Singh Uma M, Yadav Shailesh, Dixit Shilpi, Ramayya P Janaki, Devi M Nagamallika, Raman K Anitha, Kumar Arvind
Department of Plant Breeding, International Rice Research Institute-South Asia Hub, ICRISAT Patancheru, India.
Department of Plant Breeding, International Rice Research Institute-South Asia Hub, ICRISATPatancheru, India; Department of Plant Breeding, International Rice Research InstituteMetro Manila, Philippines.
Front Plant Sci. 2017 Mar 2;8:286. doi: 10.3389/fpls.2017.00286. eCollection 2017.
Strong seedling vigor is desirable trait in dry direct-seeded rice (DSR) for enhancing crop establishment and the ability to compete against weeds. A set of 253 BCF lines derived from cross between Swarna and Moroberekan was phenotyped for early vigor (EV) and 8 related traits ., early uniform emergence (EUE), shoot length (SHL), stem length (SL), shoot fresh weight (SFW), total fresh weight (TFW), shoot dry weight (SDW), total dry weight (TDW), and root dry weight (RDW). Composite interval mapping analysis using genotypic data from 194 SNP markers identified six genomic regions associated with traits on chromosomes 3, 4, 5, and 6 with phenotypic variance ranging from 2.5 to 18.6%. Among them 2 QTL regions; one on chr3 (id3001701-id300833) and the other on chr5 (wd5002636-id5001470) were identified as QTL hotspots A and B respectively and expressed consistently in field as well as glasshouse condition. The majority of QTLs identified for early vigor, and related traits were clustered in the QTL hotspots A ( ) and QTL hotspot B ( ). Ten putative candidate genes ., 1-alpha-amylase precursor, 2-glutamate decarboxylase, 1-ethylene-insensitive 3, 3-expansin precursor, and 3-phenylalanine ammonia-lyase associated with the target traits were identified in the selected QTL regions. Mutations were identified in the coding region of alpha-amylase precursor and ethylene-insensitive 3 gene between the parents which can be utilized in marker assisted breeding. Trait relationships among the agro-physiological traits were examined to select the best genotypes for the given traits for use in future breeding programs.
强幼苗活力是旱直播水稻（DSR）中一个理想的性状，有助于提高作物的立苗率和与杂草竞争的能力。对一组由Swarna和Moroberekan杂交产生的253个回交导入系（BCF）进行了早期活力（EV）及8个相关性状的表型分析，这些性状包括早期均匀出苗（EUE）、苗长（SHL）、茎长（SL）、地上部鲜重（SFW）、总鲜重（TFW）、地上部干重（SDW）、总干重（TDW）和根干重（RDW）。利用194个单核苷酸多态性（SNP）标记的基因型数据进行复合区间作图分析，确定了6个与第3、4、5和6号染色体上性状相关的基因组区域，表型变异范围为2.5%至18.6%。其中2个数量性状位点（QTL）区域，一个位于第3号染色体（id3001701 - id300833），另一个位于第5号染色体（wd5002636 - id5001470），分别被确定为QTL热点A和B，并且在田间和温室条件下均能稳定表达。鉴定出的大多数与早期活力及相关性状的QTL都聚集在QTL热点A（ ）和QTL热点B（ ）中。在选定的QTL区域中鉴定出10个假定的候选基因，即1 - α淀粉酶前体、2 - 谷氨酸脱羧酶、1 - 乙烯不敏感3、3 - 扩张蛋白前体和3 - 苯丙氨酸解氨酶，它们与目标性状相关。在亲本之间的α淀粉酶前体和乙烯不敏感3基因的编码区发现了突变，这些突变可用于标记辅助育种。研究了农业生理性状之间的性状关系，以选择具有给定性状的最佳基因型用于未来的育种计划。
