Kumari Rima, Kumar Pankaj, Sharma V K, Kumar Harsh
Department of Agricultural Biotechnology and Molecular Biology, Dr. Rajendra Prasad Central Agricultural University, Pusa (Samastipur), Bihar 848125 India.
Physiol Mol Biol Plants. 2019 Mar;25(2):407-419. doi: 10.1007/s12298-018-0623-3. Epub 2018 Nov 17.
Salt tolerance status at early seedling stage in 30 rice varieties including two tolerant (Pokkali and CSR-36) and two susceptible (IR-29 and IR-64) checks was assessed under different levels of salinity (0, 4, 8 and 16 dS m) created by salt mixture of NaCl, CaCl, NaSO in 7:2:1 ratio. Overall salinity tolerance indices clearly reflected that 17 varieties including the two tolerant checks were highly tolerant, seven varieties exhibited moderately tolerant, whereas six varieties including the two susceptible checks had highly susceptible response to salt stress. Molecular profiling of 13 tolerant and 5 susceptible rice varieties by using 24 SSR markers revealed 8.5 alleles per primer with altogether 114 shared and 91 unique allelic variants. Considering the allele number, polymorphism information content and polymorphism percent, SSR primers RM 302, RM 8094, RM 10665, RM 10694, RM 10748 and RM 10825 appeared to be highly polymorphic and comparatively more informative. Hierarchical classification and spatial distribution patterns based on amplification profiles dependent similarity indices unambiguously discriminated these 18 varieties in accordance with their salt tolerance response. Sequential exclusion of primers in further analysis led to validation of RM 140, RM 1287, RM 3412, RM 10745, RM 10764 and RM 10772 for their efficiency to distinguish salt tolerant varieties from susceptible ones. A specific combination of either four (RM 1287, RM 3412, RM 10764 and RM 10772) or even two markers (RM 1287 and RM 3412) also seemed to be equally effective in discrimination of entries according to their salt stress responsiveness. Principal coordinate analysis completely corroborated hierarchical classification of the varieties. Salt tolerance donors identified and SSR primers validated in the present study may be further utilized in the development of salt stress tolerant varieties of rice.
利用氯化钠、氯化钙、硫酸钠按7:2:1比例混合配制的盐溶液，在0、4、8和16 dS m等不同盐度水平下，对包括两个耐盐品种（Pokkali和CSR - 36）及两个盐敏感品种（IR - 29和IR - 64）在内的30个水稻品种在幼苗早期的耐盐状况进行了评估。总体耐盐性指数清楚地表明，包括两个耐盐对照品种在内的17个品种具有高度耐盐性，7个品种表现为中度耐盐，而包括两个盐敏感对照品种在内的6个品种对盐胁迫具有高度敏感反应。利用24个SSR标记对13个耐盐和5个盐敏感水稻品种进行分子图谱分析，每个引物检测到8.5个等位基因，共发现114个共享等位变异和91个独特等位变异。综合等位基因数量、多态性信息含量和多态性百分比来看，SSR引物RM 302、RM 8094、RM 10665、RM 10694、RM 10748和RM 10825表现出高度多态性且信息含量相对较高。基于扩增图谱相关相似性指数的层次分类和空间分布模式，根据这些品种的耐盐反应，明确区分了这18个品种。在进一步分析中依次排除引物，验证了RM 140、RM 1287、RM 3412、RM 10745、RM 10764和RM 10772区分耐盐品种和敏感品种的有效性。四个引物（RM 1287、RM 3412、RM 10764和RM 10772）或甚至两个标记（RM 1287和RM 3412）的特定组合，在根据品种对盐胁迫的反应进行区分时似乎同样有效。主坐标分析完全证实了品种的层次分类。本研究中鉴定出的耐盐供体和验证的SSR引物可进一步用于培育耐盐水稻品种。
