Study On Tissue Culture And In Vitro Flowering Of Pentas Lanceolata

Pentas lanceolata,which is also known as star flower is a culcivar of perennial plants of Pentas Rubiaceae,colourful and exquisite flowers which makes Pentas lanceolata have high ornamental value.Pentas lanceolata with traditional breeding methods can not meet the consumer demands.As a new flower ornamental type,vitro flower is novel has many advantages,such as cleanliness,beauty,delicacy and so on,but the vitro flowers species are few.The study on tissue culture has important theoretical and practical dignificance,it can help increase breeding rate of Pentas lanceolata,enrich the species of the in vitro flowers and genetic research of Pentas lanceolata.Four culvivars 'Starla','Butterfly','Northern lights','NewLook' were selected to study the in vitro flowering of Pentas lanceolata.The research focused on the following parts,including tissue culture of Pentas lanceolata,main influencing factors of in vitro flowering and flowering period extended.The main results were as follows:1)?Suitable explants for the induction of asventitious buds were stems,suitable medium for induction of asventitious buds was:MS+6-BA1.0 mg/L+NAA0.3 mg/L.? suitable medium for adventitious bud proliferation was:MS+6-BA1.5 mg/L+NAAO.3 mg/L.?Suitable medium for seedling strengthening was selected.Plantlets were strong and leaf stretched well on the medium MS+IBA0.5 mg/L,adding CCC2.0 mg/L(for“Starla','Butterfly','Northern lights')or CCC1.0 mg/L(for'NewLook')individually.2)A reliable and efficient in vitro flowering induction system of Pentas lanceolata was establishmented.?The culture environmnet was 23±2?,light intensity 2500-30001ux,illumination time 14 h/d.?Suitable medium for inducing in vitro flowering was:MS+ KT0.5 mg/L+IBA0.8 mg/L+sucrose 4%,adding PP3330.5 mg/L('Starla','Northern lights')or PP3330.2mg/L('Butterfly','NewLook')individually.?Plantlets with 4 or more sections of shoot stem were necessary for flower buds induction.The induction time was declined with the subculture number was 2 or more.The induction time was declined with the light intensity increased.3)Suitable medium for extending the flowering period was:MS(NH4N03)+sucrose 4%+agar 0.5?0.6%,adding PP333 0.5 mg/L('Starla','Butterfly','NewLook')or PP333 0.3 mg/L('Northern lights')individually.