水稻发芽期和幼苗前期耐碱性的鉴定方法研究

通过采用4种不同浓度的Na2CO3模拟碱胁迫，以水稻发芽期发芽势和发芽率的相对碱害率以及幼苗前期的根数、根长和苗高的相对碱害率为鉴定评价指标，研究水稻发芽期和幼苗前期耐碱性鉴定的碱胁迫条件。结果表明，水稻发芽势对碱胁迫的反应较发芽率更为敏感；根长对碱胁迫的反应较苗高和根数更为敏感；幼苗前期对碱胁迫的反应较发芽期更为敏感。在0．15％或0．20％Na2CO3胁迫下水稻发芽势和发芽率的相对碱害率平均值、方差和变异幅度较大。且其分布均匀合理，可作为水稻发芽期耐碱性鉴定的碱胁迫条件；而在0．10％或0．15％Na2CO3胁迫下，幼苗前期根数、根长和苗高的相对碱害率以及综合相对碱害率的平均值、方差和变异幅度较大，且分布相对均匀合理，可作为水稻幼苗前期耐碱性鉴定的碱胁迫条件。在碱胁迫下，水稻发芽势、发芽率、根数、根长和苗高的表型值分别与它们自身的相对碱害率呈极显著的负相关；发芽率的相对碱害率与根数、根长和苗高的相对碱害率呈显著的正相关；发芽期的综合相对碱害率与幼苗前期的综合相对碱害率呈显著的正相关；因此，以水稻发芽期的耐碱性可间接判断水稻幼苗前期的耐碱性。

Studies on Screening Methods for Alkaline Tolerance at Germination Period and Early Seedling Stage in Rice

Using four different Na_2CO_3 concentration as simulating alkaline stress,the relative alkali damage rate(RADR) of rice germinative energy(GE) and germination rate(GR) at germination period,RADR of rice root length(RL),seedling height(SH) and root number(RN) at early seedling stage were looked as evaluation indexes,so the alkaline stress concentration for evaluation of alkaline tolerance at germination period and early seedling stage in rice was studied.The results showed that germinative energy(GE) was more sensitive to alkaline stress than germination rate(GR),RL was more sensitive to alkaline stress than SH and RN,early seedling stage was more sensitive to alkaline stress than germination period.The mean value,variance and range of variance for RADR of GE and GR under 0.15% or 0.20% Na_2CO_3 stress were larger and their distribution was more reasonable that was good condition for the evaluation of alkaline tolerance at germination period.The mean value,variance and range of variance for RADR of RB,RL,SH and total value at early seedling stage under 0.10% or 0.15% Na_2CO_3 stress were larger and their distribution was more reasonable,that was good condition for the evaluation of alkaline tolerance at early seedling stage.GE,GR,RN,RL and SH were negatively related to their RADR;RADR of GR was significantly associated with RADR of RN,RL and SH.Total RADR at germination period was significantly correlated with total RADR at early seedling stage.Therefore the alkaline tolerance at early seedling stage would indirectly evaluated by the alkaline tolerance at germination period.