Study On 2n Pollen In Chinese Jujube

Sizes of mature pollen for 142 cultivars in Jujube Repository in Cangxian County(JRCC)and 82 cultivars in National Jujube Repository(N JR)were studied by TTC dying method and the effects of different parts of canopy,shoot age,node location and flower grades on proportion of 2n pollen were also analysed in the paper.The main results were as follows:1 The opening time(take horizonal sepal period as criterion)of 142 cultivars in JRCC were observed and analysed and it showed that flowers of 47.88%cultivars including Wuhe 68,Wuhe 72,Wuhe 76,Wuhe 95,Zanhuangdazao,Jinsixinlhao etc.opened from 15:00 to 17:00.And 27.24%cultivars including Huizao,Hupingzao,Dongzaol00, Dongzao 101,Dongzao 38 etc.blossomed at 05:00-08:00.Nearly 15.49%cultivars including Xiaozao 1,Xiaozao 75,Dongzao 70 and Dongzao103 etc.blossomed at 9:00-11:00.2 Percentages of 2n pollen,30%bigger than normal,differed with cultivars. Thirty-three cultivars including 4 Wuhe strains,6 Jinsixiaozao strains and 2 Dongzao strains etc.produced 2n pollen naturally.Linglingzao showed the bigggest percentage of 2n pollen of 9.41%while Zanhuangdazao,Jinsixinlhao,Meimizao,Wanshuyuanling, Xiaozao 3,Heiyezao,S161,Wuhe 95,Wuhe 68,Lingzao(Jiangsu)and Xiaopingding between 0.10%-0.60%in JRCC.Among 81 cultivars in N JR,43 cultivars had been found prodcuing 2n pollen naturally.Yingluozao showed the bigggest percentage of 2n pollen of 3.71%while Zhongyangmuzao and Zanhuangchangzao between 1.0%-1.5%,Jinsixiaozao, Huizao,Yunchengxiangzao,Taiguhupingsuanzao,Goutouzao and Jinxianmuzao of 0.50%-1.00%,Henanxiaoyuanzao,Qingxuyuanzao,Tailihong,Chuanlingzao,Hebeimuzao, Sanbianhong,Xiyaozao,Guangdongbaizao,Pingyaodazao,Nanjingdamuzao,Liuyuezao, and Guanyangduanzao of 0.10%-0.50%.3 The conclusion is that the 2n pollen size is 1.5 times bigger than the normal pollen in Chinese jujube cultivars from Jujube Repository in Cangxian County and National Jujube Repository.4 Colchicine concentrations effected the inducing results.With the concentration increasing from 0.05%-0.50%,the 2n pollen rates are bigger from0.10%,0.30%,0.40%, 0.50%than 0.05%0.20%and CK.The proper colchicine treatment time was about 15days before blossoming. 5 The percentage of 2n pollen in north part of the canopy was significantly higher than that in south part of the canopy.Flowers at the six node and the first geade flowers had bigger percentage of 2n pollen.The 1st grade flowers had bigger percentage of 2n pollen.