Studies Of Bauhinia Variegate Allelopathy On Five Shrub Species

In order to study the allelopathy of Bauhinia variegate on Ixora chinensis,Rhoeo spathaceo, Aspidistra elatior, Cordyline fruticosa and Excoecaria cochinchinensis, and to investigate the feasibility of the B. variegate collocation with these five shrub species, the extracts of branches and leaves of B. variegate were selected as the material for experiment.Physiological and photosynthetic indexes were used to discusse B. variegate allelopathy effects on these five shrub species.The results are as follows:(1) B.variegate water extraction effecting on activities of SOD of these five shrub species showed a high concentration to promote and low concentration to restrain. The 1:24B. variegate water extraction played important roles in increasing activities of SOD of I. chinensis and C. fruticosa, while the 1:6 water extraction of B. variegate restrained activities of SOD of A. elatior and C. fruticosa obviously.(2) B.variegate water extraction effecting on chlorophyll content of these five shrub species showed a high concentration to promote and low concentration to restrain. The 1:24water extraction of the B. variegate played important roles in increasing the content of chlorophyll a of R. spathaceo and C. fruticosa, and also promoted the content of chlorophyll b of I. chinensis and R. spathaceo. The 1:6 B. variegate water extraction restrained the content of chlorophyll a of R. spathaceo, and also inhibited the content of chlorophyll b of R. spathaceo, A. elatior and E. cochinchinensis.(3) There were obvious influence of B.variegate water extraction effecting on chlorophyll fluorescence of these five shrub species, and different concentrations had different effects. The Y(?)?ETR and NPQ of I. chinensis,R. spathaceo and C. fruticosa could be restrained by the 1:6 B. variegate water extraction, but the 1:24 one played import roles in increasing the Y(?)?ETR and NPQ of R. spathaceo and C. fruticosa. Two different concentrations of the B.variegate water extraction could promote the chlorophyll fluorescence of A. elatior and E. cochinchinensis.(4) There were obvious influence of different concentrations of B.variegate water extraction effecting on the photosynthetic capacity of these five shrub species, and general assays showed promoted growth at low concentration and inhibited growth at high concentration. 1:24 water extraction of B. variegate promoted the photosynthetic capacityof I. chinensis,R. spathaceo, A. elatior and C.fruticosa, while played import roles in increasing the Pn of I. chinensis, the Cond of A. elatior,the Tr of R. spathaceo and C. fruticosa. The photosynthetic capacity of I. chinensis, R. spathaceo, A. elatior and C.fruticosa could be restrained by the 1:6 B. variegate water extraction, while inhibited the Cond and Tr of I. chinensis, Cond of R. spathaceo and C. fruticosa, Tr of A. elatior. Two different concentrations of the B.variegate water extraction could restrain the photosynthetic capacity of E. cochinchinensis.(5) The allelopathic effects of B.variegate water extraction on these five shrub species could be conprehensively evaluated with the arithmetic mean value of RI. The allelopathy of high concentration of B.variegate water extraction ranked as follows: R.spathaceo>C. fruticosa>I. chinensis>A. elatior>E. cochinchinensis. The allelopathies of low concentration of B.variegate water extraction were ranked as follows:R.spathaceo>A. elatior>I. chinensis>C. fruticosa>E. cochinchinensis. The results showed that under the high concentration, to fit with B.variegatewell were E. cochinchinensis and A. elatior, and under the low concentration, the plants were R. spathaceo and A. elatior.Integratedly, the most suitable plant for collocation with B. variegate was A. elatior.