Abstract:

According to the probability and mathematical statistics theory,19 quantitative characters and their distributions of 124 Chinese jujube(Ziziphus jujuba Mill.)varieties were studied.The results showed that acid can be titrated in fresh fruit,growth period,soluble sugar of dry fruit,length of second branch,internode length of growing branch,length of bearing branchlet,flower number of bearing branchlet,weight of fruit kern conformed to the normal distribution;but those of per fruit weight,Vc of fresh fruit,soluble sugar of fresh fruit,edible percent of fruit,acid can be titrated in dry fruit,fruit number per bearing branchlet,internode number of secondary branch conformed to χ² distribution.The values of normally distributed characters could be divided,in a unified way,into 5 grades by 4 dividing points:(X-1.281 8S),(X-0.524 6S),(X+0.524 6S) and (X+1.281 8S),or into 3 grades by (X-0.524 6S) and (X+0.524 6S).In the former case,the occurence probability of 1～5 grade was 10%,20%,40%,20% and 10% respectively.Through comparison,characters conforming χ² distribution may be simply treated as those conforming normal distribution for convenience.Index system of probability grading for 19 quantitative characters was built.

Key words: Chinese jujube (Ziziphus jujuba), Quantitative character distribution, Probability grading, Index system