关键词: 白刺, 果实, 变异

Abstract: Nitraria tangutorum Bobr. is an endemic and dominant plant in the salinized desert areas of central Asia. With characters of drought resistance, salt resistance and sand loving, it is a good species for wind break and sand fix. Its fruit, rich in amino acids, micro elements and vitamins etc., is very nourishing. Nitraria tangutorum is a more evolutionary species in the Nitraria genera. Its differentiation is intense, the variability of characters is rich, especially, the variability of fruit is more intense than that of the nutritional organs. The natural form types formed after variability provide the precious material base for selection and directive breeding. In order to master the quantitative characteristics and regularities of fruit variability of Nitraria tangutorum, we conducted a systematic survey in Minqin county of Gansu one of main distribution areas of Nitraria. Based on the survey results and the variability of fruit size, shape, color and taste, and the environmental differences in different distribution areas, the nature fruits and seeds of 66 natural individuals selected are acquired, which represent the overall fruit variability of Nitraria tangutorum in this region. Their main characteristics are measured and the statistically analyzing results are as follows:(1) The variability of size, shape, color, taste, meat content and sugar content of natural Nitraria tagutorum fruit in Minqin desert area is very complicated, which provided a good base for the selection of improved plants. (2) The variability of size, shape, color and taste of natural Nitraria tangutorum fruit is big between plants while small within plants, the normal value of variability coefficient within plant is only 50% or less as that between plants. The length, diameter and weight of fruit, which indicating the fruit size, are different with each other. Variability coefficient between plants is 015, while within plant only 006-008; The fruit shape variability within plant is smaller than the indices of fruit size, which shows that the stability of variability within plant is better. This provides a possibility for the selection of improved plants. (3) The relativity among different growing indices indicating the size of fruit and fruit kernel are evident (α 001), which shows that these indices indicating the size of fruit and kernel keep pace in growth. However, the correlation between fruit or kernel shapes and indices indicating fruit and kernel size shows that the changes of fruit shape and kernel shape are relatively independent on other indices. The relativity between fresh rate and fruit characteristics is significant, while not significant between fruit rate and kernel characteristics. The correlations between sugar content and fruit size, fresh rate are negative, that means the bigger the fruit is and the higher the fresh rate is, the poorer the sugar content is. So, the sugar content is greatly influenced by the change of environmental conditions.

Key words: Nitraria tangutorum Bobr., Fruit, Variability