STUDIES ON PHYSIOLOGICAL BACKGROUND ABOUT DIFFERENCES AMONG ANTHER CULTURE ABILITIES OF RICE Evaluation and Analysis of Anther Culture Characteristics in Gansu Wheat Cultivars and Backbone Parents Effect of Male-Gametocide on the Culture Ability in Indica Rice Studies on the Analysis of Variance and Major/Minor Factors of Medium Components Influencing the Efficiency of Anther Culture Ability Studies on the Effect of Bleeding Sap of Towel Gourd(Luffa Cylindrica Roem)on Rice Anther Culture