Kumquat is conducive to the studies of flower and fruit traits,and related gene expression in the flower and fruit using genetic transformation since juvenile period is short and may blossom many times per year,but the rate of seedling regeneration in kumquat still needs to be improved.This study used internode stem segments of‘Yangshuo’ Kumquat(Fortunella spp.Swingle) in Guangxi as the materials.When using the seed-lings cultured in darkness for 25 days and light for 10 days as explants and MS+3 mg/L 6-BA as regeneration culture medium to grow about 50 days, the adventitious bud regeneration rate could exceed 80%. And after agrobacterium infection,using co-cultivation medium( MS + 2 mg/L 6-BA + 1 mg/L NAA + 1 mg/L KT) and selection medium(MS + 3 mg/L 6-BA+ 50 mg/L Kanamycin) as culture conditions,13.3% resistant shoot regeneration rate was obtained.The buds were cut down from the explants and placed in the rooting medi-um (1/2 MS+3 mg/L IBA+1 g/L activated carbon) 86%of the rooting rate was obtained.Finally,the research established an effective regeneration system by studying the various factors affecting regeneration frequency of adventitious shoots and resistant shoots.

将包含载体pPtcor∷8Ptcor8∷YFP的农杆菌EHA105转入到不抗寒的柠檬中,并对转化体系进行了优化.研究结果表明,再生培养基中的6-BA的浓度,卡那霉素(Kan)浓度以及除草剂(Basta)的浓度对柠檬的转化效率有明显影响;再生培养基配方为MT+ 0.5 mg/L 6-BA,添加75 mg/L kan或10 mg/L Basta时能够有效筛选到抗性芽,并获得了3株转基因柠檬植株,YFP阳性率为3.6％.

To increase the genetic transformation efficiency of sweet orange infected by Agrobacterium,an explant derived from internode stem segments of sucarri orange seedling was adopted to optimize light regimes and co-cultivation condition for the growth.Meantime,seedless gene was transferred to succari orange.The results revealed that explant from seedling had higher regeneration and transformation rate under the condition of cultured 20 d in darkness first and then exposed 10 d in lighting environment.Acetosyringone(AS) concentration was a key factor impacting transformation rate,and the optimal performance of transformation was under 20 mg/L concentration of co-cultivated medium with a temperature 19 ℃ and pH 5.4–5.7.The positive rate could reach 29.4% through the analysis of GUS staining,which were further proved by PCR analysis that the foreign gene was indeed integrated into the host genome.

【Objective】 In order to obtain hybrid seedlings of pummelo citron,【Method】Shatian pummelo as female parent and citron as male parent were used in cross breeding program.Embryo rescue technology was used for embryo growth,and sequence-related amplified polymorphism(SRAP) molecular maker was used to identify parents(Shatian pummelo and Citron)and theirs hybrids according to the polymorphism.【Result】 Results showed that twenty-seven hybrids were finally got and five of them were identified by primer combinations Me6-Em5 and Me10-Em12 finally.【Conclusion】MT+GA3(1 mg.L-1) was suitable for hybrid embryo rescue and SRAP makers could be used to indentify them.The real hybrids could be used to build resistant and diseased pool by BSA and to find related genes resistant to citrus canker.

Using epicotyls of kumquat(Fortunella crassifolia Swingle)seedlings growing in vitro as explants,an efficient regeneration system was established.The results show that,using 35-day-old epicotyl segments of kumquat,and based on the culture media of MS+6-BA 2.0 mg/L+NAA 1.0 mg/L+KT 1.0 mg/L+sucrose 3%+agar 0.8%(pH5.7)in the tempreture of 26℃ for a 16/8 h light/dark cycle and without dark-culture,adventitious shoots regenerated from 90%of the epicotyl explants.