水稻资源芽期和苗期耐盐碱性综合评价及耐盐基因分析

Comprehensive evaluation of salt-alkali tolerance of rice germplasms at germination and seedling stages and analysis of salt-tolerant genes

摘要:

培育耐盐碱水稻品种是应对全球人口日益增长的重要途径之一。文中以21份耐盐碱性不同的水稻品种(系) 为材料，在芽期和苗期设置6个不同盐碱浓度处理，测定了发芽势、发芽率、芽长、根长、根数、芽鲜重和苗鲜总重等指标，以各指标盐害率的平均值作为耐盐碱性的综合评价标准。结果表明随着盐碱浓度的提升，对种子萌发和生长的抑制越明显。在1% NaCl加0.25% NaHCO₃溶液处理下，发芽率盐害率变异最大，为0%–89.80%。在所有浓度处理下，各性状指标的盐害率都具有相似的变化趋势。筛选到4份综合耐盐碱能力强(大酒谷、日本晴、魔王谷和02428) 和7份弱的种质资源。比较了4份耐盐碱强和3份耐盐碱弱的资源耐盐基因序列：OsHAL3和OsRR22基因在7份材料中没有差异，SKC1和DST基因在耐盐碱强和耐盐碱弱的品种之间有明显的变异。研究结果为进一步挖掘水稻耐盐碱基因和培育耐盐碱水稻新品种提供了种质资源和理论基础。

Abstract:

Cultivating salt-alkali tolerant rice varieties is one of the important ways to meet the increasing food demand of growing global population. In this study, twenty-one rice germplasms with different salt-alkali tolerance were treated with six salt-alkali concentrations at germination and seedling stages. The germination potential, germination rate, shoot length, root length, root number, fresh weight of shoot and seedlings were measured. The average value of salt damage rate was used to evaluate the salt-alkali tolerance. As the salt-alkali concentration increases, the inhibition on seed germination and growth became more obvious. Upon treatment with 1% NaCl plus 0.25% NaHCO₃, the salt damage rate of germination rate has the largest variation, ranging from 0% to 89.80%. The salt damage rate of each trait shows a similar trend at all concentrations. Four germplasm resources with strong salt-alkali tolerance (Dajiugu, Nippobare, Mowanggu and 02428) and 7 sensitive germplasms were screened. The salt-tolerant gene sequence of 4 salt-alkali tolerant varieties and 3 sensitive germplasms were analyzed. OSHAL3 and OsRR22 were identical among the 7 germplasms, but SKC1 and DST showed clear variations between the salt-alkali tolerant and sensitive germplasms. Besides the salt-alkali tolerant germplasm resources, this study can also serve as a reference for mining of genes involved in salt-alkali tolerance and breeding of salt-alkali tolerant rice varieties.