The Genetic Diversity And Growth And Development Of Narcissus

Narcissus is a famous bulb flower.After many years of breeding and artificial cultivation,it generates many species and cultivars,such as Narcissus tazetta and exotic daffodil cultivars,showing genetic diversity.However there is no identical scientific system to analyze its genetic diversity.Coupled with inadequate studies on Narcissus’ growth and development,its germplasm resources can not be fully utilized which limits the planting,cultivars introducing and promoting of Narcissus.This present study firstly analyzes Narcissus genetic diversity in both morphological and molecular level.Further,efforts were made to explore the methods that would be advangageous to the growth and development of Narcissus tazetta.Moreover,the adaptability of several exotic daffodil cultivars in Chinese environment were observed and studied.The results are hopefully to serve as references for the planting and utilization of Narcissus.The main results are shown as follows:1.24 morphological characteristics of nine Narcissus samples were observed and further analyzed by mathematic classification method.The results showed that the morphological diversity level of five exotic daffodil samples was higher than that of four Narcissus tazetta samples.7 morphological characteristics of exotic daffodil samples,including stalk strength,budding period,full blossoming period,flower bud color,corolla color,petal color and leaf color,presented obvious variations,with coefficients from 33.33% to 91.67%.5 morphological characteristics of Narcissus tazetta,including stalk number,flower number,corolla diameter,early flowering period and full bolossoming period,had variation coefficients from 37.04% to 51.79%.Clustering analysis based on morphological characteristics indicated that nine Narcissus samples could be divided into 2 categories: one class comprised by four Narcissus tazetta samples,the other comprised by five exotic daffodil samples.The genetic relationship between Narcissus tazetta and exotic daffodil samples was far away.2.Random amplified polymorphic DNA(RAPD)molecular markers were used to analyze genetic diversity of nine Narcissus samples.Results showed that 13 out of 40 random primers could amplify the stable products.13 random primers received 95 amplification bands,in which 81 bands were polymorphic,accounting for 85.30% of the total number of bands.4 Narcissus tazetta samples were classified as a class,with the genetic similarity between 0.894 and 0.975.5 exotic daffodil samples were classified as the other class,with the genetic similarity between 0.747 and 0.894.Meanwhile,Narcissus tazetta samples and exotic daffodil samples differed from each other,as their genetic similarity was only between 0.273 and 0.368.The clustering result validiated the morphological classification.3.4 different concentrations of spermidine(Spd)aqueous solution were used in hydroponic cultivation of Chongming Narcissus(Narcissus tazetta var.Chinensis).The results showed that the leaf thickness was increased ranging from 0.09 cm to 0.20 cm;the early flowering period was brought forward for 2 to 7 days;the full bloom period were brought forward for 5 to 7 days.The best effect was observed under the treatment with 0.5 mmol/L Spd.The plant height,leaf width,protein content and starch content of Chongming Narcissus were 36.00 cm,2.43 cm,2.17 mg/g,8.68 mg/g,improved by 11.30%,11.40%,56.80%,50.40% respectively,compared with the control group.Meanwhile,the earliest budding time was present 3 days earlier than the control group,and its first bloom time and full bloom time were 7 days earlier than the control group.4.Growth,development and photosynthetic characteristics of exotic daffodil cultivars ’Shangnong Ruhuang’ and ’Shangnong Hongying’ were observed.The results showed that two exotic daffodil cultivars both can sprout,grow,bloom and reproduct normally.Main corms with different diameters possessed different biological characteristics.The characteristics of vegetative growth(ramet number,leaf number,leaf width,leaf thickness)and development growth(stalk height,flower diameter,corolla diameter,petal length,petal width)decreased with the decrease of the main corm diameter.Weight and number of bulbs had significantly increased after planting.The growth rate of bulbs weight increased with the decrease of the diameter of the main corms,while the growth rate of bulbs number decreased with the decrease of the diameter of the main corms.Two exotic daffodil cultivars had the same Pn change trend ’bimodal curve’,and appeared obvious ’photosynthetic noon break’ phenomenon.Photosynthetic characteristics of mid-April were strongger than mid-May.The Pn,E,Ci and Gs values in ’Shangnong Hongying’ were strongger than that in ’Shangnong Ruhuang’.