枣树数量性状的概率分级研究

借助计算机和概率理论对枣树9个主要数量性状的品种间变异和分布特征及其规范化分级方法进行了探讨,结果表明,变异系数以单果重最大,达51.95％,可食率最低,仅2.67％;果实制干率、生育期、维生素C和可溶性固形物含量及花径和叶长的取值遵从正态分布;单果重、可食率和枣吊长度近似X2分布;对正态分布性状可统一用(x-1.2818S)、(x-0.5246S)、(x 0.5246S)和(x 1.2818S)4个分点分为5级,从而使性状值落入1～5级的概率分别为10％、20％、40％、20％和10％,或用(x-0.5246S)和(x 0.5246S)2个分点分为3级,性状值落入3级的概率分别为30％、40％和30％。文中还列出了3级和5级分级标准,并对分点值的规范化处理及概率分级的优缺点等进行了讨论。

Studies on the Variations and Probability Gradings of Major Quantitative Characters of Chinese Jujube

The variations and distributions of 9 major quantitative characters among cultivars of Chinese jujube and standardized probability grading method of these characters were studied. The results showed that there were significant differences among characters in variability. The coefficent of variation was highest in per fruit weight (51.95%) and lowest in edible rate of fruit ( 2.67%) . According to the results of X2 rest, the distributions of values of drying rate of fruit, growth period of flower and length of leaf, conformed to the normal distribution, but those of per fruit weight, edible rate of fruit and length of bearing branchlet looked rather like X2 distribution. The values of normally distributed characters could be divided, in a unified way, into 5 grades by 4 dividing points: ( X -1.2818S), ( X -0.5246S) , ( X 0.5246S) and ( X 1.2818S), or into 3 grades by ( -0.5246S) and ( X 0.5246S) . In the former case, the occurence probability of 1 - 5 grdeis 10%, 20%, 40%, 20%, and 10% respectively; in the latter case, the probability of 1- 3 grade is 30%, 40%, and 30% respectively. Dividing points of 3 and 5 grades divisions on above mentioned 9 characters were listed. The advantages and shortages of probability grading and the standardization method of its dividing point, and the distribution specificities of qualitative characters in Chinese jujube, were also discussed.