水稻叶片叶绿素和过氧化氢含量的QTL检测及上位性分析

研究水稻叶片叶绿素和过氧化氢含量的遗传规律，对探讨光合代谢产物遗传规律和开展高产育种具有重要指导意义。利用由日本晴／Kasalath∥日本晴的杂交组合衍生的98个回交重组自交家系(BC1F9)所组成的BIL(backcross inbred lines)群体，在第1、2、3和10染色体上分别检测出5个与叶绿素含量相关的QTL和2个影响剑叶过氧化氢含量的QTL，其中位于第1染色体的RFLP标记C86和C813之间的q-Chll对叶绿素含量的影响最为显著，对表型变异的贡献率达22％，其增效基因来自粳稻品种日本晴；同时在该区间检测到1个与剑叶过氧化氢含量相关的QTL:q-H2O2I,对过氧化氢含量的减效基因来自日本晴品种。上位性分析结果显示影响叶绿素含量及过氧化氢含量的非等位QTL之间存在显著的上位性效应。具有上位性效应的QTL分布于第2、6、11和12染色体上，未检测到与q-Chll或q-H2O2I互作的位点。暗示日本晴品种的RFLP标记C86和C813之间存在1个能够提高叶绿素含量，同时又能降低过氧化氢含量的主效QTL，其加性效应显著而不存在上位性效应。

QTL and Epistatic Interaction Underlying Leaf Chlorophyll and H2O2 Content Variation in Rice (Oryza sativa L.)

It is meaningful to study the genetics of the traits associated with photosynthesis such as leaf chlorophyll and H2O2 contents for high yield breeding in rice.A mapping population of 98 BC1F9 lines (backcross Inbred Lines,BIL),derived from a backcross of Nipponbare (japonica)/Kasalath(indica)∥Nipponbare by the single-seed-descent methods,was employed to map quantitative trait loci (QTL) underlying such rice traits as leaf chlorophyll and H2O2 contents.Five and two QTLs were detected for leaf Chlorophyll and H2O2 content variation,respectively.Among the QTLs detected,q-Chl1 on chromosome 1 accounted for 22% variation for leaf chlorophyll content variation.The alleles from Nipponbare increased stature at the locus;On the other hand,q-H2O21 which associated with H2O2 content was also located on the same region as q-Chl1.The alleles from Nipponbare decreased stature at this locus.The 2 traits have the 2 QTL sharing the same chromosome locations,which was located between C86 and C813 on chromosome 1.Epistasis analysis showed QTL with interaction distributed on chromosome 2,6,11 and 12.However,no QTL interacted with q-Chl1 or q-H2O21 was detected.It can be deduced that alleles from Nipponbare at the region between C86 and C813 on chromosome 1 increases leaf chlorophyll content and decreases H2O2 content at the mean time with significant additive effect but little epistasis.