不同钾效率水稻品种苗期的根系形态与生理指标

摘要

Two potassium efficient( KE) and inefficient ( KIE) rice varieties were chosen as experimental materials to study the difference in root morphological and physiological indexs and their relationships with postassium utilization effi-ciency at seedling under two potassium levels(5 mg/L and 40 mg/L) by hydroponic culture. Results showed that the indexs of root morphology and physiology including the root dry weight, root volume, total absorbing surface area of root, active ab-sorbing surface area of root, root oxidation ability of α-NA in KE rice were all higher than those in KIE rice type. All the indexs of both rice types at 40 mg/L potassium application level are greater than those at 5 mg/L potassium level. The rela-tive potassium utilization efficiency has no significant correlation with relative root dry weight( RRDW) , relative ratio of ac-tive absorbing surface area to total absorbing surface area( RRAT) , relative ratio of total absorbing surface area to volume ( RRTV) , was positively correlated with relative ratio of root/shoot( RRRS) and was negatively correlated with relative root volume(RRV), relative root oxidation ability of α-NA, relative root active absorbing surface area (RRAA)and total ab-sorbing surface area(TASA). Potassium-efficient rice is characterized by good root morphology and root activity. There-fore, RRRS, RRV, RRAA and TASA could serve as indexes for selecting potassium-efficient rice germplasm.%选用2个钾高效型和2个钾低效型水稻品种为试验材料，通过水培试验，研究了5 mg/L和40 mg/L两个钾水平下，水稻苗期根系形态与生理指标的差异及其与钾素利用率的相关性。分析表明，其根系干质量、根系体积、总吸收面积、α-NA氧化量，在相同的供钾水平下，钾高效水稻品种均大于钾低效型；在40 mg/L供钾水平下，不管是钾高效型还是钾低效型水稻品种，根系干质量、根系体积、总吸收面积、α-NA氧化量均大于5 mg/L供钾水平下的。相关性分析结果表明，水稻相对钾素利用效率与其相对根系干质量、相对活跃吸收面积比、相对比表面积相关性不显著，而与相对根冠比之间呈显著正相关，与相对根体积、相对α-NA氧化量、相对活跃吸收面积、相对总吸收面积呈极显著或显著的负相关关系。说明，良好的根系形态和根系活力是钾高效水稻品种的一种特征，相对根冠比、相对根体积、相对α-NA氧化量、相对活跃吸收面积、相对总吸收面积可以作为苗期钾高效水稻基因型的筛选指标。