Characteristics of Roots Traits in Conventional Indica Rice Cultivars with Large-Panicle Difference of Nitrogen Accumulation and Translocation in Conventional Indica Rice Cultivars with Different Nitrogen Use Efficiency for Grain Output Characteristics of Dry Matter Accumulation and Distribution in Conventional indica Rice Cultivars with Different Nitrogen Use Efficiency for Grain Output Main Index of Source and Sink in Nitrogen Use Efficiency for Grain Output in Conventional Indica Rice Cultivars Characteristics of Source-Sink Related Parameters in Conventional Indica Rice Cultivars with Different Types of Sink Potential General Characteristics of Nitrogen Uptake and Utilization in Conventional Indica Rice Cultivars with Different Panicle Weight Types Characteristics of Yield and Yield Components in Conventional Indica Rice Cultivars with Different Nitrogen Use Efficiencies for Grain Output