2021年9月21日 星期二
‘中山杉302’×墨西哥落羽杉回交子代叶片光合性状和 叶绿素含量的QTL定位
QTL mapping of photosynthetic traits and chlorophyll content in leaf of backcross progenies of Taxodium ‘Zhongshanshan 302’×T. mucronatum
2021年 第30卷 第3期 页码[1-7]    下载全文[2.9MB]  
摘要

对‘中山杉302’(Taxodium ‘Zhongshanshan 302’)×墨西哥落羽杉(T. mucronatum Tenore)回交子代叶片的光合性状(包括净光合速率、气孔导度、胞间CO2浓度和蒸腾速率)及叶绿素含量(包括叶绿素a、叶绿素b和总叶绿素含量)进行统计分析,并对这些性状进行QTL定位。结果表明:这7个性状的频率呈正态分布。净光合速率均值为3.91 μmol·m-2·s-1,气孔导度均值为0.23 mmol·m-2·s-1,胞间CO2浓度均值为190.94 μmol·mol-1,蒸腾速率均值为5.17 mml·m-2·s-1,叶绿素a、叶绿素b和总叶绿素含量均值分别为0.48、0.16和0.64 mg·g-1;胞间CO2浓度变异系数最小(7.39%),其余6个性状变异系数较大,均在25.00%及以上,以气孔导度变异系数最大(43.48%)。QTL定位结果表明:除蒸腾速率和叶绿素b含量外,其余5个性状共定位到8个主效QTLs,包含98个SLAF标记,且这些主效QTLs的置信区间不同。净光合速率、气孔导度和叶绿素a含量各定位到1个主效QTL,分别位于1号连锁群(q1-1)和11号连锁群(q11-1和q11-2),各包含25、3和13个SLAF标记,解释表型贡献率分别为5.68%、7.85%和10.95%;胞间CO2浓度定位到2个主效QTLs,均位于6号连锁群(q6-1和q6-2),各含3和1个SLAF标记,解释表型贡献率分别为9.76%~10.70%和0.62%;总叶绿素含量定位到3个主效QTLs,分别位于1号连锁群(q1-2)和11号连锁群(q11-3和q11-4),各包含26、26和1个SLAF标记,解释表型变异率为6.51%~6.64%、9.66%和6.60%。并且,q6-2的加性效应值为正值,其余QTLs的加性效应值均为负值。研究结果显示:这8个主效QTLs的置信区间不同,不存在“一因多效”现象,且这些QTL区间基因主要参与光合性状和叶绿素含量的负调控。

Abstract

Statistical analysis was conducted for photosynthetic traits (including net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, and transpiration rate) and chlorophyll content (including chlorophyll a, chlorophyll b, and total chlorophyll contents) in leaf of backcross progenies of Taxodium ‘Zhongshanshan 302’×T. mucronatum Tenore, and QTL mapping was performed for these traits. The results show that the frequency of these 7 traits shows a normal distribution. The mean of net photosynthetic rate is 3.91 μmol·m-2·s-1, that of stomatal conductance is 0.23 mmol·m-2·s-1, that of intercellular CO2 concentration is 190.94 μmol·mol-1, that of transpiration rate is 5.17 mmol·m-2·s-1, and those of chlorophyll a, chlorophyll b, and total chlorophyll contents are 0.48, 0.16, and 0.64 mg·g-1, respectively; the coefficient of variation of intercellular CO2 concentration is the smallest (7.39%), while those of other 6 traits are relatively large, all of them are 25.00% and above, and the coefficient of variation of stomatal conductance is the largest (43.48%). The QTL mapping result shows that except for transpiration rate and chlorophyll b content, other 5 traits are mapped to 8 major QTLs, which contain 98 SLAF markers, and the confidence intervals of these major QTLs are different. Net photosynthetic rate, stomatal conductance, and chlorophyll a content are each mapped to 1 major QTL, which locate at No. 1 linkage group (q1-1) and No. 11 linkage group (q11-1 and q11-2), each contains 25, 3, and 13 SLAF markers, respectively, and their rates of explaining phenotypic variation are 5.68%, 7.85%, and 10.95%, respectively; intercellular CO2 concentration is mapped to 2 major QTLs, which locate at No. 6 linkage group (q6-1 and q6-2), each contains 3 and 1 SLAF markers, respectively, and their rates of explaining phenotypic variation are 9.76%-10.70% and 0.62%, respectively; total chlorophyll content is mapped to 3 major QTLs, which locate at No. 1 linkage group (q1-2) and No. 11 linkage group (q11-3 and q11-4), each contains 26, 26, and 1 SLAF markers, respectively, and their rates of explaining phenotypic variation are 6.51%-6.64%, 9.66%, and 6.60%, respectively. In addition, the additive effect value of q6-2 is positive, while that of the other QTLs are negative. It is suggested that the confidence intervals of these 8 major QTLs are different, and there is no “one cause-multiple effects” phenomenon, and these QTL interval genes are mainly involved in negative regulation of photosynthetic traits and chlorophyll contents.

关键词落羽杉属; ‘中山杉’; 光合性状; 叶绿素; QTL定位; SLAF标记
Key wordsTaxodium Rich.; T. ‘Zhongshanshan’; photosynthetic trait; chlorophyll; QTL mapping; SLAF marker
作者郭金博1,2, 华建峰1, 殷云龙1, 杨颖1
所在单位1. 江苏省中国科学院植物研究所(南京中山植物园) 江苏省落羽杉属树木种质创新与繁育工程研究中心, 江苏 南京 210014;2. 南京林业大学生物与环境学院, 江苏 南京 210037
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基金项目国家自然科学基金资助项目(31700588); 江苏省政策引导类计划(引进外国人才专项)资金项目(BX2020010); 中央财政林业科技推广示范资金项目(苏[2020]TG04)