Study On In Vitro Culture Of Cucurbita Moschata Unftilized Ovary (Ovule)

In this experiment,7cultivars of Cucurbita moschata were utilized to study in vitroculture of Cucurbita moschata unfertilized ovary (ovule). The effect of genotypes,developmental stages, heat shock in darkness, hormone varieties and concentration,disinfection methods on the induction of Cucurbita moschata embryoid from in vitrogynogenesis was studied to screen the appropriate conditions to induce embryoid; Theoptimum condition of in vitro culture of Cucurbita moschata fertilized ovule was alsoscreened; Rooting conditions of test-tube plantlet was also studied to obtain the favorabletechnique of in vitro gynogenesis of Cucurbita moschata. The results are as follows:1. The effect of genotypes on the induction of embryoid: Ovules of6cultivars in thisexperiment showed enlargement and green callus after cultivation, the ratio ofenlargement and green callus can be72.81％-78.57％; While Yunv seldom showedenlargement and green callus after cultivation, with the ratio of11.30%.2. The effect of developmental stages on the induction of embryoid: Exlant (in vitro ovary)obtained1day before or on the blossom day showed no difference on enlargement andgreen callus with the ratio68.75%and73.75%; Explant (in vitro ovule) obtained2weeksafter blossom showed high ratio of enlargement and green callus as70%, while explantobtained4weeks after blossom present low ratio as48.98%.3. Heat shock in darkness promoted the enlargement and emergence of green callus of ovule.4. TDZ significantly promote the emergence of green callus to80.77%-88.46%forunfertilized ovary, while TDZ and NAA+6-BA showed ideal results with the ratio of46.43%-64.29%and47.62%-61.90%, GA3restrain the green callus of ovule.5. Disinfection after the section of ovule promoted the emergence of embryoid.6. Exlant (in vitro ovule) obtained4weeks after fertilization showed high tendency ofembryo with the ratio of86.61%for unfertilized Cucurbita moschata.7.0.5mg/L of GA3promoted the emergence of long and thick root which favors the surviveduring seedling adaptation.