[The history and prospect of rice genetic breeding in China].

Rice breeding in China has experienced three major leaps of dwarf breeding, heterosis utilization and green super rice cultivation, accompanied by six important processes: dwarf breeding (the first green revolution), three-line hybrid rice cultivation, two-line hybrid rice cultivation, inter-subspecies heterosis utilization, ideal plant type breeding and green super rice cultivation. The breeding subject ranges from the unique trait of high yield to the complex traits of resistance, high quality and high yield. The breeding concept is gradually upgraded from high yield and quality to the second green revolution concept of "less investment, more output, and better environment".

[The application of genome editing in identification of plant gene function and crop breeding].

Plant genome can be modified via current biotechnology with high specificity and excellent efficiency. Zinc finger nucleases (ZFN), transcription activator-like effector nucleases (TALEN) and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system are the key engineered nucleases used in the genome editing. Genome editing techniques enable gene targeted mutagenesis, gene knock-out, gene insertion or replacement at the target sites during the endogenous DNA repair process, including non-homologous end joining (NHEJ) and homologous recombination (HR), triggered by the induction of DNA double-strand break (DSB).

Expression patterns of photoperiod and temperature regulated heading date genes in Oryza sativa.

In plants, flowering is a major biological phenomenon, which is regulated by an array of interactions occurring between biotic and abiotic factors. In our study, we have compared the expression profiles of flowering genes involved in the flowering pathway, which are influenced by conditions like photoperiod and temperature from seedling to heading developmental stages in two Oryza sativa indica varieties, viz., Zhenshan 97 and Minghui 63 using a expression network approach.

[Ghd7, a pleiotropic gene controlling flag leaf area in rice].

Photosynthesis is the unique source of energy for plant. Flag leaf contributed the majority of photosynthate after rice flowering. Ghd7 is a pleiotropic gene, which can significantly increase rice production.

[Discovery of QTLs increasing yield related traits in common wild rice].

Common wild rice (Oryza rufipogon) is an important genetic resource. Discovery of desirable alleles in wild rice will make important contributions to rice genetic improvement. In this study, Zhenshan 97 as the recurrent parent and wild rice as the donor parent were used to develop a BC2F1 population.

Quantitative trait loci for rice yield-related traits using recombinant inbred lines derived from two diverse cultivars.

The thousand-grain weight and spikelets per panicle directly contribute to rice yield. Heading date and plant height also greatly influence the yield. Dissection of genetic bases of yield-related traits would provide tools for yield improvement.

[A new rice dwarf1 mutant caused by a frame-shift mutation].

A dwarf mutant C6PS, which has the similar phenotype as the recessive mutant Dwarf1 (d1), was produced from tissue-cultured plants of Zhonghua 11. In its progeny (T2), the ratio of tall to dwarf plants was in agreement with the expected segregation ratio (3:1) of a single Mendelian inheritance gene, which indicated that the variation of plant height is caused by a single gene. To locate the mutation, C6PS was crossed with Zhenshan 97 and Mudanjiang 8 for producing two F2 populations of F2 (CM) and F2 (CZ), respectively.

A major QTL, Ghd8, plays pleiotropic roles in regulating grain productivity, plant height, and heading date in rice.

Rice yield and heading date are two distinct traits controlled by quantitative trait loci (QTLs). The dissection of molecular mechanisms underlying rice yield traits is important for developing high-yielding rice varieties. Here, we report the cloning and characterization of Ghd8, a major QTL with pleiotropic effects on grain yield, heading date, and plant height.

QTL analysis for flag leaf characteristics and their relationships with yield and yield traits in rice.

Photosynthesis of carbohydrate is the primary source of grain yield in rice (Oryza sativa L.). It is important to genetically analyze the morphological and the physiological characteristics of functional leaves, especially flag leaf, in rice improvement.

Analysis of digenic epistatic effects and QE interaction effects QTL controlling grain weight in rice.

Immortalized F(2) population of rice (Oryza sativa L.) was developed by randomly mating F(1) among recombinant inbred (RI) lines derived from (Zhenshan 97B x Minghui 63), which allowed replications within and across environments. QTL (quantitative trait loci) mapping analysis on kilo-grain weight of immortalized F(2) population was performed by using newly developed software for QTL mapping, QTLMapper 2.

[Mapping QTLs for horizontal resistance to sheath blight in an elite rice restorer line, Minghui 63].

This study was conducted with a recombinant inbred line (RILs) population consisting of 240 recombination lines, derived from an elite combination, Zhenshan 97B x Minghui 63. The RILs and their parents were grown in a randomized complete design with two replications in the years of 1999 and 2000. Sheath blight response ratings for the population and their parents were identified by an improved method of inoculation, which was carried out with short woody toothpicks incubated with a Rhizoctonia solani strain, RH-9, and inserted the third sheath in the late tillering/green ring stage of growth.

Quantum dispersion and its exponential growth of a wave packet in chaotic systems.

The quantum correspondence of one particular signature of classical chaos--the exponential instability of motion--can be characterized by the initial exponential growth rate of the spreading of the propagating quantum wave packet. The growth rate is approximately twice the classical maximum Lyapunov exponent of the system. In the regular case, the dispersion of the wave packet is only due to the usual quantum effect that should vanish in the classical limit.

Genetic analysis of the panicle traits related to yield sink size of rice.

In the study, ten panicle traits associated with yield sink size were measured in a recombinant inbred population derived from Zhenshan 97 x Minghui 63. Generally, spikelets per panicle were more closely correlated with number of secondary branch per panicle, spikelets on secondary branch per secondary branch, and spikelet density. A total of 53 QTL were detected for ten traits in two years.