Evaluation Of Container Lotus (Nelumbo) And Effects Of Cultivation Conditions On Their Morphogical And Physiological Characteristics

The lotus is a perennial aquatic plant belonging to Nelumbo in Nelumbonaceae,which is widely used.At present,there is a lack of excellent container lotus cultivars on the market,and there is also a lack of evaluation of cultivars.In particular,cultivation techniques,such as selection of cultivation substrate types and fertilization,are insufficiently studied.In order to sceen the high-quality container lotus cultivars to meet market,and determine the effects of different cultivation measures on container lotus,this study investigated the container lotus market in China through questionnaires,and used Analytic Hierarchy Process(AHP)method to establish a comprehensive evaluation system for cultivars,and to select excellent container lotus cultivars.The effects of excessive fertilization and biochar addition in substrate on the morphogical and physiological characteristics of container lotus were discussed.The results included:1.The market and consumption potential of container lotus were investigated by 2524 questionnaires.The results indicated that the container lotus market in China has a great potential,but the market problems remain,such as lack of good cultivars,efficient cultivation and management techniques.The container lotus that people like are multiple colored,followed by pink and white colors;the favourible flower form are single,followed by semi-double and double petals;the bowl-shaped flower is most choosen;light fragrance and inverted cone or bowl-shaped pods are more welcome;the long flowering period and the quality of cultivars are mainly concerned.For order price,10~20 yuan is suitable for seedlings,and 30~50 yuan for the potted plants;People having experience in lotus cultivation are more willing to buy the seedlings or lotus seeds,while those without experiences want to order the potted mature plants.2.The evaluation system for container lotus cultivars was established by AHP method by evaluating 102 cultivars: the flowering characteristics and cultivation characteristics are the important factors affecting the market of container lotus cultivars.The flower-plant height ratio,flowering color,cultivar's adaptability and resistance to diseases and insects are also important.The experts prefer the medium-sized and double cultivars,and the public prefers the small,single cultivars.A total of 19 cultivars,such as 'Da Shi','Jiao Yang",'Xin Pipacheng' and 'Bai Juhua',were evaluated as the excellent container lotus.3.When Excessive Peter Professional compound fertilizer No.12(15-20-25)was applied to the container lotus 'Jinling Nvshen',the ornamental traits of the plants were affected,and the damage of mature and young leaves was different;the outer petals of the flower became browned and dried,and the flower opening angle was reduced;slight over-fertilization had little effect on plant growth.Moderate and severe excessive fertilization resulted in a decrease in leaf thickness and plant height as the degree of stress increased.The physiological performances showed that leaf water potential decreased,the leaf membrane permeability increased,the malondialdehyde(MDA)content increased first and then decreased,proline(Pro)continued to accumulate,the plant chlorophyll content decreased,and photosynthesis was inhibited.4.When the Carya illinoinensis biochar was added to the cultivation soil for container lotus,and the pH values and EC values of the cultivation solution increased with the increase of the biochar-soil ratio.The occurrence of lotus leaves and buds were advanced,the flowering period was advanced and prolonged,and the flowering period of lotus was in the treatmens with 5% and 10% of biochar.Morphological index of the aboveground part and the length of the inflated propagules in the underground part,the number of underground propagule branches and fresh weight increased.Adding 10% of the biochar in culture soil was the best,and the plants with treatment of 15% biochar had good growth in the early stage,but poor growth in the later stage;the addition of biochar increased the relative chlorophyll content and enhanced the photosynthesis of the plants.The content of N in the underground propagulesr was the highest in the plants cultivated in the subtracte with 10% biocha,and the highest content of P and K in the underground propagules occurred in the plants cultivated in the substrate with 15% biochar.