Plant Regeneration From Anther And Acquirement Of Haploid In Chinese Jujube

Homozygous diploid could be obtained by chromosome doubling of haploid rerenerated from anther in plant breeding. This study revealed effects of many factors on callus formation and plant regeration in anther culture of Chinese jujube. An optimized system for plant regeneration from Chinese jujube anther was establised and haploid was obtained. The result was as follows:1 Selection of explant for anther cultureCallus could be efficiently induced from anther in which microspore was at the late uninucleate stage. Simutniously, the bud was green or light green..2 Callus induction from antherCallus formation from anther in Chinese jujube was influenced by genotype, basic medium, carbon source, hormones and light. Callus could be induced from anther when 1/2 MS , 20g/L maltose, 1.0mg/L2,4-D as well as dark enviroment was used in culture.Callus could be efficiently induced from Chinese jujube anther in the medium l/2MS+1.0mg/L 2,4-D +3.5g/Lagar+20g/L maltose. Among five cultivars, i.e., 'Zanhuangdazao','Dongzao', 'Lajiaozao', 'Fupingdazao', and 'Yueguang',the highest rate of callus formation from anther appeared in 'Dongzao' and reached 70.26%. Yet the lowest rate in 'Fupingdazao' was only 7.76%. Callus formation was more easier under dark than light.Of various pretreatments, both concentration and treatment period of mannitol significantly influnced the callus fomation; The optimal treatment combinations of mannitol for cultivar 'Zanhuangdazao' and 'Fupingdazao' were both dipping anthers in 0.1-0.5 mol/L mannitol for 3 days, with highest callus rate of 98.89% and 82.22%, respectively. However, the rate of callus decreased when mannitol treatment was kept for too much time. The callus rate was not obviously correlated with browning rate.There was difference of low or high temperature in accelerating callus formation from anther of different cultivars. Low temperature (4℃) pretreatment did not significantly accelerate the callus induction of anther, and in case of cultivar 'Dongzao' and 'Yueguangzao' callus rates were significantly reduced. The effects of High temperature (35℃) pretreatment on callus induction rate (increasing, decreasing, or keeping stable) changed with cultivars.3 Proliferation and differentiation of callusProliferation and differentiation of callus from anther was significantly affected by genotype, hormones, carbon source and basic medium. 1.0mg/LTDZ was effective in proliferation and differation of callus. The differentiation rate of callus in five cultivars was higher in MS medium supplemented with 2.0mg/L triacontanol than. KT,BA,ZT,TDZ. However, triacontanol was not helpful for callus proliferration. Callus proliferation and differentiation was accelerated when they were cultured in MS medium supplemented with maltose. In contrast, callus usually became brown and even died in medium supplemented with sugar and glucose4 Chromosome ploidy of regenerated plant and acquirement of haploidRegenerated plants consisted of haploid, diploid, triploid and mixoploid and its composition was diffferent in five cultivars. Diploid appeared in all five cultivars, and triploid appeared in 'Zanhuangdazao', and mixoploid in 'Dongzao', 'Lajiaozao', and 'Fupingdazao'. However, Haploid was only obtained in 'Dongzao' and 'Fupingdazao' and diploid in 'Zanhuangdazao'. Probably, haploid in 'Dongzao' and 'Fupingdazao' and diploid in 'Zanhuangdazao' originated in microspore. Haploid of 'Dongzao' and 'Fupingdazao' was obtained for the first time in this study.