, a Quantitative Trait Locus for Rice Grain Shape, Encodes a RING-Type E3 Ubiquitin Ligase.

Grain weight and grain shape are important traits that determine rice grain yield and quality. Mining more quantitative trait loci (QTLs) that control grain weight and shape will help to further improve the molecular regulatory network of rice grain development and provide gene resources for high-yield and high-quality rice varieties. In the present study, a QTL for grain length (GL) and grain width (GW), , was firstly fine-mapped into a 21.

Control of Grain Weight and Size in Rice (Oryza sativa L.) by OsPUB3 Encoding a U-Box E3 Ubiquitin Ligase.

Grain weight and size, mostly determined by grain length, width and thickness, are crucial traits affecting grain quality and yield in rice. A quantitative trait locus controlling grain length and width in rice, qGS1-35.2, was previously fine-mapped in a 57.

Control of Thousand-Grain Weight by in Rice.

Grain weight and size are important traits determining grain yield and influencing grain quality in rice. In a previous study, a quantitative trait locus controlling thousand-grain weight (TGW) in rice, , was mapped in a 70.7 kb region on chromosome 10.

Fine-mapping of , a quantitative trait locus for grain weight in rice ( L.).

Background: Grain weight is a grain yield component, which is an integrated index of grain length, width and thickness. They are controlled by a large number of quantitative trait loci (QTLs). Besides major QTLs, minor QTLs play an essential role.

Importance of the Interaction between Heading Date Genes and for Controlling Yield Traits in Rice.

Appropriate flowering time is crucial for successful grain production, which relies on not only the action of individual heading date genes, but also the gene-by-gene interactions. In this study, influences of interaction between and on flowering time and yield traits were analyzed using near isogenic lines derived from a cross between rice cultivars ZS97 and MY46. In the non-functional background, the functional allele promoted flowering under both the natural short-day (NSD) conditions and natural long-day (NLD) conditions.

Dissection and fine-mapping of two QTL for grain size linked in a 460-kb region on chromosome 1 of rice.

Background: Grain size is a key determinant of grain weight and a trait having critical influence on grain quality in rice. While increasing evidences are shown for the importance of minor-effect QTL in controlling complex traits, the attention has not been given to grain size until recently. In previous studies, five QTL having small effects for grain size were resolved on the long arm of chromosome 1 using populations derived from indica rice cross Zhenshan 97///Zhenshan 97//Zhenshan 97/Milyang 46.

Assessment and genetic analysis of heavy metal content in rice grain using an Oryza sativa × O. rufipogon backcross inbred line population.

Background: Heavy metal accumulation in rice is a growing concern for public health. Backcross inbred lines derived from an interspecific cross of Oryza sativa × O. rufipogon were grown in two distinct ecological locations (Hangzhou and Lingshui, China).

Rice Flowering Locus T 1 plays an important role in heading date influencing yield traits in rice.

Important role of flowering genes in enhancing grain productivity in rice has become well recognized for a number of key genes regulating the florigen production, but little has been known for the two florigen genes themselves. In this study, pleiotropism of Rice Flowering Locus T 1 (RFT1), one of the two florigen genes in rice, was firstly evaluated using near isogenic lines (NILs) carrying RFT1 alleles from the indica rice cultivars Zhenshan 97 (ZS97) and Milyang 46, respectively, and then determined by transformation of the RFT1 allele into a japonica rice variety, Zhonghua 11. The RFT1 allele was shown to delay heading and increase plant height, grain weight, grain number and grain yield, indicating that RFT1 plays an important role in the growth and development of rice.

Detection of QTLs for Yield Heterosis in Rice Using a RIL Population and Its Testcross Population.

Analysis of the genetic basis of yield heterosis in rice was conducted by quantitative trait locus mapping using a set of 204 recombinant inbred lines (RILs), its testcross population, and mid-parent heterosis dataset (H). A total of 39 QTLs for six yield traits were detected, of which three were detected in all the datasets, ten were common to the RIL and testcross populations, six were common to the testcross and H, and 17, 2, and 1 were detected for RILs, testcrosses, and H, respectively. When a QTL was detected in both the RIL and testcross populations, the difference between TQ and IR24 and that between Zh9A/TQ and Zh9A/IR24 were always in the same direction, providing the potential to increase the yield of hybrids by increasing the yield of parental lines.

