枣树数量性状的分布类型及其概率分级指标体系

DISTRIBUTION AND PROBABILITY GRADING INDEX SYSTEM OF QUANTITATIVE CHARACTER OF CHINESE JUJUBE

以收集于我国主要产枣区的 1 2 4个枣品种 1 9个重要数量性状的多年调查结果为基础资料 ,利用概率和数理统计理论 ,借助计算机对各数量性状取值的分布类型进行了 χ2 检验。结果表明 :鲜枣可滴定酸、生长期、干枣可溶性糖、二次枝长、枣头平均节间长、枣吊长、枣吊花数、果核重等 1 0个数量性状符合正态分布 ;而单果重、鲜枣Vc、鲜枣可溶性糖含量、可食率、干枣可滴定酸、果吊率、二次枝节数等 9个性状符合 χ2 分布。正态分布性状可统一用 (X -1 2 81 8S)、(X -0 5 2 46S)、(X +0 5 2 46S)和 (X +1 2 81 8S)分为 5级 ,使 1～ 5级的出现概率分别为 1 0 %、2 0 %、40 %、2 0 %和 1 0 % ,或用中间 2个分点分为 3级。经比较研究 ,χ2 分布性状可近似的按正态分布性状处理。文中给出了枣树主要数量性状的概率分级指标体系。

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 χ+2 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 χ+2 distribution may be simply treated as those conforming normal distribution for convenience.Index system of probability grading for 19 quantitative characters was built.