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Antimicrobial peptide is a polypeptide with antimicrobial activity. Antimicrobial peptide genes Np3 and Np5 from Chinese shrimp (Fenneropenaeus Chinensis) were integrated into Oryza sativa L. subsp. japonica cv. Aichi ashahi by Agrobacterium mediated transformation system. PCR analysis showed that the positive ratios of Np3 and Np5 were 36% and 45% in T0 generation, respectively. RT-PCR analysis showed that the antimicrobial peptide genes were expressed in T1 generation, and there was no obvious difference in agronomic traits between transgenic plants and non-transgenic plants. Four Np3 and Np5 transgenic lines in T1 generation were inoculated with Xanthomonas oryzae pv. oryzae strain CR4, and all the four transgenic lines had significantly enhanced resistance to bacterial blight caused by the strain CR4. The Np5 transgenic lines also showed higher resistance to bacterial blight caused by strains JS97-2, Zhe 173 and OS-225. It is suggested that transgenic lines with Np5 gene might possess broad spectrum resistance to rice bacterial blight.

The ‘double T-DNA’ binary vector p13HSR which harbored two independent T-DNAs, containing hygromycin phosphotransferase gene (hpt) in one T-DNA region and three target genes (hLF, SB401, RZ10) in another T-DNA region, was used to generate selectable marker-free transgenic rice by Agrobacterium-mediated transformation. The regenerated plants with both the three target genes and the selectable marker gene hpt were selected for anther culture. RT-PCR analysis indicated that target genes were inserted in rice genomic DNA and successfully transcribed. It took only one year to obtain double haploid selectable marker-free transgenic plants containing the three target genes with co-transformation followed by anther culture technique, and the efficiency was 12.2%. It was also noted that one or two target genes derived from the binary vector were lost in some transgenic rice plants.

A thermo-insensitive pale green leaf mutant (pgl2) was isolated from T-DNA inserted transgenic lines of rice (Oryza sativa L. subsp. japonica cv. Nipponbare). Genetic analysis indicated that the phenotype was caused by a recessive mutation in a single nuclear-encoded gene. To map the PGL2 gene, an F2 population was constructed by crossing the mutant with Longtefu (Oryza sativa L. subsp. indica). The PGL2 locus was roughly linked to SSR marker RM331 on chromosome 8. To finely map the gene, 14 new InDel markers were developed around the marker, and PGL2 was further mapped to a 2.37 Mb centromeric region. Analysis on chlorophyll contents of leaves showed that there was no obvious difference between the mutant and the wild type in total chlorophyll (Chl) content, while the ratio of Chl a / Chl b in the mutant was only about 1, which was distinctly lower than that in the wild type, suggesting that the PGL2 gene was related to the conversion between Chl a and Chl b. Moreover, the method of primer design around the centromeric region was discussed, which would provide insight into fine mapping of the functional genes in plant centromeres.

The effect of a 1–5 day low temperature treatment applied at different stages during panicle development on the male sterility of 5460S, a thermo-sensitive genic male sterile rice line (TGMSR), was studied. Before and after the period of low temperature treatments the plants were continuously grown under 14.75 h daylength and 29.6° C average temperature (max. 33° C/min. 29° C) in growth chambers in order to avoid any other possible influences on the male sterility. The results indicate that the plant responses to low temperature was dependant on the developmental stage of the young panicle. The stages from formation of pollen mother cell to late uninucleate of pollen grains were the most sensitive to temperature. It is concluded that the critical temperature for the fertility change from male sterile to partially fertile in ‘5460S’ is about 28.5° C in the sensitive panicle development stages under the condition studied.

A great progress has been made in two-line hybrid rice in China. Up to 2010, a total of 427 two-line hybrid combina- tions (cultivars) had been registered. In recent years, two-line hybrid rice has become an important type in rice production in China. Photoperiod-thermo sensitive genic male sterile (PTGMS) lines are the basis of two-line hybrid rice. In this paper, the rela- tionship of 130 PTGMS lines used as parents of registered hybrid combinations and/or with the right of protection of new varieties was analyzed, and 126 of 130 PTGMS lines that the relationship defined were traced back to their original PTGMS lines as a starting point. The pedigree of the 73 PTGMS lines used for producing hybrid combinations with large scale planting and/or the right of protection of new varieties was analyzed in detail, and the breeding methods of the 126 PTGMS lines were analyzed. The relationship between the photoperiod-thermo response type and the pedigree of the PTGMS lines was discussed. We also pro- posed that selecting the proper PTGMS materials by pedigree analysis is as important as photoperiod and temperature controlling for studying the molecular mechanism of photoperiod-thermo response in PTGMS lines. Open sharing of the PTGMS resources has the great significance for accelerating the breeding of new practical PTGMS lines and minimizing the adverse environmental

Donor plants of rice (Oryza sativa L. subsp.indica. C.V. Si-Xi-Zhan) were grown in 9 phytotrons with a 3 thermoperiods (average temperature 29.7°C, 25.7°C or 23.5°C) ×3 photoperiods (14.75h, 14.00h or 13.25h) design. It was found that the callus initiation rate was higher if plants grew under mid or short photoperiod and mid or low temperature. The highest one was 42.24% under the condition of 25.7°C/14.00 h. The frequency of green plantlet regeneration was more that 20% under the conditions of 23.5°C or 25.7°C/13.25 h. The ratio of green plantlet to albino was also higher under short photoperiod condition. The suitable season for indica anther culture was discussed.