水稻茎秆形态特征与抗倒伏能力对外源植物生长调节剂的响应差异

Morphological characteristics and lodging resistance of rice stems and its response to exogenous plant growth regulators

【目的】研究水稻茎秆形态特征、解剖结构及抗倒伏指标对不同外源植物生长调节剂的响应差异,分析抗倒伏相关性状间的关系,为水稻的抗倒伏高产优质栽培提供理论依据。【方法】以粳稻品种南粳9108为供试材料,以始穗期喷施清水为对照(CK),设3种植物生长调节剂处理,分别为乙烯利(10×10-3mL/L)、劲丰(5 mL/L)和多效唑(300 mg/L),测定不同处理水稻成熟期的茎秆形态特征、解剖结构及抗倒伏指标。【结果】水稻茎秆形态特征与抗倒伏能力对不同外源植物生长调节剂的响应不同。乙烯利和劲丰处理显著降低水稻的株高、秆长和重心高度(P<0.05,下同),提高基部节间的机械组织和薄壁组织厚度,增加茎秆中的储藏物质及维管束的数目和面积,提高了基部节间充实度,增加茎秆茎粗和壁厚,使得节间抗折力大幅提高,倒伏指数显著降低,水稻抗倒伏能力有效增强;多效唑处理则无显著效果。相关性分析结果显示,倒伏指数与株高、重心高度和秆长呈极显著正相关(P<0.01,下同),与茎粗、壁厚、充实度、抗折力及维管束的数目和面积、机械组织和薄壁组织则呈极显著负相关;茎秆机械组织与茎粗、壁厚、薄壁组织、抗折力及维管束数目和面积均呈极显著正相关。【结论】水稻始穗期喷施乙烯利和劲丰能显著影响植株茎秆的形态特征、解剖结构及抗倒伏指标,降低茎秆倒伏指数,提高植株的抗倒伏能力。

【Objective】The effects of exogenous plant growth regulators on morphological characteristics,anatomical structure and lodging resistance in rice stem and the analysis of the correlation between lodging-related traits were studied to provide the theoretical support for rice with lodging resistance and high yield cultivation.【Method】Nanjing 9018 was taken as the material in the study.At the heading stage,the control was applied with clean water(CK),three other plant growth regulators were used,which were ethephon(10×10-3 m L/L),Jinfeng(5 mL/L)and Paclobutrazol(PP333,300 mg/L),respectively.The effects of different exogenous plant growth regulators on morphological characteristics,anatomical structure and lodging resistance of rice stems were studied.【Result】The response of morphological characteristics and lodging resistance of rice stems to different exogenous plant growth regulators were different.Ethephon and Jinfeng treatments significantly reduced the plant height,stem length and gravity height in rice(P<0.05,the same below),and increased the thickness of mechanical tissue and parenchyma at the base internodes,promoted the storage materials and the number and area of vascular bundles in stem,thus increased the stem density at the base internodes,enhanced stem diameter and wall thickness,and made bending strength highly raised.Therefore,the lodging index of rice was significantly decreased and the lodging resistance of rice was effectively enhanced.However,PP333 treatment had no significant effects.The correlation analysis showed that lodging index was extremely positively correlated with plant height,gravity height and stem length(P<0.01,the same below),but extremely negatively correlated with stem diameter,wall thickness,stem density,bending strength,the number and area of vascular bundles,mechanical tissue and parenchyma.The mechanical tissue of stem was extremely positively correlated with stem diameter,wall thickness,parenchyma,bending strength and the number and area of vascular bundles.【Conclusion】Ethephon and Jinfeng spraying at the heading stage of rice can significantly affect the morphological characteristics,anatomical structure and lodging resistance index,thus reducing the lodging index for rice stems and improving the lodging resistance of rice plants.