Lotus,belonging to Nelumbonaceae and Nelumbo,is a kind of aquatic perennial herbaceous flowers.As one of the top-ten traditional famous flowers in China,it has rich cultural heritage and high ornamental value,and it is one of the aquatic plant which is applied highest frequency in landscape.Although the variety of lotus is rich,compared to other well-known ornamental flowers,lotus flower color is still relatively simple and the breeding and basic research of lotus are still very weak.In this study,we have carried out the following work of lotus flower color breeding:(1)Flower color is one of the major ornamental elements and determines the ornamental value of lotus.The investigate of different varieties of lotus flower color resources,on the one hand,it provides reference for variety identification and production application,on the other hand,it be used for the correlation analysis of these traits(such as plant height,flowers,flower size,flowering).(2)Through the transformation of Arabidopisis thaliana tt4 mutants and petunia,we verify lotus(chaicone synthase,CHS)gene function,which help to improve and innovate lotus’s flower color.(3)Based on the function of CHS gene,we transformed the CHS,GUS(β-glucuronidase gene)gene into lotus by pollen tube to establish the genetic transformation system.(4)Beacase summer limites lotus ornamental period,this is a great restriction on the development and the application of lotus.By anti-seasonal cultivation,we let lotus bloom in winter and spring,which stimulate the production and application of lotus.The main results were as follows:1.Acccording to the investigation results of 83 lotus flower colors,we found that the RP color is most,comprised 65%of all;The dual color,accounting for 17%of the total;WG,YG and GY accounting for 7%,5%,6%respectively.Lotus varieties lack deep yellow,blue,purple and dark series.2.According to the investigation statistics of 150 lotus varieties about spire and flower color,the Pearson correlation analysis shows that petal and spire color were significantly positive correlation(P<0.01),the correlation coefficient as much as 0.568.So there is a certain correlation between spire and flower color.3.The functional verification of lotus Chalcone synthase gene(CHS2,HSA):The two over vectors of CHS2 and CHSA were transformed into Arabidopsis mutants tt4.We attained transgenic plants:CHS2,11 plants;CHSA,12plants.Then they were transformed into petunia W115 by grobacterium-mediated leaf disc transformation.We attained transgenic plants:CHS2,5 plants;CHSA,0 plants.The phenotype result of CHS2 is no significant difference in color.4.The study on the genetic transformation system of lotus:The expression vector of GUS gene and lotus CHS gene were transferred into lotus species(’Jianxuan 17’,’Hongxianglian’ and ’Xihu Honglian’)via pollen-tube pathway of germ line transformation.We got more than 400 seeds.Among these transgenic seeds we got 15 positive plants by PCR assay.It was primarily evidenced that the target gene was introduced into the lotus.5.Put lotus in artificial climate chamber in winter,and more appropriate conditions for the cultivation facilities are as follows:temperature 28℃,humidity of 60%.During the bloom-accelerating cultivation in winter,the three species(’Caixia’,’Jinxiu’,’Baiyi Tianshi’)have successfully bloom in December and January;During the bloom-accelerating cultivation in spring,by the early April,stand leaves was up to 95cm and no buds appearred;During the bloom-accelerating cultivation in winter and spring,seed growth was slow,almost no growth,let alone bloom.In addition,pest and disease damage and growth problems of lotus during the experiments can provide references for further technical improvement. |