Effects of controlled micro-/nanosurfaces on osteoblast proliferation.

Micro-/nanostructured implant surfaces mimicking natural bone architecture are expected to have positive effects on osteoblast proliferation. In this study, to clarify the optimal microstructure scale on micro-/nano-titanium surfaces, highly controlled microstructure surfaces were fabricated with a titania nanotube oxide layer by sandblast treatment and electrochemical anodization. Average surface roughness (R ) and mean width of the profile elements (R ) increased in proportion to the size of the blasting media.

QTL pyramiding for improving of cold tolerance at fertilization stage in rice.

Vigorous cold tolerance at the fertilization stage (CTF) is a very important characteristic for stable rice production in cold temperature conditions. Because CTF is a quantitatively inherited trait, pyramiding quantitative trait loci (QTLs) using marker-assisted selection (MAS) is effective for improving CTF levels in rice breeding programs. We previously identified three QTLs controlling CTF, qCTF7, qCTF8 and qCTF12, using backcrossed inbred lines derived from a cross between rice cultivar Eikei88223 (vigorous CTF) and Suisei (very weak CTF).

Genetical and morphological characterization of cold tolerance at fertilization stage in rice.

Cold temperature during the reproductive phase leads to seed sterility, which reduces yield and decreases the grain quality of rice. The fertilization stage, ranging from pollen maturation to the completion of fertilization, is sensitive to unsuitable temperature. Improving cold tolerance at the fertilization stage (CTF) is an important objective of rice breeding program in cold temperature areas.

Selection for low-temperature germinability on the short arm of chromosome 3 in rice cultivars adapted to Hokkaido, Japan.

In plant breeding with intensive selection, the haplotype patterns in the targeted chromosomal regions may become monogenic among local populations with the most desirable combination of loci. This study demonstrated that the chromosomal region surrounding qLTG3-1 was under selection during rice breeding programs in a local region of Japan, Hokkaido. qLTG3-1 is a major quantitative trait loci controlling tolerance to low-temperature at the seed germination stage in rice, termed low-temperature germinability.

The fertility restorer gene, Rf2, for Lead Rice-type cytoplasmic male sterility of rice encodes a mitochondrial glycine-rich protein.

Cytoplasmic male sterility (CMS) is associated with a mitochondrial mutation that causes an inability to produce fertile pollen. The fertility of CMS plants is restored in the presence of a nuclear-encoded fertility restorer (Rf) gene. In Lead Rice-type CMS, discovered in the indica variety 'Lead Rice', fertility of the CMS plant is restored by the single nuclear-encoded gene Rf2 in a gametophytic manner.

Genetic effects of major QTLs controlling low-temperature germinability in different genetic backgrounds in rice (Oryza sativa L.).

The effects of QTLs are demonstrated basically within the population used in the original QTL analysis as the difference between the alleles of the parental varieties. For the efficient use of QTLs in breeding programs, it is necessary to assess whether the QTL exhibits its genetic effect when it is introgressed into different genetic backgrounds. Extensive studies of tolerance to low temperature at the seed germination stage (called low-temperature germinability) in rice revealed that 2 major QTLs on chromosomes 3 and 11, qLTG3-1 and qLTG11, have large effects.