Mapping of Quantitative Trait Loci for Contents of Macro- and Microelements in Milled Rice (Oryza sativa L.).

Macro- and microelement contents are important traits for nutritional quality in rice. In this study, quantitative trait loci (QTLs) for the contents of seven mineral elements in milled rice were detected using recombinant inbred lines (RILs) of the indica rice cross Zhenshan 97/Milyang 46, followed by the validation and fine mapping of a QTL region on the short arm of chromosome 6. A total of 20 QTLs distributed on chromosomes 1, 3, 5, 6, 10, and 11 were detected in the RIL population.

[Mapping QTL for rice milling and appearance quality traits in indica rice].

Quantitative trait loci (QTL) controlling six milling and appearance quality traits were analyzed over 2 years using recombinant inbred lines derived from two indica rice Teqing and IRBB. A total of 30 QTL for these traits were detected, of which eight were for brown rice rate (BRR), two for milled rice recovery (MRR), two for head rice recovery (HRR), seven for grain length (GL), five for grain width (GW), and six for length/width ratio (LWR). The QTL were distributed on all chromosomes except for chromosomes 4 and 12.

Validation and dissection of quantitative trait loci for leaf traits in interval RM4923-RM402 on the short arm of rice chromosome 6.

Validation and dissection of a QTL region for leaf traits in rice which has been reported in a number of independent studies were conducted. Three sets of near isogenic lines (NILs) were originated from a residual heterozygous line derived the indica cross Zhenshan 97B/Milyang 46. They were overlapping and totally covered a 4.

Progress in research and development on hybrid rice: a super-domesticate in China.

Background: China has been successful in breeding hybrid rice strains, but is now facing challenges to develop new hybrids with high-yielding potential, better grain quality, and tolerance to biotic and abiotic stresses. This paper reviews the most significant advances in hybrid rice breeding in China, and presents a recent study on fine-mapping quantitative trait loci (QTLs) for yield traits.

Scope: By exploiting new types of male sterility, hybrid rice production in China has become more diversified.

[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.

Genetic dissections of partial resistances to leaf and neck blast in rice (Oryza sativa L.).

In a recombinant inbred line (RIL) population of indica rice, two subpopulations composed of susceptible lines were selected for mapping of partial resistance to leaf blast with two isolates of the pathogen. A third subpopulation composed of susceptible lines with similar heading time was used for mapping of partial resistance to neck blast with a third isolate. The traits measured for partial resistance included diseased leaf area (DLA), lesion size (LS) and lesion number (LN) for leaf blast and lesion length (LL) and conidium amount (CA) for neck blast.

[Analysis of gene expression profiles during host-Magnaporthe grisea interactions in a pair of near isogenic lines of rice].

A pair of near isogenic lines G205 and G71 were selected from recombinant inbred lines (RIL) of Zhong156 x Gumei2. On the resistance locus Pi-25(t), G205 had the resistant allele that was from Gumei 2 while G71 had the susceptible allele that was from Zhong156. For the genetic background, different alleles were detected on only 24 loci out of the 672 RFLP or SSLP loci surveyed.

[Mapping of fertility-restoring genes with main effects and epistatic effects for CMS-DA in rice].

A test-cross population was established for mapping genes conditioning fertility restoration for dwarf-wild-abortive cytoplasmic male sterility(CMS-DA) in rice. A recombinant inbred line(RIL) population consisting of 210 lines was derived from the cross Xieqingzao B/Miyang 46, in which Xieqingzao B is the maintainer line of CMS-DA Xieqingzao A, and Miyang 46 is the restorer line. Each of the RILs was crossed to Xieqingzao A, and the resulting F1s were used for phenotyping of the spikelet fertility in 1999 and 2000.