Studies On Rapid Propagation And Polyploid Breeding Of Ananas Comosus (L.) Merrill

Pineapple (Ananas comosus (L.) Merrill) is a perennial herbaceous plant and a well-known fruit in the world. It has very high economical, nutritious and officinal value, having the call. Polyploid breeding is an important approach for improving the output, quality and resistance of pineapple. Now, there are a few reports and applications about polyploid breeding of pineapple, especially artificial inducing. Pineapple polyploidies have not been obtained by physics or chemistry methods. In the study, Comte de Paris and Yellow Mauritius were the trial materials. The rapid micropropagation system in vitro of pineapple was studied. Additionally, the methods of inducing pineapple polyploid were tested by colchicine for obtaining tetraploid germplasm. Then the characteristics of tetraploid and diploid pineapple were compared. The research established the base for polyploid breeding of pineapple, having a great value in pineapple breeding.The explants were dipped in the scour 10 minutes and washen, then sterilized 90 seconds by 75% alcohol and 10min by 0.1% HgCl₂, rinsed 4⁵ times by sterilized water .The crown bud is the best explant, but sucker is suit for cosmically production.The appropriate medium for inducing buds from explants was MS+ 3.0mg/L 6-BA + 0.2mg/L NAA, induction rate was 56.7% and mean of axilla buds was 3.12. When MS+0.5mg/L 6-BA+0.2mg/L NAA was used as multiplication medium, making use of liquid culture medium in static state, Comte de Paris' multiplication coefficient reached 13.9 and Yellow Mauritius' multiplication coefficient was 15.0 after 30 days. The best rooting medium was 1/2MS+ 0.5mg/L IBA+0.05% AC, the induction rate was 100%, the states of plantlets and roots were good. The surviving rate of plantlets was above 99.3% after transplanted to the ground.The ploidy of plantlets in vitro were identified and the numbers of chromosome were 50(2n=2x=50). Under the condition of tissue culture, the inducing polyploid of pineapple was carried out by colchicine. Two methods were used and compared. The tetraploid plantlets were obtained by immersing buds in various concentrations of colchicine solution, and inoculating buds in the mediums containing colchicine. The result indicated that the way of immersing buds was better. It was the most effectively induced by immersing buds in 0.3% colchicine solution for 4 days, which had the most tetraploid plantlets, Comte de Paris' inductive frequency was 36.7% and Yellow Mauritius' inductive frequency was 30.0%. Buds were incoculated in the medium contained...