The Study On Biological Characteristics And Artificial Cultivation Of Solanum Nigrum L In Qinghai Province

Solanum nigrum L,growing in Qinghai province was considered the experimental material in this article.The botanical and ecological characteristics of Solanum nigrum L were studied using the Pointing Field method.The resource abundance of Solanum nigrum L in Qinghai province was investigated using statistical tools. Studies on cultivation of Solanum nigrum L,were carried out in the experimental fields of Xining area.These studies included germination characteristics and planting methods.The phenophase,growing,and the concentration of photosynthetic pigments between the cultivateded and the wild Solanum nigrum L were compared.The characteristics of photosynthetic physiology of the cultivated and the wild Solanum nigrum L was studied using a CI-30/PS portable photosynthesis cryoscope.The resistant physiological characteristic of cultivated and wild Solanum nigrum L were also determined and discussed.The protein content in cultivated and wild Solanum nigrum L fruit and leaf were independently analyzed using a Kelvin nitrogen auto-analyzer and the method of Mas light blue G-520 dyeing.Finally,we provided measures of conservation and reasonable utilization of Solanum nigrum L.It was concluded that Solanum nigrum L could only grow in areas between 1800 meters and 2300 meters above sea level in Qinghai Province.Solanum nigrum L could typically be found growing in damp and fertile places such as grassland,edge of farm lands,road side and hill slopes.It was found that Solanum nigrum L was capable to adapt to different environmental factors such as altitude,climate,sunlight,and soil conditions.However Solanum nigrum L was never found in areas of more than 2300m above sea level.Solanum nigrum L was most abundant and most frequently found in Ledu county., Solanum nigrum L found in the Xining area was found to have the tallest plant height. The highest population density,of Solanum nigrum L was found in Jianzha County while the lowest population density was seen in Ledu County.The plant coverage of Solanum nigrum L was the largest in Minhe County.Solanum nigrum L in Pinan County had the highest plant dry weight.Jianzha County saw the lowest abundance. plant height,plant coverage,frequency and plant dry weight.The overall reserves of yearly resource of Solanum nigrum L were about 4.3×10⁶kg in Qinghai Province.Measures like after ripening,soaking seeds with hot water,GA₃,and KNO₃ all could effectively improve the germination rate of Solanum nigrum L seeds,no matter the seeds had been stored in greenhouse or refrigeration.The highest germination rate was seen when the refrigerated seeds were treated with 300 mg/L GA₃.The effect of the after ripening treatment on germination rate was statistically significant(p＜0.05). The effects of soaking seeds with hot water,GA₃,KNO₃,low temperature treatment on germination rate were all statistically significant(p＜0.01).The suitable time in a year for sowing Solanum nigrum L in the Xining area was around late April and early May.The sowing density should be 35～50g seeds in every 667m² of land.The seeds usually sprouted around six days after sowing.64.02%of the sowed seeds sprouted. The sprouts were transplanted after seven or eight days and 83.33%of the sprouts survived the transplantation.667m² of land could produce around 5000kg of fresh stems,leafs and fruits.The phonological cycles of the cultivated and wild Solanum nigrum L in Xining area could both be divided into seedling emergence stage, seedling stage,branch stage,squaring stage,flowering stage,filling stage and withered stageripening stage.Every phonological phase stage of the planted Solanum nigrum L happened earlier than those of its wild counterpart,and therefore the entire reproductive cycle for planted Solanum nigrum L was shorter.Compared to the wild Solanum nigrum L,the cultivated Solanum nigrum L appeared to be in much better conditions with higher plant height,greater weight of one thousand of seeds,greater weight of dried plant and greater weight of fresh plant.The cultivated Solanum nigrum L contained higher level of pigments Chla,Chlb,and Chlt but lower level of pigments Car,Chla/Chlb,and Car/Chlt,if compared with the wild Solanum nigrum L.Statistical results demonstrated very significant(P＜0.01) differences of the Chlb,Chlt levels,significant(P＜0.05) differences of the Chla,Car,Chla/Chlb levels,and insignificant difference of the Car/Chlt level(P＞0.05) between the cultivated and the wild Solanum nigrum L.Bimodal distribution patterns were observed in the daily variation of net photosynthetic rate of both the cultivated and the wild Solanum nigrum L.The overall net photosynthetic rate observed in the cultivated Solanum nigrum L was higher than that observed in the wild Solanum nigrum L.Correlation analysis indicated that there was an extremely significant inverse correlation between the photosynthetic active radiation and the net photosynthetic rate.Extremely significant positive correlation was observed between the relative humidity and the net photosynthetic rate.The internal C0₂ concentration and the temperature was significantly inverse correlated to the net photosynthetic rate.The instantaneous water usage efficiency was significantly and positively correlated to the net photosynthetic rate.The activity of the antioxidases SOD,POD,and CAT found in the wild Solanum nigrum L was stronger than those found in the cultivated Solanum nigrum L.The difference of the SOD and POD activity was significant(P＜0.05),while the difference of the CAT activity was extremely significant(P＜0.01),between the cultivated and the wild Solanum nigrum L.The content of malondialdehyde and soluble sugars was higher in the wild Solanum nigrum L of extreme significance.The protein content in the fruit of the cultivated Solanum nigrum L was extremely significantly higher than that of the wild Solanum nigrum L.The protein content in leafs of the cultivated Solanum nigrum L was significantly higher than that of the wild Solanum nigrum L.The methods of local conservation and transplantation conservation should be applied simultaneously to protect the Solanum nigrum L resources.Any exploitation work of the Solanum nigrum L resources should not compromise their conservation. Extensive research and development work would be required to allow the development of more new and sophisticated Solanum nigrum L based products.For the first time,this article systemically summarizes the comprehensive studies carried out on the Solanum nigrum L in Qinghai province.It aims at providing a practical and theoretical basis for further studies,application and protection of the Solanum nigrum L resources of the Qinghai-Tibetan Plateau.