Microspore Culture And Chromosome Doubling Of Strawberry In Vitro Culture

Strawberry is a kind of perennial herbaceous plant in the Rosaceae family, which is a major berry crop around the world. It has highly edible and economical value. We firstly got haploidy by culturing free microspores of strawberry and optimized the inducing system in this paper. At the same time, we studied on the way to inductio the strawberry in two different methods, including colchicines induced vitro leaves and colchicines induced shoot tip meristem. We got doubling lines from both of these methods, which has an important significance for strawberry veriety improvement.In this research, we took 6 different strawberry varieties as materials. The investigation on the ralationgship between ctology development periods of microspores and the characteristic of flower, we screened the period of embryo occurrence (the period which can induce embryo occrence) and researched the related factors which influence microspores culturation. By obzerviton of different development period of microspores, finding that there was an closely relation between microspores development period and bud diameter, and also had some relation to sepal length and petal color. When the diameter of flower buds were in 0.50～0.90 cm, most of the microspores of strawberry developed at uninuclete microspore at periphery. There was slightly differences among different varieties. Study on culturing free microspores in strawberry, we taked F. mandschurica Staudt and F. viridis Duch. as materials. Both of them are belonging to wild strawberry. We firstly did research on strawberry cultured system of strawberry. As a result, we got a embryoid from F. mandschurica Staudt, and the rate of embryo formation has a significant differences among different genotypes. Adding 0.25% coconut and 1.0 mg/L 2,4-D to medium can improve embryo yield, but adding NAA or 6-BA did not have the effect. Low temprerature had a key role to the occurrence of microspores, the best treatment time is one day under low temperature. Adding 0.1 g/L active carbon into medium can effectively increase embryo yield, and reduce ratio of browning phenomenon.In the research of inducing octoploid, we taked Fragaria×ananassa 'Benihope' and 'Xuemi' as materials. We used colchicines induced shoot tip meristem and vitro leaves two different methods and got choromsome doubling plants including 9-ploid,10-ploid, 11-inploid,12-inploid,14-ploid and 16-ploid. Then we observed the field performance of doubling plants of Fragaria x ananassa 'Xuemi'. The result showed that the best effect of methods of inducing shoot tip meristem was 0.2% colchicines with 20min, which survival rate was 70.3% and mutational rate was 83.3%. We got were mostly 9x-16x doubling lines from this way. The best effect of methods of inducing shoot tip meristem was 0.3% colchicines with four days, which regeneration rate of strawberry leaves was 40.5% and mutational rate was 100%. We also got 16-ploid plants in this way.