The Establishment Of Virus-Free Strawberry Breeding System In Jurong Jiangsu

Strawberry (Fragaria ananassa. Duch) is a kind of renascent species classified to Rosaceae, Fragaria,2n=8x=56, which belongs to a herbaceous perennial plant. It is called small berries in horticulture. With attractive bright color, good flavor, aroma and rich nutrient, strawberry has being developed rapidly in Jurong,Jangsu. Production area becomes larger. Strawberries are vegetative propagated from runners that are often infected by a number of viruses in the perennial cultivation. The quality and yield of strawberries infect by viruses were declined severely. According to Beker (1956) reports, infected by a kind of Latent virus, the yield of strawberry will descend from21to35percent. The loss of yield in strawberry due to infect by two or more viruses is estimated to be43-59percent. Moreover, this caused the berries with the inferior quality, increased acid and decreased sugar. As we known there is little effect on controlling virus-disease by chemicals, so using virus-free stocks is an efficient way to inhibit the propagation s of the disease. Strawberry anther culture is a vital method to obtain virus-free stock. We study on the system of strawberry anther culture, transplanting techniques of tube-seedlings of free-virus strawberry,"Second generation-seedling " production, cultivated character of paddy field by the three breeds strawberry of, Mingbao, Fengxiang, Hongjia to provide a theoretical basis and technical support for breeding system of virus-free strawberry plants.1. The callus inducting rate was increased significantly and the quality of the callus was the best when the anthers at the uninucleate stage were pretreated in4℃for3days.2. Incubating temperature of anther culture significantly affects the quality of callus that is hard-packed, green color, vigorous callus and easy to being divided.3. Studing the anther of different inflorescence on the rate of callus induction. The results showed that the first inflorescence is most suitable for anther culture in callus induction and conducive to plant regeneration as soon as possible.4. Different phytohormones ration was related to strawberry callus induction, propagation of sprout. There is a big difference between callus structures, induction rate and buds differentiation due to different phytohormones ratio and different species. The results were as follows:(1) MS+6-BA2.0mg/L+IAA4.0mg/L+KT0.1mg/L was optimal induction medium to callus induction for three species. And the medium dense is light green, the surface of both is processes.(2) To Mingbao and Hongjia, MS+0.7%agar+3%lactose+6-BA2.0mg/L+NAA0.2mg/L+ZT0.2mg/L was proved to be optimal differentiation medium; however, to Feng xiang, MS+0.7%agar+3%lactose+6-BA5.0mg/L+NAA0.1mg/L was best choice.(3) To three test species, MS+0.1mg/L NAA+0.7%agar+3%sucrose+6-BA1.5mg/L was proved to be optimal sprout enrichment culture medium for bud proliferation, which have1.9of the average multiplication, robust bud, favors to propagation and cultivate seedlings.5. Domestication and transplantation technology and other factors that affected survival rate and growth of strawberry virus-free plantlets and "second generation miller" breeding were studied in this experiment, The result showed that the strawberry virus-free plantlets is suited to being transplanted in the spring and autumn.The effect of transplanting and acclimation of strawberry virus-free plantlets grew well in "garden soil:peat:sand:curing manure=1:1:0.5:0.5".The propagation coefficient of virus-free plantlets had an advantage over conventional plantlets to three test species."Mingnbao","Fengxiang" and "Hongxia" of free-virus have2.5,2.6,3.1times of the conventional one respectively on the propagation coefficient.6. Three varieties of virus-free plantlets transplanted in the same matrix (garden soil: peat:sand:curing manure=1:1:0.5:0.5), and the performance of growth potential was: Mingbao>Fengxiang>Hongjia.7. The average chlorophyll contents of three virus-free species strawberry was2.994mg/g.fw, and increased by21.58%compared to the controlled. The activity of CAT and POD was also superior to those of conventional plantlets.8. Mingbao and Hongjia obtained from the anther culture had excellent growth vigor and potential productivity. But the fruiting habit of virus-free plantlets of Fengxing must be continued to being observed.