摘要
在耐旱性筛选设施内对一套水稻重组自交系群体(共185个株系)进行两年的水分胁迫和非胁迫处理,调查每穗颖花数(SNP)、单边柱头外露率(PSES)、双边柱头外露率(PDES)和柱头总外露率(PES)等4个开花相关性状。方差分析结果显示年份、株系和水分处理,以及相互间互作的效应均达显著水平。表型相关以PSES和PES间最高(r=0.9752***),其次为PDES和PES(r=0.7150***),最次为PSES和PDES间(r=0.5424***)。利用203个SSR标记建立的连锁图,胁迫和非胁迫条件下各检测到6个SNP的主效QTL,3～4个PSES、PDES和PES的主效QTL;检测到1～9对上位性QTL影响颖花数和柱头外露率。大部分加性和上位性效应的贡献率较低(0.76%～9.92%),仅有少数QTL或上位性QTL解释总方差的10%以上。一些主效和上位性QTL在PSES、PDES和PES间被共同检测到,解释了不同柱头外露率指标间高度正相关关系。几乎没有在水分胁迫和非胁迫两种条件下都检测到的QTL,暗示着干旱对颖花数和柱头外露率有严重的影响。
Four flowering related traits, spikelet number per panicle （SNP）, percentage of single exserted stigma （PSES）, dual exserted stigma （PDES） and total exserted stigma （PES） of a RI population with 185 lines under water stress and non-stress conditions for 2 years, were investigated in a drought tolerance screening facility. ANOVA results showed high significance between years,lines, and water stress treatments, together with interactions among them in pairs. Highest phenotypic correlation was found between PSES and PES （r=0.9752＊＊＊）, followed by PDES and PES （r=0.7150＊＊＊）, and PSES and PDES （r=0.5424＊＊＊）. Based on a linkage map of 203 SSR markers, six main effect QTLs were detected for SNP and three or four main effect QTLs were associated with PSES, PDES and PES under stress or non-stress conditions. There were one to nine pairs of epistatic QTLs influencing SNP and stigma exsertion. The contribution rates of additive and epistatic effects seemed to be in a low magnitude for most cases （0.76%-9.92%） while a few QTLs or QTL paris explained more than 10% of total variance. Some main effect QTL and epistasis were commonly detected among PSES, PDES and PES, explaining the high positive correlation between them. Few QTLs were detected under both water stress and non-stress condition, implying that drought had severe impact on the genetic behaviors of both spikelet number and stigma exsertion.
基金
This work was supported by the Grants from Chinese Ministry of Agriculture (No. 948-2001-101), Chinese Ministry of Science and Technology (No. 2003AA207010), Shanghai Municipal Science and Technology Commission (No. 02ZC14082), and the Rocke-feller Foundation.
