Study On The Flower Bud Differntiation And The Change Of Endogenous Polymines In Different Apricot Varieties

Apricot is originated from our country.Because of its hige nutritional and medical value,which has been widely planted in many areas of northern China. However,as a result of its higher pistils abortion ratio and ealier inflorescence,most Chinese apricot cultivars have a low seed setting rate, which greatly restrict the development of apricot industrial in our country.Eleven apricot cultivars were selected as research objects,this paper studied the relationship between dynamic change of endogenous polyamines and bud differentiation's stage in different apricot varieties, illustrate the characteristics of bud differentiation in different apricot varieties and first proposed the relationship of apricot buds differentiation and endogenous polyamines in order to provide evidence for high-yield cultivation techniques of apricot. The main resons are as follows:1. The process of Apricot flower buds morphological differentiation can be divided into six stages:undifferentiation period, differentiation period, calyx differentiation period, petal differentiation period, stamen differentiation period and pistil differentiation period. The whole flower bud differentiation process focused on late in June to late in September.2. All research objects experienced the same process of morphological differentiation,but the time of beginning and the total time are different.Luotuohuang and Sulian 4 started differentiation earliest,about on June 20,and the whole process sustained 83 and 90 days respectively.Jidanxing,Zaoshuheiyexing and Fengweimeigui beginned to differentiation about on July 4,and lasted 76,83 and 103 days respectively. Chuanzhihong,Yinxiangbai,Pinaizi and Fengweihuanghou started differentiation on July 11,and lasted 69,69,76å'Œ96 days respectively.Anjianghuanna and Weidi started differentiation latest,about on July 18,and lasted 79 and 99 days respectively.3. The beginning of apricot flower buds morphological differentiation was accompanied by synthesis of a large number of polyamines. During the whole differentiation, the content of Spermidine was highest, Spermine took second place, and Putrescine was least. The content of Spermidine and Spermine increased significant during calyx differentiation period, petal differentiation period and pistil differentiation period, but decreased during stamen differentiation period.4. The content of Spermine was approximately changeless from after differentiation until after blooming. After differentiation, the content of Putrescine and Spermidine always kept low level, however, it started increased after beginning of expanding stage. In the flower bud expanding stage, the content of Putrescine started decreasing after reached the highest level, while Spermidine decreased fast after reached the highest level in initial bloom stage.