spinosa David ex Fr.with a diameter of 5 cm was cut in-to short-cut wood with a length of 40 cm，which was chopped every 10 cm to obtain cataphracted cuts；a pit with a length of 80 cm，a width of 40 cm and a depth of 30 cm was digged，the bottom of which was laid with a layer of fallen birch leaves with a compacted thickness of 1 cm，above which was laid with a layer of short-cut wood of Quercus spinosa David ex Fr.By turns，one branch with fungus was placed at the two ends of the short-cut wood and each cataphracted cut，re-spectively，and culture medium（birch saw dust 3 parts+clean coarse river sand 1 part，the same below）was filled in gaps between the short-cut wood and covered the short-cut wood by a thickness of 0.5 cm；and 3 layers were provided by doing so，and the medium with a thickness of 5 cm was finally laid thereon followed by fallen birch leaves. The above process was began in late February and finished at the end of March.

Methods

Experiment design At Kangding forest farm with an altitude of 2 800 m，three following habitats were selected：habitat A-plastic greenhouse，habitat B-birch forest of shady slope，habitat C-shrubbery of sunnyslope；each habitat was set with 6 experiment u-nits，each of which had an area of 2 m×0.5 m；and in each unit of each habitat，the seed stem G of wild Geg was sown together with short-cut wood ofQuercusspinosa David ex Fr. growing Armillariella mellea.After har-vest，statistic analysis was performed according to group data average hy-pothesis test method to compare the difference between overall tuber yields，mature tuber yields and drying rates of the three habitats.

Sowing，management and harvest

（1）Sowing．Sowing was carried out in early April by the method of sowing seed stem and fungus-growing material together.Seed selection was performed to make the seed stems for the three habitats accordant.In each unit，fungus-growing tree trunks were laid in parallel every 10 cm，on which a layer of seed stem（1.2 kg）were sown uniformly with a depth of 20 cm next to growing points of rhizomorph.The seed stem was then covered by cul-ture medium with a thickness of 5 cm followed by fallen birch leaves，and water was finally sprinkled profoundly.

（2）Management after sowing and harvest.The habitat A was controlled at a temperature of 18-25℃ and a humidity of 65%-70%.The tempera-tures and humilities of habitats B and C were left naturally.Harvest was car-ried out at the end of April of next year.

lnvestigation items Overall tuber yield：Harvest was performed while re-moving impurities including mud and sands，and the fresh weight of all tu-bers （including the juvenile tuber，the immature tuber and the mature tuber）in each experiment unit was obtained as the whole tuber yield.

Mature tuber yield：All the mature tuber in each unit was weighed to get a fresh weight.Drying rate of the mature tuber：The mature tuber was washed and weighed to get a fresh weight，then it was steamed，and dried in an oven at 80℃to be weighed for a dry weight，and the ratio of dry weight（kg）to fresh weight（kg）of all the mature tu-ber in each unit was thus obtained as the drying rate of the mature tuber in each unit.

Results and Analysis

Overall tuber yields of wild Geg by asexualpropagation in different habitats

As shown in Table 1，the overall tuber yields obtained by asexual propagation with the seed stem of the first sexual generation had a very sig-nificant difference between different habitats （the result by t test，similarly hereinafter）.The average overall tuber yields of the plastic greenhouse（A），the brich forest of shady slope and the shrubbery of sunny slope （C）were of 9.52，6.85 and 3.42 kg/m2，respective-ly.The overall tuber yield of the green-house habitat was higher than that of the birch forest habitat by 38.98%，and higher than that of the shrubbery habi-tat by 178.36%；and the overall tuber yield of the birch forest habitat was higher than that of the shrubbery habi-tat by 100.29%.

From the variable coefficient of overall tuber yield，the greenhouse habitat，the birch forest habitat and the shrubbery habitat were of 4.277%，13.718%and 16.182%，indicating that the asexual propagation of wild Geg in the greenhouse habitat could achieve a very stable overall tuber yield.The high yield obtained in greenhouse was universal，while the overalltuber yields of the other two habitats were unstable.

Mature tuber yields of wild Geg by asexualpropagation in different habitats

As shown in Table 2，the asexual propagation with the seed stem of the first sexual generation in different habi-tats resulted in the mature tuber yields with very significant differences.The average mature tuber yields obtained in the plastic greenhouse，the birch forest of shady slope （B）and the shrubbery of sunny slope（C）were of 6.70，3.52 and 1.45 kg/m2，respective-ly.The mature tuberyield ofthe greenhouse habitat was higher than that of the birch forest habitat by 90.34%，and higher than that of the shrubbery habitat by 362.07%；and the mature tuber yield of the birch forest habitat was higher than that of the shrubbery habitat by 142.76%.

It could been seen that the vari-able coefficients（CV∥%）of mature tuber yield for the greenhouse habitat，the birch forest habitat and the shrub-bery habitat were of 4.995%，13.508% and 26.080%，indicating that the asex-ual propagation of wild Geg in the greenhouse habitat realized a very stable mature tuber yield.The high overall tuber yield obtained in green-house was universal，while the mature tuber yields of the other two habitats were unstable.

Mature tuber drying rate of wild Geg by asexual propagation in different habitats

Drying rate of plant product refers to the ratio of dry weight to fresh weight，and a greater numerical value indicates more dry matter.From Table 3，the drying rate obtained by asexualpropagation with the seed stem of the first sexual generation varied with dif-ferent habitats to different extents.The average drying rates obtained in the plastic greenhouse，the birch forest of shady slope and the shrubbery of sun-ny slope were of 23.84%，27.23%and 30.72%，respectively，indicating that the dry matter content of the mature tu-ber in greenhouse habitat was signifi-cantly lower than those of the mature tubers in the birch forest and shrub-bery habitats.

