[Genetic analysis of starch branching enzyme activity in rice grain].
To make an genetic analysis of starch branching enzyme (Q enzyme) inheritance, which is important in catalyzing the formation of amylopectin and thereby raising the amylopectin/amylose ratio of starch in rice grains, a linkage map of 207 DNA markers were constructed by using 247 recombinant inbred lines derived from an indica-indica rice cross Zhenshan 97B/Milyang46. In 2002 and 2003, the activities of starch branching enzyme of the parents and 247 RILs were measured 10 d and 20 d respectively after flowering (Table 1). A total of 3 quantitative trait loci (QTLs) were detected to have significant additive effects on Q enzyme activities 10 d after flowering with 10% phenotypic variations explained for the three QTLs (Table 2, Fig.1). Meanwhile, qQ10-6 with significant QTL x environment interaction was detected. Epistasis analysis detected 5 and 2 significant additive-by-additive interactions for Q enzyme 10 d and 20 d respectively after flowering (Table 3), and three pairs of QTLs 10 d after flowering with significant epistasis x environment interactions were detected, explaining 3% to 12% of the phenotypic variation. The results showed that the environmental factors had obvious effect on the gene expression of Q enzyme activity in rice grain. Meanwhile, the location of qQ10-6 in relation to that of QTLs for gelatinization temperature, gene loci involved in ADPG pyrophosphorylase and soluble starch synthase were discussed with the help of a genetic map.
Shen
Bo
B
National Center for Rice Improvement and State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China.
Zhuang
Jie-Yun
JY
Fan
Ye-Yang
YY
Ying
Jie-Zheng
JZ
Yang
Juan
J
Sun
Li-Xiang
LX
Fei
Ji-Hui
JH
Zheng
Kang-Le
KL
D015061:1,4-alpha-Glucan Branching Enzyme / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D012275:Oryza / Q000201:enzymology / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D040641:Quantitative Trait Loci / Q000235:genetics
D010940:Plant Proteins; D015061:1,4-alpha-Glucan Branching Enzyme