Abstract:
Objective Shape and quality of the grains of Fuhui 676, a premium high-yield, high-quality, stress resistant, highly adaptable restorer of rice, were studied for further improvements.
Method Along with Fuhui 676, which was previously bred by the Rice Research Institute at Fujian Academy of Agricultural Sciences, Minghui 63, Shuhui 527, Minghui 86, and Fuhui 673 were planted at the experimental stations in Fuzhou, Quanzhou, and Sanming. At maturation, grains were harvested and sun-dried to measure the length, width, thickness, 1000-grain weight, and quality. Genomic DNA of the plants was extracted by CTAB method; Wx fragments amplified by PCR; restriction enzymes analyzed by means of Acc I digestion; polymorphism of the first base of Wx gene intron 1 determined by agarose gel electrophoresis and sequence analysis; total RNA of the grains extracted by Trizol method; and expressions of the grain-shape-and-quality-related genes at different grain-filling stages analyzed by SYBR Green I fluorescent quantitative PCR (qRT-PCR).
Result In general, the Fuhui 676 grains measured 10–11 mm long, 2.70 mm wide, 2.00 mm thick, and 27.0–31.0 g per 1000-grains. After dehulling, they yielded more than 81% brown rice with a gel consistency of more than 60.0 mm and an amylose content in the range of 13%–18%, which met the 1st grade standard. The grains had a higher head rice rate than those of the other 4 restorer lines; and the chalkiness rate and degree higher than those of the parents, Minghui 63 and Shuhui 527, but lower than those of Minghui 86 and Fuhui 673. The first base of Wx gene intron 1 in the restorers was T, i.e., of the Wxb genotype. The expression of GL7 related to grain shape in Fuhui 676 decreased significantly on the 11 d of grain-filling, while those of GS3, SGL, and GIF1 increased initially and then decreased with a peak appeared on the 7 d; that of GW8 decreased at first and then increased to the highest level on the 11 d; that of the quality-related Chalk5 reached the maximum on the 7 d but nearly dissipated on the 11 d; and those of ALK, OsSSI, and OsBEIIb rose to a peak on the 7 d and followed by a decline. The expression patterns of those genes in Fuhui 676 were completely different from those in the other 4 restorers.
Conclusion Fuhui 676 produced long grains of high head milled rice rate, brown rice rate, gel consistency, and amylose content of 1st grade rice. The Wx genotype of Fuhui 676 was Wxb. The expression patterns of GL7, GS3 and ALK, OsSSI, OsBEIIb related to grain shape and quality in Fuhui 676 were distinctively different from those of the other tested restorer lines.