Dissecting the Genetic Basis of Extremely Large Grain Shape in Rice Cultivar ¡®JZ1560¡¯

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• 作者：Jie-Zheng Ying ; Ji-Ping Gao ; Jun-Xiang Shan ; Mei-Zhen Zhu ; Min Shi ; Hong-Xuan Lin
• 关键词：Rice ; Quantitative trait locus ; Additive effect ; Grain shape
• 刊名：Journal of Genetics and Genomics
• 出版年：2012
• 出版时间：20 July, 2012
• 年：2012
• 卷：39
• 期：7
• 页码：325-333
• 全文大小：927 K

文摘

Rice grain shape, grain length (GL), width (GW), thickness (GT) and length-to-width ratio (LWR), are usually controlled by multiple quantitative trait locus (QTL). To elucidate the genetic basis of extremely large grain shape, QTL analysis was performed using an F₂ population derived from a cross between a japonica cultivar ¡®JZ1560¡¯ (extremely large grain) and a contrasting indica cultivar ¡®FAZ1¡¯ (small grain). A total number of 24 QTLs were detected on seven different chromosomes. QTLs for GL, GW, GT and LWR explained 11.6 % , 95.62 % , 91.5 % and 89.9 % of total phenotypic variation, respectively. Many QTLs pleiotropically controlled different grain traits, contributing complex traits correlation. GW2 and qSW5/GW5, which have been cloned previously to control GW, showed similar chromosomal locations with qGW2-1/qGT2-1/qLWR2-2 and qGW5-2/qLWR5-1 and should be the right candidate genes. Plants pyramiding GW2 and qSW5/GW5 showed a significant increase in GW compared with those carrying one of the two major QTLs. Furthermore, no significant QTL interaction was observed between GW2 and qSW5/GW5. These results suggested that GW2 and qSW5/GW5 might work in independent pathways to regulate grain traits. ¡®JZ1560¡¯ alleles underlying all QTLs contributed an increase in GW and GT and the accumulation of additive effects generates the extremely large grain shape in ¡®JZ1560¡¯.