In Vitro Induction Of Autopolyploid From Colchicines-treated Callus Of Pepper And The Analysis Of Their Peroxidase Isoenzyme

Pepper (Capsicum annuum L.) is one of the important vegetables and condiments. In order to laying down the foundation for the selecting and breeding of polyploid of pepper,a experiment of induction polyploids of pepper by colchicines treatment in clones of pepper was carried out.Calli were induced by culturing hypocotyls of pepper in the MS medium supplemented with 2.0mg/L 6-BA and l.Omg/L NAA. The diploid wound callus was treated by adding colchicines into the medium and by immersing into colchicines solution for different concentrations and periods. Colchicine concentrations were four levels of 100,500,1000 and 2000 mg/L,and treatment periods were of 1,2,4 and 6 days for the former and 24,48 and 72h for the latter. The results showed that both the two methods can induce polyploid cells,but the former was better than the latter in the induction rate and operating. The induced effects on pepper callus treated by colchicines with different concentrations and different time were varying,and were better in 500-1000 mg/L with 4-6 days. 1000 mg/L with 4 days was the best and its doubling efficiency was up to 80%. Microscopic examination of callus and shoot tips showed that the chromosome number of tetraploid was 2n=4x=48,while that of diploid was 2nr=2x=24.In this paper,we also study the change of peroxidase isozymes of the callus were treated by adding colchicines into the medium and the regenerated tetraploid plants. The results showed that callus and the plants had different regulated modeson peroxidase. Compared with the control,the band number and activity of peroxidase isozymes of callus treated with colchicines were raised obviously,and two new enzyme bands appeared,while the regenerated tetraploid plants only showed the activity raising. And the regenerated tetraploid and its diploid were different in inheritance.By the upper research,the best induction method of pepper polyploid and appropriate concentration and periods of colchicines were obtained. The acknowledge of polyploid was deeper via the morphological and cytological examination and peroxidase isozymes...