秧苗伤根对水稻分蘖的影响机理及外源调控

Exogenous regulation and influence of root cutting on rice tiller

以同一杂交亲本组合中背景和生育期相近姊妹系DN20和DN22为供试材料,通过盆栽试验研究秧苗伤根对寒地水稻分蘖的影响机理及外部调控。结果表明,插秧时秧苗根系受伤显著抑制秧苗生长早期分蘖发生和形成、植株全氮和可溶性糖含量,根系受伤程度越大抑制效果越明显,插秧前喷施6-BA有利于促进伤根秧苗早期分蘖发生和形成,增施氮肥为促进早期分蘖发生和形成的最佳措施。插秧时秧苗根系受伤显著降低秧苗分蘖过程中OsMADS57基因转录表达量,显著提高OsTB1、OsD3和OsD14基因转录表达量,秧苗根系受伤程度越大基因转录表达量变化程度越高,增施氮肥有利于提高OsMADS57基因转录表达量,显著抑制秧苗分蘖过程中OsTB1、OsD3和OsD14基因转录表达量;插秧前喷施6-BA对OsMADS57、OsD3和OsD14基因转录表达量无显著影响,但显著降低OsTB1基因转录表达量。

The rice sibling lines DN20 and DN22 with similar genetic background and growth period from the same cross combination were used as experimental materials. The pot experiment was conducted to study the influence of root cutting and the exogenous regulation on rice tiller formation at early stage in cold region. The results showed that seedling root cutting significantly inhibits early tiller formation, total nitrogen content and soluble sugar content, which is positively related to the extent of root cutting. At early seedling stage, application of 6-BA prior to transplanting promotes tiller formation, while nitrogen application was the optimal measurement to promote tiller formation. Moreover, seedling root cutting decreased OsMADS57 expression level and increasd the expression level of OsTB1, OsD3 and OsD14 significantly, whose up-regulation and down-regulation depended on the extent of seedling root cutting. Nitrogen application was conducive to enhancement of OsMADS57 expression and inhibition of OsTB1, OsD3 and OsD14 expression at tillering stage. Application of 6- BA had no significant effect on expression of OsMADS57, OsD3 and OsD14, but significantly decreased OsTB1 expression level.