Effects Of Colchicine Treatment On The Seed Germination And Seedling Growth Of Bauhinia Variegate

Bauhinia variegate is a typical species of south china,with excellent variety characteristics and genetic improvement potentialities.This paper aims to find the appropriate concentration and processing time of colchicines solution for cultivating Bauhinia variegate and would select special target individual,while pfovide theory and technology guide for its further germplasm work innovation.The mature seeds of Bauhinia variegate were studied by treating with 0.05%?0.10%?0.15%?0.20% colchicines solution for 12,24,36 and48 h respectively,and the seeds soaked with distilled water were taken as control,the effects on growth and physiological indexes such as seed germination,seeding growth were investigated.The result shows as follows:(1)While the colchicine concentration above 0.15%,seed embryos have injured and become malformations,such as root hair area shortened,embryo hypertrophy and smooth,elongation of radical decreased and root growing point damaged.With the increase of colchicines concentration,seed germination rate decreased.0.20% colchicines solution caused death of the seeds,and 0.05%,0.10% colchicines solution treatment for 24 h was the most beneficial to the germination of the seeds.With the increase of colchicines solution concentration,the radical elongation was inhibited in different degrees;colchicine could cause the inhibition effect on continue development of germinating seed embryo.(2)While the colchicine concentration blow 0.15%,seedling height is higher.High concentration of colchicine inhibited the growth of seedlings,and played a significant role in dwarfing.The average diameter of colchicine treatment group is greater than t he control group in general(except 0.10%),when the colchicine concentration was 0.05%,the diameter reached the maximum;at the same concentration,with the prolonging of treatment time,will increase the seedling ground diameter,when 36 h,the diameter reached the maximum;Colchicine can change the shape of leaves to a certain extent,the high concentration of colchicine makes the leaves become larger and wider,so that the depth of the leaves gradually decreased.(3)The contents of chlorophyll and carotenoid in leaves of seedlings were reduced by colchicine treatment.With the increase of colchicine concentration,the activity of SOD increased firstly and then decreased,and the content of soluble protein in the leaves of the seedlings increased,With the extension of time,the soluble protein content of leaves decreased gradually.After colchicine treatment,the content of MDA in the leaves of seedlings increased in different degrees,and the content of MDA was the highest when treated with 36 h.(4)The light saturation point of Bauhinia variegate was greater than that of the control group,the light compensation point of the control group was less than that of the control group when the concentration is not more than 0.10%.Colchicine enhanced the utilization ability of weak light.The apparent quantum efficiency of the treatment group was increased.When the concentration of 0.05% was used to treat 36 h,the Fm value was the highest.The values of NPQ and ETR decreased with the extension of treatment time.