Study On The Culture Character Of Ralstonia Solanacearum And In Vitro Identification Of Pogostemon Cabin (Blanco) Benth Resistant To Bacterial Wilt

Pogostemon cabin(Blanco) Benth is one of the plant of Labiatae Posgustemon Desf.Its above-ground part has the functions of removing dampness,appetizing and preventing vomiting,and clearing away summer heat.It is the major raw materials of some famous traditional Chinese patent medicine,such as the "Zhengqi Pills","Huo pills gall",and "Oral anti-viral Liquid".In addition,the cablin patchouli volatile oil which withdraws from the cablin patchouli may also use in producing the spice,the fixative and the pesticide so on daily life necessities,is the pharmaceutical industry and light industry important raw material.However,Pogostemon cabin(Blanco) Benth suffers from a serious disease,the bacterial wilt,which is a typial vascular bundle disease caused by Ralstonia solanacearum.The bacterial wilt occurs during the whole growing period of Pogostemon cabin(Blanco) Benth,and the situation is more serious in hot and wet climate.The bacterial wilt can spread from one plant to another through soil.Until now,the bacterial wilt has not been effectively controlled,so Pogostemon cabin(Blanco) Benth is urgent to need to cultivate new varieties of disease-resistant,but in the process of breeding for disease resistance,resistance germplasm screening method is the first issues to be considered.In this dissertation,the plant regeneration was obtained from the explants of Pogostemon cabin(Blanco) Benth cultured in vitro.And the effects of culture environment on Ralstonia solanacearum growth were studied.After that, we established the identification methods of Pogostemon cabin(Blanco) Benth resistant to bacterial wilt.This study will lay a foundation for the selection of the germplasm resistant to bacterial wilt.1.Review of researches in domestic and abroadAfter reviewing lots of literatures in domestic and abroad,the general situation of the studies of Pogostemon cabin(Blanco) Benth was summarized,including ancient literature record,idioplasm resources, cultural technique,tissue culture and so on.The overview of the classification of Ralstonia solanacearum and Ralstonia solanacearum pathogenic mechanism has been provided.Meanwhile,the classification of the plant disease resistance and the basic appraisal method of the plant disease resistance have been introduced.2.In vitro culture of Pogostemon cabin(Blanco) BenthUsing the terminal buds and leaf segments from Pogostemon cabin(Blanco) Benth as materials,the ability of shoot formation was compared.The results showed that terminal bud and leaf buds can be induced sucessfully and the terminal bud sprouting was faster.When the cultural time arrives for 10 days,the germination rate of terminal bud reaches 85.74%;When the cultural time arrives 25 days,the germination rate of terminal bud and leaf blade can both reach 100%.For the number of explants in terms of budding,leaf blade was much more than terminal bud.When the cultural time arrives for 10 days,the number of leaf blade in terms of budding reach 35.75.And compared characters of Pogostemon cabin(Blanco) Benth which is cultured in MT culture medium and 1/2MT culture medium.The result indicated:Pogostemon cabin(Blanco) Benth in the 1/2MT culture medium can grow quickly,but also easely become be aging.3.The cultivative characteristics of Ralstonia solanacearumRalstonia solanacearum was cultured in NA culture medium,according to the regression equation y=1.8662x-0.0458(R~2=0.9904) linear relationship, a number of factors on the bacterium Ralstonia solanacearum concentration were tested.The results showed that:the bacterium Ralstonia solanacearum concentration and its metabolites is relatively high which was cultured in temperature 30℃,pH 7,air content in cultural bottles no less than 60 percent and its cultural time no less than 12 hours.4.In vitro identification of Pogostemon cabin(Blanco) Benth resistant to bacterial wiltThe bacterium cell or bacterial crude toxins from Ralstonia solanacearum was used as selected pressure;in vitro identification of Pogostemon cabin (Blanco) Benth resistant to bacterial wilt was studied.The result indicated that the explants and plants without root of Pogostemon cabin(Blanco) Benth growth receives the varying degree inhibition.When the bacterium Ralstonia solanacearum concentration was 0.31×10~8 cfu/ml,0.38×10~8 cfu/ml,0.52×10~8 cfu/ml,the difference of effect of bacterial crude toxins from Ralstonia solanacearum on the height nodular stem segment is obvious;when bacterium Ralstonia solanacearum concentration in MT culture medium was 1.34 cfu/ml,the leaf wilt rate of plants without root and the NA content in MT culture medium was positively related.The bacterial crude toxins from Ralstonia solanacearum of low concentration has the inhibitive effect for striking root of plants without root,the bacterial crude toxins of high concentration can wilt the leaves of plants without root.The root rate of plants without root was 0,when the bacterium Ralstonia solanacearum concentration was higher than 1.0314×10~8 cfu/ml;the leaf fusarium rate of plants without root was 0,when the bacterium Ralstonia solanacearum concentration was less than 1.5473×10~8 cfu/ml.