Vol. 21 >B. Research Notes>IV. Genetics of disease and insect resistance |
22. | Fine mapping of pgwc8 gene affecting percentage of grains with chalkiness in rice (Oryza sativa. L) |
X. Y. WAN1, J.F. WENG1, H.Q. ZHAI2 and J.M. WAN1,2* 1) State Key Laboratory of Crop Genetics & Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China 2) Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China * Corresponding auther: E-mail: wanjm@njau.edu.cn, wanjm@caas.net.cn, Fax: +86-25-84396516) |
For quality rice varieties, the endosperm should be free of chalkiness since the chalky grains have the lower density of starch granules compared to translucent ones and are more prone to breakage during milling. Also, both longitudinal and transverse cracks occur easily in chalky kernel when steamed, reducing palatability of cooked rice. Percentage of grains with chalkiness (PGWC) in rice is quantitatively inherited. Identification
of QTLs affecting PGWC and elucidation of its genetic mechanism would
be useful for marker-assisted selection (MAS) to increase breeding efficiency.
Up to now, there have been several studies on primary mapping of QTLs
for PGWC (He et al. 1999; Tan et al. 2000). But no reports
were found concerning stability analysis and fine mapping of QTLs affecting
PGWC in rice. et al. 1999) in two years and four sites, and detected a stable
expression QTL qPGWC8 with average R2 of 23.7% underlying
PGWC in the G1149-R727 interval on chromosome 8 (Table 1 and Fig. 1a).
Then, a F2 secondary population (BC4F2)
was developed through backcrossing CSSL50, one of the target
CSSLs harboring qPWGC8 allele, with the genetic background parent,
Asominori. |
Vol. 21 >B. Research Notes>IV. Genetics of disease and insect resistance |