Table 1 Effects of different habitats on overall tuber yields of wild Geg by asexual propagation

Table 2 Effects of different habitats on mature tuber yields of wild Geg by asexual propagation

Table 3 Effects of different habitats on mature tuber drying rate of wild Geg by asexual propagation

dfe=10；t0.01=3.169；t0.05=2.228；**represented a very significant difference；*represented a significant difference.

It could been seen that the vari-able coefficients（CV∥%）of drying rate for the greenhouse habitat，the birch forest habitat and the shrubbery habitat were of 3.372%，6.134%and 6.510%，indicating that the asexual propagation of wild Geg in the green-house habitat obtained a very stable dry matter content.The dry matter content obtained in greenhouse was universal，while the dry matter con-tents of the other two habitats were un-stable.

Dry mature tuber yields of wild Geg by asexual propagation in different habitats

The dry mature tuber yield was equal to the product of mature tuber yield multiplied by the drying rate of the mature tuber.From the contents in table 2 and Table 3，the average yields of dry mature tubers in the plastic greenhouse，the birch forest of shady slope and the shrubbery of sunny slope were of 1.60，0.96 and 0.45 kg/m2，respectively.The dry mature tuber yield of the greenhouse was higher than that of the birch forest by 66.67%，and higher than that of the shrubbery by 255.56%，and mean-while，the dry mature tuber yield of the birch forest was higher than that of shrubbery by 113.33%.

Conclusions and Discus-sion

Domesticating cultivation of wild Geg in Ganzi prefecture needing creation or selection of good habi-tat

In the three habitats，the plastic greenhouse achieved high and stable overall tuber yield and mature tuber yield but a low and stable dry matter content of the mature tuber，while the other two habitats were on the con-trary.This was because the plastic greenhouse was endowed with easily regulated and stable temperature and humidity to satisfy the demand from growth and development of wild Geg and the symbiotic fungus as much as possible.The tubers of wild Geg in the greenhouse grew rapidly，and the an-nual growing period was long，resulting in the high overall tuber yield and ma-ture tuber yield as well as a high water content in the mature tuber.Mean-while，the temperatures and humilities under the brich forest of shady slope and the shrubbery of sunny slope changed with the nature which was unstable，and thus could not satisfy the demand from growth and development of wild Geg and the symbiotic fungus easily.The wild Geg tubers in the brich forest and the shrubbery grew with the speeds which were lower overall and uneven，and such phenomenon was more prominent in the shrubbery of shady slope due to large changes of temperature and humidity.As a result，very significant difference or significant difference existed in overalltuber yields，mature tuber yields and mature tuber drying rates of wild Geg in differ-ent habitats.Therefore，when con-ducting domesticating cultivation of wild Geg in Ganzi prefecture at the ar-eas with a high altitude，a good habitat should be selected or constructed，the first choice being greenhouse，the second choice being birch forest of shady slope and similar broadleaved deciduous forest of shady slope.

Broadleaved deciduous forest of shady slope for imitating wild planting of wild Geg in Ganzi pre-fecture being the best

Imitating wild planting is a kind ofhuman-assisted cultivation performed in imitated field growth environment or directly in wild environment，with the purpose of using the unity of plant and natural condition for production of re-spective plant product.ZHANG et al. deemed that the wild Geg obtained by the imitating wild planting was en-dowed with the quality close to wild state as well as increased yield，and in addition，the destruction to ecological environment by wild Geg cultivation was reduced［3］.In fact，the imitating wild planting of wild Geg also reduced the occupation of inadequate farmland by totally-artificial cultivation.

As mentioned above，different habitats had very significant or signifi-cant influences on total tuber yield，mature tuber yield and mature tuber drying rate of wild Geg in Ganzi pre-fecture，so a suitable environment was necessary when performing imitating wild planting on it.In summary，on the basis of the characteristics of plastic greenhouses and birch forest of shady slope，the most ideal habitat for imitat-ing wild planting of wild Geg is warm，moist，for example，broadl-eaved de-ciduous forest with stable temperature and humidity conditions，which not on-ly can satisfy the demand by wild Geg for water and heat directly，but also can satisfy the requirement of growth and development of symbiotic fungus to satisfy the requirement of wild Geg to nutrients，thereby better improving the yield and quality of wild Geg.The first choice of such habitat is Yusaping forest farm having an altitude of 1 800 m near to the river valley of Dadu Riv-er.There is much rain and fog at this region all the year round，with an an-nual average temperature above 13℃.Under the broadleaved deciduous forest in such habitat，naturally-grow-ing wild Geg has a higher yield.Sec-ondly，such habitat also can be found in the main producing area of wild Geg in Ganzi prefecture，i.e.，Kangding，Luding，Danba and Jiulong.

Reference

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［2］XIE XQ（谢学强）.Effect of Armillariella mellea on Sexual Reproduction of Gastrodia elata f.glauca in Ganzi Prefec-ture（蜜环菌对甘孜州野生乌天麻有性繁殖的影响）［J］.Hubei Agricultural Sci-ences（湖北农业科学），2011，50（17）：3562-3565.

［3］ZHANG BH（张博华），LIU W（刘威），ZHAO Z（赵致），et al.Research on life history and phenological period of wild-stimulated cultivated Gastrodia elata f. elata in Guizhou（贵州仿野生栽培红天麻的生活史及物候期研究）［J］.China Journal of Chinese Materia Medica（中国中药杂志），2014，39（22）：4311-4316.

Responsible editor：Yingzhi GUANG

Responsible proofreader：Xiaoyan WU

Supported by Key Natural Science Program of the Education Department of Sichuan province（12ZA103）.

*Corresponding author.E-mail：xxqiang2005@126.com

Received：July 20，2015 Accepted：August 25，2015