Effects Of Hormone On Panicle Traits And Plant Type Traits Of Rice During Panicle Differentiation Stage

Six rice cultivars of indica and japonica were used as test materials to study the effects of spraying epi-brassinosteroid, salicylic acid, gibberellin, cytomin with lower, medium and high concentrations on the panicle traits of rice during panicle differentiation stages, which including bract differentiation stage (T1), branch differentiation stage (T2), spikelet primordium differentiation stage (T3), pollen mother cell formation and meiosis stage (T4), pollen filling stage (T5). Panicle traits of indica and japonica rice in response to exogenous hormone were investigated, determining optimal spraying stages and concentrations of hormone for regulating panicle traits and rice plant types. The terminal goal to provide a theoretical basis and reference for the application of hormone production by way of regulation of rice panicle traits and plant type traits. The results were as follows:Panicle length and grain number were extremely significantly higher than that of check, but the differences between different concentrations of epi-BR were not significant after spraying epi-BR with different concentrations. The difference on seed setting rate of primary branch was not significant, but epi-BR with medium concentrations could significantly increase seed setting rate of secondary branch, so promote the seed setting rate of whole panicle. Grains weight (include thousand grains weight of primary and secondary branch) fell significantly after applying epi-BR. Larger the concentrations, lower the seed setting rate. Grain density fell significantly after applying epi-BR, but low and medium concentrations of epi-BR were more effective on decreasing grains density than that of high concentrations. After spraying epi-BR at different periods of panicle differentiation, the effect of promoting panicle length were T4>T1>T5>T3>T2, the effect of promoting grain number were T1>T3>T2>T4>T5. The effect of promoting panicle seed setting rate were more obvious at the pollen mother cell formation and meiosis (T4), the effects of different spraying periods on the differences of branch number and thousand grains weight were not significant, the more delay the spraying periods, the more obvious the effect of grains density decreased. There was interaction effect between the spraying periods and concentrations. We made sure the best combination of spraying periods and concentrations aimed at regulating effect of different panicle traits.Panicle length, number of primary branch, grain number were extremely significantly higher than that of check, but the differences between different concentrations of epi-BR were not significant after spraying epi-BR with different concentrations. The difference on seed setting rate of primary branch was not significant, only medium concentrations of setting rate of primary branch significantly higher than that of check,but seed setting rate and seed setting rate of secondary branch were extremely significantly higher than that of check, lower concentrations is best. but small vascular bundles in neck, top second internode small vascular bundles, grain density fell significantly after applying epi-BR. After spraying SA at different periods of panicle differentiation, the effect of promoting panicle length were T5>T4>T2>T1>T3, the effects of promoting grain number were T5>T4>T1>T2>T3. The effect of promoting panicle seed setting rate and seed setting rate were more obvious at the pollen mother cell formation and meiosis (T4). There was interaction effect between the spraying periods and concentrations. We made sure the best combination of spraying periods and concentrations aimed at regulating effect of different panicle traits.Panicle length was extremely significantly higher than that of check, and the differences between different concentrations of GA were significant after spraying GA with different concentrations. GA with medium concentrations can significantly. increase the seed setting rate (include seed setting rate of primary branch and seed setting rate of secondary branch). Number of secondary branch, thousand grains weight (include thousand grains weight of primary branch and thousand grains weight of secondary branch), grain density fell significantly after applying GA. Flag leaf angle and top third leaf angle were extremely significantly higher than that of check, and the differences between different concentrations of GA were significant after spraying GA with different concentrations. Top second leaf angle, flag leaf length, top second leaf length, top third leaf length, top second internode length, top thirnode length were extremely significantly higher than that of check. After spraying epi-BR at different periods of panicle differentiation, the effect of promoting panicle length were T4>T3>T5>T2>T1, the effects of promoting grain number were T1>T5>T3>T2>T4.The effect of promoting panicle seed setting rate and large vascular bundles in neck were more obvious at spikelet primordium differentiation stage (T3), the more delay the spraying periods, the more obvious the effect of grains density decreased. There was interaction effect between the spraying periods and concentrations. We made sure the best combination of spraying periods and concentrations aimed at regulating effect of different panicle traits. On the whole, treatment with GA with medium concentration (50mg/L) at bract differentiation stage (T1) was the most beneficial to increase yield.Panicle length seed setting rate of secondary branch and seed setting rate were extremely significantly higher than that of check, but the differences between different concentrations of CTK were not significant after spraying CTK with different concentrations. Grain number used low concentrations were higher, other treatments and CK were not significant. small vascular bundles in neck,grains weight and grains density fell significantly after applying CTK, Flag leaf angle, top second leaf angle, top third leaf angle top third internode length were extremely significantly higher than that of check, but flag leaf length, top second leaf width and top third leaf width lower than that of check. After spraying CTK at different periods of panicle differentiation, the effects of promoting panicle length were bract differentiation stage (T1) extremely significantly higher than that of other stage. The effects of promoting grain number were T1>T5>T4>T2>T3. The effect of promoting panicle seed setting rate were more obvious at pollen mother cell formation and meiosis stage (T4), the more obvious the effect of grains density decreased was at spikelet primordium differentiation stage (T3). Top second internode large vascular bundles and top second internode small vascular bundles were more obvious at branch differentiation stage (T2). There was interaction effect between the spraying periods and concentrations. We made sure the best combination of spraying periods and concentrations aimed at regulating effect of different panicle traits.