In order to provide breeding high-quality parent material for seedless watermelon,taking small-type diploid watermelon line A8as material,tetraploid plants of watermelon were induced by treating the growing points of seedlings with different concentration Oryzalin and lasting different treating time.Autotetraploid plants were selected and identified basing on morphology,flow cytometry,hybridization and characterization.Then observed a stable tetraploid material after three quarters' continuous cultivation,observation and filtering.The results showed that different treatments could obtain tetraploid watermelons by processing with Oryzalin.The most effective way was extirpating interiorleaf at the 8th day after sowing,then treating the growing points of seedlings with 100mg/L Oryzalin for 6d.The treatmented seedlings could all survival and the induction frequency of tetraploid watermelon was 30.59%.

'E-xigua 16'is a new middle-ripening watermelon cultivar derived from the cross '01P005'×'01P011'.The average fruit mass is about 3.0-3.5 kg,and the yield is 30.0-37.5 t · hm-2.The fruit is long-ball with dark-green stripes on surface.The flesh is bright red,with juicy and crisp.It tastes very sweet.The pericarp is thin but hard to crack.It is resistant to diseases and suitable for storing and transporting.

Melon(Cucumis melo L.) polyploidy mutation methods and polyploidy identification methods on melon polyploidy mutation are reviewed,while the research issues in the future are prospected.

Using seedling-derived cotyledon of triploid watermelon 'Mitong' as explants,the influences of sterilization method of seed sterilization,different sampling areas and dark culture on adventitious shoots induction were studied.The results showed that under the same cultivation condition,the differentiation of adventitious shoots from proximal cotyledon was more easily than from other areas of cotyledon,and adventitious shoots' differentiation ability reduced gradually from the nearly hypocotyl area to the distal end.The study indicated that dark culturing could not improve(sometimes reduces) the cotyledon adventitious shoot induction of triploid watermelon.

Objective:Retrospective evaluations of two different chemotherapy regimens in children with acute promyelocytic leukemia(APL)were made to assess clinical significance of abnormal fusion gene and observe the therapeutic efficacy as while. Method:Thirty cases of newly diagnosed APL patients,including 16 males and 14 females,from 1990 to 2010 were divided into two groups-A and B,according to different chemotherapy regimens at different time.Sixteen children in group A diagnosed from 1990 to 2000 were treated with ARTA and chemotherapy,and fourteen children in group B diagnosed from 2001 to 2010 were treated with the main regimen consist of ATRA,As203 and chemotherapy.23 children expressed PML /RARa fusion gene positive with 12 children in group A and 11 children in group B.Statistics analysis was made on the SPSS13.0. Result:Both groups gained 100% CR rate.The CR time of group A was(32.3±7.2)days compared with(25.9±8.3)days of group B(P<0.05).The median time that PML/RARa fusion gene switched to negative in group A was(13.6±10.6)months compared with(3.2±1.7)months of group B(P<0.01).68.8 % Children in group A gained disease-free survival,and 31.2% died.All 14 children in group B were still disease-free survival(P<0.05).The relapse rate of group A was higher than group B,P=0.039.There was no significant difference in heart,liver and renal toxicity between two groups(P>0.05).But children in group A were much more likely to gain bone marrow suppression(P<0.01). Conclusion:The regimen combined ATRA with As2O3 could shorten CR time and the time of PML/RARa fusion gene switching to negative,reduce relapse rate and chemotherapy-related deaths.This regimen is safe and effective for children with APL.

At present,most watermelon cultivars are not resistant to low temperature,so understanding the physiological and biochemical changes and determining the related indexes of watermelon under the low temperature stress,can contribute to the development of the resistance breeding and facility cultivation of watermelon.This article reviews the research progress of watermelon physiological and biochemical indexes under low temperature stress,pointing out the further directions of research and breeding and simple preventive measures,in order to provide references for the related research and practical production.

Cotyledon excised from seedlings of watermelon 'Hitong' were used as explants,an efficient plant regeneration system via organogenesis was established in triploid watermelon 'Mitong'.The results showed that 88.33% explants could regenerate to adventitious shoots on MS medium with 1.0 mg/L 6-BA and 0.1 mg/L NAA.The elongation media was MS+0.2 mg/L 6-BA.90% adventitious shoots were successfully rooted on a 1/2MS medium with 0.5 mg/L IBA.