| Arundina graminifolia,which has high ornamental and medicinal value,is a perennial herbaceous plant of Orchid.In recent years,the wild resoures of A.graminifolia was destroyed very seriously,mainly due to habitat destruction and over-collection,which is listed in the national second level of protection of rare and endangered plants.At present,there are still few researches on the conservation of A.graminifolia.In order to provide basic information for the protection,development and utilization of A.graminifolia,the floral structure and breeding system,rapid propagation technology and polyploid induction were carried out.The main research findings are as follows:1.The flowering of the cultivated population of A.graminifolia in the experimental site was observed.The blooming stage of A.graminifolia was from August to October,and the single flowers blooming time lasts?3.42±0.83?days.The pollen activity and stigmatization of A.graminifolia within 3 days were determined by in vitro culture and benzidine hydrogen peroxide method and the results showed a downward trend.At the same time,on the basis of screening the optimum culture medium for pollen germination,the pollen activity of A.graminifolia decreased with the prolongation of storage time and the increase of storage temperature.The experiment of breeding system showed that A.graminifolia was self-compatible and there was no automatic self-flowering and pollination.Artificial pollination indicated that 89.71%fruit set by self-pollination and 79.49%by cross-pollination.The morphology of fruit produced by different pollination modes was obviously different at about 30 days to 60 days,but the difference of seed morphology was not significant.The seed viability of different periods after pollination was quite different.The TTC?2,3,5-Triphenyltetrazolium chloride?test results indicated that the seed viability were the highest after 60 days after pollination,up to 94.20%.The germination test results were in accordance with the TTC test results,and the seed germination rate was the highest after 60 days after pollination,up to 95.50%.2.The results indicated that:the optimum medium for seed germination of A.graminifolia was 1/2 MS+Agar 7 g.L-1+sucrose 30.0g.L-1+activated carbon 1 g.L-1+coconut milk 100 mL.L-1+NAA 1.0mg.L-1+6-BA 2.0 mg.L-1+Hua-bao No.1 0.5 g.L-11 with the germination rate of 83.79%.The optimum medium for differentiation was 1/2 MS+Agar 7 g.L-1+sucrose 30.0 g.L-1+activated carbon 1 g.L-1+coconut milk 50 mL.L-1+NAA?0.51.0?mg.L-1+6-BA?2.02.5?mg.L-1+Hua-bao No.1?11.5?g.L-1.The optimum medium for bud proliferation was 1/2 MS+Agar 7 g.L-1+sucrose 30 g.L-1+activated carbon 1g.L-1+IBA 1 mg.L-1+6-BA 3 mg.L-1+NAA 0.5 mg.L-1+mashed potato100 g.L-11 with the average proliferation rate of 1.36.The optimum medium for rooting was 1/2 MS+Agar 7 g.L-1+sucrose 30 g.L-1+activated carbon 1 g.L-1+IBA 0.2 mg.L-1+6-BA 2 mg.L-1+NAA?0.20.5?mg.L-1+mashed banana 100 g.L-1.The optimum culture medium for seedling transplanting was perlite:peat soil=1:1 with the survival rate of 98%,and the transplanting effect is good.3.The results of the study on adventitious bud induction of A.graminifolia showed that:the top bud of A.graminifolia were sterilized best when it was soaked in 2%sodium hypochlorite for about 12 minutes to 15 minutes and the upper stem segment of A.graminifolia were sterilized best when it was soaked in 10%sodium hypochlorite for about12 minutes to 15 minutes.MS+Agar 7 g.L-1+sucrose 30 g.L-1+activated carbon 2 g.L-1+NAA 0.5 mg.L-1+6-BA?1.52?mg.L-1+Hua-bao No.1?11.5?g.L-11 was suitable for the induction and proliferation of adventitious buds in the top bud and upper stem segment of A.graminifolia.The highest induction rate of adventitious buds was 40.00%,and the maximum increment coefficient was 6.00.4.The results of polyploidy induction of A.graminifolia showed that0.10%colchicine soaking for 12 h had the highest induction rate at23.33%?n=60?and the treatment of adding 0.05%colchicines in medium acquired the best induction rate at 21.67%?n=60?.The mortality of different treatments increased with the increase of colchicine concentration and treatment time.Colchicine had toxic effect on plant subculture,and the toxic effect of mixed culture method was longer than that of soaking method.There were significant differences between polyploid and diploid plants in morphology,cytology and chromosome.The stem and leaf diameter of polyploid plants became thicker,which was 46.20%larger than that of normal plants,and the leaf type index decreased by 50.12%.The leaf of polyploid plants became 47.83%thicker than that of normal plants.The stomata and guard cells diameter of polyploid plants were increased and the stomatal density decreased.The guard cell area of polyploid plants were 59.87%larger than that of normal plants,and the stomatal density decreased by 45.99%.At the chromosome level,the number of chromosomes in normal plants was 2n=2x=40 and the number of chromosomes in polyploid plants increased significantly. |
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