关键词: 白刺, 果实性状, 遗传力, 选优, 遗传增益

Abstract: The heritabilities of different fruit characters of free pollinated family of Nitraria tangutorum were statistically estimated by using offspring parent regression. Based on a systematic survey to Nitraria tangutorum in Minqin county of Gansu, the nature fruits and seeds of selected 66 natural free pollinated families which represent the overall fruit variability of the species in this region are acquired. The main characters such as fruit size, shape, color, taste, fresh rate and sugar content are measured. Raising seedlings using collected seeds of different families was conducted to obtain the data of offspring of different families. Regression coefficient (b) was calculated by taking the parent data and offspring data as independent variable and dependent variable respectively, and the heritabilities (h²) of different characters were estimated by using a formula: h²=2b. The results showed that some fruit characters such as the minor diameter, shape, color, taste, fresh rate of fruit and dernel shape, were more heritable than other fruit characters, which indicated that the variations of these characters were controlled mainly by genetic factors, and the variation of other characters mainly by environmental factors. The more heritable characters as major indices can be applied to the classification of fruit form types of Nitraria tangutorum, of which the minor diameter, taste and fresh rate of fruit can be used to evaluate the fruit quality and select the excellent parents. Family selection (selecting rate 1/10) concerned with the minor diameter and fresh rate of fruit for selecting the excellent parents obtained larger genetic gains with 3 91% and 1 96% respectively, and the total fruit meat could increase by 6 2%. The selecting result was satisfactory.

Key words: Nitraria tangutorum, Fruit characters, Heritability, Selection of excellent parent, Genetic gain